Loading...
HomeMy WebLinkAbout; ; Beach Replenishment S Oceanside & Cardiff; 1997-04-01r c r rL. L c L L L c Environmental Assessment for Beach Replenishment at South Oceanside and Cardiff/Solana Beach, California i Prepared by U.S. Department of the Navy H L- April 1997 TABLE OF CONTENTS SECTION TITLE ABSTRACT EXECUTIVE SUMMARY PAGE AB-1 ES-1 1 1.1 1.2 1.3 1.4 1.5 INTRODUCTION Background Purpose and Need Location of the Proposed Action Relevant Federal, State, and Local Statutes, Regulations and Guidelines Interagency Coordination 1-1 1-1 1-4 1-5 1-8 1-15 2.1 2.2 2.3 2.3.1 2.3.2 2.3.3 2.4 DESCRIPTION OF THE PROPOSED ACTION AND ALTERNATIVES Alternative Selection Criteria Proposed Action - Beach Replenishment Alternatives Considered North Oceanside (Oceanside Harbor to the Oceanside Pier) South Oceanside (Loma Alta Creek to Buena Vista Lagoon) Solana Beach No Action Alternative 2-1 2-1 2-2 2-7 2-7 2-7 2-8 2-8 3 3.1 3.1.1 3.1.2 3.2 3.2.1 3.2.2 3.3 3.3.1 3.3.2 AFFECTED ENVIRONMENT Geology and Soils South Oceanside Solana Beach Coastal Wetlands South Oceanside Solana Beach Water Resources South Oceanside Solana Beach 3-1 3-1 3-1 3-4 3-5 3-5 3-6 3-7 3-7 3-9 211602000 TABLE OF CONTENTS (Continued) SECTION 3.4 3.4.1 3.4.2 3.5 3.5.1 3.5.2 3.6 3.6.1 3.6.2 3.7 3.7.1 3.7.2 3.8 3.8.1 3.8.2 3.9 3.9.1 3.9.2 TITLE Biology South Oceanside Solana Beach Land Use and Recreation South Oceanside Solana Beach Safety and Environmental Health South Oceanside Solana Beach Aesthetics South Oceanside Solana Beach Structures and Utilities South Oceanside Solana Beach Noise South Oceanside Solana Beach PAGE 3-9 3-9 3-13 3-15 3-15 3-17 3-18 3-19 3-19 3-19 3-19 3-21 3-21 3-21 3-24 3-26 3-26 3-28 4 4.1 4.1.1 4.1.2 4.2 4.2.1 4.2.2 4.3 4.3.1 4.3.2 4.4 4.4.1 4.4.2 ENVIRONMENTAL CONSEQUENCES Geology and Soils South Oceanside Solana Beach Coastal Wetlands South Oceanside Solana Beach Water Resources South Oceanside Solana Beach Biology South Oceanside Solana Beach 4-1 4-1 4-1 4-4 4-6 4-7 4-8 4-11 4-11 4-13 4-13 4-13 4-16 211602000 TABLE OF CONTENTS (Continued) SECTION 4.5 4.5.1 4.5.2 4.6 4.7 4.7.1 4.7.2 4.8 4.8.1 4.8.2 4.9 4.9.1 4.9.2 TITLE Land Use and Recreation South Oceanside Solana Beach Safety and Environmental Health Aesthetics South Oceanside Solana Beach Structures and Utilities South Oceanside Solana Beach Noise South Oceanside Solana Beach PAGE 4-19 4-19 4-20 4-21 4-21 4-22 4-22 4-23 4-23 4-24 4-25 4-27 4-27 5 5.1 5.2 5.2.1 5.2.2 5.2.3 5.2.4 5.2.5 5.2.6 5.2.7 5.2.8 5.2.9 CUMULATIVE IMPACTS Cumulative Projects Cumulative Environmental Effects Geology and Soils Coastal Wetlands Water Resources Biology Land Use and Recreation Safety and Environmental Health Aesthetics Structure and Utilities Noise 5-1 5-1 5-4 5-4 5-4 5-5 5-5 5-6 5-6 5-6 5-7 5-7 IRREVERSIBLE OR IRRETRIEVABLE COMMITMENTS OF RESOURCES 6-1 THE RELATIONSHIP BETWEEN LOCAL SHORT-TERM USE OF THE HUMAN ENVIRONMENT AND THE MAINTENANCE AND ENHANCEMENT OF 211602000 ill TABLE OF CONTENTS (Continued) LONG-TERM PRODUCTIVITY SECTION TITLE 8 LIST OF PREPARERS 7-1 PAGE 8-1 9 10 LIST OF AGENCIES AND PERSONS CONSULTED REFERENCES 9-1 10-1 LIST OF FIGURES NUMBER TITLE 1-1 Regional Location Map 1 -2 South Oceanside Beach Fill Site 1 -3 Solana Beach Fill Site 2-1 South Oceanside Typical Berm Cross-Section 2-2 Solana Beach Typical Berm Cross-Section 2-3 Beach Replenishment Sites 3-1 Recreational Surfing Sites 3-2 South Oceanside Receiver Site Existing Views 3-3 Solana Beach Receiver sites Existing Views 3-4 Existing Structures and Utilities South Oceanside Site 3-5 Existing Structures and Utilities Solana Beach Site 4-1 Mean Sea Level Shoreline Response South Oceanside Site 4-2 Mean Sea Level Shoreline Response Solana Beach Site 5-1 Cumulative Projects PAGE 1-6 1-7 1-11 2-4 2-5 2-9 3-16 3-20 3-22 3-23 3-25 4-2 4-5 5-2 211602000 IV TABLE OF CONTENTS (Continued) LIST OF TABLES NUMBER TITLE PAGE 3-1 Longshore Sediment Transport Rate Estimates for the Oceanside Littoral Cell 3-3 3-2 Expected Grunion Runs for 1997 3-11 3-3 Ambient Conditions at South Oceanside 3-27 3-4 Ambient Conditions of CardifFSolana Beach 3-28 3-5 Relevant Property Line Standards 3-29 4-1 Required Distances (ft) for Noise Mitigation at Receiver Sites 4-26 5-1 Inlet Maintenance Responsibility 5-5 LIST OF ATTACHMENTS LETTER TITLE I FY '97 MCON Project P-706 Channel Dredging, Beach San Transport and Sedimentation Report Phase 1: South Oceanside and Solana Beach, Draft Preliminary Report by Frederic R. Harris, Inc., 1997 211602000 This Page Intentionally Left Blank 211602000 VI ENVIRONMENTAL ASSESSMENT FY97 BEACH REPLENISHMENT AT SOUTH OCEANSIDE AND CARDIFF/SOLANA BEACH, CALIFORNIA ABSTRACT The Department of the Navy has prepared an Environmental Assessment (EA) to analyze the placement of dredged material on beaches in South Oceanside and Cardiff/Solana Beach for beach replenishment. This action is being undertaken to accommodate the disposal of dredged material as a result of dredging operations in San Diego Bay for the homeporting of a NIMITZ class aircraft carrier and to comply with the San Diego Association of Government's Shoreline Preservation Strategy for the San Diego Region. The proposed action is scheduled to be implemented starting July 1997. This document is intended to be a "tiered" EA based on analyses provided in the 1995 Environmental Impact Statement for the Development of Facilities in San Diego/Coronado for the Homeporting of One NIMITZ Class Aircraft Carrier. Due to subsequent changes in the location of receiver beaches, as identified in the EIS, the EA evaluates the potential effects of beach replenishment and associated operations (i.e., barge placement, sediment disposal, and grading) at the proposed South Oceanside and Solana Beach receiver sites and addresses the following site specific environmental issues: geology and soils, coastal wetlands, water resources, biology, land use and recreation, safety and environmental health, aesthetics, utilities, and noise. Prepared by: U.S. Department of the Navy Cooperating Agency: U.S. Army Corps of Engineers, Los Angeles District Point of Contact: Mr. Patrick McCoy Southwest Division Naval Facilities Engineering Command 1220 Pacific Highway San Diego, California 92132-5190 (619) 556-8706 April 1997 211602000 AB-1 This Page Intentionally Left Blank 211602000 AB-2 EXECUTIVE SUMMARY The proposed action involves the onshore placement of dredged material as beach replenishment at receiver sites in South Oceanside and Solana Beach. Beach replenishment operations include transport of sediment via hopper dredge from dredging locations in San Diego Bay, placement of the dredge at various offshore locations, pumping of sediment onto the receiver beaches, and placement of sediment using grading equipment. The purpose and need of the proposed action is to replenish beaches with critical erosion problems, in accordance with a request submitted to the Navy by the San Diego Association of Governments' (SANDAG) Shoreline Erosion Committee. Beach replenishment would provide an immediate benefit by maximizing onshore beach fill in the Oceanside Littoral Cell, rather than placing sediment in the nearshore zone. Implementation of the proposed action is intended to provide a wider recreational beach, reduce erosion, and protect the shoreline. Beach replenishment would occur at one receiver site in South Oceanside and two sites in Solana Beach. Approximately 405,218 cubic meters (m3) (530,082 cubic yards [cy]) would be placed onshore at South Oceanside, and approximately 435,802 m3 (570,091 cy) would be placed at two sites in Solana Beach. The South Oceanside receiver site includes Oceanside City Beach and extends from Seagaze Drive to the Loma Alta Creek outfall. The two Solana Beach receiver areas consist of a northern site, located along Cardiff State Beach off Highway 101, and a southern site, located along Fletcher Cove Beach Park from Cliff Street to Dahlia Drive. Sand placement operations would occur at South Oceanside for 48 days during July, August, and September 1997, and at Solana Beach for 30 days during September and October 1997. Beach replenishment operations would occur 24 hours per day, seven days a week. A summary of impacts for each environmental issue analyzed in this Environmental Assessment is included below. 211602000 ES-l GEOLOGY AND SOILS The proposed action would result in short-term changes to the existing beach profile. Beach fill would be spread by littoral processes, and would affect beach areas north and south of the receiver sites, causing widening of beach areas other than the receiver sites. However, this effect would be short-term, as sand transport modeling predicts that beach fill would be transported off beaches into the nearshore zone over a period of two years. Accumulation of sediment in the nearshore environment would potentially affect breaking waves less than one meter (m) (3.3 feet [ft]) in height. However, this effect would be negligible, and is not considered significant. Beach fill would be transported through natural seasonal and littoral processes. Onshore beach fill is predicted to erode over a one to two year period, moving into the nearshore area. The maximum sediment movement is predicted to extend approximately 450m (approximately 1,500 ft) offshore and 3,000 m (9,850 ft) upcoast and downcoast of the South Oceanside site, and 300 m to 350 m (985 to 1,150 ft) offshore and 3,000 m (9,850 ft) upcoast and downcoast of the Solana Beach sites. A minor increase in average sand thickness is anticipated on the order of 0.1 to 0.2 m (4 to 8 inches) at all receiver sites. No significant impacts to coastal geology or littoral processes are anticipated. COASTAL WETLANDS The proposed action would cause accumulation of sediments at lagoon inlets and creek/river outfalls in the vicinity of the receiver sites. Specifically, the San Luis Rey River and Loma Alta Creek would potentially be affected by replenishment at South Oceanside; San Elijo Lagoon and San Dieguito Lagoon would potentially be affected by replenishment at Solana Beach. Fill activities could cause buildup of sediments on the beach in front of the identified coastal wetland areas, thereby blocking outfall or tidal flow. However, monitoring of ocean inlets at each of these sites would occur subsequent to the proposed action. To ensure that there would be no increase in lagoon mouth closures, a monitoring plan would be established with the approval of the Army Corps of Engineers in consultation with the appropriate resource agencies. Baseline profiles would be measured prior to discharge and monitored through July 1, 2001. Areas to be monitored include lagoon mouths, entrance channel, lagoon interior, or adjacent areas. The Navy would provide for 211602000 ES-2 mitigation of any increased rates of accumulation of sand or mouth closures that are determined to occur as a result of the discharge above and beyond existing conditions, as determined by the Army Corps of Engineers in consultation with the resource agencies, mitigation would consist of opening a closed lagoon mouth, and/or removing accumulated sediment attributable to the discharge. The Navy has obtained written and verbal assurance from SANDAG and affected municipalities that SANDAG and affected municipalities will implement the foregoing monitoring, documentation, and mitigation as well as other requirements related to potential effects on ocean inlets. These assurances are presently being formalized in a memorandum of agreement (MOA) between SANDAG and the Navy to cover areas of potential effect per Navy modeling. San Elijo and San Dieguito Lagoon are subject to the MOA. Agua Hedionda and Batiquitos Lagoons are also included out of deference to the resource agencies and an abundance of caution. The possibility of measurable effect on these last two is remote, per Navy modeling. Implementation of these measures would reduce impacts to below a level of significance. WATER RESOURCES The proposed action would cause a temporary increase in turbidity, potentially affecting water quality conditions in the nearshore environment. Increased turbidity caused by suspended particles in the water column would occur as a result of return water from pumping operations. Turbidity would potentially affect marine organisms and kelp/surfgrass beds in the nearshore area. However, the proposed action includes the use of longitudinal dikes to reduce turbidity during sand placement operations. Additionally, approximately 97 percent of the beach fill consists of larger grain size material (>63 |im) which settles rapidly and would not significantly increase turbidity. Time intervals between pumping operations allow time for suspended particles to settle. Therefore, turbidity would be minimized in the nearshore environment, and is not anticipated to cause significant impacts. RWQCB conditions require that supernatant from a .loaded barge be collected three times a week and analyzed for polar and non-polar oil and grease. Furthermore, weekly monitoring of bacteria contamination 100 feet down-current of the discharge point is required per the Waste Discharge Requirements. These RWQCB conditions will help verify that there are no significant impacts to water quality. 211602000 ES-3 BIOLOGY The proposed action would bury intertidal organisms at all three receiver beaches, resulting in mortality. Subtidal organisms would be affected by erosion of beach fill, resulting in burial of nonmobile subtidal invertebrates. However, characteristic organisms of the intertidal and subtidal zones would be expected to recolonize at a rapid rate. As onshore sand placement would be short-term, no significant impacts to intertidal and subtidal organisms are anticipated. Giant kelp beds offshore the Solana Beach receiver sites could be affected by barge operations associated with the proposed action. A sinker line running from the barge to the beach would be placed on the ocean floor to support the pump line. Placement of the sinker line could affect existing kelp beds. Kelp surveys in the Solana Beach area have been completed and sinker line placement is planned to avoid kelp bed habitat. Additionally, the kelp beds would be surveyed at least 30 days prior to proposed operations in order to ensure no adverse impacts. Sensitive marine resources in the nearshore environment could be affected by transported beach fill from the proposed action. Sensitive marine resources include rocky intertidal reefs, intertidal vegetated reefs (including feather boa kelp, surfgrass, sea fans, and sea palms), and nearshore reefs with giant kelp. However, beach fill placement has been designed to avoid these sensitive marine resources. Sediment transport studies indicate no significant adverse impacts would occur. Although no significant impacts to sensitive marine resources are expected, the Navy would prepare and implement a monitoring plan to verify no significant impacts. The program would include pre-discharge baseline studies and post-discharge monitoring effective from the date of issuance of this permit through July 1, 2001 to confirm that the discharge operations of sand materials has not resulted in any long-term net loss of sensitive marine resources. Mitigation would be the restoration of like habitat at a 1:1 ratio as a first priority. Consideration will be given to the construction of artificial reefs (~ one acre) as mitigation to offset project impacts at a 1:1 ratio if like habitat restoration efforts are not feasible as determined by the Corps, in consultation with the resource agencies. Should mitigation be required, as determined by the Corps in consultation with the resources agencies, total mitigation costs shall not exceed $700,000. 211602000 ES-4 California grunion may spawn on the receiver beaches during the sand placement period. Sand replenishment activities could potentially bury their eggs or change the beach profile resulting in mortality. If grunion are observed spawning, discharge of sand shall immediately cease in a buffer zone surrounding the area of spawning. The buffer zone shall extend 20 meters shoreward of the highest high water mark at the spawning area, and run 30 meters upcoast and 30 meters downcoast from the spawning area. A sand dike, parallel to the shoreline above the 20 meter buffer zone, shall be constructed along the entire 60 meter lateral extent of the buffer zone in a way that will ensure that the discharge water will not enter the spawning area. The spawning areas shall be recorded and mapped and provided to the Corps and resources agencies in a written report within 24 hours of the spawning event. A schematic drawing of any diked spawning buffer areas shall be submitted to the Corps and resource agencies with each written report.. The buffer zone would be in place for a minimum of 14 days (the period of time for eggs to hatch). This would mitigate impacts to the grunion and would allow sand replenishment activities to continue in areas not effected by spawning. The proposed action is not anticipated to affect sensitive bird species in the vicinity of sand deposition operations. Sensitive species occurring in the vicinity of receiver areas include the California least tern, Western snowy plover, and California brown pelican. Each of these species forage in the vicinity of the receiver sites. The tern and pelican utilize offshore waters, while the plover typically utilizes intertidal habitat. Foraging areas would be reduced by proposed operations; however, as these species are mobile, they can move to adjacent unimpacted areas for foraging activities. No significant adverse impacts to sensitive species would occur. LAND USE AND RECREATION The proposed action is consistent with all local, state, and federal land use plans. No impacts resulting from inconsistencies with applicable land use plans would occur. Additionally, the proposed action is compatible with the existing recreational uses in the receiver beach areas. Short-term impacts to recreation would occur at the receiver sites during sand placement operations. Recreational users would be dispersed to other local beaches in the area until operations were complete. Sediment transport is not anticipated to affect surf breaks dependent on subtidal reefs in the vicinity of the receiver beaches. Additionally, beneficial 211602000 ES-5 impacts to surf conditions (beach breaks) are anticipated from the formation of offshore sandbars. Long-term benefits to recreation would result from the proposed action; therefore, no significant impacts are identified. SAFETY AND ENvmoNMEisrrAL HEALTH Short-term impacts to safety would occur at the receiver sites during placement operations. The use of grading and construction equipment would create a hazardous condition, and cause potentially adverse impacts to public safety. However, the Navy would restrict public access to the receiver areas during replenishment operations. A 100- foot buffer zone would be maintained, and fencing, barricades, and flagmen would be utilized as necessary. Additionally, a 150 m by 150 m (approximately 500 ft by 500 ft) buffer area would be maintained around the barge offshore to ensure no impacts from barge placement or pumping operations. Scarps, defined as cuts in the beach berm due to wave action, could form in the vicinity of the receiver beaches subsequent to sand placement. Scarps are a function of the existing beach berm height and wave height, and occur naturally along the shoreline. As beach berm heights would not be increased due to proposed fill operations, scarps larger than those forming under natural conditions would not occur. Therefore, no significant safety hazards would occur as a result of sand placement. AESTHETICS The proposed action would cause temporary adverse visual impacts during sand placement operations. Coastal views in the vicinity of the receiver areas would be impacted during operations due to the offshore barge and grading operations. However, these impacts would be short-term. The proposed action would have long-term beneficial effects to visual resources due to replenishment of the receiver beaches and eradication of the existing eroded beach profiles. Therefore, no significant visual impacts would result. STRUCTURES AND UTILITIES Existing structures and utilities in the vicinity of the South Oceanside and Solana Beach receiver areas were surveyed for potential impacts due to sand placement. Public and private access stairs, sea walls, storm drains, and sewer outfalls were documented and 211602000 ES-6 potential effects were assessed. No significant impacts to existing structures or utilities would occur. NOISE The proposed action would exceed the nighttime noise levels as permitted in the local noise ordinances. The cities of Oceanside, Solana Beach, and Encinitas have noise ordinances which set allowable noise limits during daytime and nighttime hours. Grading operations associated with the proposed action would exceed the nighttime noise thresholds identified in each of the local jurisdiction's noise ordinances. However the project was able to qualify for and has obtained a variance which brings it into compliance with the local noise ordinance. Therefore, the Navy is able to conclude that the noise impacts will not be significant. 211602000 ES-7 This Page Intentionally Left Blank 211602000 ES-S SECTION 1 INTRODUCTION 1.1 BACKGROUND As a directive of the 1993 Base Realignment and Closure (BRAC) process, the Department of the Navy will be relocating one NIMITZ class aircraft carrier (CVN homeport) from Naval Air Station Alameda, San Francisco Bay, California to San Diego Bay. In order to accommodate the carrier, it is necessary for the Navy to dredge the carrier berthing area, turning basin, and the San Diego Bay navigation channel. Disposal of suitable dredged material is proposed at various receiver beach sites in San Diego County. As required under the National Environmental Policy Act (NEPA) (42 U.S.C. 4321- 4347), an Environmental Impact Statement (EIS) was prepared by the Navy which analyzed the environmental effects of the homeporting project, entitled "Final Environmental Impact Statement for the Development of Facilities in San Diego/Coronado to Support the Homeporting of One NIMITZ Class Aircraft Carrier." This document is herein referred to as the Homeporting EIS. A Record of Decision (ROD) for the Homeporting EIS was issued by the Department of the Navy on December 15, 1995. Environmental impacts analyzed in the document included dredging operations, disposal of dredged material, construction of berthing and maintenance facilities, and mitigation for the loss of shallow bay habitat. In conjunction with the CVN homeporting project, the Navy is proposing beach replenishment onshore in the intertidal and shallow subtidal zones at South Oceanside and Solana Beach. As part of the Homeporting EIS, various beach areas were identified as suitable for disposal of dredged materials. These areas included sites within close proximity to the proposed South Oceanside and Solana Beach receiver sites. Based on the location of these proposed receiver beaches and the proposed modifications to the Army Corps of Engineers (ACOE) 404/10 permit previously issued to the Navy for the disposal of dredged material, it was determined that a site-specific EA be prepared through the use of tiering from the previously prepared EIS (as described in the Council on Environmental Quality [CEQ] Regulations, 40 CFR Part 1508.28). This EA is intended to refine the analysis already presented to the public and provide detailed site- specific analyses required in order to modify the ACOE 404/10 permit. The following is 211602000 1-1 a summary of resource areas previously analyzed in the Homeporting EIS which do not require further analysis as part of the proposed action. Economics As discussed in the Homeporting EIS, beach replenishment using dredged sediments is generally considered a beneficial use of dredged materials. Beach erosion is a major problem along many beaches in southern California. Over half the shoreline along the San Diego coast has critical erosion problems that will cost the region's economy millions of dollars. San Diego Association of Governments (SANDAG) expects annual erosion related costs to continually increase. Beach replenishment is one of the most cost effective shoreline management alternatives for the region and is considered a beneficial impact for land use and development since it widens beaches, thus protecting property values and enhancing recreation facilities. Further analysis for this particular resource is not required for this EA. Traffic Implementation of the proposed action would require delivery of construction equipment to the beach receiver sites. Construction vehicles would be driven to and kept on site for the duration of beach replenishment activities. Beach replenishment activities associated with the proposed action would not significantly affect transportation and circulation, as the proposed action would generate very few trips. Any increases in traffic volumes would be temporary, no long-term impacts to existing transportation and circulation patterns would occur. Since the proposed action does not present any new significant issues which were not already identified in the Homeporting EIS, further analysis is not required for this EA Air Quality The majority of dust generated from beach replenishment activities would originate from grading of the disposed sand and would not exceed the significance threshold for emissions based on the Homeporting EIS. Emissions and dust generated by the proposed action would be temporary and short-term and would comply with regulations set forth by the San Diego County Air Pollution Control District (APCD) Rules and Regulations. Equipment would be properly maintained to reduce emissions and vehicle speed on the 211602000 1-2 beach would be kept to a minimum to reduce the formation of dust clouds. Therefore, further analysis of this resource is not required as part of this EA. Cultural Resources Based on the ACOE's permit modification for the beach replenishment sites, the National Register of Historic Places was consulted and no cultural resources were identified. In addition, the San Diego Museum of Man conducted an internal record search (17 March 1997) and found no archaeological sites recorded within the proposed beach receiver sites. Further, beach areas are subject to repeated wave action that is continually bringing sediments onto the beach and causing heavy erosion; therefore, no significant impacts to cultural resources would occur as a result of the proposed action and further analysis of this resource is not required for this EA. Environmental Justice In order to comply with Executive Order 12898 (Federal Actions to Address Environmental Justice [EJ] in Minority and Low-income Populations), ethnicity and poverty status in the vicinity of the proposed beach receiver areas have been compared to city, state, and national data to determine if any minority or low-income communities could potentially be disproportionately affected by the proposed action. Based on the location of the proposed action along the coastline where property values are typically high, the proposed beach receiver sites do not represent an area that would be considered a minority or low-income community. In addition, community resources would not be burdened and no adverse health conditions would be created. Therefore, further analysis of this resource is not required as part of this EA. The following site-specific issues are addressed and analyzed in this EA: Geology, Coastal Wetlands, Water Resources, Biological Resources, Land Use and Recreation, Safety and Environmental Health, Aesthetics, Utilities, and Noise. Preparation of the EA is in compliance with CEQ Regulations of July 1, 1986 (40 CFR 1500-1508), Department of the Navy Procedures for Implementing the National Environmental Policy Act (32 CFR 775), and the guidelines contained in the Chief of 211602000 1-3 Naval Operations Environmental and Natural Resources Program Manual (OPNAVINST 5090. IB) of November 1,1994. 1.2 PURPOSE AND NEED The U.S. Navy Proposes to dispose of suitable dredged material from San Diego Bay to beach receiver sites at South Oceanside and Solana Beach as Phase I of onshore beach nourishment efforts associated with dredging operations in San Diego Bay for the homeporting of a NIMITZ class aircraft carrier, as previously described in the Homeporting EIS. The purpose and need of the proposed beach nourishment activities is to replenish beaches with critical erosion problems, in accordance with the request submitted to the Navy by SANDAG's Shoreline Erosion Committee on June 6, 1996. This would provide immediate benefit by maximizing onshore beach fill in the Oceanside littoral cell, rather than placement of sand in the nearshore zone. Implementation of the proposed project would be designed to provide a wider recreational beach, reduce erosion, and protect the shoreline. To successfully accomplish beach nourishment, the design needs to incorporate proper width, berm height, and slope specifications. Furthermore, the beach fill needs to be placed as far updrift (north) as possible within each jurisdiction to be sufficiently successful. Beaches in Oceanside littoral cell have been steadily eroding. Because future shoreline erosion has the potential to increase both beach loss and property damage in these areas, SANDAG has developed the "Shoreline Preservation Strategy for the San Diego Region" which identifies regional coastal areas with critical shoreline problems. SANDAG and local communities have provided input regarding specific sites for placement of sand and have chosen South Oceanside and Solana Beach for beach replenishment. Implementation of the proposed action would contribute to the replenishment of narrow beaches with sand to ensure that they are wide enough to provide increased property protection and recreational capacity, thereby meeting the objectives of the Shoreline Preservation Strategy. The Shoreline Erosion Committee of SANDAG requested that the following volumes of sand be allocated nearshore and onshore to beach cities and state beaches: 211602000 1-4 Site Million Cubic Yards Imperial Beach (nearshore) 1.70 Mission Beach (nearshore) .86 Torrey Pines (onshore) .65 Del Mar (nearshore) .45 Solana Beach (onshore) .57 Encinitas (onshore) 1.14 South Carlsbad (onshore) .55 North Carlsbad (onshore) .55 South Oceanside (onshore) .53 Under the ACOE Section 404/10 Permit, all nearshore sites have been permitted. The purpose of the Phase I beach replenishment effort is to provide onshore beach nourishment at South Oceanside and Solana Beach. Phase II (presented in separate environmental documentation) proposes to place sand at Torrey Pines State Beach, Encinitas, South Carlsbad and North Carlsbad for the same purpose. 1.3 LOCATION OF THE PROPOSED ACTION Implementation of the proposed action would occur on beaches in South Oceanside and Solana Beach in San Diego County, California (Figure 1-1). The proposed replenishment for the Solana Beach site is composed of two smaller receiver beach areas, Cardiff and Solana Beach. The South Oceanside receiver beach is located south of the Oceanside Pier between Seagaze Drive and the Loma Alta Creek inlet, which comprises the majority of Oceanside City Beach and the area known as Escondido Junction (Figure 1-2). A segment of approximately 2.1 kilometers (1.3 miles) along the beach is proposed for replenishment. This area consists of a combination of sandy beaches and rip-rap slopes from the back of existing residences to the approximate high tide mark, and gentle slopes from the high tide mark into the surf zone. 211602000 1-5 SAN \JAMUL DIEGO TIJUANA *BEACH REPLENISHMENT SITES FIGURE Regional Location Map 1-1 EVENVIR ASS'MT(ENV)\Environ AssessmentNReceiver Beach EAVSD County Map Mon» Buoy FlltlR* Olhhore RntrlttidZon* Onshore RostrletMlZoiio MnkvLIno BUhymdiy (1/1 utter Mwvii) Brtlread PACIFIC OCEAN F I G U R E South Oceanside Beach Fill Site 1-2 04/1897 The Solana Beach receiver site is comprised of two locations, one northern and one southern (Figure 1-3). The northern receiver beach lies along Cardiff State Beach immediately west of Highway 101 and south of the San Elijo Lagoon inlet. Although this area is not within the city limits of Solana Beach, due to its close proximity to the other receiver beach it is considered part of the Solana Beach receiver site. The northern receiver beach extends approximately 1 kilometer (0.6 mi) north from the parking area turnout for Cardiff State Beach, west of Highway 101. Existing beach conditions at this location consist of steep cobble slopes with rip-rap supporting sections of Highway 101. The southern receiver beach extends approximately 1.1 kilometer (0.7 mi) from Cliff Street to Dahlia Drive and comprises Fletcher Cove Beach Park. Steep cliffs abut the southern receiver beach and the area consists of a gently sloping sand beach with scattered rocks and cobbles. 1.4 RELEVANT FEDERAL, STATE, AND LOCAL STATUTES, REGULATIONS AND GUIDELINES National Environmental Policy Act of 1969 (NEPA) NEPA requires that federal agencies consider potential environmental consequences of proposed actions in their decision-making process. NEPA's intent is to protect, restore, or enhance the environment through well informed federal decisions. The Council on Environmental Quality (CEQ) was established under NEPA for the purpose of implementing and overseeing federal policies as they relate to this process. In 1978, the CEQ issued Regulations for Implementing the Procedural Provisions of the National Environmental Policy Act (40 Code of Federal Regulations [CFR] §1500-1508 [CEQ 1978]) which were revised in 1986. These regulations specify than an EA be prepared to: • briefly provide sufficient analysis and evidence for determining whether to prepare an Environmental Impact Statement (EIS) or a Finding Of No Significant Impact (FONSI); • aid in an agency's compliance with NEPA when an EIS is deemed unnecessary; and • facilitate EIS preparation when one is necessary. 211602000 1-9 Clean Water Act (CWA) Section 311F33USC 13211 Section 311 of the CWA prohibits and regulates liability for the discharge of oil or hazardous substances into or upon waters of the U.S. or adjoining shorelines or which may present an imminent and substantial danger to natural resources or the public health or welfare, including, but not limited to fish, shellfish, wildlife, shorelines, and beaches. Clean Water Act Section 404(W1) Guidelines Section 404 of the CWA establishes a program to regulate the discharge of dredge and fill material into waters of the U.S., including dredged material placed in the ocean for beach replenishment or other beneficial uses. The proposed action complies with the guidelines promulgated by the Administrator, Environmental Protection Agency, under the authority of Section 404(b)(l) of the CWA (33 U.S.C. 1344). The primary purpose of fill activities is for beach replenishment. The 404(b)(l) evaluation was prepared for nearshore disposal as part of the homeporting project and a 404/10 permit was acquired by the Navy. The 404/10 permit sets conditions on a proposed action in order to reduce potential environmental impacts realized as part of the 404(b)(l) evaluation. The Navy has applied for a modification to the 404/10 permit in order to implement the proposed action. The modified permit is required prior to the start of onshore sand placement operations because the permit as originally issued only addressed nearshore disposal of dredged material. Rivers and Harbors Act Section 10 of the Rivers and Harbors Act authorizes the ACOE to regulate all activities that affect the course, capacity, or coordination of waters of the U.S. Coastal Zone Management Act of 1972 and California Coastal Act of 1976 The Coastal Zone Management Act of 1972 requires management programs for coastal zones, and is implemented through the California Coastal Act of 1976. Onshore disposal of dredged material requires a Coastal Consistency Determination (CCD) due to possible affects to resources in the coastal zone. A CCD has been prepared for the proposed action and submitted to the California Coastal Commission under separate cover. The 211602000 1-10 Ittu,. .. fcr-n -" ta>. HIKoricalMndraumKtlp B«d CmoplM1871 lo 1MB PATCH REEF * <\ \ • ' LOW RELliF REEF w/DENSE fURf|RAj»S SAND W/PATCH REEF AND 8URFQRAB8 Solana Beach Fill Site California Coastal Commission concurs with the findings in the CCD, as recorded in a public hearing on April 8, 1997. Therefore, the proposed action is consistent with the Coastal Zone Management Act and the California Coastal Act. National Oceanic and Atmospheric Administration (NOAA) Federal Consistency Regulations NOAA Federal Consistency Regulations (15 CFR 930) require that federal actions be consistent with the Coastal Zone Management Act of 1972. As described above, compliance with the Coastal Zone Management Act has been satisfied through the preparation and certification of a CCD with the California Coastal Commission. Executive Order 11990 This order requires that governmental agencies, in carrying out their responsibilities, provide leadership and "take action to minimize the destruction, loss, or degradation of wetlands, and to preserve and enhance the natural and beneficial values of wetlands." Implementation of the proposed beach replenishment plan would not adversely affect wetland areas near either of the project sites and, therefore, complies with this Executive Order. Endangered Species Act of 1973 (ESA) The ESA protects threatened and endangered species by prohibiting federal actions which would jeopardize the continued existence of such species, or minimizing actions which would result in the destruction or adverse modification of any critical habitat of such species. Current endangered species information was requested from the U.S. Fish and Wildlife Service (USFWS) and the National Marine Fisheries Service (NMFS) in compliance with Section 7 of the ESA. USFWS responded with concerns regarding threatened and endangered species which may occur in the vicinity of the proposed action. Specific concerns addressed the potential effects of the proposed action on foraging and breeding areas for the federally-listed California least tern, brown pelican, and Western snowy plover. 211602000 1-13 Potential impacts to threatened or endangered species include effects to foraging activities of sensitive bird species (e.g., California least tern, brown pelican, and Western snowy plover). USFWS reviewed the Public Notice for modifications to the ACOE 404/10 permit, dated 13 March 1997. USFWS concurs with the proposed action. Fish and Wildlife Coordination Act The Fish and Wildlife Coordination Act requires that any federal agency proposing to control or modify any body of water must first consult with USFWS or the NMFS. The proposed action has been coordinated with USFWS, NMFS, and the California Department of Fish and Game (CDFG). USFWS concurs with the proposed action as described above. NMFS reviewed the Draft EA dated March 1997, and also concurs with the proposed action. Migratory Bird Treaty Act of 1972 This Act prohibits the taking or harming of any migratory bird, its eggs, nests, or young without an appropriate permit. Local Jurisdictional Noise Regulations City ofOceanside Construction Noise Regulations Construction noise within the City of Oceanside is governed by the Oceanside City Code Section 38.17 and deals with specific prohibited noises. Subsection H of the City Code deals with construction equipment of a pneumatic or diesel nature. City ofSolana Beach Construction Noise Regulations Construction noise within the City of Solaria Beach is governed by Municipal Code Section 7.34.100 and deals with specific prohibited noises. Subsection A identifies limits on general construction activities, while Subsection B explains exemptions authorized by the City. 211602000 1-14 City ofEncinitas (Cardiff Receiver Beach) Construction Noise Regulations Construction noise within the City of Encinitas (Cardiff Receiver Beach) is governed by Performance Code Section 30.40.010. This section sets forth a list of performance standards dealing with any noise emissions effecting adjacent property. 1.5 INTERAGENCY COORDINATION The lead agency for the proposed action is the U.S. Department of the Navy in cooperation with SANDAG. An agency scoping meeting for the Phase I Environmental Assessment for Beach Replenishment at south Oceanside and Solana Beach was held on 21 February 1997 with the following agencies in attendance: Army Corps of Engineers U.S. Fish and Wildlife Service National Marine Fisheries Service California Coastal Commission San Diego Association of Governments U.S. Navy, Southwest Division Other agencies consulted as part of this EA process included: Environmental Protection Agency California Department of Fish and Game California Department of Parks and Recreation California Regional Water Quality Control Board (San Diego, Region 9) City of Oceanside City of Solana Beach City ofEncinitas 211602000 1-15 This Page Intentionally Left Blank 211602000 1-16 SECTION 2 DESCRIPTION OF THE PROPOSED ACTION AND ALTERNATIVES 2.1 ALTERNATIVE SELECTION CRITERIA An overall discussion of project alternatives was presented in the Homeporting EIS. Specific sites proposed for beach replenishment were established based on the following selection criteria. SANDAG Shoreline Preservation Strategy SANDAG has developed the "Shoreline Preservation Strategy for the San Diego Region" which identifies regional coastal areas with critical shoreline problems. Based on this study and input from local communities, beaches most in need of replenishment were identified. The SANDAG study was used to determine site-specific alternatives for beach replenishment. Implementation of the proposed action reflects the critical need for sand at South Oceanside and Solana Beach. Marine Resources Beach sites along the San Diego coast were analyzed for onshore beach replenishment suitability. Beach replenishment was not considered as an alternative for onshore disposal in areas that exhibited sensitive marine resources such as rocky intertidal, subtidal vegetated reefs (that hold feather boa kelp, surfgrass, sea palm, or sea fan), and nearshore reefs with giant kelp. Beach Replenishment Design Four beach fill construction template alternatives were evaluated in order to achieve the purpose of the proposed action which is to maximize beneficial use of the dredge material for recreational beach enhancement and minimize potential adverse impacts. The four alternative beach fills considered were: 211602000 2-1 • Low Berm (lower than minimum ) (+1.0 m elevation, 35:1 slope) Compared to the other alternatives, the low berm alternative would provide reduced beneficial impacts for recreation and shore protection as the berm is expected to erode at a higher rate over the short term (3 to 6 months). In addition, this alternative would be very difficult, if not impractical to construct, and would be very costly. Therefore, this alternative was not considered further. • Minimum Berm (+1.7 m elevation, 20:1 slope) The minimum berm alternative is expected to erode somewhat slower than the low berm alternative over the short term and meets the purpose of the proposed action. Scarps form on beaches at a point where waves break on the beach. This alternative is not expected to lead to a scarp significantly over 1m (3.3 ft) high. • Maximum Berm (+2.8 to 3.4 m elevation, 10:1 slope) The maximum berm alternative is expected to erode somewhat slower than the minimum berm alternative over the short term and meets the purpose of the proposed action. The berm elevation matches the natural beach berm elevation which is particular to each site location and may be different between sites. This alternative is not expected to lead to a scarp significantly over 2 m (6.6 ft) high. • Block Berm (higher than maximum ) (+4.2 m elevation, 3:1 slope) The block berm alternative is expected to erode somewhat slower than the maximum berm alternative over the short term and is very similar to the berm constructed for the Batiquitos Lagoon disposal at South Carlsbad. This profile is built with an extremely high berm elevation and steep beach slope which will likely result in a scarp height in excess of 2.5 m (8.2 ft). Therefore, this alternative was not considered further. 2.2 PROPOSED ACTION - BEACH REPLENISHMENT The proposed action involves the replenishment of sand on receiver beach sites in South Oceanside and Solana Beach as previously shown on Figures 1-2 and 1-3. Beach replenishment would be performed using suitable sediment dredged from San Diego Bay 211602000 2-2 for the homeporting of a NIMITZ class aircraft carrier at Naval Air Station North Island (NASNI) in San Diego. Dredging of the San Diego Bay channel is anticipated to yield approximately 5.4 million cubic meters (m3) of material. Receiver beaches were chosen based on compatibility with chemical and grain size sediment analyses that were performed on the dredged sediment. The proposed action would utilize approximately 841,020 m3 (1,099,970 cubic yards [cy]) of dredged sediment for use as beach replenishment at the three identified sites. Specifically, 405,218 m3 (530,082 cy) would be placed at one site in South Oceanside, and 435,802 m3 (570,091 cy) would be placed at two sites in Solana Beach (all quantities are measured in the cut). Beach replenishment at South Oceanside would involve onshore placement of sand from a point directly south of Seagaze Drive to a point directly north of the Loma Alta Creek mouth, as shown on Figure 1-2. Dredged sediment would be placed on the existing sand beach and graded to form a berm. The top of the berm would range from approximately +1.7 to 3.4 m (+5.6 to +11.2 ft) Mean Sea Level (MSL) and would be flat, extending out approximately 40 to 50 meters (130 to 160 ft). From this point, the berm would slope at a ratio between 20:1 and 10:1 (horizontal distance:vertical distance) approximately 60 to 80 m (195 to 260 ft) into the intertidal zone to an average depth of -2 m (-6.6 ft) MSL. The berm would extend approximately 2 kilometers (km) (1.2 mi). Representative cross- sections of the berm are shown on Figure 2-1. The berm construction may be adjusted during fill placement depending on actual field conditions. The beach elevation should not be constructed higher than the natural berm elevation for each beach site. Beach replenishment at the Solana Beach site would consist of the placement of dredged sediment at two locations: approximately 267,585 m3 (350,039 cy) would be placed at the northern location along Cardiff State Beach just south of the San Elijo Lagoon inlet; and approximately 168,217 m3 (220,052 cy) would be placed at the southern location between Cliff Street and Dahlia Drive, as shown on Figure 1-3. Although the northern location is not within the Solana Beach city limits, it is considered part of the Solana Beach site due to its proximity to the southern receiver area. A berm would be constructed at these locations to an elevation of approximately +1.7 to +2.0 m (+5.6 to +6.6 ft) MSL. The berms would be flat and extend out an average of 40 to 70 m (130 to 228 ft), then slope at a ratio between 20:1 to 10:1 for approximately 60 to 80 m (195 to 260 ft) to a depth of -2 m (-6.6 ft) MSL. The northern berm would extend approximately 1 km (0.6 mi), and the southern berm would extend approximately 0.7 km (0.4 mi). Representative cross-sections of these berms are shown on Figure 2-2. 211602000 2-3 TOB UJ -2 3ERM WIDTH VARIES 40M TO 50M -+1.7 M TO +3.4 M MSL SLOPE RATIO 10:1 TO 20:1 -40 0 40 80 DISTANCE (M) FROM TOP OF BERM (TOB) TYPICAL CROSS-SECTION -2 120 40 HORIZONTAL 1:1000 VERTICAL 1:100 South Oceanslde Typical Berm Cross-section E\ENVIR ASS'MT(ENV)\ENVIRON ASSESSMENT\Receiver Beach EA\Cross-sectlons FIGURE 2-1 ELEVATION MSL (M) ELEVATION MSL (M)ib o 10 4* ib o 10 «•TOB \ V.\ jiERM WIDTH VARIES \ \ i ' OOMTO \ V S s s s TOM M TO +2.81, / ^K- ^**^^ "* ™ ^ \^ ^ 'SLOPE RA'10 /] 10:1 TO 20:1 ^Clr\^l__-::^ -40 0 40 80 12 DISTANCE (M) FROM TOP OF BERM (TOB) TYPICAL CROSS-SECTION A TOB BERM WIDTH' VARIES \ 50M TO e \x OM 1 +1.8 / MSL •• ^^^ \^V "-. /^^v SLOPE RA 10 10:1 TO 20:1 tn-.^K^i. ~ ~ - . 4 2 0 -2 0 4 2 0 -2 -40 0 40 80 120 DISTANCE (M) FROM TOP OF BERM (TOB) 0 40 TYPICAL CROSS-SECTION B iSz^mSoo VERTICAL 1:100 Solana Beach Typical Berm Cross-sections FIGURE 2-2 RFNVIR ASR'MT^ENVnENVIRON ASSERSMENT\Rfionivfir Boarh EA\Croas.sec»lons Beach replenishment operations would include the use of a trailing suction hopper dredge, which would load sediment from various dredging locations in San Diego Bay and move north to the receiver beaches for sand placement. The hopper dredge would anchor approximately 500 to 1,300 m (1,640 to 4,300 ft) offshore of the receiver beach and would connect via a 1-m-dia (36-in-dia) rubber floating pump line attached to a floating platform called a "mono buoy", which is used to interconnect the floating pump line with a steel sinker pipeline that would run the rest of the distance to the beach. The mono buoy, which is less than 9 m (30 ft) in diameter and does not hold any mechanical equipment, would be anchored a minimum of 500 m (1,640 ft) offshore at a water depth of approximately -12m (-40 ft) MSL using four navigational buoys. The mono buoy would remain anchored in the same area off each receiver beach throughout pumping operations. The hopper dredge would hook up to the mono buoy, then proceed to hydraulically pump a mixture of sand and sea water through the rubber pump line onto the beach. The sand would then be graded and placed using two Caterpillar D8 bulldozers. A 966 Caterpillar forklift would be used to move the pump line. Approximately 5 to 7 construction personnel would be necessary to operate the pump line and grading equipment on the beach. The beach replenishment process would involve the construction of longitudinal dikes along the waterline in order to reduce sediment loss. The dikes would work to retain return water from the pumping operation and allow suspended particles to settle out. The hopper dredge can carry a maximum capacity of 8,520 m3 (approximately 11,000 cy) of sand per load. It is anticipated to take approximately 2 to 3 hours to hook up the pump line, pump a full load onto the receiver beach, and disconnect the line. The dredge would move south for reloading approximately 2 to 3 times per day. Travel time for reloading would depend on the distance of the receiver beach from the loading location in San Diego Bay. The dredge moves at approximately 12 kilometers per hour (7.5 miles per hour) at maximum speed. Beach replenishment operations are scheduled to run 24 hours a day, seven days a week. The proposed action is anticipated to take 48 days at the South Oceanside site, during July, August, and September and 30 days at the Solana Beach site, during September and October. During periods of high seas, the hopper dredge would be moved into harbor and anchored until better weather permits operations to resume. 211602000 2-6 Due to construction activities associated with beach replenishment operations (i.e., pumping sand onto the beach, grading, bulldozer equipment, etc.), the identified receiver beach areas would be temporarily closed to public access. Closure would be maintained on 24-hour basis during the scheduled project operation time. A 30 m (100 ft) buffer zone would be maintained between the operational area and open public beaches. The Navy would provide and maintain safety measures in the vicinity of the receiver beaches including fencing, barricades, flagmen and warning signals as necessary. In addition to onshore restricted access, an offshore area would be closed to the public to allow proper anchoring of the dredge and pumping operations. An area of approximately 150 m by 150 m (about 500 ft by 500 ft) would be restricted around the hopper dredge while it is anchored offshore of the receiver beaches. Restricted access is recommended solely for the purpose of public safety. 2.3 ALTERNATIVES CONSIDERED 2.3.1 North Oceanside (Oceanside Harbor to the Oceanside Pier) North Oceanside is the area between Oceanside Harbor and the Oceanside Pier. This alternative includes Harbor Beach, in the vicinity of the Oceanside harbor, and the San Luis Rey River mouth, along with the section of the City Beach which runs from the San Luis Rey River mouth to the Oceanside Pier. Harbor Beach affords a wide, relatively sheltered beach while the City Beach (North of the Pier ) is wide due to sand bypassing by the ACOE (Sterrett, E.H., and R.E. Flick, 1994). The beach narrows considerably south of the pier until it disappears at Wisconsin Avenue. Because the shoreline north of the pier does not have an extremely narrow beach or is in critical need of sand at this time, as the areas do south of the pier, it was rejected as an alternative for this project. 2.3.2 South Oceanside (Loma Alta Creek to Buena Vista Lagoon) This is a critical shoreline problem area characterized by highly-eroded, narrow, cobbly beaches. The St. Malo Association development is at the southern end of this reach. This area is located south (downdrift) of the proposed project site. To shift the area from the proposed project site to the south of Loma Alta Creek would not meet the purpose and need, since it would not place material in a critical shoreline problem area as far updrift (north) as practicable. The Navy investigated elongating the beach fill, thereby causing narrower and/or lower beach. A narrower and/or lower beach would also not meet the 211602000 2-7 "proper design specifications" requirement of the purpose and need. Because of these design constraints this area was rejected. 2.3.3 Solana Beach As a design alternative, the Navy investigated a design which consisted of one contiguous beach which stretched from Cardiff State Beach to Solana Vista Drive in Solana Beach. This alternative directly covered sensitive marine resources including rocky intertidal habitat, surfgrass, and subtidal high relief reefs. Therefore, this alternative was rejected due to direct placement onto sensitive marine resources. The proposed Solana Beach site eliminates direct placement onto marine resources by creating two receiver areas for disposal, thereby avoiding sensitive marine resource areas which occur between Cardiff State Beach and the City of Solana Beach. 2.4 No ACTION ALTERNATIVE Under the no action alternative, approximately 841,020 m3 of beach-compatible dredged materials would not be disposed of along the beaches in South Oceanside and Solana Beach. Instead, the Navy would dispose of the material at nearshore sites which were identified and analyzed in the Homeporting EIS (Figure 2-3). Areas analyzed for nearshore disposal included South Oceanside, Del Mar, Mission Beach, and Imperial Beach. A full environmental analysis of potential impacts to each of these nearshore sites has been evaluated in the Homeporting EIS. A Section 404/10 permit from ACOE was obtained by the Navy on April 6, 1996 (Permit No. 94-20861-DZ) allowing the Navy to utilize the identified nearshore sites for dredged material disposal. Should the no action alternative occur, the dredged material would be disposed of at permitted nearshore sites as follows: South Oceanside receiver beach material would go to the South Oceanside nearshore disposal site. Solana Beach receiver beach material (both sites) would go to the Del Mar nearshore disposal site. 211602000 2-8 Preferred Oceanside Beach Replenishment Site Alternative Oceanside Nearshore Site 3500 FEET Pacific Ocean Preferred Solana Beach Beach Replenishment Sites Alternative Del Mar Nearshore Site F I CURE Beach Replenishment Sites 2-3 This Page Intentionally Left Blank 211602000 2-10 SECTION 3 AFFECTED ENVIRONMENT 3.1 GEOLOGY AND SOILS Existing geologic conditions are based on the Beach Sand Transport and Sedimentation Report prepared by Frederic R. Harris, Inc. (FRH) (March 1997). This report provides general information on coastal geology, beaches and shoreline configuration, tides and sea level changes, wave processes, and littoral processes from a regional perspective. This report is included as Attachment I. The following sections focus on the existing geologic conditions and littoral processes that make up the individual receiver sites. 3.1.1 South Oceanside 3.1.1.1 Coastal Geology The South Oceanside receiver beach was formed from sand and rocks that originated from upland erosion. The beach consists of a relatively thin sand lense varying in width that lies on a shallow, wave cut bedrock platform. Unusually large waves can strip the rocky terrace clean by moving the sand offshore or down coast. Oceanside City Beach is relatively wide although beach widths decrease south of Wisconsin Street as the wave sheltering effect from Oceanside Harbor is gone. Beach widths south of Oceanside Harbor, however, are presently narrower than they were historically as a combined consequence of the net decrease of river sand inputs and the trapping effect of the harbor on the littoral transport of sand from the north. 3.1.1.2 Littoral Processes Beaches along the central and southern California coast are typically dynamic in nature, with constant and continual longshore and onshore/offshore sediment transport. These processes vary seasonally in intensity depending upon oceanographic and weather conditions, occurring both locally and throughout the Pacific Ocean region. Particles of sediment that are moved via this erosional process are typically suspended into the water 211602000 3-1 column by wave or current action, transported some distance by longshore currents, and deposited on adjacent beaches. The void (or erosion) left behind by this movement is normally replenished by similar sediment that has been eroded from yet another beach area. Although this process gives the illusion of stationary beaches, the actual sediment constituting beaches is in a constant state of movement (ACOE 1994). The Oceanside Littoral Cell extends from Dana Point, in Orange County, south to the Scripps-La Jolla Submarine Canyon system at La Jolla Shores, near the foot of Mount Soledad. The Oceanside Harbor complex is located approximately in the middle of this cell. The harbor jetties interrupt the natural flow of sand and to a large extent divide the cell into a sub-cell north of Oceanside Harbor. Receiver beaches are located along the southern half of the Oceanside Littoral Cell. Historical longshore transport rates and shoreline changes are well documented in the Coast of California Storm and Tidal Waves Study (CCSTWS) (ACOE 1991). This study concluded that the future condition of the beaches in northern San Diego County would be governed by cycles of accretion and erosion similar to those of the past 50 years, with accelerated trends toward erosion due to the following conditions: (1) reduction of river borne sediment due to impoundment by dams; (2) influence of Oceanside harbor; and (3) increase in the rate of sea level rise. In addition, the CCSTWS concluded that the most critical reach for future erosion is the 19.3 km (12 mi) stretch of beach immediately south of Oceanside Harbor. The South Oceanside receiver beach is included within this area. Extensive studies of longshore sediment transport rates have been conducted on the Oceanside Littoral Cell. Table 3-1 summarizes sediment transport rates, as identified by previous researchers. Results indicate a net southerly sediment transport at a rates ranging between 78,000 and 194,000 mVyr (or approximately 100,000 to 250,000 cy/yr). 211602000 3-2 Table 3-1 LONGSHORE SEDIMENT TRANSPORT RATE ESTIMATES FOR THE OCEANSIDE LITTORAL CELL Study Marine Advisers (1961) Hales (1978) Inman and Jenkins (1983) Northerly mVyr (ydVyr) 416,700 (545,000) 413,600 (541,000) 422,800 (553,000) Southerly mVyr (ydVyr) 581,100 (760,000) 491,600 (643,000) 617,000 (807,000) Net mVyr (ydVyr) 164,400 (215,000) 78,000 (102,000) 194,200 (254,000) Source: Frederic R. Harris, Inc. 1997. Historical sources of sediment for Oceanside Littoral Cell beaches include rivers, streams, and lagoons. However, since the 1950's, dams have significantly reduced these sediment sources and urbanization has accelerated the erosion rate of coastal bluffs and increased the rate of sedimentation in lagoons. Thus, current sources of onshore littoral material primarily include rivers, bluffs, and artificial fills. Several other elements also contribute to the decline of sediments within the littoral cell. Storms carry sediment away from the nearshore area and deposit it on the continental shelf. The Oceanside Littoral Cell shelf is steep; therefore, littoral material can be permanently lost from the littoral zone. Additionally, littoral transport between Oceanside and La Jolla is affected by two submarine canyons located at Carlsbad and La Jolla, which act as significant sediment sinks for littoral material. As a result of a reduction in littoral material sources, coupled with the loss of material from storms and submarine canyons, a net reduction in available natural sources of beach replenishment is occurring. 211602000 3-3 3.1.2 Solana Beach 3.1.2.1 Coastal Geology The northern Solana Beach replenishment area, along Cardiff State Beach, consists of a rocky (cobble) beach that lies on a shallow, wave cut bedrock platform. The beach area has been stripped of most of its sand from large waves which typically occur during the winter months. The northern beach is located directly seaward of San Elijo Lagoon and south of the lagoon mouth. The lagoon was formed during lower stands of sea level, when the shoreline was farther to the west and existing streams quickly eroded the exposed marine terraces. This formed steep canyons, and as the sea level rose (approximately 18,000 years ago), sediments quickly filled the lower reaches of the channels and created the lagoon. San Elijo is still currently a tidal lagoon because the channels are not completely full of sediments. The southern Solana Beach receiver beach consists of a low tide terrace, which lies in front of coastal cliffs south of San Elijo Lagoon. The steep coastal cliffs in this area have been continually forming from wave action cutting against the marine terrace. This process has occurred since the last relative still-stand of sea level, approximately 6,000 years ago (FRH 1997). The existing beach comprises the flat, rocky, shallow part of the shoreline visible during low tide. 3.1.2.2 Littoral Processes The Solana Beach receiver beaches are both within the Oceanside Littoral Cell and are subject to similar transport processes as described for South Oceanside. However, the Solana Beach receiver beaches are not located within the critical erosional area south of Oceanside Harbor (as identified by the CCSTWS). These sites are located south of the Carlsbad submarine canyon, which may slightly affect littoral transport to these areas (FRH 1997). 211602000 3-4 3.2 COASTAL WETLANDS This section provides a brief overview of coastal wetland areas in the vicinity of the South Oceanside and Solana Beach receiver beaches. Coastal wetlands discussed include creeks, rivers, or lagoons that discharge into the ocean near the proposed receiver sites (FRH 1997). For a more detailed discussion of coastal wetlands see Attachment I. 3.2.1 South Oceanside Coastal wetlands in the vicinity of the South Oceanside receiver beach include the San Luis Rey River, Loma Alta Creek, and Buena Vista Lagoon. The San Luis Rey River, located north of the receiver beach, represents a sensitive environmental resource in the vicinity of the proposed action. The mouth (outlet/inlet) of this year-round river is located just south of Oceanside Harbor. Although this river suffers from urbanization and poor water quality, it supports a diverse assemblage of wetland habitats upstream of the river mouth (City of Oceanside 1985). Loma Alta Creek, which discharges south of the proposed beach fill area, is a seasonal freshwater creek. The outlet area crosses a small sand beach that is defined by rip-rap on both sides. There is no lagoon associated with this creek, although a very small freshwater marsh exists just east of the outlet area. The creek suffers from urbanization and poor water quality (City of Oceanside 1985). The beach in front of the creek outlet is steep. During the dry season, when the creek is not running, the creek outlet is closed to the ocean by a sand berm (Attachment I). Buena Vista Lagoon, located south of the receiver beach, is the smallest of the lagoons in the area. Historically, this lagoon had 376 acres of low marsh and 290 acres of high marsh habitat. Today, it is a fresh/brackish water wetland area of 246 acres. It continues to experience sewage spills and has historically received discharges of secondary treated wastewater. The accumulated sludge, plant detritus, excess nutrients, and contained basin combine to cause eutrophic conditions. Nonetheless, the lagoon supports a diverse assemblage of sensitive bird species (e.g., Light-footed clapper rail, California Least tern, Belding's savannah sparrow, and California brown pelican) (see Attachment I; 211602000 3-5 Section 4.3.3). The lagoon is a State Ecological Reserve managed by the California Department of Fish and Game (CDFG). Buena Vista Lagoon is no longer connected to the ocean, due to the construction of a fixed weir in 1940 to provide a year-round aquatic environment. Excess seasonal freshwater runoff flows over the weir to the ocean. The weir is located in the back end of a small pocket beach, approximately 44 m (145 ft) behind the crest of a longshore cobble berm. High tides do not usually wash over the weir; however, evidence suggests that high waves occasionally overtop the weir during the winter. 3.2.2 Solana Beach Coastal wetlands in the vicinity of the Solana Beach receiver beaches include San Elijo Lagoon and San Dieguito Lagoon. The San Elijo Lagoon inlet is located directly north of the northern Solana Beach receiver beach. San Elijo Lagoon is approximately 900 acres in size and includes the San Elijo Lagoon Ecological Reserve which comprises 590 acres and is managed by the California Department of Fish and Game and the San Diego County Department of Parks and Recreation. The lagoon supports a multitude of habitats including coastal salt marsh, tidal channels, mudflats, and freshwater marsh habitats. Adjacent to the wetland are upland chaparral and riparian habitats. Habitat quality has been degraded from historical conditions by changes in hydrology, land use surrounding the watershed, urbanization, sedimentation resulting in poor water quality, introduction of exotic species, and severely limited tidal action (County of San Diego 1995). A combination of these effects have resulted in regular closures of the lagoon mouth. San Dieguito Lagoon is located approximately 1.6 km (1 mi) south of Fletcher Cove Beach park. The lagoon includes a lengthy river channel, which serves as the main body of the lagoon, along with a channel tributary. Historically, the lagoon was a 604-acre salt marsh but was filled in to construct the Del Mar fairgrounds and racetrack in 1935. Today, San Dieguito Lagoon is primarily a river channel where seasonal fluvial flows dominate. The watershed consists of the San Dieguito River and its tributaries; however, the Lake Hodges Dam restricts storm flows on the river, affecting the natural function of the lagoon. During drought periods, the ocean inlet is typically closed. During wet years, storm flows would blow out the ocean inlet barrier and scour the river bed in the lagoon. Wastewater discharges and sewage spills have historically occurred in the lagoon, which 211602000 3-6 have contributed to increased eutrophic conditions. The wetland acreage of the lagoon totals 520 acres, however, 259 acres are represented by highly disturbed, agricultural, and nonvegetated habitat. The lagoon serves as nesting and foraging habitat for several shorebirds and water fowl. 3.3 WATER RESOURCES Water quality in the vicinity of the receiver beaches is affected by a number of physical processes and chemical properties. Physical processes include tides and water levels, currents, wave exposure, and littoral processes. Chemical properties are characterized by temperature, salinity, dissolved oxygen, and water visibility (turbidity). The following is a discussion of the factors that contribute to the quality of existing water resources at each of the sites. 3.3.1 South Oceanside 3.3.1.1 Physical Processes Southern California has a mixed semi-diurnal tide with two high tides and two low tides, each of different magnitude, every 24 hours and 50 minutes. The range between mean high and low water is approximately 1.1 m (3.7 ft) and the diurnal (daily) range is approximately 1.6 m (5.4 ft) (ACOE 1996). Tide data in the vicinity of Oceanside ranges from a lowest observed tide of 0.0 (-3.3 ft) MSL to highest observed tide of +2.38 m (+7.7 ft) MSL (Moffat and Nichols 1983). Local currents in the nearshore waters are complex and include longshore currents which flow parallel to the shore and cross-shore currents which move in an onshore-offshore direction. The combination of these currents make up the littoral transport process. Longshore currents in the coastal zone are driven primarily by waves striking the shoreline at oblique angles. Overall, longshore currents produce a drift and sediment transport from north to south. Wave exposure affects the receiver beach from the south and west. For further discussion of littoral transport processes affecting the receiver sites, refer to Section 3.1. 211602000 3-7 3.3.1.2 Chemical Properties Due to the local physical characteristics of the area, the water column is well mixed vertically, with seawater temperatures ranging between 13.9 and 23.9 degress Celsius (57 and 75 degrees Fahrenheit). Salinity in the coastal area typically varies between 33 and 35 parts per thousand (ACOE 1996). High dissolved oxygen concentrations are maintained by tidal and wave action, while low concentrations result from respiration by aquatic organisms, poor circulation, and oxidation of organic matter. A dissolved oxygen level equal to or greater than 5 parts per million (ppm) has been recommended as a generalized standard of acceptable water quality for aquatic life (EPA 1986). Dissolved oxygen concentrations are routinely measured off the coast of Encinitas, approximately 24 km (15 mi) south of South Oceanside and directly north of Solana Beach. Average recorded dissolved oxygen levels are 10 ppm (ACOE 1996). 3.3.1.3 Turbidity Turbidity refers to the total amount of suspended sediments in the water column. Increases in turbidity can affect fish growth, propagation, feeding, and respiration. Turbidity is caused by the presence of fine sediments (i.e., silts and clays) in the water column. It reduces the transparency of seawater and therefore reduces the amount of light available for phytoplankton and photosynthesis. Suspended silt particles in the water column will increase turbidity; however, larger sand particles (>63 jam) will settle out rapidly and not cause a significant increase in turbidity. Testing of the dredged material suitable for beach disposal determined that approximately 97 percent of the sand is greater than 63 |im (U.S. Navy 1996). Sampling of the water near the receiver beaches indicates that nearshore water visibility typically ranges between 1.5 and 6 m (5 and 20 ft) (ACOE 1996), however, visibility is significantly reduced in the surf zone due wave action. Therefore, intertidal waters of the receiver beaches are characteristically turbid due to the high energy activity in the nearshore environment. 211602000 3-8 3.3.2 Solana Beach Physical, chemical, and turbidity conditions for the Solana Beach receiver beaches are generally the same as those for the South Oceanside site. 3.4 BIOLOGY The following section provides a brief introduction to the existing biological communities occurring within the beach replenishment areas. Biological descriptions are based on existing literature (MEC 1995; ACOE 1994,1996; FRH 1997). 3.4.1 South Oceanside The South Oceanside receiver site is characterized by sandy beaches within the intertidal zone. No plant growth has been found on the proposed receiver beach due to: 1) absence of reef habitat for the plants to attach; and 2) seasonal erosion and replenishment of sand (ACOE 1994). The intertidal zone - the area between the highest high tide and the lowest low tide - can be divided into three areas (upper, middle, and lower) based on the frequency and duration of inundation by seawater. Organisms that live within this zone have adapted to a continually changing environment and physical factors such as grain size, slope, and biological tolerances which have influenced species diversity, abundance, and distribution. Beach hoppers (Orchestoided), the predatory isopod Excirolana chiltoni, and three species of polychaetes are commonly found in the upper intertidal zone (Thompson et al. 1993). Sand crabs (Emerita analogd) are common in the middle intertidal zone but move with the tide throughout the intertidal area. Polychaetes, snails, and the bean clam (Donax gouldi) are also found in the middle intertidal zone. Polychaetes and nemerteans dominate the lower intertidal area (Straughan 1982). Areas that are permanently inundated are defined as subtidal. At the South Oceanside site, the sandy substrate found in the intertidal zone extends into the subtidal zone. Shallow water (less than 10 m) epifaunal invertebrates are dominated by suspension feeders; carnivores and scavengers are dominant in waters greater than 10 m (33 ft) (Morin et al. 1985, 1988). Epifaunal invertebrate abundance declines as depth increases and infaunal invertebrate abundance increases, most likely due to an increase in sediment stability (Barnard 1963). 211602000 3-9 Fish diversity and abundance can vary spatially (vertical and horizontal stratification within the water column) and temporally (day and night, seasonally). California corbina (Menticirrhus undulatus) and barred surfperch (Amphistichus argenteus) are common in shallow subtidal areas, often darting into the surf zone to feed on sand crabs. Other fishes that commonly occur over sandy bottoms include topsmelt (Atherinops affinis), queenfish (Seriphus politus), spotfin croaker (Roncador stearnsii), white croaker (Genyonemus lineatus), California halibut (Paralichthys californicus), shovelnose guitarfish (Rhinobatos productus), and round stingray (Urolophus halleri) (ACOE 1994). The invertebrate and fish species that occur at the Oceanside receiving site produce planktonic larvae. Larvae are produced by adults within the receiving site, carried on ocean currents, and deposited elsewhere. Adults that settle within the receiving site are brought in on ocean currents. California grunion (Leuresthes tennis) can be found seasonally in the nearshore waters of the South Oceanside receiver beach. Grunion typically use sandy beach areas for spawning from March through mid-September with peak activity between April and June. However, due to their unique spawning behavior along the coast, exact locations where spawning would occur can not be determined. Expected grunion runs during the scheduled time of the proposed action are provided in Table 3-2. Grunion are managed as a game species by the California Department of Fish and Game (CDFG). Based on Expected Grunion Runs for 1997, the potential exists for grunion to spawning at the South Oceanside receiver beach during sand replenishment activities. Spawning takes place at nighttime during high tides with the eggs being deposited in the sand. The eggs hatch after 10 to 14 days during the next high tide series. Numerous shorebird species forage in the intertidal zone of the Oceanside receiving area, a majority of which are winter visitors. Species that may be seen in the Oceanside receiving area include American avocet (Recurvirostra americand), black-bellied plover (Pluvialis squatarold), greater and lesser yellowlegs (Tringa melanoleuca and T.flavipes), spotted sandpipers (Actitis macularid), willets (Catoptrophorus semipalmatus), long-billed curlews (Numenius americanus), marbled godwit (Limosa fedoa), and sanderlings (Calidris alba). Western gulls (Larus occidentalis), California 211602000 3-10 Table 3-2 EXPECTED GRUNION RUNS FOR 1997 Month June July August Source: Calif. Dept. Day 6 7 8 9 22 23 24 25 6 7 8 9 21 22 23 24 5 6 7 8 20 21 22 23 offish Su Mo Tu We Su Mo Tu We Su Mo Tu We Mo Tu We Th Tu We Th Fr We Th Fr Sa and Game, 1997 Time 10:30 PM 11:05PM 11:45PM 12:30 AM llrOOPM 11:45PM 12:45 AM 01:50 AM 10:45 PM 11:20PM Midnight 12:40 AM 10:50 PM 11:40PM 12:30 AM 01:40 AM 11:OOPM 11:35PM 12:10 AM 01:00 AM 11:35PM 12:30 AM 01:35 AM 03:00 AM 12:30 AM 01:05 AM 01:45 AM 02:30 AM 01:00 AM 01:45 AM 02:45 AM 03:50 AM 12:45 AM 01:20 AM 02:00 AM 02:40 AM 12:50 AM 01:40 AM 02:30 AM 03:40 AM 01:00 AM 01:35 AM 02: 10 AM 03:00 AM 01:35 AM 02:30 AM 03:35 AM 05:00 AM 21]602000 3-11 gulls (Larus calif or nicus), ring-billed (Larus delewarensis), and herring gulls (Larus argentatus) are also common at the Oceanside receiving area. California sea lions (Zalophus californicanus) and harbor seals (Phoca vitulind) occur offshore and may, infrequently, use the beach. Dolphins and porpoises have been observed offshore and within the surfzone. Sensitive species are those that are listed by the U.S. Fish and Wildlife Service (USFWS) as threatened, endangered or are proposed for listing as threatened or endangered. Sensitive birds that may occur in the South Oceanside receiver area include the California brown pelican (Pelacanus occidentalis californicus), California least tern (Sterna antillarum browni), and western snowy plover (Charadrius alexandrinus). The federally listed (endangered) California brown pelicans have been observed in the vicinity of the South Oceanside receiver site and forages and rests in nearshore waters. This species is tolerant of human activity near its daytime roosts and readily utilizes various man-made structures (i.e., piers, breakwaters, buoys) as roosting sites. Brown pelicans breed at the Coronado Islands, which are approximately 56 km (35 mi) south of the South Oceanside site. The federally listed (endangered) California least tern is a migratory bird that visits southern California's coastline from April through mid-September. This species breeds in open, unvegetated sandy areas and forage on small fish in nearshore waters near their breeding colonies. California least terns are not expected to nest at the South Oceanside receiving site due to the presence of humans; however, they may forage in the nearshore waters. The federally listed (threatened) western snowy plover nests in flat open areas with sandy or saline substrates and breeding typically occurs from March to mid-September. Snowy plovers forage on invertebrates in the intertidal zone. Western snowy plovers have not historically occurred along the South Oceanside receiver site and are not expected to nest in the area due to high human presence. 211602000 3-12 3.4.2 Solana Beach The northern beach area of the Solana Beach receiver site is very narrow with predominant cobble and gravel sized material. The structures, roadway, and parking lot are protected by continuous rip-rap revetment along the beach. A reef area is located directly north of the receiver beach and a low relief reef consisting of dense surfgrass is located south of the replenishment area (Figure 1-3). Kelp beds are present on the hard substrate offshore of the Solana Beach site. The southern beach area is narrow, backed by high, wave-cut and eroding cliffs. Several small rocky projections occur along the beach. There are sandy areas in the upper intertidal zone and hard substrates (i.e., cobble, sandstone, or boulder reefs) interspersed among sand channels in the shallow subtidal areas. A high relief reef is located directly north of the receiver beach. A sand area with patch reef and surfgrass lies within the replenishment area. The sandy intertidal and subtidal areas of the Solana Beach receiver site have invertebrate and fish species that are similar to the species found in the sandy intertidal and subtidal areas of the South Oceanside receiver site. However, in contrast to the South Oceanside receiver site, the Solana Beach receiver site has boulder and low relief reefs in the intertidal and subtidal zones (MEC 1995). Algal species associated with these reef areas include brown, red, and corallines. Invertebrates include the red sea urchin (Strongylocentrotus franciscanus), giant seastar (Pisaster giganteus), lobsters, and gorgonians. The fish species include species typically associated with subtidal reefs such as perches (family Embiotocidae), garabaldi, senorita, and kelp and sand bass. Shorebirds, water birds, and marine mammals occurring or expected to occur at the Solana Beach site are also similar to those for the Oceanside site. Historically, kelp beds (Macrocystis pyrifera) have been present in the nearshore area off Cardiff and Solana Beach. El Nino events such as those which occurred in the early 1980s and 1990s reduced kelp density and area resources. Figure 1-3 reflects the maximum extent of emergent kelp canopy over the past 22 years. The kelp beds were resurveyed in March 1997. The trend over the last 10 years indicates a gradual increase in emergent kelp canopy in the area. Red (fleshy and coralline), green, and brown algae occur within the kelp beds. 211602000 3-13 Surfgrass (Phyllospadix torreyi) beds exist near the receiver beach area and have been found on some of the hard substrates found from the southern end of Cardiff State Beach to Tide Park (MEC 1995). Surfgrass beds provide an important habitat for a diverse assemblage of algae, fish, and invertebrates. Epibenthic invertebrates that may occur in the sandy substrate include white urchins (Lytechinus pictus) and the sea star (Astropecten verrilli). Amphipod crustaceans are dominant in shallow subtidal sandy habitats and polychaetes are dominant in deeper (greater than 20 m) waters (Thompson et al. 1990). Invertebrate diversity is expected to be higher on the hard substrates and include bryozoans, gorgonians, purple urchins (Strongylocentrotus purpuratus), soft corals, sponges, gastropods, and crustaceans. California Spiny Lobsters (Panuliris interruptis) are also common amongst the hard substrate off the Solana Beach receiver beaches. Numerous fish species that are important to recreational fisherman occur offshore of the Solana Beach receiver beaches. Fish diversity and abundance within reefs and kelp beds are influenced by the presence or absence of kelp and substrate relief (Cross and Allen 1990). Kelp beds are not important spawning areas for fish, but do provide refuge and foraging areas for juveniles and adults (Cross and Allen 1990). California sheephead (Semicossyphus pulcher), garibaldi (Hypsypops rubicundus), blacksmith (Chromis punctipinnis), rockfish (Sebastes spp.), kelp bass (Paralabrax clathratus), surfperch (Family Embiotocidae), and opaleye (Girella nigricans) are commonly found in southern California kelp beds and rocky reefs. Sensitive avian species known to occur in the vicinity of the Solana Beach site include California least tern and Western snowy plover. Least terns have been recorded in the vicinity of San Elijo Lagoon and utilize nearshore areas for foraging (MEC 1995). The Western snowy plover occurs in small numbers along the beach in the western portion of San Elijo Lagoon year-round, but is most common during fall and winter (MEC 1995). The plover feeds on invertebrates in sandy intertidal areas in the vicinity of the lagoon. 211602000 3-14 3.5 LAND USE AND RECREATION The proposed beach replenishment areas are located in northern San Diego County along the Pacific Ocean, within the jurisdictions of the cities of Oceanside, Encinitas, and Solana Beach. Regional access is provided by Interstate 5 (1-5) to the east, SR-56 to the south, and SR-78 to the north. The coastal area of northern San Diego County is generally characterized as predominately suburban residential interspersed with commercial uses. Recreational opportunities along the coast consist of a variety of activities. One of the more popular recreational activities is surfing. Figure 3-1 illustrates popular surf breaks from South Oceanside to Del Mar. 3.5.1 South Oceanside The northern portion of the site is used intensely for beach activities, while the southern portion is eroded and typically not used by the public. The area immediately adjacent to the South Oceanside site is mostly comprised of new and older residential uses. In addition, scattered commercial and retail activities, mostly associated with the tourism industry, exists along adjacent roadways. The Strand, a beach front road that extends from Seagaze Drive to Wisconsin Avenue, exists adjacent to the northern portion of the site. Loma Alta Creek is located to the south of the replenishment footprint. Recreational activities on the site include swimming, sport fishing, surfing, sailing, picnicking, and hiking. Most watersports occur adjacent to the Oceanside Pier, although there are scattered sand drift surf breaks near the proposed beach receiver site. No nearshore reefs supporting surf breaks are located in the vicinity of the South Oceanside receiver site. Surfing conditions in this area are primarily dependent upon shifting formations of nearshore sandbars. Most ocean-related recreational activities that occur at the beaches or in nearshore areas are available year-round due to the mild climate. The site is located within the Coastal Zone as designated in the City of Oceanside Land Use Element (1989). The objective of the coastal zone is to "provide for the conservation of the City's coastal resources and fulfill the requirements of the California Coastal Act of 1976." In compliance with the California Coastal Act of 1976, the City adopted a Local Coastal Program (LCP) in 1985. The coast zone boundary runs parallel to Coast Highway and 211602000 3-15 OceansideJ Oceanside Pier - Preferred Oceanside Beach Replenishment Site Warm Water Jetty Terra Mar Tomato Fatdi Grandvfew Beacon's Stonesteps Moonlight D Street GT's G Street Tree's Boneyards Swami's Dabbers Pipes Traps Pacific Ocean Preferred Solana Beach Beach Replenishment SitesTippers Cardiff Reef George's - Seaside Reef Palisades Table Tops PiUBox Cherry Hill Solana Beach River Mouth Beach Break #Del Mar FEET SOURCE: Brian Gates & Pipes F I CURE Recreational Surfing Sites west to the ocean. The north shore of Buena Vista Lagoon and an area north of Mission Avenue and east of 1-5 are also included in the boundary area. In general, the LCP requires that development not interfere with the public access to and along the shoreline. As stated in Policy A of Section 1.32 of the Land Use Element, "The City shall utilize the certified Local Coastal Plan and supporting documentation for review of all proposed projects within the Coastal Zone. Specifically, the goals and policies of the Local Coastal Program Land Use plan shall be the guiding policy review document." Also stated in the Land Use Element, in Section 3.17 Coastal Preservation, are the following policies: A. The City shall attempt to preserve shoreline beach area as a valuable recreational asset and visitor inducement. B. The City shall continue with periodic replenishment of beach sand by the Federal government until permanent beach sand management systems are decided on and implemented. 3.5.2 Solana Beach Beach replenishment activities would occur at two locations: on Cardiff State Beach west of San Eljio Lagoon and on Solana Beach from Cliff Street to Dahlia Drive (which includes Fletcher Cove). The northern Cardiff beach is characterized by cobble beaches with scattered sandy areas located adjacent to Highway 101. A few restaurants exist along the waterfront, approximately 150 m (500 ft) south of the San Elijo Lagoon inlet. The Cardiff State Beach parking area is located south of the receiver beach. The existing beach at this location is severely eroded. Recreational activities at the site include swimming, sportfishing, surfing, sailing picnicking, and hiking. Two extensively used surf breaks exist in the vicinity of Cardiff State Beach, "George's" and Cardiff Reef. "George's," which is located directly off of the receiver beach site, is a beach break, dependent on the formation of nearshore 211602000 3-17 sandbars. Cardiff Reef is located approximately 200 m (650 ft) north of Cardiff State Beach. Surfing conditions in this area are the result of a large subtidal reef. Cardiff Reef is also known as a popular scuba diving area. The southern Solana Beach receiver beach consists of steep cliffs and little beach area. Residential development exists above the receiver site along the bluff. Similar to the northern site, the southern site is severely eroded. Seaside Reef, "Palisades," and "Table Tops" are all reef breaks located approximately 500 m (1,625 ft) north of the southern Solana Beach site. Reefs within this area are extensively fished for lobster and other game fish. Further, the nearshore kelp beds are a popular dive spot year round. Also in this area is a small subtidal reef north of Fletcher Cove which supports a surf break commonly known as "Pill Box." The northern beach is within the California Parks and Recreation, State Beaches Department's jurisdiction. Currently, there are no policies or guidelines that relate to the proposed action and its associated impacts. The southern beach is within the California Coastal Commission's jurisdiction. Any decisions regarding activities on the beach would be subject to the Commission's review and approval. The proposed action has obtained a Coastal Consistency Determination (CCD) from the California Coastal Commission. 3.6 SAFETY AND ENVIRONMENTAL HEALTH Extensive sediment characterization analyses were conducted for the South Oceanside and Solana Beach receiver sites as part of the Homeporting EIS. These analyses were conducted in accordance with ACOE, EPA, and RWQCB procedures for dredged sediment. Based on the analyses, approximately 5.4 million m3 (7.0 million cy) of dredged material is considered suitable for beach replenishment, of which approximately 841 thousand m3 (1.1 million cy) would be used as beach replenishment at the identified receiver beaches. 211602000 3-18 3.6.1 South Oceanside The City of Oceanside provides lifeguard services in the vicinity of the receiver beach. The lifeguards are responsible for all recreational safety measures along the beach. Safety measures include manned lifeguard towers and regular vehicle patrols during the summer months. 3.6.2 Solana Beach The California State Department of Parks and Recreation provide lifeguard services at Cardiff State Beach in the vicinity of the northern receiver beach. Safety measures include manned towers and regular vehicle patrols during the summer months. The City of Solana Beach provides lifeguard services along the southern receiver beach. Safety measures include portable and permanent manned towers and vehicle patrols during low tide in the summer months. 3.7 AESTHETICS 3.7.1 South Oceanside The South Oceanside receiver beach is visible from several locations in the area including the Oceanside Pier, the Strand, and beach-front residences and businesses in the area. Visual resources at the South Oceanside receiver site consist of two general areas: the northern and southern portions of the receiver beach. The northern portion of the receiver beach consists of a public beach with high recreational use, while the southern portion consists of an eroded beach with low use. The northern length of the receiver beach includes the Strand, a beach-front road that runs from Seagaze Drive to Wisconsin Avenue. The view along the Strand along the east side of the road includes a mix of beach-front homes, condominiums, parks, shops, and restaurants. West of the road the view consists of a flat sandy beach which narrows as it approaches Wisconsin Avenue (Figure 3-2). The southern portion of the receiver beach from Wisconsin Avenue to Loma Alta Creek is severely eroded, and is visible only at low 211602000 3-19 a. View of northern portion of receiver beach looking south from south of Seagaze Drive. b. View of southern portion of receiver beach looking north from Loma Alta Creek outfalt. South Oceanside Receiver Site Existing Views FIGURE 3-2 E\ENVIR ASS'MT(ENV)\Environ AssessmenftReceiver Beach EA\Recelevr Beach EA No.1 tide. Beach-front homes and condominiums are located east of this portion of the receiver area (Figure 3-2). 3.7.2 Solana Beach The northern Solana Beach receiver beach is visible from Highway 101, several restaurants along the highway, the southern portion of San Elijo State Beach Campground, and residences and businesses on the bluffs north and south of San Elijo Lagoon. This receiver beach is characterized by steep cobble banks with scattered sandy areas abutting Highway 101. Development along this stretch of beach consists of several restaurants along the waterfront located approximately 150 m (500 ft) south of the San Elijo Lagoon outlet. Cobble slopes extend from the top of the beach into the surf zone from the lagoon mouth to the restaurants. South of the restaurants, towards the Cardiff State Beach parking area, rip-rap slopes extend from the edge of Highway 101 into the surf zone. The receiver beach in this area is severely eroded and consists of very little sand (Figure 3-3). The southern receiver beach sits below steep cliffs and is visible from the stairs at Solana Vista Drive, Fletcher Cove, North Seascape Surf Park, and some residences along the bluff. It currently consists of little or no existing beach area. Views of the beach along this stretch are dependent upon the tides. At high tide the beach is not visible along the majority of the receiver area, as waves crash directly against the cliffs. The only exception is the small sandy beach at Fletcher Cove which sits above the high tide mark. At low tide a low profile sand and cobble beach is visible below the cliffs (Figure 3-2). 3.8 STRUCTURES AND UTILITIES Existing conditions for structures and utilities were obtained from the Beach and Transport and Sedimentation Report, prepared by Frederic R. Harris, Inc. (Attachment I). 3.8.1 South Oceanside There are several existing structures and utilities within the shoreline area of the South Oceanside Beach site. Each structure and utility is described below. Locations are indicted on Figure 3-4. 211602000 3-21 c. View of northerly receiver area looking north from Cardiff State Beach parking area. d. View of southerly receiver beach looking south from stairway at Solana Vista Drive. Solana Beach Receiver Sites Existing Views FIGURE 3-3 BENV1R ASS'MT(ENV)\Env!ron Assessment\Receiver Beach EA\Recelevr Beach EA No.2 BEACH PHOTOGRAPH LOCATION (TYP.) 91 cm» MORTAR UNED & COATED STEEL PIPE SANITARY SEWER OCEAN OUTFALL Existing Structures and Utility Impacts — South Oceanslde Structure Sanitation Sewer Ocean Outfall Stairs O Tyson Park Stairs O Ash St. Stairs O Marron St. Ramp O Wisconsin St. Ramp 9 Foster St. Private Stairway s/o swr. ocean outfall Double 45 cm dla. RCP s/o Tyson St. Double 91 cm dla. RCP O Morron St. 45 cm dla. RCP O end of Foster St. (Se,PhN°o?e 1) 21. 22, 25 4 6 14 7 18 25 5 16A 17 Approximate Outlet InvertApprox. Q. (m, MSI) N/A N/A N/A N/A N/A N/A N/A 0.65± 1.9± 2.0± Bottom ofStolrs/RamDApprox. Q. (m. MSt.) N/A 3.3± 1.2± 1.5± 1.4± 1.7± N/A N/A N/A N/A Comments 91 cm dla. steel pipe — No apparent Impact No Impact Minor Impact — bottom portion will be covered with sand Minor Impact - bottom portion will be covered with sand Minor Impact - bottom portion will be covered with sand No Impact No Impact — lowest step Is 1.2 m to 1.5 m. above sand Storm Drain flow must be maintained No Impact Pipe Is half filled with eand — no Impact Notes: 1. Refer to Appendix D for Site Photographs. Source: Frederic R. Harris. 1997 Existing Structures and Utilities South Oceanslde Site FIGURE 3-4 3.8.1.1 Sanitary Sewer Ocean Outfall A 91-cm-diameter (36-in-dia) sewer outfall pipe is located almost perpendicular to the shoreline directly north of Loma Alta Creek. The depth of cover is unknown. This pipe was installed in approximately 1971 (Hojo 1997). 3.8.1.2 Access Stairs Public access stairs are located at the end of Tyson Street, Ash Street, and Marron Street. Ramp access exists at Wisconsin Street and Foster Street. A private stairway for beach access is located south of the sewer outfall pipe, with the stairs ending approximately 1 to 1.5 m (3 to 5 ft) above the beach sand. 3.8.1.3 Storm Drain Pipes There are two side-by-side 45-cm-dia (18-in-dia) storm drains located directly south of Tyson Street and two side-by-side 91-cm-dia (36-in-dia) storm drains at the end of Marron Street. A 45-cm-dia (18-in-dia) pipe, half filled with sand is located at the end of Foster Street. 3.8.2 Solana Beach Several structures and utilities presently exist within the shoreline area of the Cardiff/Solana Beach site. Locations are indicated on Figure 3-5. 3.8.2.1 Sanitary Sewer Ocean Outfall A 76-cm-dia (30-in-dia) sewer outfall pipe is located almost perpendicular to the shoreline between San Elijo and Cardiff State Beaches. This pipe was originally installed in 1968 by the Cardiff Sanitation District. Depth of cover is unknown. 211602000 3-24 PHOTOGRAPH LOCATION (TYP.) Existing Structures and Utility Impacts - Solatia Beach Structure Sea Wall Tide Pools Public Access Stairs O Tide Beach Park Sand Bag Retaining Wall O Tide Beach Park 45 cm dla. CMP Storm Drain O Tide Beach Park Public Access Ramp O Plaza St. 152 cm dla. Storm Drain Outfall Pipe O Plaza St. 45 cm dla. Storm Drain Pipe O Ocean Blvd. 76 cm dla. RCP Sewer Outfall Photo(See Note 1) 39 30. 40. 41 42 42 42 46. 47. 51 46-51 N/A 36, 37, 53 ApproximateOutlet InvertApprox. Q. (m, MSL) N/A N/A N/A N/A 3.0 N/A -0.3 N/A N/A Bottom ofStairs/RampApprox. D. (m, MS.) N/A N/A 1.2 N/A N/A 1.7 N/A N/A N/A Comments Base of Seawall: 1.6± - No Impact N/A No Impact Bottom of wall elev: 1.7± - No Impact No Impact No Impact Outfall under construction — maintain adequate flow path Into ocean Not found — No apparent Impact 76 cm dla. RCP Sewer Outfall - No apparent ImpactNotes: 1. Refer to Appendix D for Site Photographs. 2. All Elevations are approximate and reference MSL In meters. Source: Frederic R. Harris, Inc., 1997 FIGURE ^^SgS*^ Existing Structures and Utilities Solana Beach Sites 3-5 3.8.2.2 Access Stairs There is an existing public access staircase with a lifeguard tower located adjacent to the west end of Solana Vista Drive at Tide Beach Park. Adjacent to these stairs are a 45-cm-dia (18-in-dia) drain and a sand bag retaining wall with several 8 to 10 cm (3 to 4-in-dia) weep holes. 3.8.2.3 Storm Drain Pipes A 52-cm-dia (60 to 72-in-dia) storm drain pipe is currently under construction at the west end of Plaza Street (an extension of Lomas Santa Fe Avenue) (Nguyen 1997). An existing 45-cm-dia (18-in-dia) storm drain pipe is located west of the west end of Ocean Boulevard. However, this pipe was not visible during a site reconnaissance on March 10, 1997 and is assumed to be buried. 3.9 NOISE Current ambient acoustical conditions at the three proposed receiver beaches (e.g., South Oceanside, Cardiff, and Solana Beach) are typical of that observed for nearshore beach communities. The areas are dominated by existing noise sources including ocean surf, recreational activities, and vehicle traffic on adjacent roads. 3.9.1 South Oceanside 3.9.1.1 Noise Measurements In order to determine existing noise levels in the vicinity of the project site, a limited noise monitoring study was performed at the proposed replenishment site on 27 March 1997. Measurements were taken at the most accessible beach location (i.e., direct beach access). Ideally, meter placement corresponded to a position relatively close to existing receptors. When this condition was not possible, measurements were taken at the closest available point. A Larson Davis Model 2900 ANSI Type 1 real-time frequency analyzer was used to collect the data. A series of short-term (15 minute) sound 211602000 3-26 level and spectral measurements were taken to quantify the existing ambient conditions. All measurements were taken in the afternoon between 1 and 5 p.m. The South Oceanside area consists of mixed residential/commercial uses north of Oceanside Boulevard (to the Oceanside Pier), and wholly residential uses south of Oceanside Boulevard. Current average ambient acoustical conditions are shown in Table 3-3. From the observed readings it is apparent that the site has a relatively high background level dispersed across a wide frequency spectrum. This type of spectral response (and corresponding acoustical levels) is typical of a beach environment. Table 3-3 AMBIENT CONDITIONS AT SOUTH OCEANSIDE Location OC1 OC2 OC3 Leq (dBA) 66.3 68.4 68.4 Min (dBA) 63.7 64.5 64.4 Max (dBA) 68.3 73.2 70.7 Monitoring Locations: OC1: North of Oceanside Boulevard near the proposed sinker line landfall. GPS mark 33.11.082N/117.22.420W. OC2: Northern end of replenishment site. GPS mark 33.11.619N/117.22.892. OC3: Southern end of replenishment site. GPS mark 33.10.779W/117.22.177W. 3.9.1.2 Noise Ordinances The Oceanside City Code Section 38.17 describes specific noises that are prohibited within the City. The section of the City Code relevant to the proposed action is cited below: "Pile drivers, hammers, etc. The operation between the hours of 10:00p.m. and 7:00 a.m. of any pneumatic or air hammer, pile driver, steam shovel, derrick, steam, or electric hoist, parking lot cleaning equipment or another appliance, the use of which is attended by loud or unusual noise is prohibited. " 211602000 3-27 3.9.2 Solana Beach 3.9.2.1 Noise Measurements Noise measurements were taken at Cardiff and Solana Beach during the noise monitoring study conducted for this project on 27 March (see Section 3.9.1.1). Equipment and procedures were the same as those described for the South Oceanside site. Land use consists of mixed commercial uses adjacent to the Cardiff replenishment area and residential use adjacent to the Solana Beach replenishment area. Current average ambient acoustical conditions at the two Solana Beach locations are shown in Table 3-4. This type of acoustical response is typical of a beach environment. Table 3-4 AMBIENT CONDITIONS AT CARDIFF/SOLANA BEACH Location SOI S02 CA1 CA2 Leq (dBA) 65.5 68.7 58.7 73.6 Min (dBA) 64.0 66.1 55.5 64.2 Max (dBA) 67.6 72.0 62.7 81.4 Monitoring Locations: SOI: Southern end of Solana Beach site. GPS mark 32.59.40 IN/117.16.482 W. SO2: Northern end of Solana Beach site. GPS mark 33.00.015N/117.16.589W. CA1: Northern end of Cardiff Beach site. GPS mark 33.01.024W/117.16.876W. CA2: Southern end of Cardiff Beach site. GPS mark 33.00.481N/117.16.722W. 3.9.2.2 Noise Ordinances City of Encinitas (Cardiff Receiver Beach) Construction noise within the City of Encinitas (Cardiff Receiver Beach) is governed by Performance Code Section 30.40.010. This section sets forth a list of performance 21]602000 3-28 standards dealing with any noise emissions effecting adjacent property. The sections of the City Code relevant to the proposed action are cited below: 1. "Every use shall be so operated that the noise generated does not exceed the following levels at or beyond the lot line and does not exceed the limits of any adjacent zone " (Table 3-5). Table 3-5 RELEVANT PROPERTY LINE STANDARDS One Hour Average Sound Level Adj acent Zone 7am-1 Opm 1 Opm-7am Residential 50 dB 45 dB Multifamily Residential 55 dB 50 dB Office/Commercial 60 dB 55 dB Light Industrial/Business Park 60 dB 55 dB Note: Even though dB is cited in the ordinance, it is understood that this is A-weighted decibels (or dBA) 2. "ER/OS/PK - Would be governed by the limits applicable to the source of the complaint." (This includes area occupied by the proposed beach receiver site). 3. "The interior noise level...must not exceed {a day-night average} of 45 dB. " (It is assumed that the limit is set in A-weighted decibels). 4. "It shall be unlawful for any person on any property within the City to create any noise, or to allow the creation of any noise on property owned, leased, occupied, or otherwise controlled by such person, which causes the noise level when measured on any other property to exceed the following: a. The noise standard for cumulative period of more than 30 minutes in any hour; or, 211602000 3-29 b. The noise standard plus 5 dB for a cumulative period of more than 15 minutes in any hour; or, c. The noise standard plus up to 15 dB for a cumulative period of more than 1 minute in any hour; or, d. The noise standard plus 20 dBfor any period of time. For the purpose of this Chapter, the peak decibel reading for a noise with fluctuating noise level (such as live or recorded music) shall be considered as the noise level for the entire cumulative period of the noise... " City of Solana Beach Construction noise within the City of Solana Beach is governed by Municipal Code Section 7.34.100 which deals with specific prohibited noises. Subsection A deals with limits on general construction activities, while Subsection B explains exemptions authorized by the City. The sections of the Municipal Code relevant to the proposed action are cited below: A. "The erection, demolition, alteration or repair of any building structure or the grading or excavation of land in such a manner as to create disturbing, excessive or offensive noise during the following hours, except as hereinafter provided, is a violation of this code: 1. Before 7:00 a.m. or after 7:00 p.m., Monday through Friday, and before 8:00 a.m. or after 7:00p.m. on Saturday; 2. All day on Sunday, New Year's Day, Martin Luther King Day, President's Day, Memorial Day, Independence Day, Labor Day, Veteran's Day, Thanksgiving and Christmas Day. 211602000 3-30 B. Exceptions. 1. An owner/occupant or resident/tenant of residential property may engage in home improvement or a home construction project involving the erection, demolition, alteration or repair of a building or structure or the grading or excavation of land on a 'weekday between the hours of 7:00 a.m. and 7:00 p.m., and on weekends between the hours of 8:00 a.m. and 7:00p.m... 2. The city manager may grant exceptions of this section by issuing a permit in the following circumstances: a. When emergency repairs are required to protect the health and safety of any member of the community; b. In nonresidential zones, provided there are not inhabited dwellings within 1,500 feet of the building or structure being erected, demolished, altered or repaired or the exterior boundaries of the site being graded or excavated. C. Construction noise levels shall not exceed 75 decibels for more than eight hours (Leq[8]) during any 24-hour period when measured at or within property lines of any property which is developed and used either in part or in whole for residential purposes. In the event that lower noise limit standards are established for such construction activity pursuant to state or federal law, such lower limits shall be used as a basis for revising and amending the noise level limits specified in Subsection C of this section. " 211602000 3-31 This Page Intentionally Left Blank 211602000 3-32 SECTION 4 ENVIRONMENTAL CONSEQUENCES 4.1 GEOLOGY AND SOILS Beach replenishment using dredged sediments is generally considered a beneficial use in areas where beach erosion is a problem as the fill can be utilized to create a sand berm to provide additional recreational uses and shoreline protection. However, placement of the sand can also create a temporary change in the shoreline. Over a period of time, which is expected to be on the order of 1 to 2 years, the sand would be moved and redistributed from the placement location along shore and cross shore through natural littoral transport. At that time, the shoreline would again reach an equilibrium position which would be very similar to the existing beach profile. The shoreline would temporarily widen at locations upcoast and downcoast of the beachfill site, until natural littoral transport redistributed the sand along the coast, as described in the section below. The following analysis of coastal geology and littoral processes related to beach replenishment is based on studies performed as part of the Beach Sand Transport and Sedimentation Report prepared by Frederic R. Harris, Inc. (Attachment I). 4.1.1 South Oceanside 4.1.1.1 Coastal Geology The proposed action would place approximately 405,218 m3 (530,082 cy) of dredged sediment at the receiver location in South Oceanside. Sediment deposited on the beach would be spread along shore and cross shore through natural littoral transport. Shoreline positions were modeled based on the anticipated sediment movement and were predicted for periods of 3 months, 6 months, and 12 months after sand placement (Figure 4-1). Placement of sand on the beach at South Oceanside would widen the existing beach area to the north and south of the receiver location subsequent to pumping operations. However, results of the modeling indicate that most of the beach fill would erode over a one- to two-year period, spreading along shore and cross shore. Along shore movement of sediment would generally be confined to 3,000 m (9,850 ft) upcoast and downcoast of 211602000 4-1 -BEACH FILL -APPROXIMATE SHORELINE AT 12 MONTHS AFTER PLACEMENT LOMA ALTA CREEK -100 | -150 "55 %tO -200 S.£ -250 0)</> o>-300 | -350 JZ CO -400 -APPROXIMATE IpRE-FILL SHORELINE POSITION 12 MONTHS SAN LUIS REY GROIN OCEANSIDE HARBOR GROIN 1000 2000 3000 Shoreline Station (m) Shoreline position exagerated 5 X 4000 Source: Frederic R. Harris, Inc., 1997 BUENA VISTA LAGOON FEET Mean Sea Level Shoreline Response South Oceanside Site FIGURE 4-1 the beach fill area. Cross shore movement would generally be confined to 450 m (1,500ft) from the back of the existing beach. Seasonal cross shore movement would transport the fill material offshore in the winter and back onto the beach in the summer, repeating this trend over subsequent seasons. Seasonal loss due to natural littoral processes would occur (FRH 1997). Sediment would move to an offshore sandbar seasonally. Modeling indicates that the average maximum thickness of the sandbar would be on the order of 0.7 m to 1.4 m (2.3 ft to 4.6 ft) in the summer and 1.5 m to 2.3 m (5.0 ft to 7.5 ft) in the winter. Beach profile surveys taken from 1991 to 1994 show the offshore sandbar in Oceanside starting approximately 200 m (650 ft) offshore and extending an average distance of 200 m (650 ft) seaward (FRH 1997). Sediment movement subsequent to the proposed action would follow natural seasonal and littoral trends. A minor increase in average sand thickness is anticipated, on the order of 0.1 m to 0.2 m (0.3 ft to 0.6 ft) (FRH 1997). The increased thickness is anticipated to be greatest in the vicinity of MSL and decrease seaward. No significant impacts to coastal geology are anticipated due to sediment transport or increased sediment thickness. 4.1.1.2 Littoral Processes Sediment placed onshore at South Oceanside would be distributed along the coast by the Oceanside Littoral Cell processes. Net littoral transport in the area of the receiver beach is estimated to move south, with the capacity to move approximately 78,000 m3 to 194,000 m3 (100,000 to 250,000 cy) per year. This downcoast movement is the net result of both upcoast and downcoast movements which occur depending on the angle of wave approach. Previous placement of fills on the beach in Oceanside have not shown dramatic changes in the littoral process. Since 1955, over 10 million m3 (13 million cy) of fill have been placed onshore or nearshore in Oceanside by ACOE with no adverse impacts having been recorded. These past beach fills have been in the same range as the proposed fill quantity. Therefore, based on past fill events, placement of sediment onshore at South Oceanside would not be anticipated to change the littoral transport process. 211602000 4-3 As discussed above, it is anticipated that the majority of beach fill would be transported into the shallow subtidal area approximately two years after replenishment operations. During and after transport of beach fill, potential affects to wave activity in the vicinity of the receiver area could occur. According to the sand transport study prepared for this project (Attachment I), the beach profile would be minimally changed due to the addition of sediment to the nearshore area. It is anticipated that accretion of sediment in the shallow subtidal zone would create sand bars which would likely improve surf break conditions. Scarping could occur during time of high waves. This could cause minor changes in wave breaking characteristics and slightly increase wave energy reflection during times of low waves (approximately 1 m or less). However, this change would be negligible and is considered insignificant. 4.1.2 Solana Beach 4.1.2.1 Coastal Geology The proposed action would place approximately 435,802 m3 (570,091 cy) of dredged sediment at two receiver beaches within the Solana Beach site (Cardiff and Solana Beach). Approximately 267,585 m3 (350,039 cy) would be placed along Cardiff State Beach and approximately 168,217 m3 (220,052 cy) would be placed from Cliff Street to Dahlia Street including Fletcher Cove in Solana Beach. Sediment deposited on the beaches would be spread along shore and cross shore through natural littoral transport. Shoreline positions were modeled based on the anticipated sediment movement and were predicted for periods of 3 months, 6 months, and 12 months after sand placement (Figure 4-2). Placement of sediment on beaches at the Solana Beach site would widen the existing beach areas north and south of the receiver locations subsequent to pumping operations. Similar to the South Oceanside site, most of the beach fill would erode over a one- to two-year period, spreading along shore and cross shore. Along shore movement of sediment would generally be confined to 3,000 m (9,850 ft) upcoast and downcoast of the beach fill area. Cross shore movement would generally be confined to between 300 m (985 ft) and 350 m (1,150 ft) from the back of the existing beach (FRH 1997). Seasonal movement similar to that of Oceanside would occur. 211602000 4-4 -CARDIFF BEACH FILL - ROCKY POINT APPROXIMATE SHORELINE AT 12 MONTHS AFTER PLACEMENT- -50 ^ -100 = -150 ™ -200 -250 -300 Q> £o o> o -350 O) APPROXIMATE PRE-FILL SHORELINE POSITION -400 1800 Source: Frederic R. Harris, Inc., 1997 2800 3800 4800 Shoreline Station (m) Shoreline position exagerated 5X 5800 6800 7800 Mean Sea Level Shoreline Response Solana Beach Site FIGURE 4-2 E:\ENVIRONMENTAL\RECEIVERBEACH\RES-SOL.CDR An offshore sandbar at the northern Solana Beach fill site (Cardiff State Beach) is located approximately 130 m to 140 m (425 ft to 460 ft) offshore and extends an average distance of 170 m (560 ft) seaward. The same sandbar extends to the southern site (Fletcher Cove), starting approximately 130 m to 145 m (425 ft to 475 ft) offshore and extending an average distance of 170 m (560 ft) seaward. Subsequent to fill activities, the average maximum thickness of the sandbar would be 0.6 m to 0.9 m (2.0 ft to 3.0 ft) in the summer and 1.1 m to 2.0 m (3.6 ft to 6.5 ft) in the winter. A minor increase in sand thickness is anticipated, on the order of 0.15 m to 0.2 m (0.5 ft to 0.6 ft). The increased thickness is anticipated to be greatest in the vicinity of MSL and decrease seaward. Intertidal and shallow subtidal reefs could potentially be covered from the deposition of sediment in the substrate area. Refer to Section 4.4.2.1, Biology, for discussion of impacts to biological resources. No significant impacts to coastal geology are anticipated due to sediment transport or increased sediment thickness. 4.1.2.2 Littoral Processes Because the littoral processes within the Oceanside Cell dominate a large region of the coast, any changes to beaches in the vicinity of the Solana Beach receiver site would be similar to those affecting the South Oceanside site. A sand berm would be expected to form in the shallow subtidal area as a result of sediment transported into this zone. Any changes to breaking waves resulting from the proposed action would be similar to those previously described for South Oceanside. In addition, sand deposition is not expected to affect existing reef breaks in the area. No significant impacts to littoral processes would be anticipated to occur as a result of the proposed action. 4.2 COASTAL WETLANDS Impacts to coastal wetlands are based on studies performed as part of the Beach Sand Transport and Sedimentation Report prepared by Frederic R. Harris, Inc. (Attachment I). 211602000 4-6 4.2.1 South Oceanside Coastal wetlands identified in the vicinity of the South Oceanside receiver site include the San Luis Rey River, Loma Alta Creek, Buena Vista Lagoon, and Agua Hedionda Lagoon. The extent of influence of the South Oceanside beach fill is not expected to reach Buena Vista Lagoon or Agua Hedionda Lagoon. Vicinity "boundaries" are based on modeling from Attachment I (FRH 1997). 4.2.1.1 San Luis Rey River Sediment from the beach fill at South Oceanside is predicted to migrate northward to the vicinity of the San Luis Rey River mouth after sand placement and potentially widen the onshore beach at this location up to 10 m (32 ft) within 12 months of sand placement. Because the existing berm that crosses most of the San Luis Rey River mouth is already at a higher elevation than the predicted contribution from the proposed action, the migrating sand would not be anticipated to impact the overall configuration of the river mouth. Stormwater discharge from the river is constrained by flow through eight, 91-cm-dia (36-in-dia) pipes that pass under Pacific Street. The initial small increase in beach width at this location would be reduced over time as the sand moves back along the shoreline in a southerly direction. The predicted temporary increase in sediment at this location would not be anticipated to constrain river runoff, therefore, additional maintenance is not required with implementation of the proposed project. The City of Oceanside Streets Division is responsible for maintaining the Pacific Street Stormwater outlet on an as-needed basis for flood control. Therefore, no adverse impacts would be anticipated upon implementation of the proposed action. 4.2.1.2 Loma Alta Creek The south end of the South Oceanside receiver beach is located directly north of the Loma Alta Creek ocean outlet. The existing berm elevation adjacent to the creek is +3.2 m (+10.5 ft) MSL at Buccaneer Beach and +2.3 m (+7.5 ft) MSL at the adjacent residential property to the north. The creek maintains its flow through this berm with a creek bed elevation of approximately -0.6 to -0.8 m (-2.0 to -2.6 ft) MSL. 211602000 4-7 The proposed beach fill berm elevation of+1.7 m (+5.6 ft) would be approximately 2.4 m (7.9 ft) above the natural creek elevation. The berm would be placed directly north of the creek outlet and would be expected to spread after placement. However, the elevation of the berm would not likely exceed 1.0 m (3.3 ft) after spreading to the creek outfall. Results of the modeling analysis indicate that the beach width at Loma Alta Creek would increase after sand placement from the initial 125 m (410 ft) by approximately 11 or 12m (36 or 40 ft) over a 12-month period. This would result in an approximate 3 percent increase in the length of the creek discharge channel, potentially subjecting the channel to closure (and potential flooding) during periods of high littoral sand movement and heavy wave activity. However, wave erosion of the berm would likely reduce potential flooding problems by enabling the creek to breach the sand berm. The City of Oceanside Streets Division is responsible for maintaining the Loma Alta Creek outlet on an as-needed basis for flood control. Therefore, no adverse impacts would be anticipated to occur upon implementation of the proposed action. 4.2.2 Solana Beach Coastal wetland areas identified in the vicinity of the Solana Beach receiver areas include San Elijo Lagoon, San Dieguito Lagoon, and Los Penasquitos Lagoon. The extent of influence of the Solana Beach fill is not expected to reach Los Penasquitos Lagoon. 4.2.2.1 San Elijo Lagoon Sand migration along the shore from the Solana Beach fill is predicted to reach the San Elijo Lagoon inlet 3 to 6 months after sand placement. The beach area in the vicinity of the lagoon would widen by approximately 13 to 14 m (43 to 46 ft) over a period of 3 to 12 months after sand placement. This represents an increase in the inlet channel length by approximately 15 percent. The natural existing berm elevation in the vicinity of the lagoon inlet is approximately +1.5 to +2.0 m (+5.0 to +6.5 ft) MSL (March 1996) and increases to approximately +3.0 m (+10 ft) directly north and south of the opening. The proposed beach fill berm elevation south of the lagoon mouth at the northern Cardiff area would be +1.7 m (+5.6 ft) MSL. As the beach fill material spreads and migrates north, it would be expected to accrete to the natural berm elevation in the vicinity of the lagoon mouth. 211602000 4-8 The existing cobble beach in the area of the lagoon is transported by waves into the inlet channel bed, reducing flows and contributing to the closure of the inlet. Fill at the northern Cardiff area would be likely to cover most of the resident cobble berm, thereby reducing the cobble's mobility across the beach and its northward migration near the inlet, which would enable the inlet to stay open longer. The additional sand source and increased beach width could increase sand transport into the inlet and main lagoon channel. However, the ebb tidal velocities would potentially erode more of the sand deposited in the inlet due to the absence of cobbles in the channel and a wider mouth. The lagoon is managed as a nature reserve by the CDFG and the San Diego County Department of Parks and Recreation (SDCDPR). The SDCDPR has recently completed an extensive Enhancement Plan for the lagoon, which includes maintenance by continuous tidal flushing and actively managing the ocean inlet with dredging. Historically, San Elijo Lagoon inlet has been closed 80 percent of the time. During the last four years, the lagoon has been open 50 percent of the time. The proposed action is not expected to significantly increase the rate of closure above historical occurrences. Therefore, no adverse impacts would be anticipated to occur upon implementation of the proposed action. To ensure that there would be no increase in lagoon mouth closures, a monitoring plan would be established with the approval of the Army Corps of Engineers in consultation with the appropriate resource agencies. Baseline profiles would be measured prior to discharge and monitored through July 1, 2001. Areas to be monitored include lagoon mouths, entrance channel, lagoon interior, or adjacent areas. The Navy would provide for mitigation of any increased rates of accumulation of sand or mouth closures that are determined to occur as a result of the discharge above and beyond existing conditions, as determined by the Army Corps of Engineers in consultation with the resource agencies. Mitigation would consist of opening a closed lagoon mouth, and/or removing accumulated sediment attributable to the discharge. The Navy has obtained written and verbal assurance from SANDAG and affected municipalities that SANDAG and affected municipalities will implement the foregoing monitoring, documentation, and mitigation as well as other requirements related to potential effects on ocean inlets. These assurances are presently being formalized in a memorandum of agreement (MOA) between SANDAG and the Navy to cover areas of potential effect per Navy modeling. San Elijo and San Dieguito Lagoon are subject to the 211602000 4-9 MO A. Agua Hedionda and Batiquitos Lagoons are also included out of deference to the resource agencies and an abundance of caution. The possibility of measurable effect on these last two is remote, per Navy modeling. 4.2.2.2 San Dieguito Lagoon Sand migration along the shore from the Solana Beach fill is predicted to reach the San Dieguito Lagoon inlet 3 to 6 months after sand placement. Model results indicate that the beach area in the vicinity of the lagoon would widen by approximately 18m (59 ft) within 12 months of sand placement. This represents an approximate 10 percent increase in the lagoon inlet channel length. Due to a wide configuration and the length of the inlet at San Dieguito Lagoon, there is already a large supply of sand in the vicinity of the inlet. Any further increase in beach width would potentially modify the behavior of the lagoon ebb tidal flows, possibly slowing or dispersing the channel flow, and increasing the frequency of channel meandering. Reduced ebb flow velocities could facilitate accumulation of sand in the inlet and development of a sand sill across the mouth. Early spring or summer closure of the lagoon inlet could degrade water quality conditions in the lagoon resulting in higher water temperatures, lower oxygen concentrations, higher evaporation, and reduced circulation which could cause fish and benthos mortalities, and poor human health conditions (e.g., production of nuisance insects and high bacterial counts). Over the last 19 years the lagoon inlet has been open approximately 68 percent of the time. Historically, the lagoon was open only 30 percent of the time. However, the City of Del Mar and District 22 Agriculture Association are responsible for ensuring inlet stability for this lagoon. Dredging occurs as-needed to keep the inlet open. Therefore, no adverse impacts are anticipated due to implementation of proposed action. To ensure that there would be no increase in lagoon mouth closures, a monitoring plan will be established and mitigation will be assured as for San Elijo Lagoon as discussed above. 211602000 4-10 4.3 WATER RESOURCES The following is an analysis of factors that would potentially affect the quality of water resources within the project area (i.e., chemical properties and turbidity). 4.3.1 South Oceanside 4.3.1.1 Chemical Properties Dredged sediment from San Diego Bay was tested for compatibility with sediment found at the receiver beach site. Grain size and chemical analyses were performed on sediment samples from several areas in the Bay proposed for dredging. As specified in the Homeporting EIS, sediment analyses concluded that the proposed beach fill is clean and of compatible grain size with the receiver beaches. No impacts to water quality would occur due to the physical or chemical characteristics of the dredged sediment. 4.3.1.2 Turbidity Turbidity can be caused by the presence of fine silts or clays in the water. Fine-grained materials (<63 micrometers [|J.m]) remain suspended in the water column for longer periods of time, whereas larger grain size material (>63 urn) settles out faster. There is a lower percentage of fines in the dredged material than the native beach material. Testing has shown that the average percentage of fines in the Oceanside Littoral Cell native sediments is approximately 3 percent above MSL and 12 percent below MSL. The higher percentage of fines below MSL is attributed to the fact that finer grained materials reside at equilibrium below the shorebase. The average percentage of fines in the dredged material is approximately 3 percent (Attachment I). Therefore, the size of the beach fill material (i.e., 97 percent greater than 63 (im) would less likely cause turbidity than would occur under natural conditions. As stated in the Homeporting EIS, increased turbidity would occur along shore as a result of sediment disposal. The proposed action involves pumping a sand/sea water mixture directly onto the beach from a dredge located offshore, rather than depositing the sediments in the nearshore environment. Increased turbidity would be caused by return water from pumping operations, as suspended sediments in the sand/sea water mixture would flow into the surf zone subsequent to pumping. However, placement of sediment 211602000 4-11 on the beach would include the construction of longitudinal dikes parallel to the surf line. These dikes would act to contain return water and allow suspended sediments to settle out, thereby reducing turbidity in the return water, and subsequently reduce potential water quality impacts associated with increased turbidity. The use the longitudinal dikes is a special condition of the Sectionl 0/404 permit. Sediment pumping operations would occur in short intervals allowing suspended particles to settle out between pumping periods. The hopper dredge would take approximately one to two hours to pump a full load onto the beach, after which it would take several hours to return to San Diego Bay and reload. A minimum time interval of three to four hours is estimated between each load. Due to operational constraints (i.e., distance of receiver beaches from loading areas, speed of the hopper dredge, and time to hook up/unhook pump lines), pumping operations would occur only two to three times daily at the receiver beach. During the reloading period, turbidity in nearshore waters caused by return water from pumping operations would be able to settle before the next pumping interval began. Therefore, time intervals between pumping operations would help reduce potential water quality impacts associated with increased turbidity. Despite dike construction, large grain size, and the time interval between disposal periods, short-term increases in turbidity associated with return water from the pumping operation would still occur in the nearshore environment. In addition to a Section 404/10 permit, the proposed action must comply with a RWQCB Certification Order which also sets conditions on proposed operations. RWQCB conditions require that supernatant from a .loaded barge be collected three times a week and analyzed for polar and non-polar oil and grease. Furthermore, weekly monitoring of bacteria contamination 100 feet down-current of the discharge point is required per the Waste Discharge Requirements. These RWQCB conditions will help verify that there are no significant impacts to water quality. Significant turbidity impacts associated with the longshore transport of fill material subsequent to placement operations are not anticipated. Based on available grain size data (Attachment I), the percentage of fines (<63 |im) in the dredged sediments is essentially the same as (or less that) the native littoral sediments. This is expected due to the large portion of sediments in the outer San Diego Bay channel which reside in the littoral cell. 211602000 4-12 Therefore, as the beach fill is anticipated to have equal or fewer fines than the natural beach sediments, the loss of fines over time should be no greater than existing conditions. 4.3.2 Solana Beach Impacts to water quality at the Solana Beach receiver beaches would be similar to those identified for the South Oceanside receiver site. Impacts due to increased turbidity would be minimized by operational controls (time intervals and use of longitudinal dikes), grain size of the fill material, and permit specifications by ACOE, EPA, and RWQCB. Therefore, no adverse impacts would be anticipated upon implementation of the proposed action. 4.4 BIOLOGY This section addresses potential impacts that could result from implementation of the proposed project. Impacts may be either direct or indirect, and temporary or permanent. Direct impacts occur when biological resources are altered, disturbed, destroyed, or removed during the course of project implementation. Other direct impacts may include the loss of foraging habitat for wildlife species; and habitat disturbance that results in unfavorable substrate conditions (i.e., incompatible grain size). Indirect impacts occur when project related activities affect biological resources in a manner other than direct. Potential indirect impacts resulting from project implementation include increased sand transport and silt deposition, which could result in lagoon inlet closure and increased turbidity in the longshore environment. Both direct and indirect impacts can be classified as either temporary or permanent, depending on the duration of the impact. Temporary impacts are impacts that may be considered reversible effects on biological resources. Permanent impacts are those impacts resulting in the irreversible removal, disturbance, or destruction of biological resources. 4.4.1 South Oceanside 4.4.1.1 Sand Deposition The placement of 405,218 m3 (530,082 cy) of sand within the intertidal zone could result in the burial and death of nonmobile epibenthic and benthic invertebrates. However, this is expected to be a temporary effect to the population as recolonization of the area would 211602000 4-13 occur rapidly. Mobile invertebrates, such as crustaceans, would be are expected to move into the area within days of cessation of sand placement and other organisms would be expected to recolonize with 6 to 12 months (MEC 1995). Because the effect would be temporary and would not directly impact any sensitive species, impacts to invertebrates would be considered insignificant. Nonmobile invertebrates in the subtidal area could also be buried by fine sediments that are washed offshore from implementation of the proposed project. Since this is a natural process, most subtidal invertebrates are adapted to shallow burial by sediments. Mobile invertebrates would move vertically within the sandy substrate or horizontally to deeper waters to avoid burial; therefore, this impact would be considered insignificant. No subtidal rocky reef, kelp bed, or surfgrass habitats are located in the vicinity of the South Oceanside receiver beach. Therefore, no impacts to these marine resources would occur due to sediment placement or transport. Impacts to fish, birds, and marine mammals resulting from sand deposition would be considered insignificant. These are mobile organisms that can easily leave the area for similar foraging habitat. Ample foraging habitat is found adjacent to the Oceanside receiver site both onshore and offshore. Onshore habitat, similar to the receiver beach, is found north of Oceanside Pier. Offshore habitat not affected by pumping operations would be found north and south of the receiver area, dependent upon the size of the turbidity plume generated by pumping operations. As turbidity would not be expected to be significant, suitable offshore foraging habitat would be anticipated in the vicinity of the receiver beach during replenishment operations. Because these organisms can readily move to adjacent areas and the displacement would be temporary, this impact would be considered insignificant. California grunion may spawn on the South Oceanside receiver beach during the sand placement period. Sand replenishment activities could potentially bury their eggs or change the beach profile resulting in mortality. If grunion are observed spawning, discharge of sand shall immediately cease in a buffer zone surrounding the area of spawning. The buffer zone shall extend 20 meters shoreward of the highest high water mark at the spawning area, and run 30 meters upcoast and 30 meters downcoast from the spawning area. A sand dike, parallel to the shoreline above the 20 meter buffer zone, shall be constructed along the entire 60 meter lateral extent of the buffer zone in a way that will 211602000 4-14 ensure that the discharge water will not enter the spawning area. The spawning areas shall be recorded and mapped and provided to the Corps and resources agencies in a written report within 24 hours of the spawning event. A schematic drawing of any diked spawning buffer areas shall be submitted to the Corps and resource agencies with each written report.. The buffer zone would be in place for a minimum of 14 days (the period of time for eggs to hatch). This would mitigate impacts to the grunion and would allow sand replenishment activities to continue in areas not effected by spawning. California brown pelicans could be impacted in the immediate area of the receiving site by a temporary reduction in their prey base. However, pelicans, like their fish prey, can easily forage in adjacent offshore areas. California least terns and western snowy plovers are not known to nest at the Oceanside receiver beach and are not expected to nest in the area in the future because of human disturbance. Terns and plover may forage in the waters off the site, but can forage adjacent to the site if fish vacate the area or an increase in turbidity limits their foraging ability. To prevent turbidity impacts to California least tern and brown pelican foraging areas, the permittee shall construct longitudinal dikes of sand material parallel to the surf line with a single discharge point. The longitudinal dikes shall be constructed, where practicable, above the wave-washed zone of the beach which shall be determined by the highest tides predicted during the duration of the proposed action. Therefore, no adverse impacts to sensitive species would be anticipated upon implementation of the proposed action. 4.4.1.2 Barge Placement and Anchoring The proposed beach replenishment operations are expected to take approximately 48 days at the South Oceanside receiver site. The hopper dredge would not be in place for the entire duration as it would travel from San Diego Bay to South Oceanside on a daily basis. Anchor lines for the mono buoy and pump lines to shore would be permanently placed for the duration of the project. Pump lines and anchor points would be surveyed at least 30 days prior to the start of operations and placed to minimize impacts of sensitive resources (i.e., kelp beds, rock outcrops). Therefore, pump lines and anchor points would not result in significant impacts to these sensitive resources. The dredge would not negatively impact fish or invertebrate communities in the area and may actually attract fish to the area by providing spatial relief. The dredge would also not be expected to significantly disturb birds or marine mammals as it would not be a permanent feature and could be easily avoided. 211602000 4-15 4.4.1.3 Coastal Wetlands No adverse impacts to wetland organisms would be anticipated as a result of sand placement at the South Oceanside receiver beach. As discussed in Section 4.2, local jurisdictions are responsible for monitoring lagoon inlets and river/creek outlets located in the vicinity of the South Oceanside receiver site for flood control. Any measures needed to ensure inlet/outlet stability would be implemented by the local jurisdictions. For further discussion of potential impacts to the San Luis Rey River and Loma Alta Creek, refer to Section 4.2.1. 4.4.2 Soiana Beach 4.4.2.1 Sand Deposition Potential impacts due to the placement of 435,802 m3 (570,081 cy) of sand at the two Soiana Beach site receiver beaches are similar to those described for South Oceanside receiver site. Nonmobile epibenthic and invertebrates present on the hard substrates could be buried by sediment deposition. However, this impact would not be considered significant as the populations are expected to recover quickly and burial would affect only a limited area. Impacts to fish, birds, and marine mammals resulting from sand deposition would also not be expected to be significant as these are mobile organisms that can easily leave the area for similar foraging habitat. Due to the lack of available sand, California grunion are not expected to spawn on the Soiana Beach receiver beaches during sand placement. However, if grunion are observed spawning, discharge of sand shall immediately cease in a buffer zone surrounding the area of spawning. The buffer zone shall extend 20 meters shoreward of the highest high water mark at the spawning area, and run 30 meters upcoast and 30 meters downcoast from the spawning area. A sand dike, parallel to the shoreline above the 20 meter buffer zone, shall be constructed along the entire 60 meter lateral extent of the buffer zone in a way that will ensure that the discharge water will not enter the spawning area. The spawning areas shall be recorded and mapped and provided to the Corps and resources agencies in a written report within 24 hours of the spawning event. A schematic drawing of any diked 211602000 4-16 spawning buffer areas shall be submitted to the Corps and resource agencies with each written report.. The buffer zone would be in place for a minimum of 14 days (the period of time for eggs to hatch). This would mitigate impacts to the grunion and would allow sand replenishment activities to continue in areas not effected by spawning. On average, sand placement would occur in the intertidal/shallow subtidal zone from +2 m (+6.6 ft) MSL to -2 m (-6.6 ft) MSL, and could potentially bury sensitive marine resources found in this area of the Solana Beach receiver site. Sensitive marine resources include rocky intertidal reefs, intertidal vegetated reefs (including feather boa kelp, surfgrass, sea fans, and sea palms), and nearshore reefs with giant kelp. Rocky intertidal and vegetated, shallow subtidal reefs could potentially be damaged from the deposition of sediment in the substrate area by burying these reefs. Reef habitats that are vegetated occur just north of the San Elijo Lagoon inlet, at the southern end of Cardiff State Beach, and are found in patchy abundance from North Seascape Surf Park to the San Dieguito Lagoon inlet. No significant impacts are expected to these resources as sand placement activities are designed to avoid areas that contain sensitive marine resources and to mimic the natural beach slope of the existing beach profile. Reef breaks may temporarily be affected if sand accumulates at the reef base, but this should be in the range of natural seasonal variations of a sandy beach. The natural sand transport is a function of seasonal cycles that move sand offshore in the winter and then back onto the beach in the summer. Sand movement would be similar to natural conditions and would not move sand farther offshore than 350 m (1,150 ft) seaward of the back beach and 3,000 m (9,840 ft) up or down coast of the beachfill (FRH 1997). Therefore, since the surfgrass habitats are located between -3.3 and -6.3 m (-10.8 and -20.7 ft) MSL and experience natural seasonal sand movement, and the nearest kelp beds are found approximately 420 m (1,380 ft) offshore, sand placement and transport is not expected to significantly affect either of these sensitive marine resources. Although no significant impacts to sensitive marine resources are expected, the Navy would prepare and implement a monitoring plan to verify no significant impacts. The program would include pre-discharge baseline studies and post-discharge monitoring effective from the date of issuance of this permit through July 1, 2001 to confirm that the discharge operations of sand materials has not resulted in any long-term net loss of sensitive marine resources. Sensitive marine resources include rocky intertidal reefs, subtidal vegetated reefs including feather boa kelp, surfgrass, sea fans, and sea palms) and 211602000 4-17 nearshore reefs with giant kelp. Mitigation would be the restoration of like habitat at a 1:1 ratio as a first priority. Consideration will be given to the construction of artificial reefs (~ one acre) as mitigation to offset project impacts at a 1:1 ratio if like habitat restoration efforts are not feasible as determined by the Corps, in consultation with the resource agencies. Should mitigation be required, as determined by the Corps in consultation with the resources agencies, total mitigation costs shall not exceed $700,000. During beach replenishment operations some sand will move into the surfzone and be suspended in the water column causing an increase in turbidity. Increases in turbidity could potentially impact sensitive marine resources such as surfgrass and kelp populations. However, impacts are not expected to be significant because the sand that is being used for beach replenishment has a smaller percentage of fine material than what is presently on the beaches and the area is naturally turbid due to constant wave action (FRH 1997). In addition, the sand will be placed behind longitudinal dikes so that most of the material will settle out, thus minimizing turbidity. Sensitive avian species in the Solana Beach area include the California least tern and the Western snowy plover. The tern utilizes offshore waters for foraging activities in the vicinity of the receiver sites and the plover utilizes sandy intertidal habitat for foraging. Replenishment operations could affect the intertidal zone in the receiver areas by causing short-term increases in turbidity in longshore waters, thereby causing a reduction in the forage base. However, these birds are mobile and would be able to move to adjacent beach areas or nonimpacted waters for foraging activities. Therefore, no adverse impacts to sensitive species would be anticipated to occur upon implementation of the proposed action. 4.4.2.2 Barge Placement and Anchoring Beach replenishment operations are expected to take approximately 30 days at the Solana Beach receiver site. Placement and operation of the hopper dredge, mono buoy, and pump lines would be the same as those described for South Oceanside receiving site. The dredge would not negatively impact fish or invertebrate communities in the area and may actually attract fish to the area by providing spatial relief. The dredge would also not be expected to significantly disturb birds or marine mammals as it would not be a permanent feature and could be easily avoided. 211602000 4-18 Extensive kelp beds are located directly offshore of the Solana Beach receiver site. Portions of the kelp beds could be distressed by placement of sinker lines. If the equipment were moored or placed directly on the kelp plants, the plants could be crushed or damaged. The kelp beds would be surveyed at least 30 days prior to pumping operations. As shown in Figure 1-2, the mono buoy and sinker line would be placed to minimize impacts to the kelp bed areas. Therefore, no significant adverse impacts to existing kelp beds would be anticipated upon implementation of the proposed action. 4.4.2.3 Coastal Wetlands No adverse impacts to wetland organisms would be anticipated as a result of sand placement at the Solana Beach receiver beaches. As discussed in Section 4.2, local jurisdictions are responsible for monitoring lagoon inlets and river/creek outlets located in the vicinity of the Solana Beach receiver areas. Any measures needed to ensure inlet/outlet stability would be implemented by the local jurisdictions. For further discussion of potential impacts to San Elijo Lagoon and San Dieguito Lagoon, refer to Section 4.2.2. 4.5 LAND USE AND RECREATION 4.5.1 South Oceanside Implementation of the proposed action would not change existing uses of the site. Further, the proposed action would not conflict with the goals and policies contained in the Oceanside General Plan. A Coastal Consistency Determination (CCD) has been prepared for the proposed action in accordance with federal and state regulation. The Navy has determined that the onshore placement of dredged material at the designated South Oceanside Beach receiver site is consistent to the maximum extent practicable with all applicable policies of the Coastal Act. Therefore, no land use policy conflicts would occur. The recreational activities most likely to be disturbed by beach replenishment activities include surfing, swimming, diving, surf fishing, sport fishing, sailing, and other beach uses such as picnicking and sun bathing. Because of public safety concerns associated with heavy equipment operations on the beach, replenishment operations would require the receiver beach site and offshore area be closed temporarily to the public. The closure and 211602000 4-19 restricted access to the area would occur for a period of 48 days during July, August, and September, which would result in a redistribution of beach activities to surrounding areas. This would be a temporary localized effect and would not result in a permanent significant condition. Without beach replenishment, beach use would decline as beach conditions continue to deteriorate (i.e., erosion). Once the beaches have been replenished, recreational activities would resume and be enhanced. The proposed action would result in a beneficial impact by ensuring long-term recreational uses. 4.5.2 Solana Beach Land use impacts to the Solana Beach receiver areas would be similar to those for the South Oceanside site. However, replenishment at the Solana Beach receiver beaches would require the beach to be closed for only approximately 30 days in September and October. This would be a temporary localized effect and would not result in a permanent significant condition. As with the South Oceanside replenishment effort, the proposed action would result in a beneficial impact by ensuring long-term recreational uses. As discussed in the Homeporting EIS, changes to wave action and consequently surfing conditions could occur if dredged material were placed in the longshore area. With the movement of beach sand through littoral processes, offshore bars could develop over time thereby affecting beach breaks dependent on the formation of sandbars. However, as changes in the formation of offshore sandbars is a naturally-occurring event, this effect is not considered a significant impact. Special attention was given to the design of the replenishment sites to avoid direct placement of sand on reef areas supporting surf breaks; specifically, Cardiff Reef, Seaside Reef, "Palisades," "Table Tops," and "Pill Box." Implementation of the proposed action would also avoid impacts to the nearshore dive areas at Cardiff and Seaside Reefs because dredged material would not extend beyond 350 m (1,150 ft) from the existing beach. Some sediment accumulation is anticipated in reef areas within 350m (1,150 ft) of the beach; however, natural transport processes move sediments through these reef areas under normal conditions. Therefore, no adverse impacts would be anticipated upon implementation of the proposed action. 211602000 4-20 4.6 SAFETY AND ENVIRONMENTAL HEALTH The following analysis is applicable to both the South Oceanside and Solana Beach sites. Implementation of the proposed action would create an unsafe situation on receiver beaches during sand placement due to the amount of heavy equipment being used to grade and dress the beaches. During discharge operations, the receiver areas would be closed to ensure public safety. The closure would affect the existing beach area and the offshore area between the hopper dredge and the receiver beach. A buffer zone of 30 m (100 ft) would be provided between the operations area and any open public beach areas. The Navy would provide all necessary safety measures in the vicinity of the receiver beaches including fencing, barricades, and flagmen as necessary. Additionally, a 150 m by 150 m (approximately 500 ft by 500 ft) buffer area would be maintained around the hopper dredge in the offshore waters to allow proper anchoring and pump line operation. In order to ensure that no vessels would enter the offshore restricted zone, the anchoring area would be included in the Notice to Mariners, which is overseen by the U.S. Coast Guard. No significant impacts to public safety would be anticipated to occur upon implementation of proposed action. A scarp is defined as the cut in the beach berm face caused by wave action. Scarp height is a function of the breaking wave height and the elevation of the existing beach berm. Scarps develop naturally along the beach profile and vary in height under different wave conditions. Large scarps may result in safety hazards due to significant changes in the beach profile (i.e., a drastic drop in elevation). Because scarps are a function of beach berm height, the placement of fill on the receiver beaches would not increase scarp height provided fill is placed to the height of the existing beach berm (FRH 1997). The proposed action specifies that beach fill will not be placed above the height of the existing beach berm. Therefore, safety impacts due to increased scarp heights are not anticipated. 4.7 AESTHETICS San Diego's coastal beaches are one of the region's greatest visual resources. For this reason, the coastal areas of San Diego County are considered a highly sensitive visual resource. Coastal beaches offer scenic high quality views that are considered a trademark of the southern California area. Any construction or operation that would cause 211602000 4-21 permanent degradation of existing views along coastal beaches would be considered a significant visual impact. 4.7.1 South Oceanside The proposed action would alter existing views along the receiver beach during proposed beach replenishment operations. Proposed operations include a hopper dredge anchored offshore, beach grading equipment, and several construction personnel operating the pump line and equipment. The proposed action is anticipated to take 48 days at the South Oceanside receiver beach. Pumping and construction operations during this time would degrade existing coastal views in the area. However, subsequent to beach replenishment operations, the receiver beach would be enhanced. Sand replenishment would widen the existing beach, thereby eliminating views of the eroded beach area south of Wisconsin Street. In addition, pumping and construction operations would be short-term. Therefore, no long-term adverse visual impacts would occur due to implementation of the proposed action. Beach fill material associated with disposal operations could be darker in color than existing beach sand due to organic materials in the sediment; however, fill material would be washed and reworked by waves, bleached under exposure to the sun, and mixed with existing sand. Any discoloration of the sediment would be short-term (ACOE 1984) and no permanent adverse visual conditions would result from the discoloration of fill materials at the receiver beach. 4.7.2 Solana Beach Similar to the South Oceanside receiver site, views of the northern Solana Beach receiver area would be degraded during pumping and construction operations associated with the proposed action. However, because beach replenishment operations would be short-term and the proposed action would improve existing coastal views in the area, no permanent adverse visual impacts would occur. Similarly, views of the southern Solana Beach receiver area would be degraded from pumping and construction operations associated with the proposed project. However, as. the proposed action would improve long-term views in the area through the creation of a 211602000 4-22 sand beach and the proposed operation would be short-term (a total of 30 days), no permanent adverse visual impacts would occur. There would be no long-term impacts due to discoloration of the dredged fill material at either of the Solana Beach receiver areas. As stated above, natural processes including wave washing, sun exposure, and mixture with existing sand would abate any adverse visual conditions associated with sediment color. 4.8 STRUCTURES AND UTILITIES The following structures and utilities analysis describes potential impacts associated with the proposed action. Because an increase in service demand would not occur, this analysis focuses on displacement or disruption of structures and utilities. Information contained in this section is derived from the Beach Sand Transport and Sedimentation Report, prepared by Frederic R. Harris, Inc. (Attachment I). 4.8.1 South Oceanside A tabular summary of the impacts to structures and utilities at the South Oceanside site is shown on Figure 3-4. 4.8.1.1 Sanitary Sewer Ocean Outfall The existing sanitary sewer ocean outfall pipe located just north of Loma Alta Creek would not be impacted by the proposed action. The pipe would not be displaced and interruption in service would not occur because the pipe is located beneath the surface. The proposed beach fill would be beneficial for this outfall structure because the proposed quantity of sand would serve as additional cover to protect the pipeline. 4.8.1.2 Access Stairs The public access stairs at the end of Tyson Street would not be affected by beach replenishment. The bottom 0.5 m (1.5 ft) of the public stairs at the end of Ash Street and at Matron Street would be covered by the fill which would tend to stabilize these stairways. The bottom 0.3 m (1.0 ft) of the public ramp access at Wisconsin Street would be covered with fill as a result of the proposed action; however, this would not restrict 211602000 4-23 access to the beach. The public access ramp at Foster Street would not be affected. A private stairway with access to the beach is located south of the sewer outfall. No impacts to this structure as a result of the proposed action would occur. 4.8.1.3 Storm Drains There are two storm drain pipes located south of Tyson Street. The outlets are approximately 1.0 m (3.3 ft) below the proposed fill level. However, potential impacts are not anticipated as implementation of the proposed action would require storm drain discharge flow paths to remain unobstructed. The City of Oceanside would be responsible to maintain discharge flow paths at these storm drains after project implementation. The existing outlet for the double storms drains at the end of Marron Street would be approximately 0.2 m (0.6 ft) above the proposed sand fill, therefore, there would be no impact to these drains. The pipe at the end of Foster Street is presently half filled with sand. The outlet would be approximately 0.3 m (1.0 ft) above the proposed sand fill, therefore, there would be no impact to this pipe. 4.8.2 Solana Beach A tabular summary of the impacts to structures and utilities at the Solana Beach site is shown on Figure 3-5. 4.8.2.1 Sanitary Sewer Ocean Outfall Impacts to the sewer outfall at Cardiff Beach would be similar to those for the outfall at the South Oceanside receiver beach site. A beneficial effect would occur because the proposed sand fill would provide additional protective covering for the outfall pipe. No significant impacts would occur to this structure. 4.8.2.2 Access Stairs The access stairs at Tide Beach Park and adjacent drain pipe and retaining wall are located above the proposed fill area, therefore, the proposed action would not impact access to the beach or adjacent structures. 211602000 4-24 4.8.2.3 Storm Drain Pipes Proposed sand fill would not be placed in the vicinity of the discharge pipe or the outlet flow path of the storm drain currently under construction at the west end of Plaza Street; therefore no adverse impact is anticipated. The storm drain outlet located at the west end of Ocean Boulevard is buried and, therefore, would not be significantly impacted by the proposed action. 4.9 NOISE Significance criteria to determine noise impacts are based on whether or not any of the following conditions apply: 1. The proposed action creates a projected sound level in excess of set construction noise zoning standards; or, 2. The proposed action's operational schedule is in violation of local construction noise standards; or, 3. Site-specific noise levels (e.g., on beach) created by the proposed action are in excess of current ambient levels. 4. The proposed action complies with local noise ordinances. Table 4-1 identifies predicted sound levels at each receptor and corresponding mitigation distances which would reduce sound levels to below a level of significance, based upon sound level data of similar equipment (Ogden 1995, 1997) and the known distances from individual noise sources to their respective receptor points (i.e., residential and/or inhabited structures). It should be noted that these mitigation distances are only applicable during daytime hours (typically 7 a.m. to 7 p.m.) and that a noise variance would still be required to perform nighttime operations. Past sound measurements conducted on the proposed beach sites (Chambers Group 1992) have shown sound levels ranging from 56 dBA Leq-h to as high as 70 dBA Leq-h. In applying the significance criteria to projected sound levels, the crux of the significance question became whether or not local noise ordinances could be complied with. Criteria one and two were largely subsumed in that question. Criteria three, ambient noise levels, is relevant but not dispositive in itself. 211602000 4-25 Table 4-1 REQUIRED DISTANCES (ft) FOR NOISE MITIGATION AT RECEIVER SITES Impact Criteria Distances (ft) Beach Site/Equipment Oceanside Receiver Beach Slurry Pump Diesel Dozer/Cattail Cardiff Receiver Beach Slurry Pump Diesel Dozer/Cattail Source Level @50 Feet 70 80 70 80 Distance to Nearest Receptors 1,400 30 1,400 100 Level @ Nearest Receptors 41 84 41 74 ... to Local Ordinance Level complies 88 complies 1,581 ...to 70 dBA Ambient 50 158 50 158 ...to 50 dBA Ambient 500 1,581 500 1,581 Solana Beach Receiver Beach Slurry Pump Diesel Dozer/Cattail 70 80 1,400 100 41 74 complies 88 50 158 500 1,581 Threshold Criteria: • Oceanside: Typically set by CUP (Oceanside City Code Section 38.17). Past trends has set level at 75 dBA Leq(8h) during the hours of 7 a.m. and 7 p.m. • Cardiff: Set by City of Encinitas though noise ordinance (Code Section 30.40.010) or CUP. Value taken will be 50 dBA Leq-h (worst case) during the hours of 7 a.m. to 10 p.m. • Solana Beach: Set by City of Solana Beach though noise ordinance(Municipal Code Section 7.34.100). at 75 dBA Leq(8h) during the hours of 7 a.m. and 7 p.m. 211602000 4-26 4.9.1 South Oceanside Onshore beach replenishment activities would use an offshore hopper dredge as the sediment transport vessel. The sand would be mixed with sea water to form a slurry which would be pumped through a nozzle onto the receiver beach. The sand would then be moved and leveled out using small diesel dozers. In addition, diesel trucks could be required to move sand from one point to another. Any final grooming of the beach would be completed using a cattail assembly behind the dozers described above. Based on the noise analysis conducted for the Homeporting EIS, the diesel dozers would exceed ambient noise levels (50 to 70 dBA) within a certain distance from the receptor, as indicated in Table 4-1. However, exposure levels would not be expected to significantly exceed ambient noise levels during daytime operations. At night, noise from implementation of the proposed project would be more audible and possibly intrusive to nearby sensitive receptors as ambient noise levels are typically lower (at or less than the Lmin values shown in Section 3.9). Furthermore, operation of the dozers and cattail 24 hours a day would exceed the City of Oceanside construction noise ordinance from both operational (time usage) and sound exposure considerations (see Section 3.9). Physical mitigation of the site (i.e., noise walls, etc.) would not be feasible due to engineering constraints of the property line/surf breakwall interfaces. However the project was able to qualify for and has obtained a variance which brings it into compliance with the local noise ordinance. Therefore, the Navy is able to conclude that the noise impacts will not be significant. 4.9.2 Solana Beach Operations at the Solana Beach receiver site would be similar to those for the South Oceanside site. Operation of the slurry pump onboard the hopper dredge would be inaudible at any of the sensitive receptors examined. The diesel dozers would exceed ambient noise levels within a certain distance from the receptor, as indicated in Table 4-1. However, exposure levels would not be expected to significantly exceed ambient noise levels during daytime operations. 211602000 4-27 Nighttime activities from implementation of the proposed project would be more audible and possibly intrusive to nearby sensitive receptors as ambient noise levels are typically lower at night. Furthermore, operation of the dozers and cattail 24 hours a day would exceed the City of Encinitas (Cardiff receiver beach) and Solana Beach construction noise ordinances from both operational (time usage) and sound exposure considerations (see Section 3.9). Physical mitigation of the site (i.e., noise walls, etc.) would not be feasible due to engineering constraints of the property line/surf breakwall interfaces and the steep and high cliff faces present at the Solana Beach site. However the project was able to qualify for and has obtained a variance which brings it into compliance with the local noise ordinance. Therefore, the Navy is able to conclude that the noise impacts will not be significant. 211602000 4-28 SECTION 5 CUMULATIVE IMPACTS 5.1 CUMULATIVE PROJECTS The National Environmental Policy Act (NEP A) requires an analysis of incremental effects of an action that are cumulatively considered when viewed in connection with closely related present, planned, or reasonably foreseeable future actions. In general, effects of a particular action of group of actions would be considered cumulative impacts under the following conditions: • effects of several actions occur in a common location; • effects are not localized (i.e., can contribute to effects of an action in a different location); • effects on a particular resource are similar in nature (i.e., effects the same specific element of a resource; and • effects are long-term (short-term impacts tend to dissipate over time and cease to contribute to cumulative impacts). Cumulative projects consist of other beach replenishment or beach nourishment projects which are ongoing or are planned to occur in northern San Diego County from Oceanside south to Torrey Pines State Beach (Figure 5-1). Cumulative projects are identified below: A. Oceanside Harbor Dredging at Oceanside Harbor has been ongoing. The harbor is typically dredged semi-annually for maintenance purposes. In 1996, approximately 110,000 cubic meters (m3) (140,000 cubic yards [cy]) of dredged material was placed in the nearshore zone in Oceanside. In 1997, approximately 175,000 m3 (225,000 cy) is expected to be placed on beaches in Oceanside. B. Marine Corps Santa Margarita Desiltation The U.S. Marine Corps at Camp Pendleton dredged areas of the Santa Margarita River in order to maintain the river channel and remove built up sediment. Approximately 30,000 m3 (40,000 cy) of sediment was placed in the nearshore zone 211602000 5-1 SAN ^Sweetwater \ JAMUL LEGEND COMPLETED PROJECTS ONGOING/PERIODIC PROJECT <ooo) 1,000's OF CUBIC YDS.OF SAND SOURCE: San Diego Association of Governments BEACH REPLENISHMENT SITES Cumulative Projects FIGURE 5-1 BENVIR ASS'MT(ENV)\Environ AssessmenftReceiver Beach EA\SD County Map in South Oceanside. This project was completed in 1994. Additional maintenance dredging of the Santa Margarita River channel is planned in 1997-98. C. Oceanside Beach Nourishment The City of Oceanside and the La Paz County Landfill in Arizona have developed a program to trade desert sand from the landfill for trash from the City of Oceanside. Trucks will haul trash from Oceanside to La Paz, and return with sand. Approximately 8,000 m3 (10,500 cy) will be deposited as beach nourishment on various Oceanside city beaches. D. Agua Hedionda Lagoon A phased maintenance dredging project began in Agua Hedionda Lagoon in 1995. Phases II and III were completed in 1996, which resulted in the placement of over 150,000 m3 (193,000 cy) of dredged material on beaches north of the inlet jetty and south of the outlet jetty in Carlsbad. E. Batiquitos Lagoon Efforts to restore Batiquitos Lagoon have resulted in dredging of approximately 1,375,000 m3 (1,800,000 cy) of sediment from the lagoon. A beach replenishment project completed in 1995 placed sediments dredged from the lagoon on beaches in north Carlsbad, south of Agua Hedionda Lagoon, and in south Carlsbad, north of Batiquitos Lagoon. In order to maintain areas of the lagoon, an ongoing dredging project is planned. F. Moonlight Beach The Moonlight State Beach project is an ongoing beach replenishment plan that places approximately 770 m3 (1,000 cy) of sediment on the beach in Encinitas on a yearly basis. G. San Elijo Lagoon Mouth Opening The San Elijo Lagoon Mouth Opening project is an annual maintenance dredging project. In 1996, approximately 4,500 m3 (6,000 cy) of sand and cobble was placed on the beach 300 yards south of the lagoon mouth in Encinitas. In 1997, another 4,500 m3 (6,000 cy) of sand and cobble is expected to be placed on the beach south of the lagoon. 211602000 5-3 H. Lomas Santa Fe Drive Grade Separation The Lomas Santa Fe Drive Grade Separation project is expected to begin in early 1997 and conclude in 1998. The project is expected to result in the placement of 30,000 m3 (40,000 cy) of sand at Fletcher Cove in Solana Beach. I. U.S. Navy Homeporting The Navy plans to place approximately 5.4 million m3 (7 million cy) of dredged sediment on several beaches in northern San Diego County as part of the homeporting of an aircraft carrier in San Diego Bay. In addition to the two receiver beaches (South Oceanside and Solana Beach) identified in the proposed action, the Navy plans to place sediment on beaches in north Carlsbad, south Carlsbad, Encinitas, and Torrey Pines State Beach. 5.2 CUMULATIVE ENVIRONMENTAL EFFECTS 5.2.1 Geology and Soils Because the Oceanside littoral cell has been eroding and a reduction of natural sources for beach replenishment is occurring, implementation of the proposed action is a beneficial impact and cumulatively contributes to the reduction of erosion at these beach sites. Therefore, implementation of the proposed action would be a cumulatively beneficial impact. 5.2.2 Coastal Wetlands Dredge and discharge operations associated with the proposed action together with cumulative projects in the area are being implemented for enhancement and replenishment purposes. Further, inlet maintenance programs are currently in place at San Luis Rey River, Loma Alta Creek, San Elijo Lagoon and the San Dieguito River. Refer to Table 5- 1 for inlet maintenance responsibilities. These programs ensure that no significant impacts occur to the value and function of coastal wetlands. Therefore, no significant cumulative impacts would occur to coastal wetlands as a result of the proposed action. 211602000 5-4 Table 5-1 INLET MAINTENANCE RESPONSIBILITY Inlet Maintenance Lagoon / Inlet Responsibility San Luis Key River City of Oceanside Loma Alta Creek City of Oceanside San Elijo Lagoon California Department of Fish and Game / San Diego County Department of Parks and Recreation San Dieguito Lagoon City of Del Mar 5.2.3 Water Resources The proposed action would be implemented in accordance with permit specifications as provided by the Army Corps of Engineers (ACOE), the Environmental Protection Agency (EPA), and the Regional Water Quality Control Board (RWQCB). Placement of sediment on the beach would include the construction of longitudinal dikes parallel to the surf line. Sediment pumping operations would occur in short intervals allowing suspended particles to settle out between pumping periods. CRWQCB certification conditions require approved testing and monitoring of sediment and water proposed for beach replenishment. Therefore, an increase in turbidity anticipated with the proposed action would not be expected to degrade water quality in the nearshore environment on a cumulative level. 5.2.4 Biology Implementation of the proposed action is expected to short-term result in cumulative negative impacts to non-sensitive species (i.e., mobile and non-mobile invertebrates) that inhabit the intertidal and surf zone of the sandy beaches where onshore beach replenishment activities occur. However, once replenishment activities are complete, non- 211602000 5-5 sensitive species will repopulated in the areas. No cumulative impacts are expected to occur to sensitive habitats (reefs) or species (i.e., grunion, surfgrass, or giant kelp). Strict engineering control will ensure that beach replenishment is limited to the areas that will not impact sensitive habitats and species. No impacts to grunion will occur due to implementation of a monitoring program that will halt replenishment activities if grunion are observed spawning. Therefore, no cumulative impacts are expected to occur to the biological resources. 5.2.5 Land Use and Recreation Beach replenishment activities would be compatible with existing coastal land uses. Additionally, no inconsistencies with federal, state, or local land use plans were identified. Therefore, no cumulative land use impacts would occur. Recreational activities would be temporarily distributed to other local beach areas due to the proposed project. Beach areas in the vicinity of the receiver beaches are capable of accommodating additional recreational users, as there is no maximum capacity. Therefore, no cumulative recreational impacts would occur. 5.2.6 Safety and Environmental Health Safety measures associated with the proposed action include onshore and offshore closure to public access, safety buffer zones, onshore barricades, and safety personnel as necessary. Because these safety measures will only be needed on a short-term basis for the length of beach replenishment activities, no cumulative impacts to safety and environmental health are would occur. 5.2.7 Aesthetics Cumulative visual impacts are dependent on the scenic quality of the region and the type of project proposed in the area. The coastal region of San Diego County is considered to be a highly scenic area. Proposed sand placement activities along the beaches would result in short-term visual impacts that would cease at the end of construction activities. The proposed action is considered to have long-term beneficial visual impacts, as beach replenishment would widen San Diego beaches currently affected by erosion and improve 211602000 5-6 coastal views. Therefore, implementation of the proposed action would have cumulative beneficial visual impacts along the coast. 5.2.8 Structures and Utilities The cumulative projects would not increase the regional demand for existing utility services such as water, sewer, gas and electric, solid waste and wastewater. Short-term cumulative interruption of services would be avoided by project-by-project monitoring efforts. It is not anticipated that any long-term cumulative disruption impacts would occur. 5.2.9 Noise Construction activities associated with the proposed action would likely generate a change to noise levels in the vicinity of the receiver beaches for the duration of the project. Noise changes at the receiver beaches would not contribute to cumulative noise impacts due to the distance between proposed beach receiver areas and beach replenishment activities would most likely not occur concurrently with other projects similar in nature. In addition, increases in noise levels will only be short-term and will return to existing levels upon completion of beach replenishment activities. Therefore, no cumulative noise impacts would occur with implementation of the proposed action. 211602000 5-7 This Page Intentionally Left Blank 211602000 5-8 SECTION 6 IRREVERSIBLE OR IRRETRIEVABLE COMMITMENTS OF RESOURCES Resources which are irreversibly or irretrievably committed to a project are those that are typically used on a long-term or permanent basis; however, some are considered short-term resources that cannot be recovered and are thus also considered irretrievable. These resources may include the use of non-renewable resources such as fuel, wood, or other natural or cultural resources. Human labor is also considered a non-retrievable resource because labor used for the proposed action would not be used for other purposes. The unavoidable destruction of natural resources which limit the range of potential uses of that particular environment would also be considered an irreversible or irretrievable commitment of resources. The proposed beach replenishment activities at South Oceanside and Solana Beach would result in the placement of approximately 841,020m3 (1,099,970 cy) of dredged beach-compatible fill material. The dredged material has already been committed as part of the Homeporting project; thus, the need for a disposal site (or sites) is eminent. The proposed action would result in the consumptive use of non-renewable energy sources and labor required to operate barges, trucks, pumping equipment, and grading equipment. These commitments of resources could have otherwise been applied to projects other than the proposed action. However, the proposed action would not result in the use of a substantial amount of resources, and would be short-term in nature. Additionally, no natural resources would be permanently destroyed and beach replenishment would be considered a beneficial use of the dredged material. 211602000 6-1 This Page Intentionally Left Blank 211602000 6-2 SECTION 7 THE RELATIONSHIP BETWEEN LOCAL SHORT-TERM USE OF THE HUMAN ENVIRONMENT AND THE MAINTENANCE AND ENHANCEMENT OF LONG-TERM PRODUCTIVITY The objective of the proposed action is to provide a beneficial use for the disposal of dredged materials, replenish sand at receiver beaches to widen existing beaches and reduce erosion potential, and increase recreational opportunities at the two receiver beach sites for long-term use. Disposal of beach-compatible dredged material on the receiver beaches is considered a beneficial use of dredged materials, and would support the San Diego Association of Government's (SANDAG's) Shoreline Preservation Strategy, polices contained in the Oceanside and Solano Beach General Plans, and the project objectives. The proposed action would help to preserve the long-term use of the receiver beaches as recreational resources. Implementation of the proposed action would not result in any environmental impacts that would significantly narrow the range of beneficial uses of the environment or pose long-term risks to health, safety, or the general welfare of the public communities surrounding the receiver beaches. Rather, the project would provide for future beneficial beach resources (e.g., recreation activities). 211602000 7-1 This Page Intentionally Left Blank 211602000 7-2 SECTION 8 LIST OF PREPARERS This Environmental Assessment was prepared for, and under the direction of, the U.S. Department of the Navy and the Army Corps of Engineers, by Ogden Environmental and Energy Services Co., Inc. and Frederic R. Harris, Inc. Members of the professional staff are listed below: Ogden Environmental and Energy Services Co., Inc. Project Management Paul Amberg, Project Manager B.A. Environmental Studies Quality Assurance Shawna Anderson M.A. Geography Howard Cumberland M.S. Biology Technical Analysts John Conley B.A. Geography Karen Ames B.S. Public and Environmental Affairs Sandy Fleming B.A. Political Science 211602000 8-1 Jacqueline Dompe B.A. Business Administration and Environmental Studies Stacey Baczkowski M.S. Biology Geographic Information Systems Pat Atchison, GIS Manager M.A. Geography Andrew Hanes B.S. Geography Jay Tessier B.S. Geology U.S. Navy, Southwest Division Patrick McCay Environmental Planner Mitchell Perdue Soils Conservationist 211602000 8-2 SECTION 9 LIST OF AGENCIES AND PERSONS CONSULTED U.S. Fish and Wildlife Service Gail C. Kobetich, Field Supervisor Doreen Stadtlander, Fish and Wildlife Biologist National Marine Fisheries Service Robert Hoffman, Fisheries Biologist California Coastal Commission Sherilyn Sarb, Supervisor of Permits San Diego Association of Governments Stave Sachs, Senior Regional Planner California State Department of Parks and Recreation Dennis Stoufer, Lifeguard Supervisor II City of Oceanside Ray Duncan, Lifeguard Manager City of Solana Beach Rick Roswall, Lifeguard Daryle Mitchell, Associate Palnner City of Encinites Chris Miller, Planning Technician 211602000 9-1 This Page Intentionally Left Blank 211602000 9-2 SECTION 10 REFERENCES Barilotti, D.C. 1983. Measurements needed to determine the ecologically important effects of discharged wastes in kelp bed habitats. In: W. Bascom (ed.). The Effects of Waste Disposal on Kelp Communities. Southern California Coastal Waters Research Project, Long Beach, CA. pp. 163-180. Barnard, J.L. 1963. Relationship of Benthic Amphipoa to Invertebrate Communities of Inshore Sublittoral Sands of Southern California. Pacific Naturalist 3:439-467. Butler Roach Group. 1995. Evaluation of Potential Impacts to Marine Biota from the Beach Replenishment Component of the Proposed Lomas Santa Fe Drive Grade Separation Project. Prepared by MEC Analytical Systems, Inc. April. California Chamber of Commerce. 1995. California Environmental Compliance Handbook. California Coastal Commission. 1995. Coastal Consistency Determination for the Development of Facilities in San Diego to Support the Homeporting of One NIMITZ Class Aircraft Carrier. May. California Regional Water Quality Control Board (RWQCB). 1995. Waste Discharge Requirements for the U.S. Navy Dredge and Fill Activities, Homeporting Project, San Diego County. Order No. 95-118. December. Carlsbad Opportunistic Sand Project. 1995. Opportunistic Beach Fill Practice to Reduce Impacts. Prepared by Moffatt & Nichol, Engineers. March. City of Oceanside. 1986. Land Use Element. Adopted September, updated January 1989. City of Oceanside. 1985. Local Coastal Program, Land Use Plan. 10 July. City of Oceanside. 1974. Oceanside General Plan. Resolution No. 74-226. 27 November. City of Solana Beach. 1988. Solana Beach General Plan. Updated January 1997. Devinny, J.S. and L.A. Volse. 1978. Effects of sediments on the development of Macrocystis pyrifera gametophytes. Marine Biology 48:343-348. Duncan, Ray. 1997. Lifeguard Manager, City of Oceanside. Personal communication, 11 March. 211602000 10-1 Environmental Protection Agency (EPA). 1986. Environmental Assessment for Relocation of the Naval Command, Control and Ocean Surveillance Center/Research, Development, Test, and Evaluation Detachment Located at the Marine Corps Air Station Kaneohe, Hawaii, to NCCOSC RTD&E, San Diego, California. U.S. Department of the Navy. November 1992. Frederic R. Harris, Inc. 1996. Kelp Bed Locations Along the San Diego County Coast. Prepared by H. Elwany, L. H. Dean, K. Zabloudil, B. Van Wagenen, and R. Flick. 10 September. Gerard, V.A. 1984. The light environment in a giant kelp forest: Influence of Macrocystsis pyrifera on spatial and temporal variability. Marine Biology (Berlin) 84:189-195. Kobetich, Gail C. 1997. Field Supervisor, U.S. Fish and Wildlife Service. Letter to Army Corps of Engineers, Los Angeles District. 5 March. La Paz County Landfill. 1996. Oceanside Beach Nourishment Demonstration Project. Prepared by H. Elwany, J. Nichols, W. Gayman, and R. Flick. 7 July. Lobban, C.S., P.J. Harrison, and M.J. Duncan. 1985. The physiological ecology of seaweeds. Cambridge University Press, Cambridge. 242pp. Moffat and Nichols, Engineers. 1983. Experimental Sand Bypass System at Oceanside Harbor, California. Phase I Report: Data Collection and Analysis. Morin, J.G., J.E. Kastendiek, A. Harrington, and N. Davis. 1985. Organization and patterns of interactions in a subtidal sand community on an exposed coast. Marine Ecology Progress Series 27:163-185. Morin, J.G., J.E. Kastendiek, A. Harrington, and N. Davis. 1988. Organisms of a subtidal sand community in Southern California. Bulletins Southern California Academy of Sciences 87:1 -11. Roswall, Rick. 1997. Lifeguard Services. City of Solana Beach. Personal communication, 11 March. San Diego Association of Governments (SANDAG). 1993. Shoreline Preservation Strategy for the San Diego Region. July. San Diego Association of Governments (SANDAG). 1996. Year End Report to Shoreline Erosion Committee on Opportunistic Sand Projects. 26 November. 211602000 10-2 Sterrett, E.H. and R.E. Flick. 1994. Shoreline Erosion Assessment and Atlas of the San Diego Region, Vol. II. California Department of Boating and Waterways. Sacramento, CA. Stoufer, Dennis. 1997. Lifeguard Supervisor II, California State Department of Parks and Recreation. Personal communication, 12 March. Straughan, D. 1982. Inventory of the natural resources of sandy beaches in Southern California. Allan Hancock Foundation, Los Angeles, CA. 447pp. Thompson, B., J. Dixon, S. Schroeter, and D.J. Reish. 1993. Ecology of the Southern California Bight: A Synthesis and Interpretation. Chapter 8, Benthic Invertebrates. University of California Press. Thompson, B., J. Dixon, S. Schroeter, D. J. Reish. 1990. Chapter 8 Benthic Invertebrates. In: Dailey, M. D., D. J. Reish, and J.W. Anderson (eds.). 1990. Ecology of the Southern California Bight: A Synthesis and Interpretation. U.S. Department of the Interior Minerals Management Service and Ocean Studies Institute. U.S. Army Corps of Engineers (ACOE), Los Angeles District. 1996. Department of the Army Permit No. 94-20861-DZ. U.S. Army Corps of Engineers (ACOE), Los Angeles District. 1996. Environmental Evaluation for the Encinitas Shoreline, San Diego County, California. March. U.S. Army Corps of Engineers (ACOE), Los Angeles District. 1994. Final Environmental Assessment for Oceanside Harbor Maintenance Dredging, San Diego County, California. August. U.S. Army Corps of Engineers (ACOE), Los Angeles District. 1997. Public Notice of Permit Modification for Department of the Army Permit No. 94-20861-DZ. U.S. Army Corps of Engineers (ACOE), Waterways Experiment Station. 1984. Shore Protection Manual. U.S. Department of the Navy, Naval Facilities Engineering Command Southwest Division. 1996. Distribution of Resuspended Sediment from Dredging of the Navigation Channel - San Diego Bay. August. U.S. Department of the Navy. 1995. Final Environmental Impact Statement for the Development of Facilities in San Diego/Coronado to Support the Homecoming of One NIMITZ Class Aircraft Carrier. Volumes 1-3. Prepared by Ogden Environmental and Energy Services, Inc. November. 211602000 10-3 U.S. Department of the Navy. 1995. Record of Decision for the Development of Facilities in San Diego/Coronado, California to Support the Homeporting of One NIMITZ-Class Aircraft Carrier. U.S. Department of the Navy, Naval Facilities Engineering Command Southwest Division. 1995. Sediment Characterization Report of NIMITZ Class Aircraft Carrier Homeporting Facilities, Naval Air Station North Island. Prepared by Ogden Environmental and Energy Services, Inc. 211602000 10-4 ATTACHMENT I FY '97 MCON Project P-706 Channel Dredging Naval Air Station North Island Coronado, California Southwest Division Naval Facilities Engineering Command 1220 Pacific Highway San Diego, CA 92132-5187 28 March 1997 Preliminary Beach Sand Transport and Sedimentation Report Phase 1: South Oceanside and Solana Beach SOUTHWESNAVFACENGCOM FY 97 MCON PROJECT P-706 CHANNEL DREDGING BEACH SAND TRANSPORT AND SEDIMENTATION REPORT PHASE I: SOUTH OCEANSIDE AND SOLANA BEACH TABLE OF CONTENTS Page No. ES EXECUTIVE SUMMARY ES.l Background ES-1 ES.2 Approach ES-3 ES.3 Results ES-3 ES.4 Conclusions ES-4 1.0 INTRODUCTION 1.1 Background - Proposed On-shore Beach Fills 1-1 1.2 Scope of Work 1-4 1.3 Purpose 1-5 1.4 Approach & Methodology 1-7 1.5 Information and Data 1-8 1.6 Metric Conversion 1-8 1.7 Abbreviations 1-9 2.0 STUDY AREA ENVIRONMENTAL CONDITIONS 2.1 Coastal Geology 2-1 2.2 Beaches and Shoreline Configuration 2-1 2.2.1 Beaches 2-3 2.2.2 Coastal Marine Terraces 2-3 2.2.3 Sea Cliffs 2-4 2.2.4 Lagoons and Creeks 2-4 2.3 Tides and Sea Level Changes 2-4 2.3.1 Tidal Datum and Tidal Elevations 2-5 2.3.2 Storm Surge 2-5 2.3.3 Sea Level Rise 2-6 2.4 Wave Processes 2-7 2.4.1 Sources of Wave Energy 2-7 2.4.2 Wave Climate Seasonal Summary 2-7 2.4.3 Island Sheltering 2-9 2.4.4 Extreme Waves 2-9 28 MARCH 1997 i BEACH SAND TRANSPORT & SEDIMENTATION SOUTHWESNAVFACENGCOM FY 97 MCON PROJECT P-706 CHANNEL DREDGING BEACH SAND TRANSPORT AND SEDIMENTATION REPORT PHASE I: SOUTH OCEANSIDE AND SOLANA BEACH TABLE OF CONTENTS (continued) Page No. 3.0 LITTORAL PROCESSES AND SEDIMENT BUDGET 3.1 Littoral Transport 3-1 3.1.1 Current State of Oceanside Littoral Cell 3-1 3.1.2 Shorezone 3-3 3.1.3 Littoral Material 3-3 3.1.4 Seasonal Equilibrium Profile 3-6 3.1.5 Shelf Transport 3-6 3.1.6 Longshore Transport 3-6 3.2 Sediment Budget 3-6 3.2.1 Littoral Sand Sources 3-7 3.2.2 Littoral Sand Sinks 3-7 3.2.3 Sediment Budget Diagram 3-7 3.3 Natural Sand Supply 3-9 3.3.1 Rivers 3-10 3.3.2 Cliffs 3-10 3.4 Artificial Sand Supply 3-12 3.4.1 City of Oceanside 3-12 3.4.2 City of Solana Beach 3-12 4.0 COASTAL WETLAND AREAS 4.1 Importance of Coastal Lagoons 4-1 4.1.1 Regional Significance 4-4 4.2 Lagoon Inlet Stability 4-4 4.2.1 Ecological Factors 4-4 4.2.2 Closure Processes 4-7 4.2.3 Opening Processes 4-8 4.3 Lagoon Inlets and Creek Mouths 4-8 4.3.1 San Luis Rey River 4-10 4.3.2 Loma Alta Creek 4-10 4.3.3 Buena Vista Lagoon 4-10 4.3.4 Agua Hedionda Lagoon 4-14 4.3.5 Batiquitos Lagoon 4-17 4.3.6 San Elijo Lagoon 4-17 4.3.7 San Dieguito Lagoon 4-19 4.3.8 Los Penasquitos Lagoon 4-22 28 MARCH 1997 ii BEACH SAND TRANSPORT & SEDIMENTATION SOUTHWESNAVFACENGCOM FY 97 MCON PROJECT P-706 CHANNEL DREDGING BEACH SAND TRANSPORT AND SEDIMENTATION REPORT PHASE I: SOUTH OCEANSIDE AND SOLANA BEACH TABLE OF CONTENTS (continued) Page No. 5.0 PROJECT AND SITE DESCRIPTION 5.1 Phase I Project 5-1 5.2 South Oceanside Beach Fill 5-5 5.2.1 Existing Beach Conditions 5-5 5.3 Solana Beach Fill 5-7 5.3.1 Existing Beach Conditions 5-7 5.4 Site Visits 5-9 5.5 Structures and Utilities 5-9 5.5.1 South Oceanside 5-9 5.5.1.1 Sanitary Sewer Ocean Outfall 5-9 5.5.1.2 Public or Private Access Stairs/Ramps 5-9 5.5.1.3 Storm Drain Pipes 5-10 5.5.2 Solana Beach 5-10 5.5.2.1 Sanitary Sewer Ocean Outfall 5-10 5.5.2.2 Sea Wall and Tide Pools 5-10 5.5.2.3 Public Access Stairs, Storm Drain Pipe, and Sandbag Retaining Wall 5-10 5.5.2.4 Storm Drain Outfall 5-13 5.5.2.5 Storm Drain Outlet ! 5-13 6.0 PROJECT ANALYSIS 6.1 Approach 6-1 6.2 Beach Fill Alternative Considerations 6-1 6.2.1 Construction Considerations 6-4 6.2.2 Beach Fill Material Compatibility 6-5 6.2.3 Grain Size Effect on Berm Behavior 6-10 6.2.4 Scarp Considerations 6-13 6.2.5 Fine Grained Material 6-14 6.2.5.1 Turbidity 6-14 6.2.5.2 Release of Fines after Filling 6-17 6.2.5.3 Cementing or Hardening 6-17 6.3 Historic Beach Fill Experience 6-17 6.3.1 1983 Oceanside Beach Fill 6-18 6.3.1.1 Analysis of Sediment Transport 6-18 6.3.2 1988 Oceanside Beach Fill 6-20 6.3.2.1 Analysis of Sediment Transport 6-20 6.3.3 Conclusions 6-22 28 MARCH 1997 iil BEACH SAND TRANSPORT & SEDIMENTATION SOUTHWESNAVFACENGCOM FY 97 MCON PROJECT P-706 CHANNEL DREDGING BEACH SAND TRANSPORT AND SEDIMENTATION REPORT PHASE I: SOUTH OCEANSIDE AND SOLANA BEACH TABLE OF CONTENTS (continued) Page No. 6.4 Numerical Modeling 6-22 6.4.1 Wave Data 6-22 6.4.2 SBEACH 6-23 6.4.2.1 Profile Modeling 6-23 6.4.2.2 Limitations 6-24 6.4.3 GENESIS 6-25 6.4.3.1 Shoreline Modeling 6-25 6.4.3.2 Limitations 6-27 6.5 South Oceanside Analysis 6-28 6.5.1 Natural Variation of Sediment Transport 6-28 6.5.2 Numerical Model Results 6-28 6.5.3 Limits of Sand Movement 6-31 6.5.4. Thickness of Sand 6-32 6.5.5 Surf Conditions 6-32 6.5.6 Scarping 6-33 6.5.7 Turbidity 6-33 6.5.8 Coastal Wetlands 6-33 6.5.8.1 San Luis Rey River 6-33 6.5.8.2 Loma Alta Creek 6-34 6.5.8.3 Buena Vista Lagoon 6-34 6.5.8.4 Agua Hedionda 6-35 6.6 Solana Beach Analysis 6-35 6.6.1 Natural Variations of Sediment Transport 6-35 6.6.1.1 CardiffState BeachFill 6-35 6.6.1.2 Fletcher Cove Fill 6-35 6.6.2 Numerical Model Results 6-38 6.6.3 Limits of Sand Movement 6-40 6.6.4 Thickness of Sand 6-41 6.6.5 Surf Conditions 6-41 6.6.6 Scarping 6-41 6.6.7 Turbidity 6-41 6.6.8 Coastal Wetlands 6-41 6.6.8.1 San Elijo Lagoon 6-42 6.6.8.2 San Dieguito Lagoon 6-43 28 MARCH 1997 iv BEACH SAND TRANSPORT & SEDIMENTATION SOUTHWESNAVFACENGCOM FY 97 MCON PROJECT P-706 CHANNEL DREDGING BEACH SAND TRANSPORT AND SEDIMENTATION REPORT PHASE I: SOUTH OCEANSIDE AND SOLANA BEACH TABLE OF CONTENTS (continued) Page No. 7.0 FINDINGS AND CONCLUSIONS 7.1 Beach Fill Movement 7-1 7.2 Summary of Potential Impacts 7-2 7.3 Conclusions 7-4 7.4 Limitations and Uncertainties 7-5 8.0 REFERENCES APPENDICES Appendix A Tide and Sea Level Changes Appendix B Wave Processes Appendix C Numerical Modeling Input/output Appendix D Photographs Appendix E Dredge Area and Beach Grain Size Data Appendix F Everts Coastal Technical Memorandum Appendix G Correspondence 28 MARCH 1997 v BEACH SAND TRANSPORT & SEDIMENTATION SOUTHWESNAVFACENGCOM FY 97 MCON PROJECT P-706 CHANNEL DREDGING BEACH SAND TRANSPORT AND SEDIMENTATION REPORT PHASE I: SOUTH OCEANSEDE AND SOLANA BEACH TABLE OF CONTENTS (continued) List of Tables Table No. Title Page No. ES.l Planned On-shore Beach Disposal Site Quantities Measured in the Dredge Cut. ES-1 ES.2 South Oceanside Beach Fill Study Results ES-4 ES.3 Solana Beach Fill Study Results ES-5 1.1 Planned On-shore Beach Disposal Site Quantities Measured in the Dredge Cut.. 1-4 1.2 Metric Conversions 1-8 2.1 Sea Level Elevations and Tidal Datums for Oceanside Cell 2-5 2.2 Extreme Tides for Oceanside Cell 2-6 2.3 Wave Height - Frequency at Oceanside Cell 2-10 3.1 Depth of Shorebase 3-3 3.2 Longshore Sediment Transport Rate Estimates at Oceanside 3-7 3.3 Estimated Coarse Sediment Yields (m3/yr) 3-10 3.4 City of Oceanside Opportunistic Beach Fill 3-13 4.1 Coastal Wetlands Located Within the Project Area 4-1 4.2 Key Functions and Values of California's Coastal Wetlands 4-3 4.3 Distribution of Habitat Types in Lagoons Within the Study Area 4-5 4.4 Inlet Status of Coastal Wetlands Within the Study Area 4-6 4.5 Attributes of the Coastal Wetlands Within the Study Area 4-9 5.1 Project Beach Fill Characteristics 5-1 5.2 Natural Berm Elevations 5-6 6.1 Natural Berm Elevations 6-4 6.2 Grain Size Comparisons 6-5 6.3 SBEACH Beach Fill Model Input Data 6-24 6.4 GENESIS Beach Fill Model Input Data 6-27 6.5 Predicted Shoreline Position at South Oceanside 6-31 6.6 Predicted Shoreline Position at Solana Beach 6-40 7.1 South Oceanside Beach Fill Study Results 7-3 7.2 Solana Beach Fill Study Results 7-4 28 MARCH 1997 vi BEACH SAND TRANSPORT & SEDIMENTATION SOUTHWESNAVFACENGCOM FY 97 MCON PROJECT P-706 CHANNEL DREDGING BEACH SAND TRANSPORT AND SEDIMENTATION REPORT PHASE I: SOUTH OCEANSIDE AND SOLANA BEACH TABLE OF CONTENTS (continued) List of Figures Figure No. Title Page No. ES.l Project Site ES-2 1.1 Channel Dredge Site 1-2 1.2 Project Site 1-3 1.3 Beach Fill Study Area 1-6 2.1 Typical Shoreline Segment Cross Section 2-2 2.2 Wave Exposure for the San Diego Region 2-8 3.1 Location Map of San Diego Region Showing Boundaries Of the Three Major Littoral Cells 3-2 3.2 Generalized Diagram of Equilibrium Beach Profile 3-4 3.3 Mean Sediment Size Across the Shorerise of the Oceanside Littoral Cell 3-5 3.4 Sediment Budget at Oceanside Cell 3-8 3.5 Major Tributary Rivers and Coastal Lagoons 3-11 3.6 Historic Artificial Sand Supply - Oceanside 3-14 3.7 Cumulative Artificial Sand Supply - Oceanside 3-15 4.1 Coastal Wetland Areas 4-2 4.2 San Luis Rey River Mouth 4-11 4.3 Loma Alta Creek 4-12 4.4 Buena Vista Lagoon 4-13 4.5 Agua Hedionda Lagoon Inlet 4-15 4.6 Agua Hedionda Lagoon Inlet, Warm Water Discharge 4-16 4.7 Batiquitos Lagoon Inlet 4-18 4.8 San Elijo Lagoon 4-20 4.9 San Dieguito Lagoon 4-21 4.10 Los Penasquitos Lagoon 4-23 5.1 Existing Beach Profile at South Oceanside 5-2 5.2 Existing Beach Profile at Cardiff- Solana Beach 5-3 5.3 Existing Beach Profile at Fletcher - Solana Beach 5-4 5.4 South Oceanside Site Plan and Photograph Location Map 5-6 5.5 Solana Beach Site Plan and Photograph Location Map 5-8 5.6 Existing Structures and Utilities Impacts - South Oceanside 5-11 5.7 Existing Structures and Utilities Impacts - Solana Beach 5-12 28 MARCH 1997 v55 BEACH SAND TRANSPORT & SEDIMENTATION SQUTHWESNAVFACENGCOM FY 97 MCON PROJECT P-706 CHANNEL DREDGING BEACH SAND TRANSPORT AND SEDIMENTATION REPORT PHASE I: SOUTH OCEANSIDE AND SOLANA BEACH TABLE OF CONTENTS (continued) List of Figures (continued) Figure No. Title Page No. 6.1 Schematic of Beach Fill Construction Template Alternatives 6-3 6.2 Summary of Channel Grain Size Data 6-6 6.3 Dredge Area-1 6-7 6.4 Dredge Area-2 6-8 6.5 Composite Grain Size Distribution for the Oceanside Littoral Cell as They Existed in 1983-1984 and Composites Of Grain Size Distribution of Samples Collected in Dredge Areas 1 and 2 6-9 6.6 Grain Size Effect on Berm Behavior (Short Term) 6-11 6.7 Grain Size Effect on Berm Behavior (Long Term) 6-12 6.8 Naturally Occurring Scarp 6-15 6.9 Profile Variation after 1983 Beach Fill at Oceanside 6-19 6.10 Profile Variation after 1988 Beach Fill at Oceanside 6-21 6.11 Schematic of Initial Equilibrium Beach Profile Adjustment For Genesis Model 6-26 6.12 Seasonal Profile Variation at South Oceanside 6-29 6.13 Mean Sea Level Shoreline Response at South Oceanside 6-30 6.14 Seasonal Profile Variation at Cardiff- Solana Beach 6-36 6.15 Seasonal Profile Variation at Fletcher - Solana Beach 6-37 6.16 Mean Sea Level Shoreline Response at Solana Beach 6-39 7.1 Project Beach Fill Vs. Historic Beach Sand Sources 7-6 This report has been prepared by Frederic R. Harris, Inc., San Diego CA. Coastal Environments, Encinitas, CA provided contributions for study area environmental conditions, lagoon conditions and lagoon impact evaluation. This report has been reviewed by a Technical Advisory Group consisting of Craig Everts, Ph.D., Reinhard Flick, Ph.D. and Hany Elwany, Ph.D. Comments from the Technical Advisory Group review have been incorporated either in whole or part into this Preliminary Phase I Report. 28 MARCH 1997 viii BEACH SAND TRANSPORT & SEDIMENTATION Executive Summary SOUTHWESNAVFACENGCOM FY 97 MCON PROJECT P-706 CHANNEL DREDGING BEACH SAND TRANSPORT AND SEDIMENTATION REPORT PHASE I: SOUTH OCEANSIDE AND SOLANA BEACH EXECUTIVE SUMMARY On 26 February 1997, under contract modification PZ0008, SOUTHWESNAVFACENGCOM authorized FRH to proceed with preparation of a Beach Sand Transport and Sedimentation Report (Phases I and II) in support of the option to place channel dredge material at the on-shore beach sites for MCON P-706, Channel Dredging at Naval Air Station North Island (NASNI), Coronado, CA. Work on this Preliminary Phase I report began immediately and was completed over a four week period ending 28 March 1997. This Preliminary Phase I Report addresses two sites: South Oceanside and Solana Beach. The Phase II Report, to be contained in a separate document, will evaluate the remaining sites and discuss cumulative impacts. ES.l Background The option to beneficially use the channel dredge material for opportunistic beach fill and nearshore nourishment in the San Diego Region (Cities of Oceanside, Carlsbad, Encinitas, Solana Beach, Del Mar, San Diego and Imperial Beach), was requested of the U.S. Navy through the Shoreline Erosion Committee (SEC) of the San Diego Association of Governments (SANDAG). Dredge material quantity allocations and locations of beach fill were driven by the SEC's "Guiding Principles for Local Decisions on Sand Replenishment" and were determined by the SEC (SANDAG letter to SOUTHWESNAVFACENGCOM dated 6 June 1996). The six on-shore beach sites, which are the subject of this study, are indicated in Figure ES.l and listed in Table ES.l below. TABLE ES.l - PLANNED ON-SHORE BEACH DISPOSAL SITE QUANTITIES MEASURED IN THE DREDGE CUT (m3) SITE APPROXIMATE LOCATION QUANTITY PHASE I BEACHES South Oceanside Solana Beach 3rd Street to Loma Alta Creek Cardiff State Beach- South of San Elijo Lagoon Fletcher Cove 405,218 265,585 168,217 PHASE II BEACHES North Carlsbad South Carlsbad Encinitas Torrey Pines Buena Vista Lagoon to Oak Avenue Palomar Airport Road to Ponto Drive South of Batiquitos Lagoon to 5th Street Los Penasquitos Lagoon to Torrey Pines TOTAL 420,510 420,510 871,620 496,970 3,050,630 28 MARCH 1997 ES-1 BEACH SAND TRANSPORT & SEDIMENTATION *S. OCEANSIDE OCEAN SIDE CARLSBAD CHANNEL DREDGING PROJECT NAVAL AIR STATION NORTH ISLAND PACIFIC OCEAN * PHASE I BEACH ** PHASE II BEACH ENCINITAS SOLANA BEACH "5> **TORREY PINES y i ESCONDIDO : DEL MAR PC-WAY SANTEE EL CAJON '•-. SAN \ LA MESA < NATIONAL CITY PROJECT SITE NOT TO SCALE FY-1997 MCON PROJECT P-706 MILITARY CONSTRUCTION PROJECT DATA CHANNEL DREDGING AT NAS.N.I. CORONADO, CALIFORNIA 28 MAR 97 FIGURE ES.1 SOUTHWESNAVFACENGCOM FY 97 MCON PROJECT P-706 CHANNEL DREDGING BEACH SAND TRANSPORT AND SEDIMENTATION REPORT PHASE I: SOUTH OCEANSIDE AND SOLANA BEACH ES.2 Approach This report studies the potential beneficial and adverse impacts resulting from placement of beach fill in South Oceanside and Solana Beach. The study is based on an understanding of environmental conditions, littoral processes and coastal wetland processes, and on results of qualitative analyses and numerical modeling. Analyses have been performed using existing information that was obtained in the short time allowed to perform this study. The predominant source of data used was derived from the extensive work carried out along the San Diego coastline as part of the USACOE Coast of California Storm and Tidal Waves Study (CCSTWS). Beneficial impacts of artificial beach fills include enhanced recreation areas, improved beach access, improved surfbreak, shoreline protection and erosion control. These beneficial impacts are significant to the beach going public and to beachfront property owners since there is very little existing beach along the shoreline and property is susceptible to erosion. Possible adverse impacts include impeded beach access due to scarps, sand migration influencing lagoons, creeks and offshore habitat, modified surfing conditions, and impacts on structures and utilities. The study evaluates these impacts using historical experience, analysis of grain size effect on berm behavior, and results of numerical modeling using GENESIS and SBEACH. ES.3 Results Beach fills create a sand berm on the beach that provide recreational area and shoreline protection. However, placement of the sand on the beach creates a temporary disequilibrium in the beach profile. Over a period of time, which is expected to be in the order of 1 to 2 years, the sand will move and redistribute itself from the initial placement location through the natural littoral transport processes. The beach profile will then again reach an equilibrium position which will be very similar to the pre-fill beach profile. The shoreline will temporarily widen at locations upcoast and downcoast of the beach fill. The movement and redistribution of the beach fill could potentially cause adverse, but temporary impacts by migrating into or in front of lagoons and creeks, or offshore and along shore to sensitive habitats. Results from analysis of historic beach fills, fill grain size compatibility and numerical modeling indicate the following general conclusions regarding beach fill movement following placement: • Cross shore movement primarily limited to nearshore zone (within 400 m of backbeach) • Along shore movement will redistribute beach fill by moving material both upcoast and downcoast • Along shore limit of influence is in the order of less than 3,000 m both upcoast and downcoast from the initial beach fill area • The beach fill will spread due to longshore and cross shore transport and will cause no additional erosion of the adjacent beach beyond that which occurs naturally 28 MARCH 1997 ES-3 BEACH SAND TRANSPORT & SEDIMENTATION SOUTHWESNAVFACENGCOM FY 97 MCON PROJECT P-706 CHANNEL DREDGING BEACH SAND TRANSPORT AND SEDIMENTATION REPORT PHASE I: SOUTH OCEANSIDE AND SOLANA BEACH • Some fine grain material will move out of the beach fill below the pinchout depth and onto the continental shelf • Turbidity will be controlled by channeling hydraulically placed beach fill behind a berm until fines settle out ES.4 Conclusions Table ES.2 summarizes the potential impacts of the South Oceanside Beach Fill and Table ES.3 summarizes the potential impacts of the Solana Beach Fill. No significant adverse impacts are expected at either beach fill site. Monitoring of the beach fill material should be carried out for at least one year after construction to track the movement of sand. The physical monitoring program will consist of pre- and post-fill placement surveys which are required during construction of each beach fill as well as ongoing and proposed beach monitoring sponsored by SANDAG, the City of Carlsbad and the California Department of Boating and Waterways. Planned monitoring by SANDAG includes aerial photography, beach profile surveys and computation of changes on profile volumes and beach widths. TABLE ES.2 - SOUTH OCEANSIDE BEACH FILL STUDY RESULTS ITEM Recreation Beach Access Erosion Control Shoreline Protection Waves Offshore Habitat Structures and Utilities Oceanside Harbor Oceanside Pier San Luis Rey River Loma Alta Creek Buena Vista Lagoon IMPACT + + + + + None None None None None None None COMMENTS Increased recreation value will result from wider sandy beach. Sand is better than cobbles for access. Longitudinal access at high tide will be increased. Potential for a small scarp (in the order of 1 to 2 m) to form at the shoreline. Wider beach will temporarily postpone shoreline recession. Higher and wider berm will provide limited and temporary increase in shoreline protection. Temporal sand bar should enhance surf conditions. Beach profile change could modify wave break location. Sand is not expected to reach location of offshore habitat. Fines released from beach fill should not exceed existing conditions. Based on site visits and interviews, no impact on structures/utilities are anticipated. Sand movement into the harbor should be no more than historic. No impact. No long-term potential for increased damming of river mouth. City maintains flow path as needed. No long-term potential for increased damming of river mouth. City maintains flow path as needed. No potential for blocking flow from lagoon. Legend: "+" indicates beneficial impacts, "-" indicates adverse impacts, "None" indicates no impacts. Note: Impacts are a function of actual wave and storm conditions. Impacts indicated above are based on "normal" seasonal wave climate and study area environmental conditions. 28 MARCH 1997 ES-4 BEACH SAND TRANSPORT & SEDIMENTATION SOUTHWESNAVFACENGCOM FY 97 MCON PROJECT P-706 CHANNEL DREDGING BEACH SAND TRANSPORT AND SEDIMENTATION REPORT PHASE I: SOUTH OCEANSIDE AND SOLANA BEACH TABLE ES.3 - SOLANA BEACH FILL STUDY RESULTS ITEM Recreation Beach Access Erosion Control Shoreline Protection Waves Offshore Habitat Structures and Utilities San Elijo Lagoon Reef North of Ocean Street Headland North of Cliff St. San Dieguito Lagoon IMPACT + + + + Net + Minimal None Minimal None + Minimal COMMENTS Increased recreation value will result from wider sandy beach. Sand is better than cobbles for access. Longitudinal access at high tide will be increased. Potential for a small scarp (in the order of 1 to 2 m) to form at the shoreline. Wider beach will temporarily postpone shoreline recession. Higher and wider berm will provide limited and temporary increase in shoreline protection. Temporal sand bar should enhance surf conditions. Beach profile change could modify wave break location. No long-term impacts to reef breaks are anticipated. Sand is not expected to migrate beyond 300 to 400 m offshore. Fines released from beach fill should not exceed existing conditions. Based on site visits and interviews, no impact on structures/utilities are anticipated. Limited long-term potential for increased frequency of maintenance currently performed by the County of San Diego. Sand fill is anticipated to move away (upcoast and downcoast) from the reef due to diverging shoreline orientation. Headland receives longshore sand supply. Limited long-term potential for increased frequency of maintenance currently performed bv the City of Del Mar. Legend: "+" indicates beneficial impacts, "-" indicates adverse impacts, and "None" indicated no impacts Note: Impacts are a function of actual wave and storm conditions. Impacts indicated above are based on "normal" seasonal wave climate and study area environmental conditions. 28 MARCH 1997 ES-5 BEACH SAND TRANSPORT & SEDIMENTATION Section 1.0 Introduction SOUTHWESNAVFACENGCOM FY 97 MCON PROJECT P-706 CHANNEL DREDGING BEACH SAND TRANSPORT AND SEDIMENTATION REPORT PHASE I: SOUTH OCEANSIDE AND SOLANA BEACH 1.0 INTRODUCTION The Department of the Navy, Southwest Division, Naval Facilities Engineering Command (SOUTHWESNAVFACENGCOM), commissioned Frederic R. Harris, Inc. (FRH) on 5 December 1994 under contract N68711-94-C-l685 to provide Architect-Engineering Services for FY97 MCON Project P-706, Channel Dredging at Naval Air Station North Island (NASNI), Coronado, CA. The project consists of the following: • Dredging of the San Diego Bay Entrance Channel from the aircraft carrier turning basin to the ocean for the purpose of accommodating NIMITZ Class Aircraft Carriers at NASNI. The project will dredge approximately 5.4 million cubic meters (m3) of sediment from the channel with disposal of suitable materials at nearshore and/or on-shore beach sites in San Diego County, California and materials unsuitable for this purpose at the United States Army Corps of Engineers (USACOE) LA-5 deep ocean disposal site. The location of the channel dredge site is shown in Figure 1.1. On 26 February 1997, under contract modification PZ0008, SOUTHWESNAVFACENGCOM authorized FRH to proceed with preparation of a Beach Sand Transport and Sedimentation Report (Phases I and II) in support of the option to place channel dredge material at the on-shore beach sites. Work on a draft Preliminary Phase I report began immediately and was completed over a four week period ending 28 March 1997. Comments on the draft were received on 24 March 1997 after which this final report was completed. 1.1 Background - Proposed On-Shore Beach Fills The alternative to beneficially use the channel dredge material for opportunistic beach fill and nearshore nourishment in the San Diego Region (Cities of Oceanside, Carlsbad, Encinitas, Solana Beach, Del Mar, San Diego and Imperial Beach), was requested of the U.S. Navy through the Shoreline Erosion Committee (SEC) of the San Diego Association of Governments (SANDAG). The SEC members have collectively adopted the policy that beach sand nourishment is first on the list of potential solutions to manage the region's current and future shoreline erosion problems. This policy is stated in the Shoreline Preservation Strategy (SANDAG, 1993). Dredge material quantity allocations and locations of beach fill were driven by the SEC's "Guiding Principles for Local Decisions on Sand Replenishment" and were determined by the SEC (SANDAG letter to SOUTHWESNAVFACENGCOM dated 6 June 1996). The channel dredge material is proposed to be used for opportunistic nearshore beach nourishment and on- shore beach fill. The six on-shore beach sites, which are the subject of this study, are indicated in Figure 1.2 and listed in Table 1.1. 28 MARCH 1997 1-1 BEACH SAND TRANSPORT & SEDIMENTATION N 0 « T H ISLAND US NAVAL AIR STATION US N RESERVATION NOTE: Based on contractor work plan, materials from dredge areas (T) and @ will be placed at the on—shore beach sitesand remaining beach suitable materials will be placed atthe near—shore beach sites.-HJ£%$«M"* BEACH DISPOSAL (-16.8m MLLW PROJECT DEPTH) LA-5 DISPOSAL BEACH DISPOSAL (-14.4m MLLW PROJECT DEPTH) DREDGE AREA CHANNEL DREDGE SITE NOT TO SCALE FY-1997 MCON PROJECT P-706 MILITARY CONSTRUCTION PROJECT DATA CHANNEL DREDGING AT NAS.NJ. CORONADO, CALIFORNIA 28 MAR 97 FIGURE 1.1 ,\OCEANSIDE •CARLSBAD ESCONDIDO CHANNEL DREDGING PROJECT NAVAL AIR STATION NORTH ISLAND PACIFIC OCEAN * PHASE I BEACH ** PHASE II BEACH • ENCINITAS '•• SOLANA BEACH POWAY *SOLANA BEACH **TORREY PINES SANTEE EL CAJON MEXICAN BORDER PROJECT SITE NOT TO SCALE FY-1997 MCON PROJECT P-706 MILITARY CONSTRUCTION PROJECT DATA CHANNEL DREDGING AT NAS.N.I. CORONADO, CALIFORNIA 28 MAR 97 FIGURE 1.2 SOUTHWESNAVFACENGCOM FY 97 MCON PROJECT P-706 CHANNEL DREDGING BEACH SAND TRANSPORT AND SEDIMENTATION REPORT PHASE I: SOUTH OCEANSIDE AND SOLANA BEACH TABLE 1.1 - PLANNED ON-SHORE BEACH DISPOSAL SITE QUANTITIES MEASURED IN THE DREDGE CUT (m3) SITE APPROXIMATE LOCATION QUANTITY PHASE I BEACHES South Oceanside Solana Beach 3rd Street to Loma Alta Creek Cardiff- South of San Elijo Lagoon Inlet Fletcher Cove - Cliff Street to Dahlia Street 405,218 265,585 168,217 PHASE II BEACHES Torrey Pine Encinitas North Carlsbad South Carlsbad Los Penasquitos Lagoon to Torrey Pines State Beach South of Batiquitos Lagoon to 5th Street Buena Vista Lagoon to Oak Avenue Palomar Airport Road to Ponto Drive TOTAL 496,970 871,620 420,510 420,510 3,050,630 This Preliminary Phase I Report addresses two sites: South Oceanside and Solana Beach. The Phase II Report, to be contained in a separate document, will evaluate the remaining sites and discuss relative impacts. 1.2 Scope of Work Per contract modification PZ0008 dated 15 January 1997: Revised 7 February 1997: Revised 20 February 1997, the scope of work for this study is to prepare a Beach Sand Transport and Sedimentation Report discussing beach processes and sedimentation necessary for on-shore placement of dredged material in San Diego County, CA. The report is being prepared in two phases as follows (this report covers Phase I): • Phase I: South Oceanside and Solana Beach Preliminary report required for environmental documentation to meet permit requirements; and • Phase II: North Carlsbad, South Carlsbad, Encinitas, Torrey Pines, and Del Mar (nearshore) Report which focuses on Phase II beaches and includes Phase I analysis to address cumulative effects. 28 MARCH 1997 1-4 BEACH SAND TRANSPORT & SEDIMENTATION SOUTHWESNAVFACENGCOM FY 97 MCON PROJECT P-706 CHANNEL DREDGING BEACH SAND TRANSPORT AND SEDIMENTATION REPORT PHASE I: SOUTH OCEANSIDE AND SOLANA BEACH Per the scope of work, the reports are to include the following discussions as related to the Oceanside Littoral Cell: • Coastal Geology • Wave Processes • Tides and Sea Level Change • Sand Supply (natural and artificially-induced changes in sand supply) • Littoral Transport Rate and Direction (include impacts from project) • Lagoon Mouth Dynamics (include impacts from project) • Structures and Utilities (impacts on storm drains, outfalls, and intakes) Per the scope of work, the FRH effort includes the following: • address comments received by the USACOE and others relative to the proposed on-shore beach fills; • estimate the extent of significant amounts of sediment movement at the proposed beach fills; • consider both beneficial and adverse impacts of the on-shore placement of sand. Environmental and biological impacts to marine habitats resulting from short and long-term movement of sand (as estimated in this report) are being determined by others and are not included in the scope of this study. The general approach for the work carried out under this study is as outlined in FRH's letter to SOUTHWESNAVFACENGCOM dated 27 February 1997. In accordance with the scope of work, this study has been carried out using existing information and data. The limits of the study area, as indicated in Figure 1.3, extend from Oceanside Harbor at the northern boundary to La Jolla at the southern boundary. 1.3 Purpose The purpose of this report is to provide technical input for preparation of an Environmental Assessment (EA) for the proposed on-shore beach fills being prepared by Ogden Environmental and Energy Services. The technical input focuses on estimating the short and long-term fate (physical movement) of the dredged sand being placed at the beach fill sites and determining 28 MARCH 1997 ~5 BEACH SAND TRANSPORT & SEDIMENTATION OCEANSIDE BUENA VISTA LAGOON PT. LA JOLLA LOS .'.-PENASQUITOS '{•':•'. LAGOON Beach Fill Study Area SOURCE: USACOE. 1987 FY-1997 MCON PROJECT P-706 MILITARY CONSTRUCTION PROJECT DATA CHANNEL DREDGING AT N.A.S.N.I. CORONADO, CALIFORNIA 28 MAR 97 FIGURE 1.3 SOUTHWESNAVFACENGCOM FY 97 MCON PROJECT P-706 CHANNEL DREDGING BEACH SAND TRANSPORT AND SEDIMENTATION REPORT PHASE I: SOUTH OCEANSIDE AND SOLANA BEACH associated impacts in the context of naturally occurring physical beach processes. In addition, impacts on existing structures and utilities are discussed. 1.4 Approach & Methodology The approach for this study is to perform qualitative analyses of beach fill behavior based on an understanding of environmental conditions, littoral processes and coastal wetland processes. The qualitative analyses rely on past experience gained from placement of sand on the beach in the Oceanside Littoral Cell, and are supplemented through the use of numerical models. The following study methodology is adopted: • Summarize and present the Oceanside Littoral Cell coastal and oceanographic characteristics and beach processes including: coastal geology, beach and shoreline configuration, tide and wave conditions, littoral processes and lagoon inlet characteristics, etc.; discuss seasonal and natural variations in beach processes as they relate to the proposed beach sites. • Research and document existing pre-sand placement conditions at each beach site. Make site visits and take photographs. • Research past beach fill projects and document "prototype experience" to aid in qualitatively determining the potential fate of the dredged sand at each beach fill site. • Perform limited numerical modeling of beach erosion above MSL, offshore movement of sand and along shore sediment transport to supplement the understanding developed under bullet item 3. • Based on work performed under bullet items 1 through 4, determine potential beneficial and adverse impacts resulting from placement of sand at each beach fill site. This approach and methodology is adopted recognizing that a physical monitoring program to assess the post placement movement of sand at each beach fill will be carried out along with a biological monitoring program to assess associated impacts. The physical monitoring program will consist of pre- and post-fill placement surveys which are required during construction of each beach fill as well as ongoing and proposed beach monitoring sponsored by SANDAG, the City of Carlsbad and the California Department of Boating and Waterways. Planned monitoring by SANDAG includes aerial photography, beach profile surveys and computation of changes on profile volumes and beach widths. 28 MARCH 1997 1-7 BEACH SAND TRANSPORT & SEDIMENTATION SOUTHWESNAVFACENGCOM FY 97 MCON PROJECT P-706 CHANNEL DREDGING BEACH SAND TRANSPORT AND SEDIMENTATION REPORT PHASE I: SOUTH OCEANSIDE AND SOLANA BEACH 1.5 Information and Data This report has been prepared using existing information. The predominant source of data used was derived from the extensive work carried out along the San Diego coastline as part of the USACOE Coast of California Storm and Tidal Waves Study (CCSTWS). The CCSTWS began in the early 1980's as a result of support by local agencies for a comprehensive review of the regional shoreline. The CCSTWS is a summary report of 41 technical studies performed during the period 1983-1990. These studies summarized and highlighted the results of a large number of previous efforts concerned with the region's physical and geological nearshore processes. New results included improved estimates of seasonal and extreme beach width fluctuations and local sand budgets. Other data was made available for this study by the USACOE, the Cities of Oceanside and Carlsbad, SANDAG, and others. A detailed listing of references is included in Section 8.0. 1.6 Metric Conversion TABLE 1.2 - METRIC CONVERSIONS Multiply by 0.3048006 3.281 0.7646 1.308 0.9072 0.4047 2.471 0.02832 35.3107 2.59 0.386 1.609 0.62137 feet (U.S. Survey) meters cubic yards cubic meters short tons acres hectares cubic feet cubic meters square miles (statute) square kilometers miles (statute) kilometer To Obtain meters feet cubic meters cubic yards metric tons hectares acres cubic meters cubic feet square kilometers square miles (statute) kilometer miles (statute) 28 MARCH 1997 1-8 BEACH SAND TRANSPORT & SEDIMENTATION SOUTHWESNAVFACENGCOM FY 97 MCON PROJECT P-706 CHANNEL DREDGING BEACH SAND TRANSPORT AND SEDIMENTATION REPORT PHASE I: SOUTH OCEANSIDE AND SOLANA BEACH 1.7 Abbreviations CCSTWS CDFG CERC cm cy EA GENESIS ha km LAD mb MHW MHHW MLLW m m3 MSL NASNI NGVD ppt RCP SANDAG SBEACH SDG&E SDCDPR SEC USACOE WES USACOE Coast of California Storm and Tidal Waves Study California Department of Fish and Game Coastal Engineering Research Center centimeter cubic yards Environmental Assessment Generalized Model for Simulating Shoreline Changes hectare(s) kilometer(s) Los Angeles District millibar Mean High Water Mean Higher High Water Mean Lower Low Water meter(s) cubic meters Mean Sea Level Naval Air Station North Island National Geodetic Vertical Datum parts per thousand Reinforced Concrete Pipe San Diego Association of Governments Storm Induced Beach Change San Diego Gas and Electric San Diego County Department of Parks and Recreation Shoreline Erosion Committee United States Army Corps of Engineers Waterway Experiment Station year 28 MARCH 1997 1-9 BEACH SAND TRANSPORT & SEDIMENTATION Section 2.0 Study Area Environmental Conditions SOUTHWESNAVFACENGCOM FY 97 MCON PROJECT P-706 CHANNEL DREDGING BEACH SAND TRANSPORT AND SEDIMENTATION REPORT PHASE I: SOUTH OCEANSIDE AND SOLANA BEACH 2.0 STUDY AREA ENVIRONMENTAL CONDITIONS The San Diego shoreline is an erosional coast. This is a consequence of southern California's coastal setting and the shoreline response to ocean and atmospheric forces. Most of the San Diego shoreline consists of narrow beaches backed by steep sea cliffs. The beaches and cliffs have, for thousands of years, been subject to erosion from ocean waves abetted by a rising sea level. The most important factor that determines the existing conditions on the San Diego coast is the regional geology, especially its tectonic history. The next most important factors are the relevant beach processes defined as those physical mechanisms that alter the beach width by adding or removing sand or causing cliff retreat. Wave climate, sand supply, tides, sea level changes and weather all play a role by making wave effects more or less severe and by modulating the amount of sand reaching the beaches. The following sections discuss these factors. 2.1 Coastal Geology The regional geologic setting is fundamental to understanding the study area's beach configuration and processes. San Diego and the rest of southern California, is geologically young and seismically active due to its position on the plate boundary between the North American Plate and the Pacific Plate, two of the large crustal plates that make up the moving surface of the earth (Inman and Nordstrom, 1971). The Pacific Plate is moving northward relative to the North American Plate. The San Andreas fault zone forms the boundary between them. Until about 20 million years ago, the two plates were colliding, with the oceanic plate dipping under the continent, causing tectonic uplift. Most of the plate movement occurs along the San Andreas fault, but a portion also occurs on the San Jacinto, Elsinore, Rose Canyon, Coronado Bank, San Diego Trough and San Clemente fault systems. The complicated horizontal and vertical motions of the blocks of crust surrounded by these faults, together with long-term sea level changes, define the outlines of the San Diego coast (USACOE, 1984; Greene and Kennedy, 1978). 2.2 Beaches and Shoreline Configuration The detailed local coastal topography and beach configuration is mainly determined by wave forces acting on the geologic framework. These factors account for the area's rugged undersea and land topography, including the narrow continental shelf, the rocky substrate under most beach areas, their thin veneer of sediment, as well as the coastal marine terraces, sea cliffs and lagoons. A typical San Diego shoreline segment showing the relationships of the coastal zone features is presented in Figure 2.1. 28 MARCH 1997 2-1 BEACH SAND TRANSPORT & SEDIMENTATION Coastal Zone Continental Shelf Edge Back Beach Slope (Continental) Sea Level Shorezone Shorelin Shorerise Beach Coastal Marine Terrace Cliff „'«•'•' J I 1 t 1 1 Typical Shoreline Segment Cross Section Glossary of Shoreline Terms Back Beach Bar Beach Berm Crest Benm Littoral Transport Littoral Zone Nearshore Shorebase Shoreline Shorerise Shorezone Surfzone Landward limit of beach Elevated sand at top of nearshore slope Back beach line to top of Shorerise Seaward edge of berm Shoreline to back beach Movement of sediment across or along the Shorezone, usually wave induced Active littoral transport area Shorebase to edge of beach (nearshore slope) Maximum extent of seasonal, reversible elevation changes due to littoral transport (also known as closure depth or pinchout depth) Beach waterline Seaward of the beach within the shorezone Back beach to Shorebase (extent of the littoral zone) Seaward edge of beach to berm crest FY-1997 MCON PROJECT P-706 MILITARY CONSTRUCTION PROJECT DATA CHANNEL DREDGING AT N.A.S.N.I. CORONADO, CALIFORNIA 28 MAR 97 FIGURE 2.1 SOUTHWESNAVFACENGCOM FY 97 MCON PROJECT P-706 CHANNEL DREDGING BEACH SAND TRANSPORT AND SEDIMENTATION REPORT PHASE I: SOUTH OCEANSIDE AND SOLANA BEACH 2.2.1 Beaches Beaches form on every coastline from whatever material is available. In southern California, the beaches are made of sand and rocks that originated from upland erosion. In San Diego, as in other parts of California, most beaches consist of relatively thin sand lenses of varying width and thickness lying on the shallow, wave cut bedrock platforms. Unusually large waves can strip these rocky terraces clean by moving the sand offshore or down coast. For this reason, cobble strewn beaches are common, especially in the winter, along much of the central San Diego coast from Oceanside to La Jolla. Thicker deposits of sand form beaches and barrier spits across the lagoons and river mouths such as the San Dieguito Lagoon and San Luis Rey River. Under natural conditions, most San Diego area beaches were historically fairly narrow most of the time. This is still the situation today, especially in the reach from Oceanside to La Jolla. While Oceanside City Beach, immediately down coast of the harbor is relatively wide, beach widths pinch out south of Wisconsin Street, as the wave sheltering effect of the harbor is lost. The width of the region's beaches is controlled by the amount of available sand and by barriers to sand transport. Wave action usually has enough energy to move more sand than there is available to transport. The fact that beach widths are limited by the rate of sand supply suggests that increasing the sand supply is the most obvious element of any solution to the problem of narrow beaches. Greater sand supply can be provided by cutting sand losses and by increasing sand nourishment. The fact that there are any sandy beaches at all in most parts of San Diego is because of seasonal decreases in wave energy and because the shoreline is not perfectly plane or straight. Instead, it has natural horizontal and vertical irregularities like rocky deltas and reefs, points, headlands and coves that form local barriers to littoral transport and traps sand. The importance of relatively small coastal features, such as Swami's Point in Encinitas, or Fletcher Cove in Solatia Beach, as well as large features such as Point La Jolla, is often overlooked. These natural structures trap sand and suggest human made beach stabilization structures will need to be incorporated into the long-term strategy for enhancement projects to improve the duration and cost effectiveness of beach nourishment. 2.2.2 Coastal Marine Terraces The elevated coastal marine terraces were formed by wave erosion during successive, prolonged periods of nearly constant relative sea level. The platforms were subsequently uplifted by tectonic activity, resulting in the series of raised mesas observed today in the San Diego Region. The steep sea cliffs that back most of the region's shoreline are the seaward edges of these eroding coastal marine terraces (Kuhn and Shepard, 1984). Wave cut marine terraces are also found offshore, where they were formed at what was the shoreline during lower stands of relative sea level. 28 MARCH 1997 2-3 BEACH SAND TRANSPORT & SEDIMENTATION SOUTHWESNAVFACENGCOM FY 97 MCON PROJECT P-706 CHANNEL DREDGING BEACH SAND TRANSPORT AND SEDIMENTATION REPORT PHASE I: SOUTH OCEANSIDE AND SOLANA BEACH ' The marine terraces near the shoreline include the submerged platform near low tide level being cut by wave action at the present time. This low tide terrace started forming about 6,000 years ago, during the most recent relative still-stand of sea level (Inman, 1983). It comprises the flat, rocky, shallow part of the shorerise common along much of San Diego and often visible during low tide. Most of the sandy beaches in the area form as a veneer of sand over the low tide terrace. Low energy wave action transports the sand landward over the terrace and deposits it up in a berm against the base of the sea cliff or back beach. This sand layer varies in thickness from zero to about ten meters, depending on location, season and other factors (Tekmarine, 1988). During periods of large waves, or low sand supply, the low tide terrace may become exposed. 2.2.3 Sea Cliffs The steep sea cliffs are geologically unstable because most of them are weak sedimentary structures. The cliffs are also heavily faulted and cracked. These breaks and joints are weak and easily undermined by wave erosion, forming caves and arches which periodically collapse causing the upper cliff to fail. The area's sea cliffs suffer seasonal wave attack during winter, when beach widths are usually narrowest. The north county coast from Oceanside to Del Mar provides many examples of cliffs often exposed to waves in winter. Wave forces have attacked the cliff bases for at least about 6,000 years. This is why the bottoms of most all the local sea cliffs stand nearly vertical. As soon as a cliff slumps or slides onto the narrow beach, wave action removes the debris and redistributes it along the beach. Cliff erosion is highly site specific and episodic (Kuhn andShepard, 1984). 2.2.4 Lagoons and Creeks Numerous low lying lagoons and river channels cut through the terraces of the study area as shown in Figure 1.3. During lower stands of sea level, the shoreline was farther to the west and rivers and streams quickly eroded the exposed terraces forming steep canyons. As sea level rose during the latest episode of glacial retreat starting about 18,000 years ago, sediments quickly filled the lower reaches of these channels, creating coastal river valleys and lagoons. Many channels and river mouths are not yet completely full of sediments, and these form tidal lagoons such as Batiquitos and San Elijo. 2.3 Tides and Sea Level Changes Tides and sea level changes together determine design water levels. The water level is important for coastal processes and engineering design since it determines how high and how far shoreward the effect of breaking waves can reach. If sea levels are unusually high due to a combination of circumstances, as they were in the winter of 1982-83, large waves can result in more severe beach erosion, cliff failure, coastal damage and flooding than under normal conditions. This section 28 MARCH 1997 2-4 BEACH SAND TRANSPORT & SEDIMENTATION SOUTHWESNAVFACENGCOM FY 97 MCON PROJECT P-706 CHANNEL DREDGING BEACH SAND TRANSPORT AND SEDIMENTATION REPORT PHASE I: SOUTH OCEANSIDE AND SOLANA BEACH outlines the tide and sea level fluctuations and trends in the study area. A detailed discussion and documentation of tides and sea level changes in the study area is presented in APPENDIX A. 2.3.1 Tidal Datum and Tidal Elevations Tide heights reference a common datum, usually mean lower low water (MLLW), defined as the average of the lowest water level readings of each day over a specified 19-year interval, or tidal epoch, currently set at 1960-78. Other tidal datums include mean sea level (MSL), mean higher high water (MHHW), etc. These are derived from the water level data by appropriate statistical means. Tidal datums are referenced to benchmarks and a fixed datum such as National Geodetic Vertical Datum (NGVD), also known as the Mean Sea Level Datum of 1929. In this study, all elevations for analysis of beach processes refer to MSL, which is defined for the purposes of this report as the 1929 mean sea level (NGVD) datum. Photographs in Appendix D refer to MLLW. The astronomical tide variations for the Oceanside Littoral Cell are shown in Table 2.1. TABLE 2.1 - SEA LEVEL ELEVATIONS AND TIDAL DATUMS FOR OCEANSIDE CELL TIDES Highest observed sea level (8 Aug 83) MHHW (1960-78) Mean High Water (MHW) (1960-78) MSL (1960-78) NGVD (Sea Level Datum of 1929) MLLW (1960-78) ELEVATIONS RELATIVE TO MLLW DATUM (m) +2.38 +1.64 +1.41 +0.84 +0.78 0.00 ELEVATIONS RELATIVE TO MSL (NGVD) DATUM (m) +1.60 +0.86 +0.63 +0.06 0.00 -0.78 Note: 1. Data based on tide gage at La Jolla. 2.3.2 Storm Surge Storm surge is the portion of the local, instantaneous sea level elevation that exceeds the predicted tide and which is attributable to the effects of low barometric pressure and high wind associated with storms. Sometimes the super-elevation of sea level due to waves and wave-induced surges is included in design calculations of storm surge. A 1 millibar (mb) drop in pressure causes an approximately 1 centimeter (cm) rise in water level (Pugh, 1987). Strong storms in southern California are typically associated with 10-15 mb pressure troughs, corresponding well to the observed 10 to 15 cm storm surges (USACOE, 1991). The wind usually makes a relatively minor contribution to storm surges in the San Diego region (Flick, 1986). Table 2.2 summarize extreme tides for the study area. 28 MARCH 1997 2-5 BEACH SAND TRANSPORT & SEDIMENTATION SOUTHWESNAVFACENGCOM FY 97 MCON PROJECT P-706 CHANNEL DREDGING BEACH SAND TRANSPORT AND SEDIMENTATION REPORT PHASE I: SOUTH OCEANSIDE AND SOLANA BEACH TABLE 2.2 - EXTREME TIDES FOR OCEANSIDE CELL RETURN PERIOD (Years) 5 10 25 50 100 MAXIMUM SEA LEVEL ABOVE MLLW (m) +2.23 +2.26 +2.30 +2.32 +2.36 Notes: 1. Data based on CCSTWS report. (USACOE 1991) 2. Maximum predicted tide shown at La Jolla; Other sites may vary. 2.3.3 Sea Level Rise There is much interest in the subject of sea level rise. In particular, it is important to consider the question of what future rates of rise are likely to be, and if these rates will be greater than in the past due to the greenhouse effect and global warming. Many studies of sea level rise (and fall) exist which detail the geological evidence on time scales of the glacial ages (over the past several million years) and from the less dramatic changes over the past 100 years. Regular rise and fall in global sea level of about 150 m occurs on cycles of about 100,000 years. The shorter term trends are well documented because of the fairly large number of instrumental tide gauge records available (Hicks et al, 1983; Aubrey and Emery, 1983; Barnett, 1983). Tide measurements at Scripps Pier in La Jolla are continuous from 1924. This gauge shows a mean sea level rate of increase of about 20 cm per century over its records (USACOE, 1989). This is close to the value of about 15 cm widely accepted as representative of global sea level increase over the past 100 years (Revelle, 1983). While most scientists now believe future sea level rise will accelerate, many have cautioned against undue alarm. Because of its relatively steep open coast, the San Diego region and California hi general, is much less vulnerable to sea level rise than the east or Gulf coasts of the United States. Peak high tides, storm surges and El Nino effects all can temporarily raise water levels by several centuries worth of mean sea level rise (Flick and Cayan, 1984). It is these factors that pose the greatest potential for flooding and coastal erosion when coupled with high wave events. Coastal planners and engineers would be prudent to use at least the past century's pace of sea level rise for planning over periods up to about 25 years. The Marine Board (1987) suggests a value of 40 cm per century for 25 year design. 2.4 Wave Processes 28 MARCH 1997 2-6 BEACH SAND TRANSPORT & SEDIMENTATION SOUTHWESNAVFACENGCOM FY 97 MCON PROJECT P-706 CHANNEL DREDGING BEACH SAND TRANSPORT AND SEDIMENTATION REPORT PHASE I: SOUTH OCEANSIDE AND SOLANA BEACH Waves provide nearly all of the energy input that drives shoreline processes in southern California. In particular, waves provide the energy that moves sand both along shore and across the shore. This section outlines the seasonal and extreme wave conditions affecting the study area. Detailed discussions of wave energy sources, maximum waves, and data sources are presented in APPENDIX B. 2.4.1 Sources of Wave Energy Waves impinging on the study area come from three main sources, as illustrated in Figure 2.2: • Northern Swell, including extratropical cyclones and tropical storms in the northern hemisphere. • Southern Swell, including extratropical cyclones and tropical storms in the southern hemisphere. • Shorter period sea waves from all offshore directions generated by local sea breezes, northwest winds in outer waters and pre-frontal local seas. Waves in the swell categories originate in their respective hemispheres, north and south of the equator, and arrive in southern California after traveling over impressive distances (Munk and Snodgrass, 1957). Measurements show that over 80% of the energy in the local wave climate is in the form of waves with periods of 5 seconds and longer, indicative of swell. During times of large waves, this fraction reaches 90%. This indicates that swell waves from distant sources are by far the most important influence on the local shoreline. 2.4.2 Wave Climate Seasonal Summary The wave climate can be divided into three seasons (USACOE, 1991) as follows: • Winter (October-March) is dominated by northwesterly waves generated by north Pacific extratropical storms with occasional contributions from seas associated with the passage of storm fronts. Maximum significant wave heights reach about 10 m, with periods ranging from 12 to 21 seconds. • Spring (April-June) is a transitional period from the energetic conditions of winter to the mild climate of summer. Local storm activity earlier in the period can generate 1 to 2 m high seas with periods in the range of 5 to 10 seconds (Pawka, 1976). 28 MARCH 1997 2-7 BEACH SAND TRANSPORT & SEDIMENTATION Wave Exposure for The San Dieao Region SOURCE: USACOE, 1989 FY-1997 MCON PROJECT P-706 MILITARY CONSTRUCTION PROJECT DATA CHANNEL DREDGING AT N.A.S.N.I CORONADO, CALIFORNIA 28 MAR 97 FIGURE 2.2 SOUTHWESNAVFACENGCOM FY 97 MCON PROJECT P-706 CHANNEL DREDGING BEACH SAND TRANSPORT AND SEDIMENTATION REPORT PHASE I: SOUTH OCEANSIDE AND SOLANA BEACH • Summer (July-September) is dominated by Southern Hemisphere swell (2 m maximum heights, periods 15 to 24 seconds), and north Pacific tropical storm swell (5 m maximum heights, periods 8 to 16 seconds). Relatively strong and persistent northwest winds offshore of the Channel Islands generate higher frequency waves that can be a significant portion of the energy at the coast in the summer. Wave heights can reach 6 m, with periods of 5 to 12 seconds (USACOE, 1989). 2.4.3 Island Sheltering The Southern California Bight is noted for its offshore islands, shallow banks, canyons and generally complicated bathymetry. The coastal orientation is nearly north-south (west facing) in most of the San Diego region. The coastline orientation and the islands and banks greatly influence the swell propagating toward shore by partially sheltering southern California, including the San Diego region. The islands and banks partially shelter the coastline from the deep ocean waves, leaving only a few high wave windows or sectors where high energy can attack the coastline. Refraction, diffraction, reflection and dissipation of the incident deep ocean waves by the islands and bathymetric features further complicate the wave patterns. As a result of the complicated bathymetry and the offshore islands, coastal wave energy varies drastically as a function of even relatively small changes in the incoming direction of the deep ocean waves (Pawka and Guza, 1983; O'Reilly and Guza 1993). Equally dramatic is how much the wave height from the same offshore source can change over a short distance on the beach. Numerical wave models have been developed to simulate the propagation of deep ocean swell waves through the entire region (O'Reilly and Guza, 1992). 2.4.4 Extreme Waves Characterizing and understanding extreme wave heights in the study area is important because these waves are responsible for very rapid shoreline and beach sand volume changes. Extreme storm events have caused extensive damage along the southern California coast. A series of storms during the winter of 1982-83, and the high intensity storm of January 17-18, 1988 are examples of recent storms that seriously impacted beaches and coastal structures in southern California, including the San Diego study area. The largest waves arriving in southern California are normally generated by North Pacific extratropical storms, or by Eastern North Pacific tropical cyclones (USACOE, 1991). Table 2.3 summarizes the maximum significant wave heights that can be expected as a function of their recurrence interval and location. 28 MARCH 1997 2-9 BEACH SAND TRANSPORT & SEDIMENTATION SOUTHWESNAVFACENGCOM FY 97 MCON PROJECT P-706 CHANNEL DREDGING BEACH SAND TRANSPORT AND SEDIMENTATION REPORT PHASE I: SOUTH OCEANSIDE AND SOLANA BEACH TABLE 2.3 - WAVE HEIGHT FREQUENCY AT OCEANSIDE CELL LOCATION Oceanside Del Mar Mission Bay La Jolla (Scripps Pier) WATER DEPTH (m) 9.1 10.7 10.0 7.9 SIGNIFICANT WAVE HEIGHT (m) MEAN 1.6 1.9 2.1 1.5 5 yr 2.8 4.0 4.3 2.8 10 yr 3.1 4.4 4.9 3.2 25 yr 3.6 5.0 5.7 3.7 50 yr 3.8 5.5 6.3 4.0 100 yr 4.1 5.9 6.9 4.4 Source: USACOE, 1991 28 MARCH 1997 2-10 BEACH SAND TRANSPORT & SEDIMENTATION Section 3.0 Littoral Processes and Sediment Budget SOUTHWESNAVFACENGCOM FY 97 MCON PROJECT P-706 CHANNEL DREDGING BEACH SAND TRANSPORT AND SEDIMENTATION REPORT PHASE I: SOUTH OCEANSIDE AND SOLANA BEACH 3.0 LITTORAL PROCESSES AND SEDIMENT BUDGET The San Diego region can be divided into three littoral cells, as suggested by Inman and Frautschy (1965). From north to south, these are the Oceanside cell, the Mission Bay group of sub-cells, and the Silver Strand cell as shown on Figure 3.1. The Oceanside Littoral Cell extends from Dana Point, in Orange County south to the Scripps - La Jolla Submarine Canyon system at La Jolla Shores, near the foot of Mount Soledad. The Oceanside Harbor complex is located approximately in the middle of this cell. The harbor jetties interrupt the natural flow of sand, and to a large extent divide the cell into two sub-cells north and south of Oceanside Harbor. This study focuses on the southern half of the Oceanside Littoral Cell south of Oceanside Harbor. 3.1 Littoral Transport The historical longshore transport rate and shoreline changes at the beach fill sites are well documented in the CCSTWS (USACOE, 1991). The following discussions and data are based on this report. 3.1.1 Current State of Oceanside Littoral Cell The CCSTWS reports concluded that the future condition of the beaches will be governed by cycles of accretion and erosion similar to those of the past 50 years with accelerated trends toward erosion due to the following conditions: • the reduction of river-borne sediment due to impoundment by dams • the influence of Oceanside Harbor • the increase in the rate of sea level rise In addition, the CCSTWS concluded that the most critical reach for future erosion is the 19.3 km stretch of beach immediately south of the Oceanside Harbor. In the 10 years between 1980 and 1989 (Including the 1982-83 cluster storm and the storm of 1988), the MHHW shoreline retreated at higher rates immediately south of the harbor than the shoreline farther south to Encinitas. It was concluded that provision for increased quantity of beach nourishment material is of critical importance to stabilizing these downcoast beaches. The beach fill to be placed for this project is consistent with this important conclusion reached by the USACOE through the CCSTWS. 28 MARCH 1997 3-1 BEACH SAND TRANSPORT & SEDIMENTATION «Dana Harbor \ \San Mateo San Onofre=^.Nuclear Generating ==. Station Oceanside Harbor •.Oceanside 3H CarlsbadOCEANSIDE LITTORAL CELL tLeucadia •Encinitas ^CardiffSolana Beach La Joila "r- Mission MISSION BAY LITTORAL CELL Coronado Zuniga A Pt. Jetty >\\\\ \ SILVER STRAND LITTORAL CELL Imperial Beach Pacific Ocean Cliffed Area Tijuana River Location Map of the San Diego Region Showing Boundries of the Three Major Littoral Cells SOURCE: Flick R.E., ed. 1994 FY-1997 MCON PROJECT P-706 MILITARY CONSTRUCTION PROJECT DATA CHANNEL DREDGING AT N.A.S.N.I. CORONADO, CALIFORNIA 28 MAR 97 FIGURE 3.1 SOUTHWESNAVFACENGCOM FY 97 MCON PROJECT P-706 CHANNEL DREDGING BEACH SAND TRANSPORT AND SEDIMENTATION REPORT PHASE I: SOUTH OCEANSIDE AND SOLANA BEACH 3.1.2 Shorezone The shorezone is the active cross section of the shoreline and includes the beach and the shorerise. It is the sedimentary and solid surface associated directly with the interaction of waves and wave- induced currents and the sediments derived from land. As shown in Figure 3.2, it extends from the seaward shorebase at an approximate depth of 10 m, across the shorerise, to the beach slope and up onto the berm to the back beach line. The slope of the shorerise (nearshore slope) is generally milder than the beach slope. The depth of the shorebase is also called the closure depth, or the pinchout depth and represents the maximum depth to which seasonal, reversible elevation changes associated with the shorerise occur. The depth of shorebase at the South Oceanside and Solatia Beach Fill sites are indicated in Table 3.1. TABLE 3.1 - DEPTH OF SHOREBASE LOCATION Solatia Beach Cardiff-by-the-Sea Oceanside DEPTH OF SHOREBASE, METERS BELOW MEAN SEA LEVEL 9 9 8.5 REMARKS very little sand in littoral sediment very little sand in littoral sediment lens lens Greater amount of sand in littoral sediment lens Source: "Sediment Budget Report, Oceanside Littoral Cell" Corps of Engineers Report No. CCSTWS 90-2, Nov. 92 (ref is USACOE-LAD, 1992) 3.1.3 Littoral Material Medium to fine quartz sand comprises most of the beach and shorerise sediment resource in the Oceanside Littoral Cell (USACOE, 1990). In addition, cobbles, gravel and finer sediments from rivers and eroding coastal terraces and sea cliffs are sources of sediment. Steep-faced berms consisting of cobbles and gravel are common in the Oceanside Littoral Cell. The littoral sediments, as shown in Figure 3.3 are bimodal and have a coarse fraction in the gravel size range and a finer fraction with a peak near about 0.3 mm. Sediment samples taken for the CCSTWS (USACOE, 1984), determined the grain size distribution along the shorerise and beach. 28 MARCH 1997 3-3 BEACH SAND TRANSPORT & SEDIMENTATION SHORE ZONE -r 10.0 * • 5.0 - • 0.0 o>Q • • 5.0 -• 10.0 Distance Offshore Generalized Diagram of Equilibrium Beach Profile Notes: • S1 - Beach Slope • S2 - Nearshore Slope SOURCE: USACOE. 1991 FY-1997 MCON PROJECT P-706 MILITARY CONSTRUCTION PROJECT DATA CHANNEL DREDGING AT N.A.S.N.I CORONADO, CALIFORNIA 28 MAR 97 FIGURE 3.2 Silt and Clay Below MSL - Entire Oceanside Cell Above MSL - Entire Oceanside Cell T 50 45 •40 • 35 T30 § 25 !£ O) '5-•20 5 -• 15 • 10 - 5 10 Grain Size (mm)0.1 —(-0 0.01 Mean Sediment Size Across the Shoreface of The Oceanside Littoral Cell SOURCE: USACOE. 1990 FY-1997 MCON PROJECT P-706 MILITARY CONSTRUCTION PROJECT DATA CHANNEL DREDGING AT N.A.S.N.I. CORONADO, CALIFORNIA 28 MAR 97 FIGURE 3.3 SOUTHWESNAVFACENGCOM FY 97 MCON PROJECT P-706 CHANNEL DREDGING BEACH SAND TRANSPORT AND SEDIMENTATION REPORT PHASE I: SOUTH OCEANSIDE AND SOLANA BEACH Sediments are generally coarser near +3 m MSL and become finer toward -6 m MSL. The material on the shorerise was found to be well sorted with a surplus of coarse grains and conversely along the shelf there was a surplus of fine grains. 3.1.4 Seasonal Equilibrium Profile The beach profile is continuously changing in response to water levels and wave conditions to retain an equilibrium relation with the wave energy. Material moves on and offshore and mostly remains within the shorezone. Winter waves, usually associated with high energy, remove material from the beach to a bar at the toe of the beach limit. The offshore bar material is available to be transported back to the beach during smaller summer waves. However, finer sediments are transient and are transported seaward or along shore to areas in which they can reside in equilibrium. 3.1.5 Shelf Transport Storm waves with high energy can overwhelm the seasonal equilibrium condition and cause offshore transport of the shorezone sand to distances and depths that may result in the material not being transported back to the beach by summer waves. A significant increase in slope occurs along the Oceanside Cell at depths of about -18m MSL. Once material is transported to this depth, it is lost from the Oceanside shorezone. 3.1.6 Longshore Transport Longshore transport is the movement of sand along shore within the shorerise and the surfzone. The driving force of longshore transport is oblique breaking waves creating longshore currents and bottom stress on the littoral material. There has been extensive study of the longshore sediment transport rate in the Oceanside Littoral Cell. The transport rate has either been based on analysis of offshore and/or breaking waves, or estimations of field measured shoreline accretion or erosion rates. Table 3.2 summarizes the estimated sediment transport rate by previous researchers. The results indicate a net southerly sediment transport at a rate ranging between 78,000 to 194,000 mVyr. Some of these values are the maximum potential transport rate that may occur when there is an ample supply of sand in the littoral zone. 3.2 Sediment Budget A sediment budget is a balance of sediment flux into and out of a closed cell along a stretch of shoreline, usually delineated between natural barriers or sinks. 28 MARCH 1997 3-6 BEACH SAND TRANSPORT & SEDIMENTATION SOUTHWESNAVFACENGCOM FY 97 MCON PROJECT P-706 CHANNEL DREDGING BEACH SAND TRANSPORT AND SEDIMENTATION REPORT PHASE I: SOUTH OCEANSIDE AND SOLANA BEACH TABLE 3.2 - LONGSHORE SEDIMENT TRANSPORT RATE ESTIMATES AT OCEANSIDE SOURCE a. Marine Advisers (1961) b. Hales (1978) c. Inman and Jenkins (1983) d. USACOE(1990) e. USACOE(1990) NORTHERLY rnVyr 416,700 413,600 422,800 - - SOUTHERLY mVyr 581,100 491,600 617,000 - - NET mVyr 164,400 78,000 194,200 175,800 137,600 Notes: a, b, and c are potential longshore transport estimates, d was based on fillet formation in post 1978 and e on beach erosion durin? 1942-1960. 3.2.1 Littoral Sand Sources Natural littoral sand sources include rivers, streams, lagoons and cliff erosion. Prior to the 1920's and 1930's, rivers, streams, and lagoons served as significant sources of sand for Oceanside Littoral Cell beaches. Since then, dams have significantly reduced this source. The alluvia in lagoons and river channels represent potential sediment sources that can be dredged and used for opportunistic beach fills to offset the effects of dam construction. Such a project is planned at Agua Hedionda Lagoon and one has recently been carried out at Batiquitos Lagoon. Opportunistic beach fills, beach nourishment, bypassing and longshore transport into the study area provide additional sources of littoral materials. This project represents a valuable source of sand for the littoral cell. 3.2.2 Littoral Sand Sinks Storms and cluster storms appear to carry sand away from the nearshore area and out of the shorezone. The Oceanside Littoral Cell continental shelf slope is steep, therefore the littoral material can be permanently lost from the littoral zone. Due to the offshore losses, beaches in the Oceanside Cell can be reduced to rock and cobble during a severe winter. This implies that both long period mild weather and short-period high energy storms should be considered in evaluating the stability of the beaches within the study area. 3.2.3 Sediment Budget Diagram A qualitative description of the sediment budget is presented in Figure 3.4 depicting the relative magnitude and direction of littoral flux for the Oceanside Cell. Predicted values of littoral flux vary widely between authors and for various time periods. The sediment budget diagram divides the Oceanside Littoral Cell into two sub-cells separated by the Carlsbad Submarine Canyon, although it is believed that this canyon has no significant effect on the littoral flux. 28 MARCH 1997 3-7 BEACH SAND TRANSPORT & SEDIMENTATION LAJOLLA Lost to Canyon CARLSBADCanyon Lost to Offshore A Longshore Transport SHORERISE BERM Longshore Nourishment Cliff Erosion River Sand Transport Longshore Transport Lost to Offshore Nourishment Cliff Erosion River Sand Back to Harbor Bypassing Sediment Budget at Oceanside Cell LEGEND: • Relatively Predominate in Volume Relatively Minor in Volume SOURCE: Frederic R. Harris, Inc. FY-1997 MCON PROJECT P-706 MILITARY CONSTRUCTION PROJECT DATA CHANNEL DREDGING AT N.A.S.N.I CORONADO, CALIFORNIA 28 MAR 97 FIGURE 3.4 SOUTHWESNAVFACENGCOM FY 97 MCON PROJECT P-706 CHANNEL DREDGING BEACH SAND TRANSPORT AND SEDIMENTATION REPORT PHASE I: SOUTH OCEANSIDE AND SOLANA BEACH The northern sub-cell receives beach material predominantly from bypassing and nourishment, with diminishing river effluent and cliff erosion supply. Berm and beach material gradually move offshore to the shorerise and are transported downcoast by longshore forces (USACOE 1990). The net longshore transport is in the downcoast direction, however, there is gross transport occurring both upcoast and downcoast due to changes in seasonal wave climate. The balance between upcoast and downcoast transport has been closer recently than it had been before 1978, meaning that the net downcoast transport was stronger before 1978 (USACOE 1990). A portion of sand is moved back to Oceanside Harbor by upcoast transport. In the southern sub-cell, beach material is predominantly supplied by longshore transport from the northern sub-cell with lesser supply from cliff erosion. Beach nourishment in the sub-cell has been virtually non-existent. River effluent supplies a small portion of the influx. Berm and beach sand move offshore to the shorerise and are transported along shore as described for the northern sub-cell. The sediment transported downcoast to the vicinity of the Scripps/La Jolla Submarine Canyon system is lost from the littoral sediment budget. The information in USACOE 1991 suggests the following related to the sediment budget in the study area: • Historically, net shoreline accretion was attributed to river effluent and cliff erosion. As the river sources diminished due to urban development, shoreline accretion decreased resulting in net shoreline erosion. • Oceanside Breakwater may deflect downcoast littoral drift offshore. However, the harbor sand trap and bypassing operations may supply the downcoast beaches more material than natural processes. • The net trend of cross-shore transport is offshore carried by rip currents, although summer wave conditions recover some sand to the beach. 3 Natural Sand Supply Sand supply is one of the most critical factors affecting beach width in addition to barriers to sand transport. The input of sand to a stretch of shoreline minus the loss of sand through movement offshore or into submarine canyons is the net supply, which determines whether a beach narrows or widens. Knowing where the regional sand supply sources are and how much comes from each source is important for understanding littoral processes and beach erosion problems. Fines content and compatibility with beach material are also important in determining significance of the sand supply. 28 MARCH 1997 3-9 BEACH SAND TRANSPORT & SEDIMENTATION SOUTHWESNAVFACENGCOM FY 97 MCON PROJECT P-706 CHANNEL DREDGING BEACH SAND TRANSPORT AND SEDIMENTATION REPORT PHASE I: SOUTH OCEANSIDE AND SOLANA BEACH The two natural onshore sources of beach sand in San Diego are rivers and cliffs as described below. 3.3.1 Rivers Significant delivery of coarse sediment into the littoral system only occurs during heavy floods, which are infrequent in southern California, especially with modern damming and flood control. Flood events are reported by Brownlie and Taylor (1981) in 1937, 1938, 1941, 1969 and 1983. Annualized rates of sand supply to the south half of the Oceanside Littoral Cell from tributary rivers are estimated to be between 7,500 and 40,000 m3 (Flick, 1993). It is estimated that these rates could be between 40,000 and 135,000 m3 under natural conditions without dams or flood control (Flick, 1993). The major tributary rivers to the Oceanside Cell are shown in Figure 3.5. The latest estimates of annual sand supply from these rivers is provided in Table 3.3. TABLE 3.3 - ESTIMATED COARSE SEDIMENT YIELDS (mVyr) RIVER San Luis Rey River Loma Alta Creek Buena Vista Lagoon Agua Hedionda Lagoon Encinas Creek Batiquitos Lagoon San Elijo Lagoon San Dieguito River Los Penasquitos Lagoon TOTAL SIMONS, LI (1988) 5,000 430 0 0 160 0 0 470 0 6,210 USACOE (1990) 8,400 770 0 0 0 0 0 840 0 10,010 Source: USACOE, 1991 3.3.2 Cliffs The amount of littoral material supplied by cliffs depends on geological composition of material, size of cliff, proximity of cliffs to littoral zone and susceptibility of cliff material to erosion. The Oceanside Littoral Cell has characteristics conducive to supplying cliff sediment to the littoral system. Cliffs range in height from 10 m to 35 m and are generally fronted by narrow beaches allowing wave erosion. Annualized rates of sand supply to the south half of the Oceanside Littoral Cell from cliffs are estimated to be 24,500 m3 (USACOE, 1991). The primary contributions of sand from cliff erosion come from the Torrey Pines area at the southern end of the Oceanside Littoral Cell. 28 MARCH 1997 3-10 BEACH SAND TRANSPORT & SEDIMENTATION X V \ OCEANSIDE <_ BUENA VISTA LAGOON ^ p* A rt i c*n A r> * wCARLSBAD LOS .'•P£NASQUITOS '••;-. LAGOON / //' / / } \ 1 / / ; 1 ^ LA JOLLA / / FALSE POINT .LA JOLLA i w/ V V Major Tributary Rivers and Coastal Lagoons SOURCE: USACOE, 1987 FY-1997 MCON PROJECT P-706 MILITARY CONSTRUCTION PROJECT DATA CHANNEL DREDGING AT N.A.S.N.I. CORONADO, CALIFORNIA 28 MAR 97 FIGURE 3.5 SOUTHWESNAVFACENGCOM FY 97 MCON PROJECT P-706 CHANNEL DREDGING BEACH SAND TRANSPORT AND SEDIMENTATION REPORT PHASE I: SOUTH OCEANSIDE AND SOLANA BEACH 3.4 Artificial Sand Supply While natural sand supply on the average contributes less than 100,000 m3 per year to the littoral system south of Oceanside Harbor, artificial sand supply has annualized rates of over 420,000 m3 from Oceanside Harbor, Agua Hedionda and river dredging. This does not include the 1.75 million m3 of sand put on the beach in 1995 and 1996 from the Batiquitos Lagoon Enhancement Project. Over the past 42 years, artificially induced sand supply has delivered over 26,000,000 m3 to the sediment budget. While much of the Oceanside Harbor and Agua Hedionda contributions are actually bypassing or backpassing, in the context of this report the quantities are considered beach sand supply. The primary intent is to identify historic beach fills for comparative analyses with the beach fills proposed for this project. Artificial sand supply events for each city are described below. 3.4.1 City of Oceanside Historic beach fills resulting from various dredge events in the vicinity of the City of Oceanside are presented in Table 3.4 and Figure 3.6. The cumulative historic beach fill at Oceanside is shown in Figure 3.7. The data includes harbor construction, harbor bypass and river dredging. The decade averages at the bottom of Table 3.4 exclude non-bypass events in order to give an indication of along shore transport. The bottom line "long-term average" includes all events. Ongoing and upcoming beach fill projects in 1997 include the following: • Sand for Trash Project - + 800 m3 to south of Oceanside Blvd • Oceanside Maintenance - 172,000 m3 to south of harbor 3.4.2 City of Solana Beach Beach fill projects at City of Solana Beach include 4,600 m3 from the San Elijo Lagoon mouth to north of the Lagoon in 1996. Upcoming projects in 1997-1998 include the following: • 4,600 m3 from San Elijo Lagoon mouth to north of the lagoon • 33,000 m3 from NCTD Loma Santa Fe grade separation project to Fletcher Cove 28 MARCH 1997 3-12 BEACH SAND TRANSPORT & SEDIMENTATION SOUTHWESNAVFACENGCOM FY 97 MCON PROJECT P-706 CHANNEL DREDGING BEACH SAND TRANSPORT AND SEDIMENTATION REPORT PHASE I: SOUTH OCEANSIDE AND SOLANA BEACH TABLE 3.4 - CITY OF OCEANSIDE OPPORTUNISTIC BEACH FILL YEAR 1942 1945 1955 1960 1961 1963 1965 1966 1967 1968 1969 1971 1973 1974 (Oct74-Jan75) 1976 1977 (Dec77-Feb78) 1981 1981 1982 1983 (Oct83-Jan84) 1986 1988 (Apr-May) 1990 (Mar-Aug) 1992 1992 (Jan-Mar) 1993 (Nov-Dec) 1994(Aug) 1994 (Dec) 1996 (Jan) 1997 (Jan) SOURCE Del Mar Boat Basin (1, 500,000 cy) Entrance Channel (220,000 cy) Harbor Construction Entrance Channel Channel Harbor Entrance Channel Entrance Channel Entrance Channel Entrance Channel Entrance Channel Entrance Channel Santa Margarita River Dredging Entrance Channel Entrance Channel Entrance Channel Entrance Channel Offshore Borrow Site San Luis Rey River Dredging Entrance Channel Entrance Channel Entrance Channel Entrance Channel Bypass System Entrance channels Modified Entrance Santa Margarita River Dredging Entrance channels Entrance channels Entrance channels DISPOSAL SITE Increase grade aroundBoatBasin Upland Oceanside Beach Oceanside Beach Oceanside Beach Oceanside Beach Oceanside Beach 3rd St.- Wisconsin St. 3rd St.-Tyson St. River- Wisconsin St. River-3rd St. 3rd St.-Wisconsin St. Tyson- Wisconsin St. Tyson- Whitterby St. Tyson- Whitterby St. Tyson- Whitterby St. 6th St.-Buccaneer St. Oceanside Beach Oceanside Beach Tyson Street Tyson Street Tyson Street Tyson Street Tyson Street Tyson Street Tyson Street Wisconsin St. (WI) Near-shore WI Street Near-shore WI Street Near-shore WI Street Total 1960's 1970's 1980's 1990's Annual Average. Less 1963 harbor construction. Annual Average. Less 1973 river dredge event. Annual Average. Less 1982 river dredge event. Annual Average. Long-term Annual Average- All Events 1955 to 1997 all events. BEACH FILLQUANTITY (cy) 0 0 800,000 41,000 481,000 3,800,000 111,000 684,000 178,000 434,000 353,000 552,000 434,000 560,000 550,000 318,000 403,000 460,000 923,000 475,000 450,000 220,000 250,000 106,700 187,000 483,000 40,000 161,000 162,000 N/A 13,616,700 228,200 198,000 154,800 173,713 316,667 (m3) 0 0 612,000 31,000 368,000 2,905,000 85,000 523,000 136,000 332,000 270,000 422,000 332,000 428,000 420,000 243,000 308,000 352,000 706,000 363,000 344,000 168,000 191,000 82,000 143,000 369,000 31,000 123,000 124,000 N/A 10,410,000 174,000 151,000 118,000 133,000 242,000 Source: USACOE (1991), USACOE (Records), City of Oceanside (Records) FIGURE 3.6 - HISTORIC ARTIFICIAL SAND SUPPLY - OCEANSIDE 28 MARCH 1997 3-13 BEACH SAND TRANSPORT & SEDIMENTATION HISTORICAL ARTIFICIAL SAND SUPPLY - OCEANSIDE 3000000 2500000 2000000 co"E. >. § 1500000gra3o 1000000 500000 0 i !• Beach Fill Event i1 ! 1 ] i i 1 '- ,11 1 ll 1 1 1 1 . 1 ll . „ CMlOOO^'^h-OCOCDCDCNlOOOT— ^f^-OCOCO^1" ^" ^f lO lO IO CO CO CO <p ^^ ^^ ^^ cO OO OO O3 O5 O5O5 ^ft ^ft Oi OJ Oj O) CD Oi O} O) CO O5 O) O5 O5 O) O3 O) SOURCE: USACOE (1991). USACOE (Records). City of Oceanside (Records) FY-1997 MCON PROJECT P-706 MILITARY CONSTRUCTION PROJECT DATA CHANNEL DREDGING AT N.A.S.N.I. CORONADO, CALIFORNIA 28 MAR 97 FIGURE 3.6 CUMULATIVE ARTIFICIAL SAND SUPPLY - OCEANSIDE 120 ~- 100 - oo ^ EJ3 "55 oa10a 1942 1955 1961 1965 1967 1969 1973 1976 Year 1981 1982 1986 1990 1993 1996 SOURCE: USACOE (1991). USACOE (Records), City of Oceanside (Records) FY-1997 MCON PROJECT P-706 MILITARY CONSTRUCTION PROJECT DATA CHANNEL DREDGING AT N.A.S.N.I. CORONADO, CALIFORNIA 28 MAR 97 FIGURE 3.7 Section 4.0 Coastal Wetland Areas SOUTHWESNAVFACENGCOM FY 97 MCON PROJECT P-706 CHANNEL DREDGING BEACH SAND TRANSPORT AND SEDIMENTATION REPORT PHASE I: SOUTH OCEANSIDE AND SOLANA BEACH 4.0 COASTAL WETLAND AREAS This section discusses the existing conditions at the coastal wetlands within the study area to allow for an evaluation of potential impacts resulting from the beach fill project. Emphasis is placed on the coastal lagoons and the habitats they support. Impacts, as discussed in Section 6.0, focus on the increased probability of lagoon inlet closure. There are nine coastal wetland areas within the study area as identified in Figure 4.1. The areas are indicated in Table 4.1, listed from north to south and according to which project phase may influence them. TABLE 4.1 - COASTAL WETLANDS LOCATED WITHIN THE PROJECT AREA COASTAL WETLAND San Luis Rey River Loma Alta Creek Buena Vista Lagoon Agua Hedionda Lagoon Encinas Creek Batiquitos Lagoon San Elijo Lagoon San Dieguito Lagoon Los Penasquitos Lagoon COULD BE DIRECTLY INFLUENCED BY PHASE: I/ II I/ II I/ II I/ II II II I/ II I/ II II 4.1 Importance of Coastal Lagoons Coastal lagoons provide a number of environmental functions that are of ecological importance or have direct value to humans. They are also ecologically important at both the local and regional levels. Some of the more familiar ecological functions and values to humans are summarized in Table 4.2. Most lagoons are comprised of a number of habitats, which might include saltmarsh, mudflats, aquatic channels, channel beds, salt pannes, freshwater marsh, or brackish water marsh, and adjacent upland habitats (i.e., coastal strand, coastal sage scrub, mixed chaparral, riparian, etc.). Lagoons provide a mechanism for conveyance and dissipation of flood water, reducing erosion by slowing of runoff velocities, deposition of flood suspended sediments, shoreline stabilization, recharge of groundwater, and storage of surface water. Lagoons can serve to filter suspended 28 MARCH 1997 4-1 BEACH SAND TRANSPORT & SEDIMENTATION South Oceanside Beach Fill North Carlsbad Beach Fill South Carlsbad — * Beach Fill Encinitas Beach Fill NORTH «_ BUENA VISTA LAGOON ^ 'CARLSBAD - ° PT. LA JOLLA LA JOLLA Cardiff at Solana Beach Fill Fletcher at Solana Beach Fill Torrey Pines- Beach Fill Coastal Wetland Areas SOURCE: USACOE. 1987 FY-1997 MCON PROJECT P-706 MILITARY CONSTRUCTION PROJECT DATA CHANNEL DREDGING AT N.A.S.N.I. CORONADO, CALIFORNIA 28 MAR 97 FIGURE 4.1 SOUTHWESNAVFACENGCOM FY 97 MCON PROJECT P-706 CHANNEL DREDGING BEACH SAND TRANSPORT AND SEDIMENTATION REPORT PHASE I: SOUTH OCEANSIDE AND SOLANA BEACH TABLE 4.2 - KEY FUNCTIONS AND VALUES OF CALIFORNIA'S COASTAL WETLANDS FUNCTION VALUE COMMERCIAL FACTORS Support of commercial fisheries Provision of commercially harvested organisms Water supply and storage Coastal wetlands are important spawning and nursery areas and provide sources of nutrients for commercial fish such as flounder, perch, and English sole, and shellfish such as clams and shrimp. Because of their high natural productivity, both tidal and inland wetlands have food production potential for aquaculture enterprises. Wetlands are potential sites for groundwater recharge and surface water storage. DAMAGE PREVENTION FACTORS Pollution assimilation/water purification Flood control Erosion control Wetlands contribute to improving water quality by removing excess nutrients and excess chemical contaminants; some wetlands are used in the advanced treatment of wastewater. Riverine wetlands and adjacent floodplain lands often form natural floodways that convey floodwaters from upstream to downstream areas; wetlands can also store water during floods and slow the movement to downstream areas, thereby attenuating peak floods. Wetlands attenuate flood flows and the velocity of floodwaters, reducing erosion and promoting the release of water-borne sediment. ECOLOGICAL FACTORS Provision of critical habitat for threatened and endangered species Provision of habitat for native wildlife Provision of resting and feeding habitat for migratory waterfowl Food chain support to resident and nonresident species In California, numerous threatened or endangered species such as the Santa Cruz long-toed salamander, the clapper rail, the salt marsh harvest mouse, and the soft-haired bird's beak, all rely on wetlands for their existence. Wetlands provide essential breeding, feeding, and refuge habitats for many native animals (e.g., great blue heron, garter snake, and tiger salamander) and plants (e.g., cordgrass, salt grass, and pickleweed), which directly contributes to the maintenance of biodiversity. California's wetlands provide essential nesting, feeding, and refuge habitats for migratory birds along the Pacific flyway, which directly contributes to the maintenance of biodiversity. Wetlands have the ability to support nutrient transformations (both microbial and chemical processes); wetlands act as sources and sinks of nutrients and food and provide a medium for the transfer of these materials. OTHER FACTORS Consumptive recreation Nonconsumptive recreation Source of open space and contribution to aesthetic values Education and research Wetlands serve as recreation sites for fishing and hunting. Wetlands serve as recreation sites for hiking, boating, and bird watching. Wetlands are areas of great diversity and beauty, and provide open space for human enjoyment. Wetlands provide educational opportunities for nature observation and scientific study. Sources: California Coastal Commission, 1995 28 MARCH 1997 4-3 BEACH SAND TRANSPORT & SEDIMENTATION SOUTH WESNAVFACENGCOM FY 97 MCON PROJECT P-706 CHANNEL DREDGING BEACH SAND TRANSPORT AND SEDIMENTATION REPORT PHASE I: SOUTH OCEANSIDE AND SOLANA BEACH sediments, remove organic and inorganic nutrients, remove toxic substances, facilitate nutrient cycling, denitrification, and mineralization (NRC 1992, Mitsch and Gosselink 1993). Lagoons are one of the most important coastal ecosystems, because they exhibit very high primary and secondary biological productivity. They are both sources and sinks for nutrients and organic particulates. This productivity supports very diverse aquatic invertebrate, fish, and benthic communities and serves as important nursery habitat for a number of marine fish species. In addition, lagoons support diverse populations of resident and migratory bird species, and provide critical habitat for many threatened or endangered plant and avian species. 4.1.1 Regional Significance The lagoons in the study area are of regional importance because they each contain a different mix of habitats as indicated in Table 4.3. For example, Coastal Sage Scrub and Chaparral are unique to Batiquitos and Agua Hedionda Lagoons while Seasonal Salt Marsh is unique to San Dieguito Lagoon. They also differentially support marine fish species, and they support threatened or endangered species to various degrees of success. 4.2 Lagoon Inlet Stability Coastal lagoons will stay open to the ocean if the tidal prism is large enough to facilitate scouring of flood tide deposited sediments from the channel bed during ebb flows. Most of San Diego's lagoons have relatively small tidal prisms and flows and are constricted by bridges and other human-made features. They are dominated by flooding tides and a tendency to accumulate littoral sands which causes them to become unstable and close. Sometimes, the lagoons open occasionally in the winter when heavy rains and large tides coincide to open a channel through the more narrow and steep winter beach profile. The new inlet, however, will usually close in less than a month. Openings rarely occur in the summer when the beaches are wider and flatter (County of San Diego, 1970). The general status of the ocean inlet at each the lagoon/river is summarized in Table 4.4. 4.2~.l Ecological Factors Three ecological forcing functions control environmental conditions in San Diego's coastal lagoons: tidal flushing, seasonal fluvial runoff, and sedimentation of organics and fine sediments. When tidal flushing ceases, seasonal stormwater runoff accumulates, fresh/brackish eutrophic water conditions prevail, and plant biomass and sediments accumulate within the lagoon. The lagoon inlet may open briefly or may remain closed if the rainfall runoff is low. High evaporation during summer may cause large changes in lagoon water salinity (e.g., 2 to 50 ppt). After many years of these perturbations, the marine communities degenerate and fresh/brackish water plant communities colonize and expand. Alternatively, high runoff will breach the beach berm barrier, scour out the channel bed, and enable tidal flushing to continue for many months until inlet depositional processes close the lagoon mouth once again. When tidal flushing is sustained, primary and secondary lagoon productivity becomes more connected to the nearshore ocean environment. 28 MARCH 1997 4-4 BEACH SAND TRANSPORT & SEDIMENTATION SOUTHWESNAVFACENGCOM Frederic R. Harris, Inc. FY 97 MCON PROJECT P-706 CHANNEL DREDGING BEACH SAND TRANSPORT AND SEDIMENTATION REPORT PHASE I: SOUTH OCEANSIDE AND SOLANA BEACH TABLE 4.3 - DISTRIBUTION OF HABITAT TYPES IN LAGOONS WITHIN THE STUDY AREA Attributes Vfarine open water Estuarine open water Palustrine open water Dune Coastal scrub and chaparral Southern coastal salt marsh Seasonal salt marsh Coastal brackish/freshwatermarsh Riparian Beach Tidal estuarine flats Nontidal estuarine flats Palustrine/riverine flats Nonvegetated flats Ruderal Agricultural Nonvegetated disturbed Urban Total hectares Rank by size Buena Vista Lagoon 39 (hectares) 39 (%) 2121 6 5 1515 4 4 11 66 6 6 8 3 100 6 Agua Hedionda Lagoon 102 65 9 5 6 4 13 4 3 12 7 7 4 11 13 8 32 158 5 Batiquitos Lagoon 141 62 6 3 40 8 31 1 0 31 14 31 226 2 San Elijo Lagoon 24 10 32 13 8636 11 5 42 18 2 1 2 1 6 3 199 21 237 1 San Dieguito Lagoon 32 15 2512 2311 42 1 1 2 1 10 5 2 1 84 80 38 0 0 210 4 Los Penasquitos Lagoon 12 6 11051 6 3 43 20 2 1 2 1 84 3416 217 3 Note: Top numbers are hectares (ha below the 3 m contour) and numbers in bottom are percentage of habitat within that location. Source: Modified from Baczkowski, S. 1993 18 MARCH 1997 4-5 BEACH SAND TRANSPORT & SEDIMENTATION SOUTH WESNAVFACENGCOM Frederic R. Harris, Inc. FY 97 MCON PROJECT P-706 CHANNEL DREDGING BEACH SAND TRANSPORT AND SEDIMENTATION REPORT PHASE I: SOUTH OCEANSIDE AND SOLANA BEACH TABLE 4.4 - INLET STATUS OF COASTAL WETLANDS WITHIN THE STUDY AREA Attributes Open to ocean Closed to tidal influx Seasonally breached by flood waters or storm tides Infrequently breached Fed by fresh water creek/river Freshwater influence/type of influence: Salt Fresh Brackish San Luis Rey River + + + Loma Alta Creek + + + + Buena Vista Lagoon + + + + Agua Hedionda Lagoon + + + + Batiquitos Lagoon + + + + San Elijo Lagoon +/- +/- + + ; San Dieguito Lagoon +/- - + - Los Penasquitos Lagoon + + + ^ Note: Source "+" indicate yes "+/-" indicate marginal : Modified from County of San Diego, 1971 18 MARCH 1997 4-6 BEACH SAND TRANSPORT & SEDIMENTATION SOUTHWESNAVFACENGCOM FY 97 MCON PROJECT P-706 CHANNEL DREDGING BEACH SAND TRANSPORT AND SEDIMENTATION REPORT PHASE I: SOUTH OCEANSIDE AND SOLANA BEACH Overall the lagoon communities benefit from conversion of a lagoon dominated by a salinity regime of generally less than 15 ppt to a salinity regime of about 20 - 30 ppt. With continuous tidal flushing, the accumulated organic and fine sediment burden and associated eutrophic conditions will be reduced; the benthos, fisheries, saltmarsh will increase; species abundances and diversity, and the trophic complexity will increase; human health conditions will improve; and the potential impacts from any future spills of contaminants will be reduced. 4.2.2 Closure Processes Inlet closure is a complex process that is poorly understood, because it involves numerous variables that may interact to different degrees depending on the time duration of events. These variables include the following: • wave height and intensity • beach width and season (accretion vs erosion) • lagoon hydrology • inlet configuration • channel morphology • sediment characteristics • presence of cobbles • adjacent shore morphology Beach width is of particular importance because of its effect on the length of the inlet and volume of beach sediment available for resuspension and transport into the inlet and lagoon channels during flood tides. Consequently, changes in beach width may have an important influence on inlet dynamics. For example, a long inlet channel that crosses a broad sand beach during summer may be more sensitive to closure processes than a channel that crosses a narrow sand beach during winter. If beach cobbles are present, waves may cause the cobbles to migrate into the inlet, restrict tidal exchange, and reduce ebb flow scouring of the channel sand bed. The duration of inlet closure events may vary. Short term closures result from periods of high ocean wave activity that cause substantial sediment resuspension, transport, and deposition. A new beach berm barrier can be established across a lagoon inlet very rapidly; within hours to days. Since, however, minimal sediment is deposited within the adjacent lagoon channel, the inlet may reopen under the right conditions. 28 MARCH 1997 4-7 BEACH SAND TRANSPORT & SEDIMENTATION SOUTHWESNAVFACENGCOM FY 97 MCON PROJECT P-706 CHANNEL DREDGING BEACH SAND TRANSPORT AND SEDIMENTATION REPORT PHASE I: SOUTH OCEANSIDE AND SOLANA BEACH In December of 1994 and 1995, large storms caused inlet closure at San Elijo, San Dieguito and Los Penasquitos Lagoons. The 1994 closure lasted approximately 2 weeks after which the lagoon mouth reopened naturally. In 1995, the closures lasted until March 1996 when the lagoons were reopened from flood waters (Coastal Environments, 1995). Long-term closure events (i.e., months to years), that emerge from cumulative deposition of sediment in the inlet as well as the adjacent lagoon channel, are more difficult to reverse, because they typically require major stormwater runoff to blow out the beach berm and to scour the channel bed. As the long-term closure process matures, there may be brief episodes of limited tidal exchange, e.g., during spring tides. If tidal flushing is not restored, the eutrophic fresh/brackish water conditions will persist, evaporation during summer will cause large changes in salinity, plant biomass and sediments will accumulate within the lagoon. If low runoff conditions persist, and periods of tidal flushing become intermittent and finally cease, the marine communities in the lagoon degenerate and fresh/brackish water plant communities colonize the lagoon and expand. 4.2.3 Opening Processes When tidal flushing has ceased, seasonal stormwater runoff may accumulate and increase the lagoon water level and pressure head. Fresh/brackish water conditions may prevail for many months or blow out the barrier beach berm, scour the channel bed, and restart tidal flushing. The extent to which the channel is scoured is a significant factor in the duration of tidal flushing. The tidal flushing may continue briefly or continue for many months until depositional processes close the lagoon inlet once again. In recent years several of the lagoons, i.e., Los Penasquitos Lagoon and San Elijo Lagoon, have been successfully opened by excavation or dredging to facilitate tidal flushing. 4.3 Lagoon Inlets and Creek Mouths Coastal lagoons form one of the major features of the California coastline. Those in San Diego County are especially valuable due to their relatively undisturbed state. During most of their latter 6,000 year history, the lagoons have been open to the sea, as evidenced by examination of old Indian sites. With some exception, they have been closed to flushing by ocean waters only since the emplacement of human-made constrictions, particularly the railroad and highway embankments which are still present at most lagoon mouths. The status of the ocean inlet and fluvial input is qualitatively summarized in Table 4.5. Below is a brief discussion of each coastal lagoon and creek. 28 MARCH 1997 4-8 BEACH SAND TRANSPORT & SEDIMENTATION FY 97 MCON PROJECT P-706 CHANNEL DREDGING BEACH SAND TRANSPORT AND SEDIMENTATION REPORT PHASE I: SOUTH OCEANSIDE AND SOLANA BEACH TABLE 4.5 - ATTRIBUTES OF THE COASTAL WETLANDS WITHIN THE STUDY AREA Attributes Total wetland area (ha) Inlet open/closed Jetty Tidal prism (m3) Salinity regime (ppt) Sewage spills Historical wastevvater discharges Adjacent beach width Adjacent cobbles Watershed (km2) Number of species: Aquatic Invertebrates Special interest resources: Eel grass habitat Cordgrass Pacific Flyway Belding's Savannah Sparrow Light-footed Clapper Rail California Least Tern Brown Pelican Tidewater Goby Nursery area (flatfish) San Luis Rey River 120 Variable Sand Barrier Yes 0 0-2 No Yes 45 No 1445 U U U N, F F Loma Alta Creek 3 Open Winter/ Closed Summer No 0 0-2 No No 50 No 52 U U U Buena Vista Lagoon 100 Closed Beach Barrier No 0 2-5 Yes Yes 45 No 60 U 200 N, F N, F N, F Agua Hedionda Lagoon 158 Open Yes 850,000 32-35 No No 60 Yes 75 150 42 102 Yes N, F Yes Encinas Creek Lagoon 1 Closed No 0 0-2 No No 100 No - U U U Batiquitos Lagoon * 226 Open (as of 9 Jan 97) Yes 8,500 32-35 Yes Yes 110 Yes 137 >37 14 164 Yes N, F N, F San Elijo Lagoon 237 Open No 28,000 2-15 Yes Yes 50 Yes 200 83 10 298 Yes N, F F N, F F San Dieguito Lagoon 210 Variable Sandy Beach Barrier No 5,600 3-55 Yes Yes 100 No 898 99 38 143 N, F N, F Yes Los Peflasquitos Lagoon 217 Variable Periodic Sand Bar No 20,000 15-30 Yes Yes 80 Yes 254 34 13 68 N,F F Yes N = Nest, F=Forge, U=Unknown, *=Predredge data 28 MARCH 1997 4-9 BEACH SAND TRANSPORT & SEDIMENTATION SOUTHWESNAVFACENGCOM FY 97 MCON PROJECT P-706 CHANNEL DREDGING BEACH SAND TRANSPORT AND SEDIMENTATION REPORT PHASE I: SOUTH OCEANSIDE AND SOLANA BEACH 4.3.1 San Luis Key River The San Luis Rey River has a watershed area of 1445 km2, 900 km2 of which are located below the Lake Henshaw Dam; built in 1922. The ocean inlet as shown in Figure 4.2 is open intermittently due to the presence of a sand barrier and low fluvial flows. The wetland adjacent to the ocean inlet has an area of approximately 120 ha, of which 21 ha are open estuarine lagoon water. This wetland is primarily a fresh/brackish water habitat. The dominant habitat is riparian (52 ha). Endangered species that feed and roost in this area include California least tern and Brown pelicans. Least Bell's vireo occur in the adjacent riparian habitat. The San Luis Rey River has received historical discharges of treated wastewater. The mouth of the river was dredged in 1964 to create Oceanside Harbor. It has been estimated that construction of the dam has reduced the average sediment yield of the river by 32%. 4.3.2 Loma Alta Creek Loma Alta Creek is an industrialized, seasonal freshwater creek that discharges to the ocean between the San Luis Rey River and Buena Vista Lagoon. The creek outlet is located at the south end of the proposed South Oceanside Beach Fill as shown in Figure 4.3. The creek flows under Pacific Street through a cement culvert that is 8.5 m wide. The discharge crosses Buccaneer Beach, a small pocket sand beach that is defined by rock riprap on both sides and by Pacific Street. There is no lagoon associated with this creek. East of the culvert, the creek is defined by a very small freshwater marsh to the north and by Buccaneer State Park to the south. There is no evidence of saltmarsh east of Pacific Street and high tides probably do not pass through the culvert. The beach in front of the creek outlet is steep. Upstream, the creek supports 3 ha of freshwater wetlands. During the dry season, when the creek is not running, the creek outlet to the ocean is closed by a sand berm. 4.3.3 Buena Vista Lagoon Buena Vista Lagoon is located south of the proposed South Oceanside Beach Fill site and is shown in Figure 4.4. Buena Vista Lagoon is the smallest of the lagoons in the proposed project area. Historically, this lagoon had 152 ha of low marsh and 117 ha of high marsh habitat. Today it has a fresh/brackish water wetland area of 100 ha, 6 ha of which is remnant southern coastal saltmarsh as indicated in Table 4.3. This lagoon continues to experience sewage spills, and it has historically received a discharge of secondary treated wastewater. The accumulated sludge, plant detritus, excess nutrients, and contained basin combine to cause serious eutrophic conditions. Nonetheless, this lagoon supports foraging and nesting of endangered Light-footed clapper rails, California Least terns, and occasionally Belding's savannah sparrows, as well as foraging by Brown Pelicans. Buena Vista Lagoon is a State Ecological Reserve managed by the California Department of Fish and Game. 28 MARCH 1997 4-10 BEACH SAND TRANSPORT & SEDIMENTATION I I I I I I I I I San Luis Rey River Mouth Aenal Photograph taken 1 March 1996 Approximate Tide Elevation = - 0 6 m MSL ' , *J5tooS>*P ," **1*"' FY-1997 MCON PROJECT P-706 MILITARY CONSTRUCTION PROJECT DATA CHANNEL DREDGING AT NAS.N. CORONADO, CALIFORNIA 28 MAR 97 FIGURE 4.2 Loma Alta Creek Aenal Photograpti taken 1 March 1996. Approximate Tide Etevabon = - 0.6 m MSL I I I I I I I I I I I I I I I I I I FY-1997 MCON PROJECT P-706 MILITARY CONSTRUCTION PROJECT DATA CHANNEL DREDGING AT NAS.N.I. CORONADO, CALIFORNIA 28 MAR 97 FIGURE 4.3 I I I I I I Buena Vista Lagoon Inlet BEST ORIGINAL Aenal Photograpn taken 1 March 1996 Approximate Tide Elevation = - 0.6 m MSL FY-1997 MCON PROJECT P-706 MILITARY CONSTRUCTION PROJECT DATA CHANNEL DREDGING AT N.A.S.N.I CORONADO, CALIFORNIA 28 MAR 97 FIGURE 4.4 SOUTHWESNAVFACENGCOM FY 97 MCON PROJECT P-706 CHANNEL DREDGING BEACH SAND TRANSPORT AND SEDIMENTATION REPORT PHASE I: SOUTH OCEANSIDE AND SOLANA BEACH Buena Vista Lagoon is currently a fresh/brackish water lake that is no longer connected to the ocean. A fixed weir was constructed in 1940 in order to provide a year round aquatic environment in the lagoon, thereby ending the problem of drying out of the lagoon bed during summer. Excess seasonal freshwater runoff flows over the weir, across the beach, and discharges to the ocean. The weir is 12.2 m wide and has an elevation of+1.9 m MSL. The weir is located in the back end of a small pocket beach that has been armored on the margins with rock riprap and filled terrain. The weir is 44 m behind the crest of a longshore cobble berm. There is no evidence of saltmarsh east of the weir and high tides do not ordinarily wash over the weir. However, the presence of a small patch of beach cobbles on the lagoon side of the weir suggests that during the winter, when the beach is narrow, high waves occasionally overtop the weir. •The Buena Vista Lagoon Joint Powers Committee recently drafted (December, 1996) a strategic plan to improve the environmental conditions within the lagoon. The Committee proposes to dredge the organic burden from the bed of the lagoon and to modify the weir so that it is lengthened to 24 m and its elevation is adjustable. This would reduce the freshwater discharge flow rate across the beach by 50%, but provide greater ability to manage major floods. Several designs of an adjustable weir are being considered. One design would also enable some tidal infusion into the lagoon to create local brackish water conditions, and dry out areas that promote production of mosquitos. An alternative design would facilitate some ebb flow scouring of the adjacent lagoon channel bed, but would not permit any inflow of seawater into the lagoon. 4.3.4 Agua Hedionda Lagoon The ocean inlet to Agua Hedionda Lagoon is located south of the proposed North Carlsbad Beach Fill site and north of the South Carlsbad Beach Fill site. Agua Hedionda Lagoon is of particular interest because it has been tidal flushed since 1954 after completion of an extensive 3 million m3 dredging project to provide a deep water basin and cooling water source for SDG&E's Encina Power Plant. Two pairs of jetties were constructed to maintain tidal flow and power plant circulation; one pair armors the ocean inlet to the lagoon as shown in Figure 4.5, and a second pair armors the warm water discharge flow from the power plant as shown in Figure 4.6. Agua Hedionda has a wetland area of 158 ha and a relatively small 75 ha watershed. It has not been a site for discharge of sewage wastewater but has been subject to marine sedimentation in the West and Central Basins, and fluvial sedimentation in the East and Central Basins. The West Basin is dredged approximately every 2 years in order to sustain tidal flushing so that access to a source of cooling water is assured for operation of the power plant. Dredged sediments are typically discharged in front of the power plant between the ocean inlet and warm water discharge canal as well as south of the discharge canal. The routine dredging discharges have tended to keep a local beach cobble deposit buried, except during winter when the beach is eroded. In contrast to the other lagoons, Agua Hedionda Lagoon is a deep lagoon with limited shallow water areas or intertidal habitats, but a large tidal prism of about 0.85 million mj. Consequently it is a unique wetland because it supports eelgrass habitat in the West Basin. The West Basin also supports a commercial bivalve aquaculture farm and a marine fish hatchery. Agua Hedionda Lagoon supports endangered Belding's savannah sparrows and California least terns, and it is a nursery area for marine flatfish. 28 MARCH 1997 4-14 BEACH SAND TRANSPORT & SEDIMENTATION I I I I I I I I I I I I I I I Agua Hedionda Lagoon Inlet Aerial Photograph taken 1 March 1996 Approximate Tide Elevation = -06m MSL Jf.f,- FY-1997 MCON PROJECT P-706 MILITARY CONSTRUCTION PROJECT DATA CHANNEL DREDGING AT N.A.S.N.I CORONADO, CALIFORNIA 28 MAR 97 FIGURE 4.5 Aqua Hedionda Lagoon. Warm Water Discharge BEST ORIGINAL Aenal Photograpfi laken 1 March 1996 AppnUKimate Tide Elevation = - 0-6 m MSL FY-1997 MCON PROJECT P-706 MILITARY CONSTRUCTION PROJECT DATA CHANNEL DREDGING AT N.A.S.N.I. CORONADO, CALIFORNIA 28 MAR 97 FIGURE 4.6 I I I I I I I I I I I SOUTHWESNAVFACENGCOM FY 97 MCON PROJECT P-706 CHANNEL DREDGING BEACH SAND TRANSPORT AND SEDIMENTATION REPORT PHASE I: SOUTH OCEANSIDE AND SOLANA BEACH SDG&E plans to dredge 153,000 m3 from the West Basin in September 1997, and 58,900 m3 of sediment from the Central Basin in December 1997. SDG&E dredged 382,300 m3 of sediment from the West Basin in 1996. The Army Corps of Engineers is currently installing a new seawall in front of the Encina Power Plant between the ocean inlet and discharge canal. A similar seawall was previously constructed north of the ocean inlet. 4.3.5 Batiquitos Lagoon The new ocean inlet to Batiquitos Lagoon, as shown in Figure 4.7 is south of the proposed South Carlsbad Beach Fill and north of the Encinitas Beach Fill. The ocean inlet is armored with two jetties which are expected to enable sustained tidal flushing of the lagoon. However, due to the relatively small tidal prism of the lagoon, the lagoon is anticipated to be flood tide dominated. Consequently the West Basin and channel connecting to the Central Basin are expected to accumulate beach sand and will require routine dredging similar to that conducted at Agua Hedionda Lagoon every two years. Batiquitos Lagoon has a total wetland area of 226 ha, and is operated as an ecological reserve by the California Department of Fish and Game (CDFG). Prior to a recent major dredging project, Batiquitos Lagoon was a shallow wetland with 141 ha of estuarine water. This extensive shallow water area was very important in supporting migratory birds, particularly shorebirds and dabbling ducks, using the Pacific Flyway. The lagoon had a history of sewage spills and secondary treated wastewater was discharged to the lagoon. High input of nutrients and absence of tidal circulation resulted in excess primary productivity and accumulation of plant detritus. The frequently closed lagoon had also experienced extensive sedimentation. Although, the watershed is only 137 ha, it is sufficient to reflood the frequently closed lagoon. High evaporation during summer resulted in dramatic changes in salinity values; ranging from 3 - 60 ppt. The lagoon has also supported Belding's savannah sparrows and California least terns. A major enhancement project that involved dredging the entire lagoon, was recently completed in January 1997, so the lagoon is now tidal. This project changed out all of the habitats throughout the entire wetland. The undredged fringing marsh areas that bordered the lagoon, were impacted because they were submerged for long periods in order to facilitate the dredging process. Much of the dredged sediments was used to replenish the adjacent beach north and south of the lagoon inlet. The dredged sediments discharged to the beach covered an extensive longshore cobble berm that was the primary agent in closing the lagoon to tidal flushing. In the future, as the new sand beach deposit is eroded by waves, the cobble berm will be uncovered and become active again. The acreage, rate of maturation, and viability of the new habitats within the lagoon will not be known for several years. However, sand islands that were created with dredged sediments have been successful in fledgling California least terns and Snowy plovers. 4.3.6 San EHjo Lagoon This shallow water brackish wetland is the third largest lagoon in the proposed project area, with a total of 23 7 ha of habitat It has a relatively small watershed (200 km2) which contains several 28 MARCH 1997 4-17 BEACH SAND TRANSPORT & SEDIMENTATION Batiquitos Lagoon Inlet Aenat Photograph taken 1 March 1996. Approximate Tide Elevation = - 0 6 m MSL I I I I I I I I I I I I I I I I I FY-1997 MCON PROJECT P-706 MILITARY CONSTRUCTION PROJECT DATA CHANNEL DREDGING AT N.A.S.N.I CORONADO, CALIFORNIA 28 MAR 97 FIGURE 4.7 I I I 1 I I I I I I I I I I SOUTHWESNAVFACENGCOM FY 97 MCON PROJECT P-706 CHANNEL DREDGING BEACH SAND TRANSPORT AND SEDIMENTATION REPORT PHASE I: SOUTH OCEANSIDE AND SOLANA BEACH reservoirs. It is a unique lagoon because of the diversity of its plant communities that are represented as indicated in Table 4.3. The ocean inlet is located north of the proposed Solana Beach Fill site and is shown in Figure 4.8. Historically, San Elijo Lagoon was a fully tidal wetland. In recent years, the ocean inlet has been variable, but generally closed to tidal circulation. Over the last several years experimental excavation and high stormwater runoff events have enabled the lagoon to become tidally flushed for 2 - 6 months and the lagoon has benefitted substantially. Field monitoring studies have revealed that good tidal flushing can be achieved, colonization of mudflats by pickleweed can be stimulated, benthic invertebrates can be recruited, and support for piscivorous birds can be enhanced. The salinity regime throughout most of the lagoon is generally less than 15 ppt. Many of the habitats within the lagoon have become degraded even though it is a very successful environment for migratory birds. Fresh/brackish water marsh plant species have been encroaching from the East Basin into the Central Basin and are further curtailing circulation throughout the lagoon. San Elijo Lagoon is managed as a nature reserve by the CDFG and by the San Diego County Department of Parks and Recreation (SDCDPR). Light-footed clapper rails, California least terns, and Belding's savannah sparrows both forage and nest here, and Brown pelicans forage here. The SDCDPR has recently completed an extensive Enhancement Plan for the lagoon, which includes maintenance of continuous tidal flushing by actively managing the ocean inlet with dredging. When the lagoon is open, it has a tidal prism of approximately 0.3 million m3. Monitoring studies of ocean inlet opening events has documented the closure process which involves suspension, transport and deposition of marine sands in the inlet and main lagoon channel. The closure process is confounded by the presence of a substantial volume of cobbles that form a longshore berm south of the ocean inlet. Local waves transport cobbles into the ocean inlet where they are not readily removed by ebb tidal flows. San Elijo Lagoon is unique oceanographically because of the presence of an offshore reef which influences waves to converge from both upcoast and downcoast at the ocean inlet. Both marine sand and cobbles tend to form an offshore subtidal delta that further exacerbates the configuration and behavior of the mouth of the lagoon. 4.3.7 San Dieguito Lagoon The ocean inlet to San Dieguito Lagoon is located downcoast from the Solana Beach Fill site and is shown in Figure 4.9 This lagoon is an integral part of an extensive 142 km San Dieguito River Valley Park Conservation Plan. Although the wetland acreage totals 210 ha, 105 ha are represented by highly disturbed (ruderal), agricultural, or nonvegetated habitat as indicated in Table 4.3. San Dieguito Lagoon differs from most of the other lagoons because it currently does not have a large basin or salt marsh habitat. Instead a lengthy river channel serves as the main body of the lagoon along with a channel tributary that was enlarged by the CDFG in 1984 as a marsh enhancement project. Historically, San Dieguito Lagoon was an extensive 244 ha salt marsh. In 28 MARCH 1997 4-19 BEACH SAND TRANSPORT & SEDIMENTATION San Elijo Lagoon Inlet Aerial PHotograpn taken 1 March 1996 Approximate Tde Elevaton = - 0.6 m MSL FY-1997 MCON PROJECT P-706 MILITARY CONSTRUCTION PROJECT DATA CHANNEL DREDGING AT NAS.N.I. CORONADO, CALIFORNIA 28 MAR 97 FIGURE 4.8 San Dieguito Lagoon Inlet Aerial Photograph taken 1 March 1996. Approximate Tide Elevation = - 0 6 m MSI FY-1997 MCON PROJECT P-706 MILITARY CONSTRUCTION PROJECT DATA CHANNEL DREDGING AT N AS.N.I. CORONADO, CALIFORNIA 28 MAR 97 FIGURE 4.9 SOUTHWESNAVFACENGCOM FY 97 MCON PROJECT P-706 CHANNEL DREDGING BEACH SAND TRANSPORT AND SEDIMENTATION REPORT PHASE I: SOUTH OCEANSIDE AND SOLAN A BEACH 1935 a large area of salt marsh was filled in to construct the Del Mar fairgrounds and racetrack. Today San Dieguito Lagoon is primarily a river channel where seasonal fluvial flows often dominate water quality conditions in the lagoon. Depending upon the rate and amount of rainfall in the watershed, water quality throughout the lagoon can vary dramatically from year to year. Construction of two dams, especially Lake Hodges Dam, within the watershed has dramatically affected functioning of the lagoon. Of the total watershed of 900 km2, only 111 km2 are below the dams. During drought periods, stormwater runoff is often contained within the dams and never reaches the lagoon. Evaporation of lagoon water may increase salinity values to 55 ppt. Under these conditions the ocean inlet is typically closed. During wet years, the Lake Hodges Dam spillway may flow for several months; river flow then trenches the ocean inlet barrier, and scour out the entire river bed in the lagoon. During such times the lagoon salinity can decrease to about 3 ppt for several months. These events also greatly impact the lagoon plant and animal communities. Historically, secondary treated wastewater was discharged into San Dieguito Lagoon and there have been a number of sewage spills as well. Prolonged historical discharge of wastewater led to an excess of nutrients, accumulation of sludge and plant detritus, oxygen depletion, and eutrophic conditions. At the ocean, the San Dieguito River discharges across a broad sand beach. Depending upon tidal conditions, fluvial runoff, and beach width, the ocean inlet may have a linear configuration or may meander substantially, usually to the south. After a substantial fluvial blowout of the ocean inlet, tidal flushing may persist for many months or for more than a year. With sustained tidal flushing, fish abundances increase quite rapidly, whereas, the benthic invertebrate community recolonize at a slower rate. There is evidence of a small deposit of cobbles hi the vicinity of the inlet, but this is normally covered by beach sand. San Dieguito Lagoon provides foraging and nesting habitat for both Belding's savannah sparrows and California least terns. 4.3.8 Los Penasquitos Lagoon This lagoon has a total of 217 ha and a watershed of 253 ha. Several creeks (i.e., Los Penasquitos and Carroll Canyon) drain into the lagoon from areas that have become increasingly industrialized. It has the second largest area of southern coastal salt marsh of all the lagoons. The ocean inlet, as shown in Figure 4.10 is located north of the proposed Torrey Pines Beach Fill. The Los Penasquitos Lagoon Foundation has been successfully experimenting with keeping the ocean inlet open to enable sustained tidal flushing. Hence, the salinity regime throughout most of the lagoon has generally been between 15 - 30 ppt, which supports a large diversity offish species (25 species). Presence of a longshore cobble berm adjacent to the ocean inlet complicates maintenance of tidal exchange. Transport and deposition of cobbles into the inlet and main lagoon channel accelerates inlet closure processes. Several large sewage spills have occurred in recent years, which has led to recent replacement of an in lagoon sewage pump station. Historically, the lagoon has received discharges of secondary treated wastewater. The lagoon channel beds have accumulated deposits of sludge, plant organic detritus, and fine sediments. Substantial accumulation of sediments throughout the lagoon has reduced tidal flushing and has lead to degraded water quality conditions, degradation of salt marsh, establishment of invasive 28 MARCH 1997 4-22 BEACH SAND TRANSPORT & SEDIMENTATION ;.> Los Penasquitos Lagoon Aerial Photograph taken 1 March 1996. Approximate Tide Elevation = - 0 6 m MSL /gp^\FY-1997 MCON PROJECT P-706 MILITARY CONSTRUCTION PROJECT DATA CHANNEL DREDGING AT N.A.S.N.I. CORONADO, CALIFORNIA 28 MAR 97 FIGURE 4.10 SOUTHWESNAVFACENGCOM FY 97 MCON PROJECT P-706 CHANNEL DREDGING BEACH SAND TRANSPORT AND SEDIMENTATION REPORT PHASE I: SOUTH OCEANSIDE AND SOLANA BEACH plant species, and mortality in benthos and fish. A fresh/brackish water marsh, adjacent to the 1-5 Freeway is supported by freshwater flows from Carmel Creek. Ongoing construction of the new Highway 56 interchange with the 1-5 Freeway has increased input of turbidity and sedimentation in the lagoon. The lagoon supports a number of endangered species, including Belding's savannah sparrows, Light-footed clapper rails, California least tern, Snowy plover, Salt marsh daisy, Southern poverty weed, and Beach deerweed. 28 MARCH 1997 4-24 BEACH SAND TRANSPORT & SEDIMENTATION Section 5.0 Project and Site Description SOUTHWESNAVFACENGCOM FY 97 MCON PROJECT P-706 CHANNEL DREDGING BEACH SAND TRANSPORT AND SEDIMENTATION REPORT PHASE I: SOUTH OCEANSIDE AND SOLANA BEACH 5.0 PROJECT AND SITE DESCRIPTION The objective of the channel dredging project is to provide a deep draft navigation channel in San Diego for NIMITZ Aircraft Carriers at NASNI. Placement of sand on the beach to create beach fills is a byproduct of the channel dredging project. The purpose of the beach fills is to provide larger recreational beaches through the beneficial use of dredged material from the channel dredging. Beach fills also reduce the potential for shoreline damage and provide erosion control. However, while the proposed beach fills will provide some level of increased protection against shoreline damage and erosion, they have not been designed for this purpose. The recreational and shoreline protection benefits of the beach fill depend on berm width and height, beach fill quantity per unit length, and the grain size of both the native beach and borrow material. The ability to optimize the beach fills for either of these purposes is limited due to the natural trend of the beach to take an equilibrium profile. Grain size and quantity of fill, which are both defined by the material available within the dredge cut, also affect the behavior of the beach fill. The site locations and distribution of sediment quantities to each site were determined by the Shoreline Erosion Committee (SEC), through SANDAG. The beach fills to be constructed for this project maximize the beneficial use of the dredge material for recreational beach enhancement and minimize potential adverse impacts. This section discusses the proposed beach fills and existing conditions at each site. Discussion of existing structures and utilities including potential impacts are also included in this section. Section 6.0 will provide detailed analyses and discussion of other potential impacts and includes qualitative evaluation of various beach fill construction templates including a range of berm heights, quantities and sediment grain sizes. Important construction considerations affecting the as-built beach fill geometry are also discussed. 5.1 Phase I Project Phase I includes the placement of beach fills at two sites, South Oceanside and Solana Beach. Solana Beach has two fill areas, Cardiff State Beach and Fletcher Cove. The beach fill quantities, length and profile quantity (quantity per unit length) are shown for each beach fill in Table 5.1. Figures 5.1, 5.2 and 5.3 show the typical existing beach profile configurations for the beach fill sites. Important configuration information shown on the figures includes berm height and width, beach slope, and median grain size. The configurations are also used as data input for the numerical model analyses described in Section 6.0. At Oceanside, the beach profile is strongly concave upward. The shorebase is located at about 10m (MSL) depth. At Solana Beach, profiles are much flatter than those to the north, showing relatively little concavity. 28 MARCH 1997 5-1 BEACH SAND TRANSPORT & SEDIMENTATION 10 IUJ -10 -15 Existing Beach Profile at South Oceanside Transect OS 0930 Existing Beach Profile ' - Berm: Elevation + 3.4 m MSL j Width = 15-20m; \ -Beach: Slope = 1:35 Grain size* 0.17 mm: MHHW MLLW 100 200 300 400 500 600 700 800 Distance from Range (m) 900 1000 1100 1200 NOTES: 1. Slopes shown in vertical: horizontal 2. Grain size = average (D50) ^S™*' ,. "•"ti^^^^r FY-1997 MCON PROJECT P-706 MILITARY CONSTRUCTION PROJECT DATA CHANNEL DREDGING AT N.A.S.N.I. CORONADO, CALIFORNIA 28 MAR 97 FIGURE 5.1 10 E, _iw .0 "to IHI -5 -10 -15 Existing Beach Profile at Cardiff - Solana Beach Transect SD 0630 ; iExisting Beach Profile ] ;- Cliff Height 20 m - Berm: Elevation + 2.8 m MSL i j Widths 5m i-Beajch: Slope = 1:40 ' Grain size = 0.18 mm i i MHHW 100 200 300 400 500 600 700 Distance from Range (m) 800 900 1000 1100 1200 NOTES: 1. Slopes shown in vertical:horizontal 2. Grain size = average (D50) FY-1997 MCON PROJECT P-706 MILITARY CONSTRUCTION PROJECT DATA CHANNEL DREDGING AT N.A.S.N.I. CORONADO, CALIFORNIA 28 MAR 97 FIGURE 5.2 10 o•4=n c I UJ -10 -15 Existing Beach Profile at Fletcher - Solana Beach Transect SD 0600 Existing Beach Profile - Berm: Elevation + 2,8 m MSL i Width =15-1 Qm } -I Beach: Slope = 1:4Q •I Grain size = 0.18 mm MHHW 100 200 300 400 500 600 700 Distance from Range (m) 800 900 1000 1100 1200 NOTES: 1. Slopes shown in verticakhorizontal 2. Grain size = average (D50) FY-1997 MCON PROJECT P-706 MILITARY CONSTRUCTION PROJECT DATA CHANNEL DREDGING AT N.A.S.N.I CORONADO, CALIFORNIA 28 MAR 97 FIGURE 5.3 SOUTHWESNAVFACENGCOM FY 97 MCON PROJECT P-706 CHANNEL DREDGING BEACH SAND TRANSPORT AND SEDIMENTATION REPORT PHASE I: SOUTH OCEANSIDE AND SOLANA BEACH TABLE 5.1 - PROJECT BEACH FILL CHARACTERISTICS BEACH FILL South Oceanside Cardiff State Beach Fletcher Cove QUANTITY DREDGE CUT (m3) 405,218 265,585 168,217 BEACH FILL (m3) 328,243 216,752 136,264 LENGTH (m) 2,000 1,000 700 PROFILE QUANTITY ( m3/m) 160 200 210 Notes: 1. Profile quantity is approximate and will vary in the field based on actual beach profile at time of fill placement and variation in constructed berm width, height and foreshore slope to achieve the linear extent of the beach fill per the construction plans. 2. Beach quantity is measured in the fill and assumes a total loss of approximately 20% between the dredge cut and final pay template. Long term quantity losses in the study area between 1954 and 1987 have been about 65 to 130 m3/m (USACOE, 1990). At Oceanside and Solana Beach, the beaches increase in width from April to October, and decrease from October to April as a result of seasonal cross shore transport. 5.2 South Oceanside Beach Fill The South Oceanside Beach Fill quantity is approximately 328,243 m3 placed over 2,000 m of shoreline between Tyson Street and Loma Alta Creek as shown in Figure 5.4. 5.2.1 Existing Beach Conditions Oceanside City Beach extends from Oceanside Harbor south to Wisconsin Street. It is relatively wide, and is backed by city park facilities and "The Strand," a public roadway built on the back beach. The beach is the remnant 1916 and 1927 flood delta of the San Luis Rey River (Inman and Jenkins, 1985). It has been extensively modified by development and massive beach nourishment activity, and is sheltered from the prevailing north-west waves by the Oceanside harbor breakwaters. Long-term changes since 1888 in the shoreline position at Oceanside are very large in the vicinity of the harbor, but decrease to near zero between Wisconsin Street and Oceanside Blvd. From 1888 until 1942 when construction of the Del Mar Boat Basin began, the beaches were about 30 to 60 m wide. They fluctuated in response to discharges from the San Luis Rey and Santa Margarita Rivers. After 1942 the beaches south of the harbor retreated in response to the blocking of littoral transport by the boat basin jetties. They accreted when about three million m3 of sand dredged from the harbor was placed there between 1960 and 1963. Between 1963 and 1988, the beach south of Oceanside Pier to Agua Hedionda Lagoon retreated about 16 m. 28 MARCH 1997 5-5 BEACH SAND TRANSPORT & SEDIMENTATION SOUTH OCEANSIDEBEACH FILL PHOTOGRAPH LOCATION (TYP.) SOUTH .OCEANSIDE •91 cm DIA. MORTAR LINED & COATED STEEL PIPE SANITARY SEWER OCEAN OUTFALL SOUTH OCEANSIDE PHOTOGRAPH LOCATION MAP PHOTOGRAPHS PRESENTED APPENDIX D Notes: 1. Refer to Appendix D for Site Photographs. 2. All Elevations are approximate and reference MSL in meters.FY-1997 MCON PROJECT P-706 MILITARY CONSTRUCTION PROJECT DATA CHANNEL DREDGING AT NAS.N.I. CORONADO, CALIFORNIA 18 MAR 97 FIGURE 5.4 SOUTHWESNAVFACENGCOM FY 97 MCON PROJECT P-706 CHANNEL DREDGING BEACH SAND TRANSPORT AND SEDIMENTATION REPORT PHASE I: SOUTH OCEANSIDE AND SOLANA BEACH The Escondido Junction is a narrow, low-lying sand and cobble beach extending from Wisconsin Street south to Buccaneer Beach. Back shore development is protected by a continuous rip-rap seawall, but remains threatened by flooding during high wave events. Buccaneer Beach is a narrow spit that fronts La Salina Lagoon and the outlet of Loma Alta Creek. This is the area assigned for the northern most beach fill. Buccaneer Beach to the entrance of Buena Vista Lagoon is a fine sand and cobble beach backed by densely developed 10m high cliffs. Flooding, wave overtopping and damage from flying cobbles occurred during the winters of 1941,1978,1980 and 1983. A continuous rock revetment is in place to protect back beach developments. Beach width decreases resulting from sand losses that have occurred south of the San Luis Rey River since 1942 are most noticeable in this reach (Inman and Jenkins, 1985). 5.3 Solana Beach Fill The Solana Beach Fill is divided into two separate onshore fill areas designated as "Cardiff State Beach" in the City of Encinitas, and "Fletcher Cove" in the City of Solana Beach. The Cardiff State Beach fill quantity is approximately 216,752 m3 placed over 1000 m, and the Fletcher Cove beach fill quantity is 136,264 m3 placed over 700 m, as shown in Figure 5.5. In addition, 33,642 m3 of fill material from the Lomas Santa Fe Drive Grade Separation project will be placed immediately south of the Fletcher Cove beach fill some time this year. 5.3.1 Existing Beach Conditions Solana Beach extends from the southern boundary of San Elijo Lagoon, in the Cardiff portion of the City of Encinitas, south to the entrance of San Dieguito Lagoon in Del Mar. The beach is narrow, with fine grained sand and cobbles on exposed bedrock. It is backed by a 20 m high cliff that is developed with houses and apartments, some right at the cliff edge. Numerous caves and undercut areas form in the cliff face from wave action and scour, usually at joints, cracks and other weaknesses in the cliff formations. Cardiff State Beach is located between the San Elijo Lagoon entrance to the north and the City of Solana Beach to the south. The beach is very narrow with predominant cobble and gravel sized materials. The beach is backed by restaurant structures, County Highway S21 and the state parking lot at the south end. The structures, roadway and parking lot at the back beach are protected by continuous rip-rap revetment. Fletcher Cove is located downcoast of a headland at the City boundary between Encinitas and City of the Solana Beach. The beach is narrow, backed by high, wave-cut and eroding cliffs with houses and apartments along the crest. Several small rocky projections occur along the cove. 28 MARCH 1997 5-7 BEACH SAND TRANSPORT & SEDIMENTATION **"*»*» Av*'SAN ELUO LAGOON ALIGNMENT TARGET FOR 76 cm <)|gv RCP SEWER OUTFALL % 42 -PHOTOGRAPH LOCATION (TYP.) - FLEBEACH FILL SOLANA BEACH PHOTOGRAPH LOCATION MAP PHOTOGRAPHS PRESENTED IN APPENDIX D Notes: 1. Refer to Appendix D for Site Photographs. 2. All Elevations are approximate and reference MSL In meters. FY-1997 MCON PROJECT P-706 MILITARY CONSTRUCTION PROJECT DATA CHANNEL DREDGING AT NAS.N.I. CORONADO, CALIFORNIA 28 MAR 97 FIGURE 5.5 SOUTHWESNAVFACENGCOM FY 97 MCON PROJECT P-706 CHANNEL DREDGING BEACH SAND TRANSPORT AND SEDIMENTATION REPORT PHASE I: SOUTH OCEANSIDE AND SOLANA BEACH 5.4 Site Visits Site visits were conducted to observe existing beach conditions and evaluate the potential impacts of beach fills. Site visits were carried out during the week of 11 March 1997. Existing conditions were verified and documented at South Oceanside and Solana Beach. The field survey also determined the existence of various structures and utility facilities within or adjacent to the proposed beach fills. City representatives were contacted to determine the locations of sewer and storm drain ocean outfalls and any other facilities that could be affected by the proposed beach fill. Photographs were taken and are presented in Appendix D. Locations of Photographs are indicated on Figure 5.4 for South Oceanside and 5.5 for Solana Beach. Appendix D also includes several photographs of the beach sites taken on 22 and 23 January 1996. 5.5 Structures and Utilities 5.5.1 South Oceanside Several existing structures and utilities exist within the shoreline area of the South Oceanside Beach Fill. None are considered adversely impacted by the proposed beach fill. Each structure and utility is described below. Locations are indicted on Figure 5.6 along with a summary table indicating characteristics and impacts. Photographs are included in Appendix D. 5.5.1.1 Sanitary Sewer Ocean Outfall Mr. Paul Hojo, Supervisor of the City of Oceanside Sewer Treatment Plant, (619-966-4870), provided the information regarding the existing 91 centimeter (cm) diameter mortar lined and coated steel pipe sanitary sewer ocean outfall. This facility is approximately perpendicular to the shoreline and bears S49° 02' W from a manhole in Pacific St. that is approximately 270 meters southerly from the intersection of Crosswaithe St. The depth of cover is minimal. The beach fill will be beneficial since additional cover will be provided which will tend to protect this facility. This pipe was installed in approximately 1971. Refer to Figure 5.6 for approximate location and Appendix D for site photographs. 5.5.1.2 Public or Private Access Stairs/Ramps Public access stairs at Tyson St. Park will not be affected. The bottom 0.5 m of the public stairs at the end of Ash St. and at Marron St. will be covered by the fill which will tend to further stabilize these stairways. The bottom 0.3 m of the public ramp access at Wisconsin St. will be covered. This is not considered a significant impact. The public access ramp at Foster St. will not be affected. There is a private stairway beach access, with stairs ending 1 to 1.5 meters above the beach sand, located southerly of the 91-cm diameter sewer outfall. As such, there will be no impact at this location. Refer to Figure 5.6 for approximate location and Appendix D for site photographs. 28 MARCH 1997 5-9 BEACH SAND TRANSPORT & SEDIMENTATION SOUTHWESNAVFACENGCOM FY 97 MCON PROJECT P-706 CHANNEL DREDGING BEACH SAND TRANSPORT AND SEDIMENTATION REPORT PHASE I: SOUTH OCEANSIDE AND SOLANA BEACH 5.5.1.3 Storm Drain Pipes There are two adjacent 45-cm reinforced concrete pipes (RCPs) located just south of Tyson St. The outlet at this location is approximately 1 m below the top of the proposed fill. The storm drain discharge flow path must remain unobstructed. At the end of Marron St., there are double 91 cm diameter RCPs with the existing outlet approximately 0.2 m above the proposed sand fill. There will be no impact to this facility. At the end of Foster St., there is a 45-cm diameter RCP, half filled with sand. The outlet is approximately 0.3 m above the proposed sand fill. There will be no impact at this facility. Refer to Figure 5.6 for approximate location and Appendix D for site photographs. 5.5.2 Solana Beach There are several existing structures and utilities within the shoreline area of the Solana Beach Fills. None are considered adversely impacted by the proposed beach fill. Each structure and utility is described below. Locations are indicted on Figure 5.7 along with a summary table indicating characteristics and impacts. Photographs are included in Appendix D. 5.5.2.1 Sanitary Sewer Ocean Outfall Mr. Hans Jensen of the City of Encinitas Engineering Services Department (619-633-2776) provided the information regarding an existing 76-cm diameter RCP sanitary sewer pipe running perpendicular to the shoreline, located between the San Elijo and Cardiff State Beaches. This pipe was originally installed in 1968 by the Cardiff Sanitation District. Depth of cover is unknown. The proposed sand fill will be beneficial by providing additional cover. Refer to Figure 5.7 for approximate location and Appendix D for site photographs. 5.5.2.2 Sea Wall and Tide Pools Just south of the south end of the Cardiff State Beach parking lot is a large concrete sea wall that supports the natural slope above, the top of which is occupied by private homes. Refer to Figure 5.7 for approximate location and Appendix D for site photographs. Note that this section is listed for information only and is not included in the project limits. 5.5.2.3 Public Access Stairs, Storm Drain Pipe, and Sandbag Retaining Wall There is an existing public access staircase with a lifeguard tower located adjacent to the west end of Solana Vista Drive at Tide Beach Park, the bottom of which is at approximately 2.9 m elevation. As such, there will not be any impact to these stairs. Adjacent to these stairs is an 45- cm diameter CMP down drain, the outlet of which is at approximately 5 m elevation which will result in no impact for this pipe. The sand bag retaining wall with several 10-cm diameter weep holes has its exposed base at approximately 1.7 m elevation. Therefore, no impact to this retaining wall is expected. Refer to Figure 5.7 for approximate location and Appendix D for site photographs. 28 MARCH 1997 5-10 BEACH SAND TRANSPORT & SEDIMENTATION 1 j ! 1 i 1 i 1 i J t T* 1 Notes: 1. Refer to 2. All Elevat I 1 _ S x I ' ,, , . i ' ,' ' P ' „ ^' ' SOUTH OCEANSIDE °\ , *, ^ ' ! ' | % ls W K i g « X rs, *~ < , ^ 5) , >> i s\ 5! w to ' o 21 c^ " 1," | 1 Ff Pacific St | | 25A 1 i ' Tr\6 Strand S ^ ii ^ — ' — " " "" — 9A I-~1A | , ' SOUTH OCEAN— \ \ BEACH FILL2 — * I 2A-~ — 3A > PHOTOGRAPH LOCATION •—13 1 ^— 1 OKQ ~~^7~^^^ _24 W 25C-"258 ~H— -" ' 1 1 1 -~ 91 cm DIA. MORTAR LINEDSIDE . & COATED STEEL PIPE SANITARY SEWER (Typ •, OCEAN OUTFALL Existing Structures and Utility Impacts — South Oceonside Structure Sanitation Sewer Ocean Outfall Stairs ft Tyson Park Stairs ft Ash St. Stairs O Marron St. Ramp 9 Wisconsin Ave. Ramp © Forster St. Private Stairway s/o swr. ocean outfall Double 45 cm dia. RCP s/o Tyson St. Double 91 cm dla. RCP 8> Marron St. 45 cm dla. RCP ® end of Forster St. Appendix D for Site Photographs, ons ore approximate and reference MSL in meters. Photo Outlet Invert(See Note 1) Approx. El. (m, MSL) 21, 22, 25 N/A 4 N/A 6 N/A 14 N/A 7 N/A 18 N/A 25 N/A 5 0.65± 16A 1.9± 17 2.0± Bottom ofStairs/RampApprox. El. (m, MSL) N/A 3.3± 1.2± 1.5± 1.4± 1.7± N/A N/A N/A N/A Comments 91 cm dla. mlc steel pipe - No apparent Impact No Impact Minor Impact - bottom portion will be covered with sand Minor impact — bottom portion will be covered with sand Minor Impact - bottom portion will be covered with sand No impact No impact — lowest step is 1.2 m to 1.5 m. above sand Storm Drain flow must be maintained No impact Pipe Is half filled with sand - no Impact ^^P^\ FY-1997 MCON PROJECT P-706 ,Q k,AD n-,& -^F ^. \ IrsMArxM/r \»/ O MILITARY CONSTRUCTION PROJECT DATA IO MMK a/ mjU^yJ CHANNEL DREDGING AT NAS.N.I. Firi)RF <- RX'S5^ CORONADO, CALIFORNIA Av«SAN ELUO LAGOON . 32 / 31 _T ALIGNMENT TARGET FOR 76 Cm dia RCP SEWER OCEAN OUTFALL Tide BeachPark PHOTOGRAPH LOCATION (TYP.) Existing Structures ond Utility Impacts - Solana Beach Structure Sea Wall Tide Pools Public Access Stairs © Tide Beach Park Sand Bag Retaining Wall @ Tide Beach Pork 45 cm dia. CMP Storm Drain 9 Tide Beach Park Public Access Ramp <9 Plaza St. 152 cm dia. Storm Drain Outfall Pipe ® Plaza St. 45 cm dia. Storm Drain Pipe ® Ocean Blvd. 76 cm dia. RCP Sewer Outfall Notes: 1. Refer to Appendix D for Site Photographs. 2. All Elevations are approximate and reference MSL in meters. Photo(See Note 1) 39 38, 40. 41 42 42 42 46, 47, 51 46-51 N/A 36, 37, 53 Outlet Invert Approx. El. (m, MSL) N/A N/A N/A N/A 3.0 N/A —0.3 N/A N/A Bottom ofStairs/RampApprox. El. (m, MSL) N/A N/A 1.2 N/A N/A 1.7 N/A N/A N/A Comments Base of Seawall: 1.6± - No impact N/A No impact Bottom of wall elev: 1.7± - No Impact No impact No Impact Outfall under construction — maintain adequate flow path into ocean Not found - No apparent Impact 76 cm dia. RCP Sewer Outfall - No apparent Impact FY-1997 MCON PROJECT P-706 MILITARY CONSTRUCTION PROJECT DATA CHANNEL DREDGING AT NAS.N.I. CORONADO, CALIFORNIA „ y.R Q ZO MAK y/ nn IPF , 7MUUKL D./ SOUTHWESNAVFACENGCOM FY 97 MCON PROJECT P-706 CHANNEL DREDGING BEACH SAND TRANSPORT AND SEDIMENTATION REPORT : PHASE I: SOUTH OCEANSIDE AND SOLANA BEACH 5.5.2.4 Storm Drain Outfall Mr. Brad Nguyen of the City of Solana Beach Engineering Department (619-755-2998) provided the following information regarding a 152-cm to 183-cm diameter RCMTP storm drain pipe currently under construction at the west end of Plaza St. (extension of Lomas Santa Fe Drive). This pipe has been designed to carry a Q100 of 9.29 cubic meters per second with a V100 of 4.57 m/s. The flow line elevation of the energy dissipator is shown to be 1.52 m on the storm drain design plan. A concrete pad will extend approximately 7.6 m beyond the energy dissipator, the top of which will be at elevation 0.3 m per the storm drain design plan. Sand fill will not be placed in the vicinity of this pipe or the outlet flow path, which would have to be maintained. Refer to Figure 5.7 for approximate location and Appendix D for site photographs. 5.5.2.5 Storm Drain Outlet There is an existing 45-cm diameter storm drain pipe located at the west end of Ocean Street. However, this pipe was not visible on 10 March 1997. 28 MARCH 1997 5-12 BEACH SAND TRANSPORT & SEDIMENTATION L- L- Section 6.0 Project Analysis SOUTH WESNAVFACENGCOM FY 97 MCON PROJECT P-706 CHANNEL DREDGING BEACH SAND TRANSPORT AND SEDIMENTATION REPORT PHASE I: SOUTH OCEANSIDE AND SOLANA BEACH 6.0 PROJECT ANALYSIS 6.1 Approach The purpose of this analysis is to determine: • the beneficial impacts of the beach fills, • the short and long-term fate (physical movement) of the dredged sand being placed at the beach fill sites; and • any adverse impacts of the beach fills in the context of naturally occurring beach processes. This information will be used to prepare an Environmental Assessment for the beach fill component of the dredging project. Beneficial impacts include recreation, increased beach access, shoreline protection and erosion control. Potential adverse impacts include scarps in the beach fill that could impede beach access, and sand migration outside of the fill placement site and into sensitive marine habitats and lagoon areas. The post-placement sand movement from the project sites is difficult to accurately forecast. However, a methodology has been developed that approaches the problem using several complementary analyses that give an indication of beach fill behavior for given conditions. The methodology for the analysis of beach fill response is as follows: » Consider beach fill compatibility based on grain size distribution of dredge material and existing beach material as it is distributed along the equilibrium profile • Study historic beach fill events to determine fill response from "prototype experience" • Estimate beach fill erosion above MSL and resulting offshore sand movement using the numerical model SBEACH • Estimate longshore sand movement using the numerical model GENESIS The first two methods analyze beach fill response qualitatively, while the last two methods utilize numerical models developed by the USACOE. 6.2 Beach Fill Alternative Considerations Four beach fill construction template alternatives were evaluated in order to achieve the purpose of the proposed action which is to: 28 MARCH 1997 6-1 BEACH SAND TRANSPORT & SEDIMENTATION SOUTHWESNAVFACENGCOM FY 97 MCON PROJECT P-706 CHANNEL DREDGING BEACH SAND TRANSPORT AND SEDIMENTATION REPORT PHASE I: SOUTH OCEANSIDE AND SOLANA BEACH • maximize beneficial use of the dredge material for recreational beach enhancement and minimize potential adverse impacts The four beach fill construction template alternatives considered are detailed below and shown in Figure 6.1: • Low Berm (lower than minimum) - +1.0 m MSL elevation, 1:35 slope The low berm alternative provides reduced beneficial impacts toward recreation and shore protection since the berm is expected to erode at a higher rate over the short term (3 to 6 months) than the other alternatives. In addition, this alternative would be very difficult, if not impractical to construct, and would be very costly. Therefore, this alternative was not considered further. • Minimum Berm - +1.7 m MSL elevation, 1:20 slope The minimum berm alternative is expected to erode somewhat slower over the short term than the low berm alternative and meets the purpose of the proposed action. Scarps form on beaches at a point where waves break on the beach and this alternative is not expected to lead to a scarp significantly more than 1 m high. • Maximum Berm - +2.8 to 3.4 m MSL elevation, 1:10 slope The maximum berm alternative is expected to erode somewhat slower over the short term than the minimum berm alternative and meets the purpose of the proposed action. The berm elevation matches the natural beach berm elevation which is site specific. This alternative is not expected to lead to a scarp significantly more than 2 m high. • Block Berm (higher than maximum) - +4.2 m MSL elevation, 1:3 slope The block berm alternative is expected to erode somewhat slower over the short term than the maximum berm alternative and is very similar to the berm constructed for the Batiquitos Lagoon disposal at South Carlsbad. This profile is built with an extremely high berm elevation and steep beach slope which may result in a scarp height in excess of 2.5 m. This scarp height could adversely affect beach access. Therefore, this alternative was not considered further. Due to the grain size of the dredge material, all of the alternatives are expected to erode at similar rates over the long-term (1 to 2 years). The beach fill berm construction templates have berm widths between 40 and 60 m wide with a height of 1.7 to 1.8m above MSL and a foreshore slope of 1:20 (vertical:horizontal). The actual berm construction template (berm width, height and foreshore slope) will need to be adjusted during fill placement to achieve the linear extent of the 28 MARCH 1997 6-2 BEACH SAND TRANSPORT & SEDIMENTATION +1 .Om MSL MSL Low Berm - + 1.7mMSL Minimum Berm MSL +2.8 to 3.4 m MSL Maximum Berm +4.2 m MSL Block Berm MSL Schematic of Beach Fill Construction Template Alternatives SES FY-1997 MCON PROJECT P-706 MILITARY CONSTRUCTION PROJECT DATA CHANNEL DREDGING AT N.A.S.N.I. CORONADO, CALIFORNIA 28 MAR 97 FIGURE 6.1 SOUTH WESNAVFACENGCOM FY 97 MCON PROJECT P-706 CHANNEL DREDGING BEACH SAND TRANSPORT AND SEDIMENTATION REPORT PHASE I: SOUTH OCEANSIDE AND SOLANA BEACH beach fill in accordance with the construction plans. Adjustments will be a function of field conditions such as: actual beach profile at the time of fill placement, variability in the borrow area grain size, losses and wave climate. The beach fill berm should be constructed with an elevation of no less than the Minimum Berm Alternative and should not exceed the natural berm elevation (Maximum Berm Alternative) for each beach site as indicated in Table 6.1. Depending on actual field conditions, the foreshore slope will be in the range of 1:10 to 1:20. To minimize scarping potential, the foreshore slope should not be steeper than 1:10. TABLE 6.1 - NATURAL BERM ELEVATIONS BEACH FILL South Oceanside Cardiff State Beach Fletcher Cove ELEVATION ( m MSL) +3.4 +2.8 +2.8 Source: USACOE, 1990 Since the Minimum Berm Alternative will have a tendency to erode somewhat faster than the Maximum Berm Alternative over the short term, adverse impacts established based on the Minimum Berm Alternative are considered to be the maximum anticipated. Any adjustments in the berm geometry up to the Maximum Berm Alternative as discussed in the following section would be considered to have less of an impact than the Minimum Berm Alternative. Therefore, analysis of the Minimum Berm Alternative is considered conservative with respect to determining adverse impacts from beach fill erosion. 6.2.1 Construction Considerations The beach is a dynamic and constantly changing environment which has a natural trend toward an equilibrium profile. For this reason, flexibility in the construction template must be exercised in order to construct the beach fill. Flexibility will maximize beneficial use of the dredge material and minimize adverse impacts. Prior to placement of sand at each beach, a survey will be performed to determine the existing beach profile. Depending on the time of year at which the sand is placed, the profile will vary from that shown on the plans, as will the volume of the construction template. In order to account for this inevitable difference in the plan section versus the actual field section and to maintain the linear extent of the beach fill, the berm geometry will be adjusted in the field. One other factor affecting the actual berm geometry to be constructed is the tendency of the dredge sand to take a natural foreshore slope anticipated to be between 1:10 and 1:20. In order to minimize loss of material outside of the construction template slope, the template slope will be adjusted once the natural tendency of the material is established. The varying factors affecting the behavior of the 28 MARCH 1997 6-4 BEACH SAND TRANSPORT & SEDIMENTATION SOUTHWESNAVFACENGCOM FY 97 MCON PROJECT P-706 CHANNEL DREDGING BEACH SAND TRANSPORT AND SEDIMENTATION REPORT PHASE I: SOUTH OCEANSIDE AND SOLANA BEACH foreshore slope are the grain size of the borrow material and wave climate. The former will vary in plan and depth of the dredge cut and the latter with the time of year. However, a natural trend will emerge upon initial fill placement and the template adjusted accordingly. In summary, a construction template must be defined in order to construct the beach fill and pay the contractor. The final as-built template should be within the parameters defined by the Minimum and Maximum Berm Alternatives and determined based on actual field conditions at the time of fill placement. 6.2.2 Beach Fill Material Compatibility Material grain size compatibility is one of the single most important factors in determining the beneficial impacts of the proposed beach fill. Fortunately, the dredge sediments available from the dredge cut are of a grain size considered to be compatible with the littoral sediments in the Oceanside Littoral Cell. A summary of grain size for channel dredge areas 1 and 2 is shown in Figure 6.2. As indicated, the average D50 for these areas are 0.18 mm and 0.35 mm, respectively. Figures 6.3 and 6.4 show the composite gradation and percent passing by weight for each dredge area. Beach fill material compatibility with the dredge material is shown in Figure 6.5. As indicated, the composite grain size distribution of dredge materials from both dredge areas 1 and 2 have similar percentages of sands than the composite gradations for the Oceanside Littoral Cell and a lower percentage of fines. A summary is shown in Table 6.2. TABLE 6.2 - GRAIN SIZE COMPARISONS GRAIN SIZE CHARACTERISTICS % Fine Sand % Med. Sand D50 (mm) % < 200 Sieve (0.074 mm) %< 0.062 mm OCEANSIDE LITTORAL CELL ABOVE MSL 82 6 0.24 9 3 BELOW MSL 81 4 0.17 14 12 DREDGE AREA 1 89 5 0.18 5 3 2 71 20 0.35 4 •*> The fact that the materials are similar in grain size to those residing below MSL on the equilibrium profile in the Oceanside Littoral Cell suggests several things: 28 MARCH 1997 6-5 BEACH SAND TRANSPORT & SEDIMENTATION SUMMARY OF CHANNEL GRAIN SIZE DATA DREDGE AREA 1 2 D50 ALL DATA MAX. MIN. 0.67 0.60 0.11 0.15 TYP. RANGE MAX. MIN. 0.25 0.40 0.13 0.25 AVERAGE 0.18 0.35 % PASSING #200 SIEVE ALL DATA MAX. MIN. 23 25 2 2 TYP. RANGE MAX. MIN. 12 10 2 2 AVERAGE 5 4 % PASSING < 0.062 mm ALL DATA MAX. MIN. 19 24 1 2 TYP. RANGE MAX. MIN. 9 7 2 1 AVERAGE 3 3 # OF SAMPLES 54 23 uses CLASS SP SP* USCS CLASSIFICATION NOTES (APPLIES TO FIGURES 6.1. 6.2. 6.3): BOUNDARY CLASSIFICATION: SOILS POSSESSING CHARACTERISTICS OF TWO GROUPS ARE DESIGNATED BY COMBINATIONS OF GROUP SYMBOLS. FOR EXAMPLE GW-GC, WELL-GRADED GRAVEL-SAND MIXTURES WITH CLAY BINDER. ALL SIEVE SIZES ON THE CHART ARE U.S. STANDARD. THE TERM "SILT" AND "CLAY" ARE USED RESPECTIVELY TO DISTINGUISH MATERIAL EXHIBITING LOWER PLASTICITY FROM THOSE WITH HIGHER PLASTICITY. THE -#200 SIEVE IS SILT IF THE LIQUID LIMIT AND PLASTICITY INDEX PLOT BELOW THE "A" LINE ON THE PLASTICITY CHART, AND IS CLAY IF THE LIQUID LIMIT AND PLASTICITY INDEX PLOT ABOVE THE "A" LINE ON THE CHART. THE SOIL CLASSIFICATION SYSTEM IS BASED ON THE AMERICAN SOCIETY FOR TESTING AND MATERIAL (ASTM). A. (ASTM) D24-B7 STANDARD TEST METHOD FOR CLASSIFICATION OF SOILS FOR ENGINEERING PURPOSES. B. (ASTM) D2488 STANDARD RECOMMENDED PRACTICE FOR DESCRIPTION OF SOILS (VISUAL MANUAL PROCEDURE). FY-1997 MCON PROJECT P-706 MILITARY CONSTRUCTION PROJECT DATA CHANNEL DREDGING AT NAS.N.I. CORONADO, CALIFORNIA 28 MAR 97 FIGURE 6.2 DREDGE AREA-1 100 75 O Z t/1 CL H- 50ZUJoo:LJa 25 COBBLES GRAVEL coarse U.S. STA ^IF\^" nDFMIKIfJit vt- Urt-INlML 6432 ii , j i 1 ' i : . ;- : i t !' 100 fine WARD coarse SAND SILT OR CLAY medium fine U.S. STANDARD SIEVE NUMBERS HYDROMETER 80 UO 1.5 13/4 3/8 4 10 20 40 60 100 200 '1 . 1 i '1 ; ! • \ ; i i ii ' 'Ii. i 10 *T— \ 11 , X I— -. \ .*• 1 r-rVL-.-TTTM 1 1 1 v ^^X i '1 U' \\ \\* A \\ '\ \\ \^^ \ \ \\ \ V > 1 > 1 , . . "^—- 1 ' /^ ! ^~ ^^ \\ Xh1"*\v i\ ! 1 ; ! LMITi OF A .DATA (TYP AVERAGE ( TYPICAL R OF CJATA ( i — rO.062 m S , i . . .7~~r- r— , ._ i^-1- ------- 'i'-' •'-'•'• '<*•• '!';', ! : ! ' i j : ! ' ' • ' •f 1 i .! M ! ! TYP.j • f^P-} j • ' r: i ! ; 1 1 | i ; ( • i ' ':•., ; Q 10 20 30 LUZ 40 [^ o; 50 I-Z 60 g 03x rn70 CO H80 O90 43^-~i | UV \B? 1 0.1 0.01 0.001 I_, PARTICLE SIZE (mm) -;;;• 1 1 1 -9 -8 -7 -6 I I I -5 -4 -3 1 -2 - III I I 1 I I "Cs. 10123456789 10 f" PHI SIZE (0) /^ ^ _FY-1997 MCON PROJECT P-706 ?R y.R q7 MILITARY CONSTRUCTION PROJECT DATA CHANNEL DREDGING AT NAS.N.I. nnipF R , CORONADO, CALIFORNIA UKL ^ DREDGE AREA-2 75 O) < D_ 1- 50 LJ OtrLJ COBBLES GRAVEL coarse fine U.S. STANDARD SIEVE OPENING IN INCHES SAND coarse medium fine U.S. STANDARD SIEVE NUMBERS 6 43 2 1.5 1 3/* 3/8 4 10 • 1 i i ' r i *<GRADA OF MA i SIEVE, ilNDICA' i GR' AVEl 'THIS A f' i i -i1 • i i ' io ylsE.is • • ; i, . 1 slS ARE tfEPFE lALiFJNER THA UAL DIVER 03 SIGNIFICANT C ^E! MATERIALV NEAR 'BALI* i ' : 100 SE N SE Ji* EX # N 1 R 3 1$ T H V _t Tp 80 140 SILT OR CLAY HYDROMETER 20 40 60 100 200 .Y-Y-lYTrrrri.^>viY. Y.Y.-. \ . AflVE E '#4ftTioiv ANl S .IN OINT i 1 ' '. - i \ S> 10 N •> f v * ^* ' j •• l, : l 1 1 l :-•-: -r* :i:. , \ •^^ :-!:-. i .. i ,. ^ .•t • :\i ; V^ • ^ ^V. . ^ i ; \ ; i . i '1 1 i .i i 1 PARTICLE SIZE 1 1 1 -9 -8 -7 -6 -5 I 1 1 -4 -3 -2 -1 PHI ® I 0 1 • l ; l \ ; ^^A •'• --^T rf-.- * :ft> A '•:!•-; V V: : | % ! \ i . TSi^ ' ' * \ s -i r- \ • ! . ""' L '— - ^ •- i ' ' ' I i LIMIT TT DAT/ 1 ! f YPICA ^Fi DA *\ ! v t • • i OF ALL . (T!YP.) E (TYP.) . RANGE 'A (TYP.) 0.062 mr •si • -^T^ LJ_fci_. .'. . . i. . .'.t ! . ' ' ' 1 - !| . i ii 1 ; ; i - i : : ; : ! i : • • i ' i '. 1 i . f : j 10 20 O 40 ^a: 50 l~ LJ 60 g i t 1 70 90 0.1 0.01 0.001 [mm) II l l i l i 23456789 10 SIZE (<J>) FY-1997 MCON PROJECT P-706 ?8 MAR q7 MILITARY CONSTRUCTION PROJECT DATA CHANNEL DREDGING AT NAS.N.I. nmpr , . CORONADO, CALIFORNIA L 4 Gravel Below MSL • Entire Oceanslde Cell Above MSL • Entire Oceanside Cell Dredge Material Area 1 Dredge Material Area 2 0)u (5Q.*j O)'5 10 Grain Size (mm)0.1 0.01 Composite Grain Size Distribution for The Oceanside Littoral Cell as they Existed in 1983 -1984 and Composites of Grain Size Distribution of samples collected in Dredge Areas 1 and 2 SOURCE: Sediment Budget Report Oceanside Littoral Cell, CCSTWS. November, 1990 •;i"V;t'r^•iiS&f,f^'^%w FY-1997 MCON PROJECT P-706 MILITARY CONSTRUCTION PROJECT DATA CHANNEL DREDGING AT NAS.N.I. CORONADO, CALIFORNIA 28 MAR 97 FIGURE 6.5 SOUTHWESNAVFACENGCOM FY 97 MCON PROJECT P-706 CHANNEL DREDGING BEACH SAND TRANSPORT AND SEDIMENTATION REPORT PHASE I: SOUTH OCEANS1DE AND SOLANA BEACH • the dredge materials will reside in this area of the profile upon reaching equilibrium • under a normal seasonal wave climate, there is very limited potential for a significant percentage of materials to move offshore below the pinch-out depth • for a given wave climate, the beach fill will have a greater probability of staying on the active profile in the vicinity of MSL for a longer period of time than material with a finer composite grain size, and • although the berm construction template will erode above MSL overtime, a high percentage of the sediments will be retained within the littoral zone and contribute to long-term nourishment of the beaches in the Oceanside Littoral Cell. 6.2.3 Grain Size Effect on Berm Behavior In order to demonstrate the important relationship between grain size and erosion rates of the beach fill above MSL, the rate of beach erosion for the alternative berm construction templates was investigated using the SBEACH model which is described in Section 6.4 of this report. The berms were all modeled with the same unit quantity (160 nrVm) of fill material using seasonal wave climate, represented by the 1993 wave data. It should be noted that this analysis is only a general indication of the relationship between grain size and rate of berm erosion for a given wave climate and does not represent an absolute solution for any given beach berm under specific wave conditions. The results of the analysis, as presented in Figures 6.6 and 6.7, show the influence of the grain size and berm elevation on the erosion rate above MSL for short term conditions (3 to 6 months) and long-term conditions (1 to 2 years), respectively. The short term analysis as presented in Figure 6.6 suggests several things: • The rate of erosion of the beach fill over the short term is both a function of berm construction template geometry and grain size. • Erosion rate of the fill above MSL, however, is far more sensitive to grain size than berm geometry. The erosion rate above MSL of various berm geometries has a tendency to converge with increasing grain size. • For beach fills constructed with dredge area 1 material (D50 = 0.18 mm), the Minimum Berm Alternative will erode somewhat faster above MSL than the Block Berm and the Low Berm Alternative will erode faster than the Minimum Berm. The Maximum Berm Alternative will erode at a rate between the Block and Minimum Berm Alternatives. • For beach fills constructed with dredge area 2 material (D50 = 0.35 mm) all berm alternatives will behave similarly over the short term. 28 MARCH 1997 6-10 BEACH SAND TRANSPORT & SEDIMENTATION 1.0 T 0.9 ' 0.8 ' Grain Size Effect on Berm Behavior (Short Term) Block Berm Template Minimum Berm [Template Dredge Material Area 1 Dso = 0.18 mm £. 0.7 ' 0.6 • 0.5 •S 0.4 0.3 0.2 0.1 ' 0.0 0.15 0.2 0.25 0.3 0.35 0.4 Dso Grain Size (mm) FY-1997 MCON PROJECT P-706 MILITARY CONSTRUCTION PROJECT DATA CHANNEL DREDGING AT N.A.S.N.I. CORONADO, CALIFORNIA 28 MAR 97 FIGURE 6.6 1.0 T 09 • 0.6 •• i 0.7JwE <D 5 0.6 ••J3m Q> 1 0.5 • 0.4 '5 0.3 IDoc 02 0.1 -• 00 Grain Size Effect on Berm Behavior (Long Term) 0.15 Dredge Material Area 1 DBO = 0.18 mm Block Berm Template Minimum Berm Template 0.2 0,25 0.3 0.35 0.4 Dso Grain Size (mm) Note: Analysis based on 160 m3/m section. FY-1997 MCON PROJECT P-706 MILITARY CONSTRUCTION PROJECT DATA CHANNEL DREDGING AT N.A.S.N.I CORONADO, CALIFORNIA 28 MAR 97 FIGURES./ SOUTH WESNAVFACENGCOM FY 97 MCON PROJECT P-706 CHANNEL DREDGING BEACH SAND TRANSPORT AND SEDIMENTATION REPORT PHASE I: SOUTH OCEANSIDE AND SOLANA BEACH The long-term analysis as presented in Figure 6.7 suggests several things: • The rate of erosion of the beach fill above MSL over the long-term is primarily a function of grain size for materials with a D50 < 0.2 mm. • The rate of erosion of the beach fill over the long-term is both a function of berni geometry and grain size for materials with 0.2 mm < D50 < 0.4 mm and primarily a function of grain size for materials with D50> 0.35 mm. • For beach fills constructed with dredge area 1 material (D50 = 0.18 mm), all berm alternatives will erode at essentially the same rate. • For beach fills constructed with dredge area 2 material (D50 = 0.35 mm), the Minimum Berm Alternative will erode somewhat faster than the Block Berm and the Low Berm will erode faster than the Minimum Berm. The Maximum Berm will erode at a rate between the Block and Minimum Berm Alternatives. In summary, given the grain size of the sand and quantity available for these opportunistic beach fills (as opposed to a deterministic beach restoration project where the primary objective would be to design and construct a beach fill for a given storm condition), the berm construction template will have only a minor affect on the short term fate of the beach fill and little, if any, effect over time. The primary controlling parameters which will determine the fate of the sand placed on the beach are: • the grain size of the material (fixed by the available dredge sediment), and • actual wave climate following placement. Whatever is constructed, wave, wave runup and cross-shore transport will tend to sort the sediments by grain size which will result in the establishment of a dynamic equilibrium profile. This is expected to occur in one to two years. 6.2.4 Scarp Considerations Scarps can develop both naturally along the beach profile and after placement of beach fill. The height of the scarp is a function of the breaking wave height and the elevation of the beach berm. Placement of the fill to a maximum elevation equal to the natural berm at each beach site will result in a potential scarp no greater than the natural occurring scarp elevation under given wave conditions. In the winter, sediments move off the beach into an offshore bar and during the summer are transported back onto the beach. Depending on the volume of sediments available to be transported onto the beach during the summer, a scarp may form along a point on the beach berm 28 MARCH 1997 6-13 BEACH SAND TRANSPORT & SEDIMENTATION SOUTHWESNAVFACENGCOM FY 97 MCON PROJECT P-706 CHANNEL DREDGING BEACH SAND TRANSPORT AND SEDIMENTATION REPORT PHASE I: SOUTH OCEANSIDE AND SOLANA BEACH where the waves break. If a large summer swell attacks the beach, a larger scarp than under normal seasonal conditions would likely develop. An example of a naturally occurring scarp is shown in Figure 6.8. This scarp is in the order of 2.0 to 2.5 m measured from the beach elevation at the waterline. As shown in the figure, naturally occurring scarps cause no significant adverse impact and have a tendency to slough due to human ingress and egress of the beach. Because the existing beaches in the Oceanside Littoral Cell are so severely eroded, placement of a berm with an elevation in excess of the natural berm elevation at South Oceanside and Solana Beach could result in a scarp height in excess of 2.5 m. Therefore, the beach fill berm should not be constructed higher than the Maximum Berm Alternative. 6.2.5 Fine Grained Material A high percentage of fine grained materials (O.062 mm) in the beach fill relative to the native beach are of concern for several reasons: • turbidity during beach fill placement • release of fines from the beach fill over time • "cementing" or hardening of the beach due to a high percentage of clay particles. Depending on the percentage of fines, these conditions could be considered as adverse impacts. However, because the percentage fines in the dredge material is less than the percent fines in the native Oceanside Littoral Cell sediments, no significant adverse impacts are anticipated. As shown in Figure 6.5, the average percentage of fines in the Oceanside Littoral Cell native sediments is approximately 3% above MSL and 12% below MSL. The higher percentage of fines below MSL is attributed to the fact that finer grained materials reside at equilibrium in the vicinity of, or below the shorebase. The average percentage of fines in the dredge material is approximately 3% in both dredge area 1 and 2. Refer to APPENDIX E for detailed grain size data. 6.2.5.1 Turbidity Turbidity during construction of the beach fill will be minimized through the construction of longitudinal dikes along the beach. Hydraulic discharge will be placed behind the dike and the return water will run behind the dike, allowing fine materials to settle out prior to mixing back into the ocean. 28 MARCH 1997 6-14 BEACH SAND TRANSPORT & SEDIMENTATION Naturally Occuring Scarp at Oceanside • Photograph taken July 31, 1960 • Approximate Tide = + 1.2 m NGVD • Approximate Berm Elevation = + 3.4 m NGVD • Steep beach face and scarp cut by large waves, possibly a southern swell ,EST' SOURCE: Flick et-# (1994) FY-1997 MCON PROJECT P-706 MILITARY CONSTRUCTION PROJECT DATA CHANNEL DREDGING AT N.A.S.N.I, CORONADO, CALIFORNIA 28 MAR 97 FIGURE 6.8 SOUTHWESNAVFACENGCOM FY 97 MCON PROJECT P-706 CHANNEL DREDGING BEACH SAND TRANSPORT AND SEDIMENTATION REPORT PHASE I: SOUTH OCEANSIDE AND SOLANA BEACH The ability to retain the return water behind the longitudinal dikes will be a function of the tide. A higher level of turbidity can be expected at high tide than at low tide, particularly at locations where there is no beach at high tide. However, since each dredge discharge event is expected to be in the order of 8,500 m3 pumped onto the beach over a 2 to 3 hour period over a beach length of approximately 40 m, the maximum release of fines is not expected to exceed approximately 6 mVm for any one discharge event. This amount will likely be smaller taking into account losses of fines during channel dredging and the fact that a portion of the fines will be retained in the beach fill. By taking these considerations into account and assuming a loss of approximately 20% fines during dredging and that approximately 40% of the remaining fines will be retained in the beach fill, maximum release during high tide conditions may be more in the order of 3 m3/m. Since the dredge materials exhibit a very low percentage of fines, a portion of which will be lost during channel dredging, the level of turbidity is expected to be low and not likely to be any greater than normally exhibited during beach filling in Oceanside by the USACOE and in Carlsbad by SDG&E. Also, since sediment discharge will be intermittent at intervals in the order of 6 to 10 hours, each for a period of 2 to 3 hours, increased turbidity will be on a temporary basis (lasting for 3 to 5 hours) for each discharge event. This is in contrast to the past permitted projects at Oceanside (by USACOE), Carlsbad (by SDG&E) and Batiquitos Lagoon which were carried out daily on a continuous basis during beach filling (8 or more hours of continuous hydraulic pumping versus 2 to 3 hours per event for this project). One last perspective would be to assume a worst case scenario where all the fines (insitu) would be retained during dredging, and that a total in the order of 10,000 m3 would be released all at once during beach filling (for South Oceanside 328,243 m3 x 0.03 = 9,847 m3). This of course will not happen for the reasons discussed above, but is used as a hypothetical example for discussion of probable impacts below. This estimated single event release of beach fill fines to the continental shelf is an order of magnitude less than the quantity of suspended solids discharged from some rivers in San Diego County during high flow events. Most investigators estimate 70 to 90% of the material discharged in the San Diego rivers is wash load, or suspended material. As an example, it is estimated that 1.7 million m3 of sediment was released from the San Luis Rey River in the flood of 1969. Approximately 70% of the material or 1.2 million m3 of sediment is estimated to have been wash load or fined grained materials and 30% sand-sized and greater. Similarly, the flood of 1978 produced a total sediment yield of 240,000 m3 from the San Dieguito River. Again, 70% of this material or 168,000 m3 is estimated to have been wash load or fine grained materials and 30% sand-sized and larger (Brownley et al, 1979). These quantities are orders of magnitude more than the maximum anticipated to be released by the beach filling. Therefore, fines released during filling are not anticipated to cause any impacts in excess of those which occur naturally. It is worthwhile to note, that silt and mud-sized material is naturally in transit across the shorebase and the continental shelf at all times. The sources of these fines are river discharge, lagoons, and cliff erosion. The materials from all of these sources are primarily silt and mud. 28 MARCH 1997 6-16 BEACH SAND TRANSPORT & SEDIMENTATION SOUTHWESNAVFACENGCOM FY 97 MCON PROJECT P-706 CHANNEL DREDGING BEACH SAND TRANSPORT AND SEDIMENTATION REPORT PHASE I: SOUTH OCEANSIDE AND SOLANA BEACH 6.2.5.2 Release of Fines after Filling Adverse impacts caused by shore-normal transport could occur if there is silt and mud-sized material in the beach fill, or if the fill migrates and reaches habitats that might suffer if covered. Silt and mud will pass across the shorebase at approximately 10m below MSL. The quantity of fines expelled from the beach fill as it is reworked will be proportional to the difference between percent fines (<0.062 mm diameter) in the beach fill and the percent fines in the insitu littoral sediment. Based on the available grain size data as depicted in Figure 6.5 and summarized in Table 6.2, the percentage of fines in the dredge sediment (insitu) is essentially the same as the littoral sediments. This is not surprising since a large portion of the sediments in the outer channel reside in the littoral cell. Since some fines are anticipated to be lost during the channel dredging, the as-placed beach fill is anticipated to have fewer fines than the natural beach sediments. Therefore, loss of fines over time should be no greater than the existing conditions. 6.2.5.3 Cementing or Hardening Cementing or hardening of the surficial sediment on the beach fill could occur if there are more than 5% clay particles (<0.002 mm) in the sediment. Since there are less than 3% total fines (silts and clays) in the dredge sediments, cementing or hardening of the beach fill is not anticipated. 6.3 Historic Beach Fill Experience There is significant data available to study "prototype experience" at Oceanside. This is made possible by the periodic harbor bypassing and other beach fill projects, in conjunction with the semiannual beach profile surveys conducted by the USACOE from 1983 to 1989 and those by SANDAG from 1990 to 1994. The historic beach fill events are described in Section 3.0 of this report. Two beach fill events were selected to present indicators of potential beach fill behavior following placement. However, it is noteworthy that more than 10 million m3 have been placed on Oceanside Beach over the last 42 years by the USACOE, and no adverse impacts have been recorded in the documentation reviewed. These past beach fills have been in the same quantity range as the individual beach fills proposed for this project. 28 MARCH 1997 6-17 BEACH SAND TRANSPORT & SEDIMENTATION SOUTHWESNAVFACENGCOM FY 97 MCON PROJECT P-706 CHANNEL DREDGING BEACH SAND TRANSPORT AND SEDIMENTATION REPORT PHASE I: SOUTH OCEANSIDE AND SOLANA BEACH 6.3.1 1983 Oceanside Beach Fill The first prototype experience is taken from the 1983 Oceanside Harbor bypass project. 363,000 m3 of material was dredged from the entrance channel of Oceanside Harbor and placed on Oceanside Beach between October 1983 and January 1984. Figure 6.9 shows beach profiles surveyed within 600 m downcoast of the dredge discharge on four different dates. None of the profiles showed any significant effect of beach fill beyond 400 m offshore, either initially or over a period of 18 months after fill placement. October 1983: The first profile was measured at the beginning of the beach fill placement. The beginning of the new beach fill berm is readily apparent. Note the slope of the beach fill is running out at approximately 1:12 slope. May 1984: This profile was measured approximately 6 months after the beach fill placement. The berm has eroded back about 6 m and is slightly lower than the initial placement. The beach slope shows a trough at approximately MLLW and another large trough around 150 m to 200 m offshore. A large bar has formed 250 m offshore. These troughs and offshore bars are indicative of winter wave attack and show the effect of winter waves on the beach fill. November 1984: The next profile was measured 12 months after the beach fill placement. The berm is narrower and lower due to continued wave erosion and littoral transport of the initial fill. The offshore bar seen in May has been moved onshore to the area from MLLW to 200 m offshore. June 1985: The last profile was measured 18 months after the beach fill placement. The top of the berm has eroded back 15m from the initial position and is 0.2 m lower. 6.3.1.1 Analysis of Sediment Transport The quantity of fill material placed in 1983 is comparable to the estimated quantity to be placed at South Oceanside. The cross-shore and along shore transport can be estimated from these fill and profile surveys. The May 1984 survey showed an increase in quantity of approximately 170 m3/m of material. The original beach fill unit quantity is assumed to have been in this order of magnitude. The profile shows that the beach fill completed in January was partially eroded after 6 months (approximately 30 m3/m) via cross-shore and along shore transport. Subsequent surveys showed continued erosion with cumulative values of 100 m3/m after 12 months and 112 m3 /m after 18 months. The quantity of fill above MSL for the beach fill is estimated to have been in the order of 75 m3/m. The loss of fill material above MSL was 27 m3/m, 38 m3/m and 47 m3/m at 6, 12 and 18 28 MARCH 1997 6-18 BEACH SAND TRANSPORT & SEDIMENTATION Profile Variation After 1983 Beach Fill at Oceanside Transect OS-0930 _ o w co " Dot 83 - During Fill (Summer) • May 84 - 6 months after fill(Winter) • Nov 84 12 months after fill(Summer) • Jun 85 -18 months after fill (Winter) ro I111 -5 ~ ~ -10 100 200 300 Distance from Range (m) 400 500 FY-1997 MCON PROJECT P-706 MILITARY CONSTRUCTION PROJECT DATA CHANNEL DREDGING AT N.A.S.N.I. CORONADO, CALIFORNIA 28 MAR 97 FIGURE 6.9 SOUTHWESNAVFACENGCOM FY 97 MCON PROJECT P-706 CHANNEL DREDGING BEACH SAND TRANSPORT AND SEDIMENTATION REPORT PHASE I: SOUTH OCEANSIDE AND SOLANA BEACH months, respectively. This means that the percent of beach fill remaining above MSL after 6, 12 and 18 months was 64%, 49% and 37%, respectively. The eroded materials appear to have been transported primarily along shore in the littoral zone since no increase in volume was detected at the shorebase. A small portion of the materials (fines), however, likely moved offshore below the shorebase. This fill was placed in October and shows the effect of wave energy transporting the beach fill to a bar approximately 150 to 200 m offshore and extending over an average width of 150 m. The maximum and average thickness of the offshore bar is 2 m and 1 m, respectively. The following summer season shows the transport of material back onshore to build the berm. 6.3.2 1988 Oceanside Beach Fill The second prototype experience is taken from the 1988 Oceanside Harbor bypass project. 168,000 m3 of material was dredged from the entrance channel of Oceanside Harbor and placed on Oceanside Beach between April and May 1988. Figure 6.10 shows beach profiles surveyed within 600 m of the dredge discharge on three different dates. None of the profiles showed significant effect of beach fill beyond 400 m offshore, either initially or over a period of 12 months after fill placement. April 1988: This profile was measured before the beach fill placement. An extreme storm event had occurred in January of this year. The characteristic steep beach slope and movement of material to an offshore bar can be seen. October 1988: The second profile was measured 6 months after the beach fill placement. Evidence of the beach fill can be seen in the wider beach and increased quantity of the overall profile. April 1989: This profile was measured 12 months after the beach fill placement at the end of the winter season. The beach slope is eroded back and a trough formed below MLLW. The profile seaward of this trough has reached an equilibrium position. 6.3.2.1 Analysis of Sediment Transport The surveys show that six months after fill placement approximately 70 m3/m of the original fill material was remaining. After 12 months approximately 55 m3/m was remaining. The material remaining above MSL was approximately 30 m3/m both at 6 and 12 months after fill placement. This fill was placed in April and shows minimal movement cross-shore during the summer months. The winter profile shows the formation of an offshore bar beginning at approximately 100 to 150m offshore and extending over an average width of 150 m. The maximum and average thickness of the offshore bar is 1.5 m and 0.7 m, respectively. 28 MARCH 1997 6-20 BEACH SAND TRANSPORT & SEDIMENTATION Profile Variation After 1988 Beach Fill at Oceanside Transect OS-0930 Apr 88 -Pre-Filt (Winter) Oct 88 - 6 months after fill (Summer) Apr 89 -.12 months after fill (Winter) 100 200 300 Distance from Range (m) 400 500 600 FY-1997 MCON PROJECT P-706 MILITARY CONSTRUCTION PROJECT DATA CHANNEL DREDGING AT NAS.N.I. CORONADO, CALIFORNIA 28 MAR 97 FIGURE 6.10 SOUTHWESNAVFACENGCOM FY 97 MCON PROJECT P-706 CHANNEL DREDGING BEACH SAND TRANSPORT AND SEDIMENTATION REPORT PHASE I: SOUTH OCEANSIDE AND SOLANA BEACH 6.3.3 Conclusions The following conclusions are drawn from these prototype beach fills: • Beach fills in quantities comparable to the proposed beach fill have been constructed in Oceanside in the past. • Variation in winter and summer profiles results in formation of an offshore bar, approximately 150 m wide, with a maximum thickness in the order of 2 to 2.5 m and an average varying from 0.7 to 1.5 m. • No significant amount of material accumulated offshore in the shorezone beyond 450 m. • The berm portion of the beach fill material was eroded over time, but a portion of the beach fill was retained above MSL for at least 12 months. • Based on the quantity of fill and type of construction, the proposed beach fills will likely behave similarly to these prototype examples. 6.4 Numerical Modeling Limited numerical modeling was performed to supplement the qualitative analysis presented above. Two beach and shoreline numerical models, SBEACH (Storm Induced BEAch Change) and GENESIS (GENEralized model for simulating Shoreline changes), which were developed by the US Army Corps of Engineers at the Waterways Experiment Station (WES) Coastal Engineering Research Center (CERC), were used to simulate the shoreline responses to the proposed beach fill in the project areas. The two models are considered the most applicable models for the study area (USACOE, 1996 and USACOE, 1989). It should be emphasized that the intent of the numerical simulations is to reveal general trends in the shoreline response to the beach fill under the assumed wave climate. The GENESIS model results, combined with the SBEACH output, provide the planner with a general understanding of the beach fill sand movement and interpretation of project impacts. GENESIS and SBEACH models were applied on each of the beach fill sites. The model I/O and results are discussed for each beach fill site with details presented in APPENDIX C. The following sections present the wave climate assumptions as well as the capability, general assumptions, and input/output requirements of the numerical models. 28 MARCH 1997 6-22 BEACH SAND TRANSPORT & SEDIMENTATION SOUTHWESNAVFACENGCOM FY 97 MCON PROJECT P-706 CHANNEL DREDGING BEACH SAND TRANSPORT AND SEDIMENTATION REPORT PHASE I: SOUTH OCEANSIDE AND SOLANA BEACH 6.4.1 Wave Data Continuous directional wave records offshore of Oceanside in approximately 10 m water depth, from 1988 and 1993 (Seymour, 1989) were used for numerical modeling input. Seasonal wave climate in the study area without the presence of large tropical or extratropical storms is well represented by 1993. In January 1988 an extreme extratropical Northern Hemisphere storm occurred. The January 17-18, 1988 storm was the largest storm measured along the southern California coast. The significant wave height at the shoreline was 4.2 m and offshore deep water heights exceeded 10 m. The rest of 1988 was less stormy than typical. The 1993 data, representing a "normal" year was used for GENESIS modeling. The 1993 data, along with the 1988 data, representing a storm event year were used for SBEACH modeling. 6.4.2 SBEACH The numerical model SBEACH was used to simulate beach profile changes in the cross-shore (offshore) direction for 1988 and 1993 wave climate and tide conditions. The model was also used to estimate erosion rates of materials placed above MSL. The model is best suited for short term storm events as sediment transport and beach profile change are driven by breaking waves and water elevation (USACOE, 1996). SBEACH was not developed to model the seasonal changes in beach width, or the accumulated effects from year-to-year. For this study the model is used to simulate erosion of the beach profile over short time periods. Beach profile changes developed from the modeling should be considered approximate when evaluating historical or seasonal profile changes and should be applied with coastal engineering judgement. The SBEACH model was validated for offshore transport and erosion of material above MSL using the before fill and after fill measured profiles for the Batiquitos Lagoon Enhancement project (Transect CB-0760) surveyed in October 1994 and May 1996. The fill was placed from October 1994 through January 1995. The berm elevation of the constructed fill was approximately +4.2 m MSL and 90 m wide with a 1:3 slope (approximately 300 mVm). The mean grain size of the fill material (D50) was in the range of 0.18 to 0.20 mm. Three months after placement of the fill, the edge of the berm receded approximately 30 m (75-90 m3/m) based on site observations. Approximately 65-70 percent of the initial fill above MSL was transported along shore and/or cross-shore after 18 months. Using these measured profiles and observations, the model transport parameters were calibrated for the offshore transport analysis. 6.4.2.1 Profile Modeling Recent beach profile surveys and existing shoreline conditions were used as the initial conditions for each of the model simulations. For each site a beach fill was modeled to estimate the offshore transport of material and to determine potential profiles during a short-term 6 month post-fill period. The beach fill profiles modeled for each site and general model assumptions are described in Table 6.3: 28 MARCH 1997 6-23 BEACH SAND TRANSPORT & SEDIMENTATION SOUTHWESNAVFACENGCOM FY 97 MCON PROJECT P-706 CHANNEL DREDGING BEACH SAND TRANSPORT AND SEDIMENTATION REPORT PHASE I: SOUTH OCEANSIDE AND SOLANA BEACH TABLE 6.3 - SBEACH BEACH FILL MODEL INPUT DATA SITE South Oceanside Cardiff - Solana Fletcher - Sofana BERM WIDTH On) 50 40 60 HEIGHT (m, MSL) +1.7 +1.7 +1.8 SLOPE 1:20 1:20 1:20 QUANTITY (mVm) 160 200 210 PRE-NOURISHMENT PROFILE TRANSECT NO. OS 0930 SD 0630 SD 0600 SURVEY DATE May96 May96/Oct87 May96/Dec89 Notes: 1. The longshore wave, current, and sediment transport process are omitted. 2. The grain sizes range from 0.20 to 0.42 mm. 3. Transport rate coefficient K = 2.5 e"7 m2/s. 4. Coefficient for slope dependent term = 0.001 m2/s. 5. Transport rate decay coefficient (Multiplier LAMM) = 0.5 6. Water temperature = 20°C. 7. Seawalls were assumed at certain locations to represent the cliffs and the existing shoreline protection The beach fill profiles were simulated for two climatological cases at each beach fill as follows: • CASE 1: 6 months of moderate wave climate (1993) • CASE 2: 6 months with a storm event (1988) Model simulations for individual sites are discussed in the following sections. Model input/output for all runs are presented in APPENDIX C. The output file contains adjusted profile data for 6 months following the beach fill. 6.4.2.2 Limitations The SBEACH program only allows for the designation of one grain size diameter to represent the entire beach profile. There are differences in the mean D50 for the back berm, beach slope and foreshore section of the existing beach profiles. In addition, the mean value for the beach fill material and the native beach sediment must be considered for the analysis. A weighted D50 average of the native sediment and proposed beach fill material for each site was used for the model. Due to this constraint, the modeled profiles often show a flatter angle from the beach to the berm crest since the designated model grain size is finer than the native material in that section. Similarly, the beach fill material in the foreshore slope has a steeper angle of repose since the model grain size is coarser than the native material. 28 MARCH 1997 6-24 BEACH SAND TRANSPORT & SEDIMENTATION SOUTHWESNAVFACENGCOM FY 97 MCON PROJECT P-706 CHANNEL DREDGING BEACH SAND TRANSPORT AND SEDIMENTATION REPORT PHASE I: SOUTH OCEANSIDE AND SOLANA BEACH 6.4.3 GENESIS The shoreline change model GENESIS was recommended as the most suitable model for evaluating the long-term trends of shoreline response to beach fills in the study area (USACOE, 1991). The basic assumptions of this shoreline response model are: • the beach profile shape is constant • the shoreward and seaward limits of the profile are constant • sand is transported along shore by the action of breaking waves • detailed structure of nearshore circulation can be ignored • there is a long-term trend in shoreline evolution Based on the model assumptions, the cross-shore movement of sand due to seasonal wave climate variation and storm waves are neglected in this model. Therefore, this shoreline response model is more suited for long-term effects which average out the cross-shore sand movement effects due to seasonal and storm waves. 6.4.3.1 Shoreline Modeling Existing MSL shoreline conditions for GENESIS modeling were approximated using currently available digital USGS quad sheet data. Accuracy of the shoreline was verified using the limited sections of shoreline which were surveyed in March 1996. The USGS data was found to be in conformity with the March 1996 data and adequate for modeling given the simplification of the overall analysis. The input data for GENESIS requires defining an equilibrium beach profile which will affect the dimensions of the berm. As the beach fill moves toward an initial equilibrium profile, it is assumed that the beach slope will take a flatter slope similar to the existing nearshore slope. A schematic presenting the initial beach profile adjustment for GENESIS is shown in Figure 6-11. GENESIS model beach fill parameters and input assumptions are shown in Table 6-4. Model simulations for individual sites are discussed in the following sections. Model input/output for all runs are presented in APPENDIX C. The output file contains shoreline positions at 3, 6, and 12 months following the beach fill. 28 MARCH 1997 6-25 BEACH SAND TRANSPORT & SEDIMENTATION 0)T3o CO"530) 0) O fi*•*c0) *•*W3 .£*^o (L On CQ E 3orLU (0 V£o (0 (T 00 CN CD LUtr Z)o Q. LU a: S§ §0o cc uj Q Ol O i O^° QJo: ££ ZO £ ?° i5 IIIfQ- oiil Q.OCQ E C <D P c S_QS ^ I «r— ^ II <D .p ^ 55 ^ -c 9- n $O O- t. O r= O 0 -Q C -^ •a- <D 1 i « ~ 01 5 II II E == 6-co^u, — 0) O Ci 10 c.riCD — LU M " iten E< SOUTHWESNAVFACENGCOM FY 97 MCON PROJECT P-706 CHANNEL DREDGING BEACH SAND TRANSPORT AND SEDIMENTATION REPORT PHASE I: SOUTH OCEANSIDE AND SOLANA BEACH TABLE 6.4 - GENESIS BEACH FILL MODEL INPUT DATA SITE South Oceanside Cardiff - Solana Fletcher - Solana ADJUSTED BERM WIDTH (m) 25 25 45 HEIGHT (m, MSL) +1.7 +1.7 +1.8 LENGTH (m) 2,000 1,000 700 WAVE ANGLE ADJUST- MENT 51° 48° MODEL LIMITS NORTH Oceanside Harbor South Jetty Santa Fe Drive (City of Encinitas) SOUTH Agua Hedionda North Jetty 1,000m South of San Dieguito Lagoon LENGTH (km) 8.7 8 Notes: 1 . Refer to Figure 6. 1 1 for adjusted berm geometry. 2. Wave angle was adjusted to the shoreline orientation from the Oceanside array (refer to Appendix for wave angle adjustment diagram). 3. 1993 wave record used with continuous 3-hour interval model run. 4. All model runs begin m July for simulated duration of 1 year. 5. Median grain size of beach sediment 0.18 mm. 6. Assumed open boundaries at the left and right limits of shoreline. 7. Assumed stone jetty at Oceanside Harbor and stone groin at San Luis Rey River mouths are impermeable and non-diffracting. 8. Seawalls were assumed at certain locations to represent the cliffs and the existing shoreline protection. 6.4.3.2 Limitations A maximum simulation period of 12 months was used in the GENESIS model analysis to predict the longshore movement of beach fill sand. The model runs were based on the assumption that regular wave climate would dominate in the 12-month period following the beach fill construction. Based on this assumption, the 1993 wave record was used as a seasonal year of wave climate. In the model run, the sediment transport parameters were not calibrated using a measured shoreline and wave record due to time constraints and limited existing survey data. The two calibration constants kj and k 2 were assigned with average values of 0.45 and 0.25. Although not calibrated, the model results are expected to represent an average condition at each site. As a result, the model analysis conducted for this study should be treated as qualitative. For a more detailed analysis, the following should be considered: • apply a long-term wave record or hindcast • perform calibration and sensitivity analysis • simulate more detailed sediment sources and sinks 6.5 South Oceanside Analysis 28 MARCH 1997 6-27 BEACH SAND TRANSPORT & SEDIMENTATION SOUTHWESNAVFACENGCOM FY 97 MCON PROJECT P-706 CHANNEL DREDGING BEACH SAND TRANSPORT AND SEDIMENTATION REPORT PHASE I: SOUTH OCEANSIDE AND SOLANA BEACH 6.5.1 Natural Variation of Sediment Transport The existing natural variation of sediment transport was evaluated through the use of seasonal beach profile surveys. Beach surveys for the South Oceanside shoreline (Transect OS-0930) were made twice a year between 1983 and 1994, one in the spring and the other in the fall. There were no surveys conducted during 1995, and the biannual surveys were started again in the Spring of 1996. Beach profile surveys taken from 1991 through 1994 show the annual variation between winter and summer profiles. The winter profile variation in these surveys shows the formation of an offshore bar starting at approximately 100 to 200 m offshore extending an average distance of 200 m as shown in Figure 6.12. The maximum and average thicknesses of the offshore bar, over the three years, are approximately 2.3 and 1.4 m, respectively. In addition, the seasonal change in sand quantity based on the surveys is approximately 60 to 150 mVm. The change in quantity is primarily attributed to material being transported along shore through natural littoral processes. 6.5.2 Numerical Model Results SBEACH modeling of the two different climatological cases produced similar offshore beach profiles (short term). The comparison of the SBEACH profile after a typical winter season following the placement of the beach fill is shown in Figure 6.12. As shown in the figure, the model profile is generally within the range of the seasonal profile shift shown in the surveys. The GENESIS model was used to simulate shoreline response from Oceanside Harbor south to Agua Hedionda Lagoon (northjetty), approximately 8,700 meters of shoreline. This shoreline was divided into 87 cells with 100 meter cell widths. The 40 m wide, 2,000 m long beach fill was located from cell 23 to cell 43. Figure 6.13 illustrates the predicted mean sea level shoreline responses to the beach fill. The stations on the figure correspond to the cell numbers in the model (i.e., cell 23 = station 2300). The results indicate a longshore spread of beach fill sand during the simulation period. The longshore spread of beach sand and resulting beach width changes at certain key locations are summarized in Table 6.5. While the shoreline modeled the area from Oceanside Harbor south to Agua Hedionda Lagoon, the area of influence indicated by the model was limited to approximately 3,000 m both upcoast and downcoast as shown in Figure 6.13. No significant effect over a 12 month period resulted beyond these limits. Refer to APPENDIX C for detailed model input/output. 28 MARCH 1997 6-28 BEACH SAND TRANSPORT & SEDIMENTATION 10 c.2 Q I -5 LLJ -10 -15 Seasonal Profile Variation at South Oceanside Transect OS 0930 Winter Summer Nourished SB EACH Season 100 200 300 400 500 600 700 800 Distance from Range (m) 900 1000 1100 1200 FY-1997 MCON PROJECT P-706 MILITARY CONSTRUCTION PROJECT DATA CHANNEL DREDGING AT N.A.S.N.I. CORONADO, CALIFORNIA 28 MAR 97 FIGURE 6.12 SOUTH OCEANStDE BEACH FILL APPROXIMATE SHORELINE AT 12 MONTHS AFTER PLACEMENT BUENA VISTA LAGOON -100 CO -150 -200 -250 -300 -350 ^00 APPROXIMATE PRE-FILL SHORELINE POSITION SAN LUIS REY GROIN OCEANSIDE HARBOR SOUTH JETTY 1000 2000 4000 'P re-Fill - • ~ 3 months •'' '6 months 12 months 50003000 Shoreline Station (m) MEAN SEA LEVEL SHORELINE RESPONSE AT SOUTH OCEANSIDE Shoreline position exagerated 5 X FY-1997 MCON PROJECT P-706 MILITARY CONSTRUCTION PROJECT DATA CHANNEL DREDGING AT N.A.S.N.I CORONADO, CALIFORNIA 6000 28 MAR 97 FIGURE 6.13 SOUTH WESNAVFACENGCOM FY 97 MCON PROJECT P-706 CHANNEL DREDGING BEACH SAND TRANSPORT AND SEDIMENTATION REPORT PHASE I: SOUTH OCEANSIDE AND SOLANA BEACH TABLE 6.5 - PREDICTED SHORELINE POSITION AT SOUTH OCEANSIDE SHORELINE LOCATION San Luis Rey River Jetty Wisconsin Avenue Loma Alta Creek Mouth Buena Vista Lagoon Inlet Agua Hedionda Lagoon Inlet SHORELINE POSITION CHANGES - PERIOD AFTER BEACH FILL 3 MONTHS m +2 +23 +13 0 0 % +3 +50 +3 0 0 6 MONTHS m +4 +23 +11 0 0 % +7 +50 +3 0 0 12 MONTHS m +10 +19 +12 0 0 % +17 +42 +4 0 0 Notes: 1 "+" indicates accretion of shoreline position from pre-fill position 2. "-" indicates retreat of shoreline position from pre-fill position 3. % indicates the increase of beach width from width surveyed in March 1996. Note that the shoreline position changes at the San Luis Rey River and Loma Alta Creek inlets represent the widening of the existing natural berm and beach. The buildup of sediment beyond the natural berm height is not anticipated due to natural inlet and outlet flow. Buena Vista Lagoon and Agua Hedionda Lagoon inlets are both out of the regional influence of the South Oceanside Beach Fill. No change in shoreline response beyond existing naturally occurring changes are anticipated in these areas. Also, the model results suggest accretion at the Oceanside Harbor south jetty and the San Luis Rey river groin followed by erosion at the Oceanside Harbor jetty after 12 months. This retreat of the shoreline in the model is attributed to the following: • the predominant northwest swell in the later 6 months of the wave record, and • Model simplification does not take into account the wave sheltering and diffraction effects of the Oceanside Harbor north breakwater. Therefore, erosion shoreward of the existing shoreline at the Oceanside Harbor south jetty is not anticipated. Also, the small increase in beach width at the San Luis Rey River groin will be reduced over time as the sand moves back along the shoreline in the southerly direction. 6.5.3 Limits of Sand Movement The general limits of sand movement following beach filling are inferred from the SBEACH and GENESIS models, the documented natural variations in the beach profiles at South Oceanside and the grain size compatibility discussions presented earlier. Based on these analyses, the following conclusions are drawn for the South Oceanside Beach Fill. 28 MARCH 1997 6-31 BEACH SAND TRANSPORT & SEDIMENTATION SOUTHWESNAVFACENGCOM FY 97 MCON PROJECT P-706 CHANNEL DREDGING BEACH SAND TRANSPORT AND SEDIMENTATION REPORT PHASE I: SOUTH OCEANSIDE AND SQLANA BEACH • The beach fill will erode above MSL over time and spread cross-shore and along shore. • The seasonal cross-shore movement of the beach fill will transport the fill material offshore in the winter, back onto the beach in the summer, and repeat in subsequent seasons with seasonal losses due to cross-shore and along shore transport. • The limits of cross-shore transport are generally confined to within 450 m of the back beach as shown in Figure 6.12. • After a number of years, the beach fill material will be sorted by grain size across the natural equilibrium profile. • The limits of long-shore transport are generally confined to 3,000 m upcoast and downcoast of the beach fill 12 months following fill placement. After achieving an equilibrium profile, anticipated to occur over a 1 to 2 year period, the transport of material is anticipated to follow the existing natural trend. • Erosion of the shoreline adjacent to the beach fill will not occur beyond that which occurs naturally. 6.5.4. Thickness of Sand The general thicknesses of sand following beach filling are inferred from the SBEACH and GENESIS models, documented natural variations in the beach profiles at South Oceanside, and the grain size compatibility discussions presented earlier. Based on these analyses, the following conclusions are drawn for the South Oceanside Beach Fill. • Sand will move to an offshore bar seasonally. The average and maximum thicknesses of sand at the bar will be in the order of 0.7 to 1.4m and 1.5 to 2.3 m, respectively. • Assuming longshore transport 3,000 m up and downcoast of the beach fill and a 450 m seaward limit of cross-shore transport, the increase in sand thickness averaged over a one year period (winter and summer) is anticipated to be in the order of 0.1 to 0.2 m. Given the grain size of the beach fill materials, the increased thickness is anticipated to be the greatest just below MSL on the equilibrium profile and decrease seaward. 6.5.5 Surf Conditions Wave breaking characteristics important to surfing are influenced by underwater features including sand bars, reefs and beach profile slopes in the surf zone. These features are a result of natural seasonal fluctuations of sediment moving on and off the beach through the natural littoral processes. Based on the historic profiles and modeling results, the following conclusions relative 28 MARCH 1997 6-32 BEACH SAND TRANSPORT & SEDIMENTATION SOUTHWESNAVFACENGCOM FY 97 MCON PROJECT P-706 CHANNEL DREDGING BEACH SAND TRANSPORT AND SEDIMENTATION REPORT PHASE I: SOUTH OCEANSIDE AND SOLANA BEACH to wave breaking characteristics and surf conditions are drawn for the South Oceanside Beach Fill. • Sand bars will tend to improve offshore surfbreaks and improve surf conditions of larger waves. • Reef breaks may temporarily be affected if sand accumulates at the reef base, but this should be in the range of natural seasonal variations of a sandy beach. • The eroding fill may buildup and flatten the beach slope shoreward of the sand bar, tending to move smaller waves away from the shorebreak. • The berm may cause slightly increased wave energy reflection at high tide. » Beneficial impacts to surf conditions from the formation of offshore bars are anticipated as discussed above. No significant adverse impacts to surf conditions are anticipated. Temporary seasonal covering (winter) of reef breaks in the nearshore is likely. 6.5.6 Scarping The increased quantity of sand resulting from the South Oceanside Beach Fill is anticipated to increase the short term occurrence of scarps. However since the berm will be constructed no higher than the natural berm elevation (the Maximum Berm Alternative), the scarp height is not anticipated to be in excess of that which would normally occur on this beach. Refer to Section 6.2.4 of this report for additional discussion. 6.5.7 Turbidity For the reasons discussed in Section 6.2.5, turbidity is not anticipated to cause any significant adverse impacts. 6.5.8 Coastal Wetlands Discussion of impacts at the lagoon mouths and creeks related to the South Oceanside Beach Fill is based on the results of the analysis performed and evaluation of existing and historic conditions. 6.5.8.1 San Luis Rey River The modeling results suggest that sand migrating upcoast from the South Oceanside beach fill would reach the vicinity of the San Luis Rey River mouth and potentially widen the MSL beach at this location up to 10 m within 12 months following fill placement. This will result in an approximate 17% increase in the length of the river mouth. This is not anticipated to affect river runoff which is constrained by eight 91 cm diameter pipes. 28 MARCH 1997 6-33 BEACH SAND TRANSPORT & SEDIMENTATION SOUTHWESNAVFACENGCOM FY 97 MCON PROJECT P-706 CHANNEL DREDGING BEACH SAND TRANSPORT AND SEDIMENTATION REPORT PHASE I; SOUTH OCEANSIDE AND SOLANA BEACH Also, since the existing sand berm that crosses most the San Luis Rey River mouth is already at a higher elevation than the predicted contribution from the beach fill, it is not likely that the beach fill will impact the overall configuration of the river mouth. Under closed river mouth conditions and during periods of low to moderate river flow, runoff may pond behind the new sand berm, spread out, and seep through the beach berm. During winter periods of moderate to strong stormwater runoff the sand berm would be rapidly breached and/or overtopped. Maintenance of the river mouth, as currently performed by the City of Oceanside, should be continued on an as-needed basis for flood control. 6.5.8.2 Loma Alta Creek The South Oceanside beach fill site is located directly north of the Loma Alta Creek inlet. The existing berm elevation adjacent to the creek is +3.2 m MSL at Buccaneer Beach and +2.3 m MSL at the adjacent residential property to the north. The creek maintains its flow through this berm with a creek bed elevation of approximately -0.6 to -0.8 m MSL. The proposed berm elevation of+1.7 m of the initial fill is approximately 2.4 m above the natural creek elevation. This berm will be placed just north of the creek mouth and is expected to spread after placement. However, the elevation of the berm is not likely to exceed about 1.0 m immediately after spreading to this area. This not anticipated to cause any adverse impact since the City of Oceanside currently builds a sand berm in front of the creek preventing flow between Memorial Day and Labor Day. During the rainy season, the City of Oceanside then excavates a temporary channel to facilitate stream flow to the ocean. Maintenance of the creek mouth should be continued to ensure adequacy of the discharge channel. The modeling results indicate that the MSL beach width at Loma Alta Creek will increase from the initial 125 m by 11 or 12 m over a 12 month period. This will result in an approximate 10% increase in the length of the creek discharge channel. This increase is not anticipated to cause any significant adverse impact. 6.5.8.3 Buena Vista Lagoon Since the existing weir at the outlet of Buena Vista Lagoon is at an elevation of+1.82 m MSL, any beach fill berm in front of the lagoon below this elevation is not likely to impact lagoon discharge to the ocean. The modeling results indicate that 12 months following fill placement, sediment from the South Oceanside beach fill will not migrate to the vicinity of Buena Vista Lagoon. No change in the shoreline response beyond existing naturally occurring changes are anticipated at this area. 28 MARCH 1997 6-34 BEACH SAND TRANSPORT & SEDIMENTATION SOUTHWESNAVFACENGCOM FY 97 MCON PROJECT P-706 CHANNEL DREDGING BEACH SAND TRANSPORT AND SEDIMENTATION REPORT PHASE I: SOUTH OCEANSIDE AND SOLANA BEACH 6.5.8.4 Agua Hedionda The modeling results indicate that 12 months following fill placement, sediment from the South Oceanside beach fill will not migrate to the vicinity of Agua Hedionda Lagoon. No change in the shoreline position beyond existing naturally occurring changes are anticipated at this area. 6.6 Solana Beach Analysis 6.6.1 Natural Variation of Sediment Transport The existing natural variation of sediment transport was evaluated through the use of seasonal beach profile surveys. 6.6.1.1 Cardiff State Beach Fill Beach profile surveys taken from 1984 and 1986-1987 show the annual variation between winter and summer profiles. The winter profile shows the formation of a sand bar starting at approximately 130-140 m offshore extending an average distance of 170 m as show in Figure 6.14. The maximum and average thicknesses of the offshore bar, over the three years, are approximately 2.0 and 0.9 m, respectively. In addition, the seasonal change in sand quantity based on the surveys is approximately 30-100 nrVm. The change in quantity is primarily attributed to material being transported along shore through natural littoral processes. 6.6.1.2 Fletcher Cove Fill Beach profile surveys taken from 1984 and 1986-1987 show the annual variation between winter and summer profiles. The winter profile shows the formation a sand bar at the end of the winter months starting at approximately 130-145 m offshore over an average distance of 170 m as shown in Figure 6.15. The maximum and average thicknesses of the offshore bar, over the three years, are 1.1 m and 0.6 m, respectively. In addition, the seasonal change in sand quantity based on the surveys is approximately 65-135 m3/m. The change in quantity is primarily attributed to material transported littorally along shore. 28 MARCH 1997 6-35 BEACH SAND TRANSPORT & SEDIMENTATION Seasonal Profile Variation at Cardiff - Solana Beach Transect SD 0630 Winter Summer Nourished SBEACH Season 100 200 300 400 500 600 700 800 Distance from Range (m) 900 1000 1100 1200 FY-1997 MCON PROJECT P-706 MILITARY CONSTRUCTION PROJECT DATA CHANNEL DREDGING AT N.A.S.N.I. CORONADO, CALIFORNIA 28 MAR 97 FIGURE 6.14 Seasonal Profile Variation at Fletcher - Solana Beach Transect SD 0600 Winter Summer Nourished SBEACH Season 100 200 300 400 500 600 700 800 900 1000 Distance from Range (m) 1100 1200 FY-1997 MCON PROJECT P-706 MILITARY CONSTRUCTION PROJECT DATA CHANNEL DREDGING AT N.A.S.N.I. CORONADO, CALIFORNIA 28 MAR 97 FIGURE 6.15 SOUTH WESNAVFACENGCOM FY 97 MCON PROJECT P-706 CHANNEL DREDGING BEACH SAND TRANSPORT AND SEDIMENTATION REPORT PHASE I: SOUTH OCEANSIDE AND SOLANA BEACH 6.6.2 Numerical Model Results A composite profile for both the Cardiff State Beach and Fletcher Cove beach fill sites was developed from the most recent profile and historic profiles. Beach surveys for the Cardiff State Beach (Transect SD-0630) and Fletcher Cove (Transect SD-0600) were conducted biannually from 1984 through 1987 and winter surveys in 1988 and 1989. There were no surveys conducted in between that year and the May 1996 surveys. In addition, the May 1996 surveys were short profiles that only extended approximately 200 m seaward to -5 m MSL. Because of this, the composite profiles were used for SBEACH modeling. SBEACH modeling of the two different climatological cases for both Solana Beach Fill sites produced similar offshore beach profiles (short term). The comparison of the SBEACH profiles after a typical winter season following the placement of the beach fill are shown in Figures 6.14 and 6.15. As shown in the figures, the model profiles are generally within the seasonal profile variations. The GENESIS model was used to simulate shoreline response to longshore transport for both Solana Beach Fill sites. The shoreline simulation covers a shoreline distance from Santa Fe Drive south for approximately 8 km to a point approximately 1 km south of San Dieguito Lagoon. This shoreline was divided into 80 cells with 100 meter cell widths. Two discrete beach fills were simulated in the model: • Cardiff State Beach: a 1,000 m long beach fill located from cell 21 to cell 31 • Fletcher Cove: a 700 m long beach fill located from cell 42 to cell 49 Figure 6.16 illustrates the predicted MSL shoreline responses to the beach fill. The stations on the figure correspond to the cell numbers in the model (i.e, cell 42 = station 4200). The results indicate a longshore spread of beach fill sand in the simulation period. The longshore spread of beach sand and resulting beach width changes at certain key locations are summarized in Table 6.6. While the modeled shoreline comprised from Santa Fe Drive to 1,000 m beyond San Dieguito Lagoon, the area of influence indicated by the model was limited to approximately 3,000 m both upcoast and downcoast as shown in Figure 6.16. No significant effect over a 12 month period resulted beyond these limits. Refer to APPENDIX C for detailed model input/output. 28 MARCH 1997 6-38 BEACH SAND TRANSPORT & SEDIMENTATION ROCKY POINT L. FLETCHER COVE BEACH FILL APPROXIMATE SHORELINE AT 12 MONTHS AFTER PLACEMENT -50 — -1000)c 8 -150CO £ -200 o 0) -250 -350 -400 1800 -APPROXIMATE PRE-FILL SHORELINE POSITION ROCKY POINT Pre-Fill- • - • - 3 months6 months12 months 2800 3800 58004800 Shoreline Station (m) MEAN SEA LEVEL SHORELINE RESPONSE AT SOLANA BEACH Shoreline position exagerated 5X 6800 FY-1997 MCON PROJECT P-706 MILITARY CONSTRUCTION PROJECT DATA CHANNEL DREDGING AT N.A.S.N.I. CORONADO, CALIFORNIA 7800 28 MAR 97 FIGURE 6.16 SOUTHWESNAVFACENGCOM FY 97 MCON PROJECT P-706 CHANNEL DREDGING BEACH SAND TRANSPORT AND SEDIMENTATION REPORT PHASE I: SOUTH OCEANSIDE AND SOLANA BEACH TABLE 6.6 - PREDICTED SHORELINE POSITION AT SOLANA BEACH SHORELINE LOCATION San Elijo Lagoon Inlet Nearshore reef Cliff Street San Dieguito Lagoon SHORELINE POSITION CHANGES - PERIOD AFTER BEACH FILL 3 MONTHS m +13 +0 +43 +9 % + 14 +0 +93 +6 6 MONTHS m +14 +0 +34 +14 % +15 +0 +74 +9 12 MONTHS m + 13 +0 +33 +18 % + 14 +0 +72 +12 Notes: 1. "+" indicates accretion of shoreline position from pre-fill position 2. "-" indicates retreat of shoreline position from pre-fill position 3. % indicates the increase of beach width surveyed in March 1996. 6.6.3 Limits of Sand Movement The general limits of sand movement following beach filling are inferred from the SBEACH and GENESIS models, the documented natural variations in the beach profiles at Solana Beach and the grain size compatibility discussions presented earlier. Based on these analyses, the following conclusions are drawn for the Solana Beach Fills. • The beach fill will erode above MSL over time and spread cross-shore and along shore. • The seasonal cross-shore movement of the beach fill material will transport the fill material offshore in the winter, back onto the beach in the summer repeating in subsequent seasons with seasonal losses due to cross-shore and along shore transport. • The limits of cross-shore transport are generally confined to within 300 to 350 m of the back beach as shown in Figures 6.14 and 6.15. • After a number of years, the beach fill material will be sorted by grain size across the natural equilibrium profile. • The limits of longshore transport are generally confined to 3,000 m upcoast and downcoast of the beach fill 12 months following fill placement. After achieving an equilibrium profile, anticipated to occur over a 1 to 2 year period, the transport of material is anticipated to follow the existing natural trend. • Erosion of the shoreline adjacent to the beach fill will not occur beyond that which occurs is naturally anticipated. 28 MARCH 1997 BEACH SAND TRANSPORT & SEDIMENTATION SOUTHWESNAVFACENGCOM FY 97 MCON PROJECT P-706 CHANNEL DREDGING BEACH SAND TRANSPORT AND SEDIMENTATION REPORT PHASE I: SOUTH OCEANSIDE AND SOLANA BEACH 6.6.4 Thickness of Sand The general thicknesses of sand following beach filling are inferred from the SBEACH and GENESIS models, the documented natural variations in the beach profiles at Solana Beach and grain size compatibility discussions presented earlier. Based on these analyses, the following conclusions are drawn for the Solana Beach Fill. • Sand will move to an offshore bar seasonally. The average and maximum thicknesses of sand at the bar will be in the order of 0.6 to 0.9 m and 1.1 to 2.0 m, respectively. • Assuming longshore transport 3,000 m up and downcoast of the beach fill and a 350 m seaward limit of cross-shore transport, the increase in sand thickness averaged over a one year period (winter and summer) is anticipated to be in the order of 0.15 to 0.2 m. Given the grain size of the beach fill materials, the increased thickness is anticipated to be the greatest in the vicinity of MSL and decrease seaward. 6.6.5 Surf Conditions For the reasons discussed in Section 6.5.5, beneficial impacts to surf conditions from the formation of offshore bars are anticipated. No significant adverse impacts to surf conditions are anticipated. 6.6.6 Scarping The increased quantity of sand resulting from the Solana Beach Fills are anticipated to increase the short term occurrence of scarps. However since the berm will be constructed no higher than the natural berm elevation (the Maximum Berm Alternative), the scarp height is not anticipated to be in excess of that which would normally occur on these beaches. Refer to Section 6.2.4 of this report for additional discussion. 6.6.7 Turbidity For the reasons discussed in Section 6.2.5, turbidity is not anticipated to cause any significant adverse impacts. 6.6.8 Coastal Wetlands Discussion of impacts at the lagoon mouths and creeks related to the Solana beach fills is based on the results of the analysis performed and evaluation of existing and historic conditions. 28 MARCH 1997 6-41 BEACH SAND TRANSPORT & SEDIMENTATION SOUTHWESNAVFACENGCOM FY 97 MCON PROJECT P-706 CHANNEL DREDGING BEACH SAND TRANSPORT AND SEDIMENTATION REPORT PHASE I: SOUTH QCEANSIDE AND SOLANA BEACH 6.6.8.1 San Elijo Lagoon Analysis results indicate that sand migrating along shore from the Solana Beach Fill would reach the inlet of San Elij o Lagoon and expand the beach width in this area by approximately 13 to 14 m over a period of 3 to 12 months after sand placement. This represents an increase in the inlet channel length by approximately 15%. The natural existing berm elevation in the vicinity of the lagoon mouth is approximately +1.5 to +2.0 m MSL (March 96) and approximately +3.0 m directly north and south of the opening. The proposed beach fill berm elevation south of the lagoon mouth at the Solana Beach - Cardiff fill site is +1.7 m MSL. As the beach fill material spreads and migrates to the north, it is expected to accrete to the natural berm elevation in the vicinity of the lagoon mouth. Local hydrographic conditions at the mouth of San Elijo Lagoon can be expected to influence sediment transport behavior. The presence of Cardiff Reef offshore affects wave conditions seaward of the ocean inlet, so that waves converge at the inlet from both upcoast and downcoast directions. Consequently, marine sand and cobbles tend to form an offshore subtidal delta that further complicates the configuration and behavior of the mouth of the lagoon. During high wave winter conditions with minimum sand on the beach, successive waves of cobble berms are transported from the south into the lagoon, line the inlet channel bed, further reduce weak lagoon ebb tidal flows, and eventually contribute to closure of the inlet. During high wave summer conditions, sand on the beach is transported from the south into the inlet and across the inlet to the north to build a sand bank on both sides of the channel. The inlet grows in length seaward due to accumulation of the sand banks. A sand/cobble delta forms offshore, slows the ebb flow further, and accelerates closure of the lagoon. The sand is also transported through the inlet and deposits in the lagoon; slowing both flood and ebb tidal velocities. The Solana Beach - Cardiff Fill is likeiy to cover most of the resident cobble berm, reduce its mobility across the beach, reduce its northward migration near the inlet, and help the inlet to stay open longer by minimizing the role of cobbles in the inlet closure process. However, the increased beach width could increase sand transport into the inlet since the source of sand is being increased. At the same time, the ebb tidal velocities should be able to erode more of the sand deposited in the inlet due to the absence of cobbles in the channel bed. Existing conditions can cause early spring or summer closure of the lagoon inlet. Historically, San Elijo Lagoon inlet has been closed 80% of the time. During the last four years, the lagoon has opened 50% of the time through inlet maintenance (Elwany, et. al., 1995). The County of San Diego and CDFG currently maintaining the lagoon mouth inlet to the ocean. The flow path of the lagoon across the beach berm should continue to be maintained as necessary. 28 MARCH 1997 6-42 BEACH SAND TRANSPORT & SEDIMENTATION SOUTHWESNAVFACENGCOM FY 97 MCON PROJECT P-706 CHANNEL DREDGING BEACH SAND TRANSPORT AND SEDIMENTATION REPORT PHASE I: SOUTH OCEANSIDE AND SOL ANA BEACH 6.6.8.2 San Dieguito Lagoon. Analysis results indicate that sand migrating along shore from the Solana Beach Fill would reach the inlet of San Dieguito Lagoon within 3 to 6 months and expand the beach width in this area 18 m within 12 months following fill placement. This represents an approximate 10% increase in the lagoon inlet channel length. Due to the wide configuration and long length of the inlet at San Dieguito Lagoon there is already a large supply of sand in the vicinity of the inlet. Any further increase hi the beach width can be expected to modify the behavior of lagoon ebb tidal flows, possibly slowing or dispersing the channel flow, and increasing the frequency of channel meandering. Reduced ebb flow velocities may facilitate accumulation of sand in the inlet and development of a sand sill across the mouth. Existing conditions can cause early spring or summer closure of the lagoon inlet. Historically, San Dieguito Lagoon was closed 70% of the time. Over the last 19 years, the lagoon has been open approximately 68% of the time (Elwany, et. al., 1995). The City of Del Mar and District 22 Agricultural Association are responsible for ensuring inlet flow for this lagoon and they excavate as-needed to keep the inlet open. 28 MARCH 1997 6-43 BEACH SAND TRANSPORT & SEDIMENTATION Section 7.0 Findings and Conclusions SOUTHWESNAVFACENGCOM FY 97 MCON PROJECT P-706 CHANNEL DREDGING BEACH SAND TRANSPORT AND SEDIMENTATION REPORT PHASE I: SOUTH OCEANSIDE AND SOLANA BEACH 7.0 FINDINGS AND CONCLUSIONS The dredging of the San Diego Bay Entrance Channel generates high potential for opportunistic beach fills in the San Diego region. Placement of sand on the beach in the Oceanside Littoral Cell is consistent with the findings of the CCSTWS (USACOE, 1991) which states that provision for increased quantity of nourishment material is of critical importance to stabilizing the beaches downcoast of Oceanside Harbor. The beach fills to be placed for this project are consistent with this important conclusion reached by the USACOE and meets the objectives of SANDAG's shoreline preservation strategy. This report studies the potential beneficial and adverse impacts resulting from placement of beach fill in South Oceanside and Solana Beach. The findings are based on an understanding of environmental conditions, littoral processes and coastal wetland processes, and on results of qualitative analyses and numerical modeling. Beneficial impacts of artificial beach fills include enhanced recreation areas, improved surf breaks, shoreline protection and erosion control, and improved cross beach and along shore access. These benefits are significant due to the lack of recreational beach at most locations and the risk of erosion to shoreline properties and cliff-top properties. Possible adverse impacts could include impeded shoreline access due to scarps, sand migration influencing lagoons, creeks and offshore habitat, modified surfing conditions, and impacts on structures and utilities. Potential impacts of sand from the proposed beach fills are summarized in this section. These findings and conclusions are based on analyses presented in Section 6, including: • Alternative Beach Fill Construction Templates (Section 6.2) • Beach Fill Material Compatibility (Section 6.2.2) • Grain Size Effect on Berm Behavior (Section 6.2.3) • Scarp Considerations (Section 6,2.4) • Fine Grained Material and Turbidity (Section 6.2.5) • Historic Beach Fill Experience (Section 6.3) • Numerical Modeling (Section 6.4) 7.1 Beach Fill Movement Beach fills create a sand berm on the beaches that provide recreational benefits and shoreline protection. However, placement of the sand on the beach creates a temporary disequilibrium in the beach profile. Over a period, which is expected to be in the order of one to two years, the sand will be redistributed from the placement location along shore and cross shore through natural littoral processes. The beach profile will then again reach an equilibrium position that will be very 28 MARCH 1997 ~\ BEACH SAND TRANSPORT & SEDIMENTATION SOUTHWESNAVFACENGCOM FY 97 MCON PROJECT P-706 CHANNEL DREDGING BEACH SAND TRANSPORT AND SEDIMENTATION REPORT PHASE I: SOUTH OCEANSIDE AND SOLANA BEACH similar to the pre-fill beach profile. The beach fill will become part of the littoral zone which will provide long-term benefits to the shoreline and may enhance future beach nourishment projects. The shoreline will widen for various durations at locations upcoast and downcoast of the beach fill. The littoral transport of the beach fill could potentially cause adverse, but temporary impacts by migrating into or in front of lagoons and creeks, or along shore and offshore to sensitive habitats. Results from analysis of historic beach fills, fill grain size compatibility and numerical modeling indicate the following general conclusions regarding beach fill movement following placement: • The beach fill construction template should have a berm elevation between +1.7 m MSL and the natural berm height, and have a slope between 1:10 and 1:20. • Scarps form naturally at the shoreline due to wave attack and are not anticipated to exceed 1 to 2 m in the beach fill area. • Cross-shore transport is primarily limited to within 450 m of the back beach. • Longshore transport will move material both upcoast and downcoast with a limit of influence in the order of less than 3000 m on either side of the beach fill. Beyond this limit, the fill will approach existing transport patterns. • The beach fill will spread due to longshore and cross-shore transport and will cause no erosion of the adjacent beach. • Some fine grain material will move out of the beach fill below the pinchout depth and onto the continental shelf. The quantity of fines and release rates are small. • Turbidity will be controlled by channeling hydraulic dredge discharge behind a dike until fines settle out. 7.2 Summary of Potential Impacts Table 7.1 summarizes the potential impacts of the South Oceanside Beach Fill as discussed in Section 6.5. Table 7.2 summarizes the potential impacts of the Solana Beach Fill as discussed in Section 6.6. No significant adverse impacts are expected at either beach fill site. Monitoring of the beach fill material should be carried out for at least one year after construction to track the movement of sand. The physical monitoring program will consist of pre- and post-fill placement surveys which are required during construction of each beach fill as well as ongoing and proposed beach monitoring sponsored by SANDAG, the City of Carlsbad and the California Department of Boating and Waterways. Planned monitoring by SANDAG includes aerial photography, beach profile surveys and computation of changes on profile volumes and beach widths. 28 MARCH 1997 7-2 BEACH SAND TRANSPORT & SEDIMENTATION SOUTHWESNAVFACENGCOM FY 97 MCON PROJECT P-706 CHANNEL DREDGING BEACH SAND TRANSPORT AND SEDIMENTATION REPORT PHASE I: SOUTH OCEANSIDE AND SOLANA BEACH TABLE 7.1 - SOUTH OCEANSIDE BEACH FILL STUDY RESULTS ITEM Recreation Beach Access Erosion Control Shoreline Protection Waves Offshore Habitat Structures and Utilities Oceanside Harbor Oceanside Pier San Luis Rey River Loma Alta Creek Buena Vista Lagoon IMPACT + + + + Net + None None None None None None None COMMENTS Increased recreation value will result from wider sandy beach area. Sand is better than cobbles for access. Longitudinal access at high tide will be increased. Potential for a small scarp (in the order of 1 to 2 m) to form at the shoreline. Wider beach will temporarily postpone shoreline recession. Higher and wider berm will provide limited and temporary increase in shoreline protection. Temporal sand bar should enhance surf conditions. Beach profile change could modify wave break location. Sand is not expected to reach location of offshore habitat. Fines released from the beach fill should not exceed existing conditions. Based on site visits and interviews, no impact on structures/utilities anticipated. Sand movement into harbor should be no more than historic. No impact. No long-term potential for increased damming of river mouth. City maintains flow path as needed. No long-term potential for increased damming of river mouth. City maintains flow path as needed. No potential for blocking flow from lagoon. Legend: "+" indicates beneficial impacts,"-" indicates adverse impacts, "None" indicates no impacts. Note: Impacts are a function of actual wave and storm conditions. Impacts indicated above are based on "normal' seasonal wave climate and study area environmental conditions. 28 MARCH 1997 7-3 BEACH SAND TRANSPORT & SEDIMENTATION SOUTHWESNAVFACENGCOM FY 97 MCON PROJECT P-706 CHANNEL DREDGING BEACH SAND TRANSPORT AND SEDIMENTATION REPORT PHASE I: SOUTH OCEANSIDE AND SOLANA BEACH TABLE 7.2 - SOLANA BEACH FILL STUDY RESULTS ITEM Recreation Beach Access Erosion Control Shoreline Protection Waves Offshore Habitat Structures and Utilities San Elijo Lagoon Reef North of Ocean Street Headland North of Cliff St. San Dieguito Lagoon IMPACT 4- + + + Net + Minimal None Minimal None + Minimal COMMENTS Increased recreation value will result from wider sandy beach. Sand is better than cobbles for access. Longitudinal access at high tide will be increased. Potential for a small scarp (in the order of 1 to 2 m) to form at the shoreline. Wider beach will temporarily postpone shoreline recession. Higher and wider berm will provide limited and temporary increase in shoreline protection. Temporal sand bar should enhance surf conditions. Beach profile change could modify wave break location. No long-term impacts to reef breaks are anticipated. Sand is not expected to migrate beyond 300 to 400 m offshore. Fines released from the beach fill should not exceed existing beach conditions. Based on site visits and interviews, no impact on structures/utilities anticipated. Limited long-term potential for increased frequency of maintenance currently performed by County of San Diego. Sand fill anticipated to move away (upcoast and downcoast) from the reef due to diverging shoreline orientation. Headland receives longshore sand supply. Limited long-term potential for increased frequency of maintenance currently performed bv City of Del Mar. Legend: "+" indicates beneficial impacts, "-" indicates adverse impacts. Note: Impacts are a function of actual wave and storm conditions. Impacts indicated above are based on "normal" seasonal wave climate and study area environmental conditions. 7.3 Conclusions The subject beach fill project will provide significant benefit to the public and is consistent with the findings of USACOE (1991) and regional policy adopted by the SEC through SANDAG. There is minimal risk of adverse impacts due to the behavior of the beach fill. This study has evaluated the potential impacts through analysis of past beach fill projects, grain size compatibility analysis and numerical modeling of littoral transport. The analysis results complement and support one another, but must be combined and used with coastal engineering judgement for practical application. The longshore transport model GENESIS provided a simulation of sand movement up and down coast. The results of this model were used to determine the extent of along shore sand movement and potential impacts on lagoons and nearshore habitats. GENESIS does not model cross-shore 28 MARCH 1997 7-4 BEACH SAND TRANSPORT & SEDIMENTATION Project Beach Fill vs. Historic Beach Sand Sources 3000 2500 •- 2000" u 3 1 •Project Fill -QHistoric-Average- E Historic Maximum 1500 " 1000 -- 500- Oceanside Littoral Cell Beach Sites FY-1997 MCON PROJECT P-706 MILITARY CONSTRUCTION PROJECT DATA CHANNEL DREDGING AT NAS.N.I. CORONADO, CALIFORNIA 28 MAR 97 FIGURE 7.1 SOUTHWESNAVFACENGCOM FY 97 MCON PROJECT P-706 CHANNEL DREDGING BEACH SAND TRANSPORT AND SEDIMENTATION REPORT PHASE I: SOUTH QCEANSIDE AND SOLANA BEACH transport and therefore retains sediment at the shoreline that might normally be transported cross -shore. The results are conservative for the purpose intended since more sand will be shown in front of the lagoons and habitats than would probably occur. While the results showed some increased beach widths in front of lagoons, the impacts are considered minimal since the lagoons currently require maintenance to remain open. The storm erosion model SBEACH simulated the movement of beach fill offshore. The model is not intended to simulate onshore transport and is used to indicate wave erosion and beach profile response. The results of this model were used to estimate the short term behavior of the beach berm under the influence of seasonal waves. The results were also used to evaluate the risk of sand covering offshore habitats. The model results are expected to show berm erosion and no reverse cross-shore transport back onto the berm. This condition is conservative in evaluating the risk to offshore habitats since the majority of the material is moved seaward on the profile. The model was validated against a known beach fill at Batiquitos Lagoon and shown to be reasonably accurate. The model results showed berm erosion that was slightly accelerated over the known case. As a comparison to this project, the Batiquitos Lagoon beach fill had nearly twice the volume per unit length (a key parameter in berm longevity) and has nearly completely eroded in the two years since its placement. Other historic beach fills at Oceanside were also analyzed. The expectation for this project is that the beach fill berm will erode away in one to two years. However, the loss of the berm does not mean that there are no long term benefits. The fill sediment will become part of the littoral process and provide continued shoreline protection, possibly contribute to the berm through onshore transport and provide a platform for subsequent beach fills. As an additional outcome of this study, key parameters relating to berm behavior were correlated to develop an understanding of their relative importance. These parameters include sediment grain size, berm height and berm volume for a given wave climate. The results of this empirical analysis are presented in Section 6.2.3. The conclusions from this analysis indicate that for a given grain size, a higher berm will last somewhat longer. However, the benefit must be weighed against the potential for an increased scarp. The cumulative impacts of Oceanside and Solana Beach project beach fills will not be significant compared to past beach fill projects. Figure 7.1 shows that the cumulative quantity of beach fill for Phase I is more than the average beach fill at Oceanside, but significantly less than the maximum event. 7.4 Limitations and Uncertainties The results and conclusions reached in this study should be used as a general indication of beach fill behavior for the "normal" seasonal conditions analyzed. Impacts will vary depending on actual wave and storm conditions. The level of detail incorporated into the analyses and modeling are commensurate with the existing information and time frame available to perform this study. 28 MARCH 1997 7-5 BEACH SAND TRANSPORT & SEDIMENTATION Section 8.0 References SOUTH WESNAVFACENGCOM FY 97 MCON PROJECT P-706 CHANNEL DREDGING BEACH SAND TRANSPORT AND SEDIMENTATION REPORT PHASE I: SOUTH OCEANSIDE AND SOLANA BEACH 8.0 REFERENCES Aldrich, J.H. and M. Meadows, 1966, Southland Weather Handbook, a Guide to the Weather and Climate of Southern California, Los Angeles, California, Brewster Publications. Aubrey, D.G. and K.O. Emery, 1983, Eigenanalysis of recent United States sea levels, Cont. Shelf Res., 2(1): 21-33. Baczkowski, S., 1993, San Dieguito Lagoon Restoration Project Regional Coastal Lagoon Resources Summary, Draft Tech. Memo. San Onofre Marine Mitigation Program, Prepared by Southern California Edison, Co., by MEC Analytical Systems, Inc. Barnett, T.P., 1983, Recent changes in sea level and their probable causes, Climatic Change, 5: 15-38. Borgman, L.E., 1987a, Stratified Population Extremal Model, presentation for Mofatt and Nichol, Engineers. Borgman, L.E., 1987b, Computation of Annual Encounter Probabilities, unpublished document prepared for the Naval Civil Engineering Laboratory. Borgman, L.E. and M. Gonzalez, 1987, Probabilities for Extremes of Dependent Events, unpublished document, University of Wyoming. Brownlie W.R. and B.D. Taylor, 1981, Sediment Management of Southern California Mountains, Coastal Plains, and Shorelines - Part C, Coastal Sediment Delivery by Major Rivers in Souther California, California Institute of Technology, Environmental Quality Laboratory Report NO. 17-C, 314pp. Brownlie W.R., T.C. Fall and B.D. Taylor, 1979, Coastal Sediment Delivery by Major Rivers in Southern California, Appendix C, Draft Final Report, Sediment Management for Southern California Mountains, Coastal Plains and Shorelines, Environmental Quality Lab, California Institute of Technology, 289 pp. California Coastal Commission, 1995, Procedural Guidance for Evaluating the Performance of Wetland Mitigation and Restoration Projects in California's Coastal Zone, Draft Technical Report, 82pp. Cayan, D.R. and R.E. Flick, 1985, Extreme Sea Levels in San Diego, California, Winter 1982-1983, SIO Ref. 85-3, Scripps Institution of Oceanography, 58 pp. Chelton, D. and R. Davis, 1980, Monthly mean sea-level variability along the west coast of North America, Jour. Phys. Oceanog, 12: 757-784. 28 MARCH 1997 8-1 BEACH SAND TRANSPORT & SEDIMENTATION SOUTHWESNAVFACENGCOM FY 97 MCON PROJECT P-706 CHANNEL DREDGING BEACH SAND TRANSPORT AND SEDIMENTATION REPORT PHASE I: SOUTH OCEANSIDE AND SOLANA BEACH Coastal Environments, 1996, Oceanside Beach Nourishment Demonstration Project, Prepared for La Paz County Landfill Coastal Frontiers Corporation, 1996, San Diego Regional Beach Monitoring Program, Prepared for the San Diego Association of Governments (SANDAG). Corson, W.D., et al, 1987, Pacific Coast Hindcast Phase II Wave Information, U.S. Army Corps of Engineers, Waterways Experiment Station, WIS Report 16. County of San Diego, 1970, Natural Resource Inventory of San Diego County, Section 5, Coastal Environment, Technical Report. County of San Diego, 1970, The Coastal Lagoons of San Diego County, A Gathering of Information on Several Technical Subjects that Interact Strongly with Development Decisions, Technical Report, 161 pp. Disney, L.P., 1955, Tide heights along the coasts of the United States, Proc. Hydraulics Div., Amer. Soc. Civil Eng., 81(660). Elwany, M.F.S., S. Aijaz and R. Flick, 1995, Long-term Probability of Open Inlet at San Dieguito Lagoon, Report submitted to Southern California Edison, Rosemead, California, CE ref 95-08, 28 pp. Everts, C. H., 1994, Shore and Beach Management Tactics Evaluation and Recommendations., Shoreline Erosion Assessment and Atlas of the San Diego Region, v. I, California Department of Boating and Waterways. Flick, R.E. and D.C. Cayan, 1984, Extreme Sea Levels on the Coast of California, Proc., 19th Int. Conf. Coastal Eng., Amer. Soc. Civil Eng., p. 886-898. Flick, R.E., 1986, A review of conditions associated with high sea levels in Southern California, Science of the Total Environment, 56: 251-259. Flick, R.E. and J.R. Wanetick, 1989, San Onofre Beach Study, Scripps Inst of Oceanog., Ref. Series No. 89-20, 51pp. Flick, R.E., and Badan-Dangon, A. 1989, Coastal Sea Levels during the January 1988 Storm off the Californias, Shore and Beach, v. 57, n. 4. Flick, R.E., The Myth and Reality of Southern California Beaches, Shore and Beach, v. 61, n. 3, p. 3-13. 28 MARCH 1997 8-2 BEACH SAND TRANSPORT & SEDIMENTATION SOUTHWESNAVFACENGCOM FY 97 MCON PROJECT P-706 CHANNEL DREDGING BEACH SAND TRANSPORT AND SEDIMENTATION REPORT PHASE I: SOUTH OCEANSIDE AND SOLANA BEACH Flick, R.E. and E. H. Sterrett, 1994, The San Diego Shoreline, Shoreline Erosion Assessment and Atlas of the San Diego Region, v. I, California Department of Boating and Waterway. Frederic R. Harris, Inc. 1996. Channel Dredging -100% Design Submittal FY97 MCON Project P-706 for Naval Air Station North Island, Coronado, California - Basis of Design Report. Prepared for Southwest Division Naval Facilities Engineering Command, v. 1. Greene, H.G. and M.P. Kennedy, 1978, Geology of the Inner-Southern California Continental Margin, California Continental Margin Geologic Map Series, Cal. Div. Mines and Geol. and U.S.G.S. Gourley M.R., 1992, Wave set-up, wave run-up and beach water table: Interaction between surf zone hydraulics and groundwater hydraulics, Coastal Engineering, v 17, p 93-144. Guza, R.T. and E.B. Thorton, 1982, Swash Oscillations on a Natural Beach, Jour. Geophys. Res., v 87, nCl,p 483-491. Guza, R.T. and E.B. Thorton, 1985, Observation of Surf Beam, Jour. Geophys. Res, v 90, n C2, p 3161-3172. Harker, A.H. and R.E. Flick, 1991, Beach and Cliff Erosion Processes at Solana Beach, California, 1984-1990, Proc. 7th Symposium on Coastal and Ocean Management, Amer. Soc. Civil Eng., p 2122-2135. Hicks, S.D., H.A. Debaugh, Jr. and L.E. Hickman, Jr., 1983, Sea-level Variations for the United States, 1855-19807 Tides and Water Levels Branch, U.S. Dept. of Commerce, National Oceanic and Atmospheric Administration, National Ocean Service, 170 pp. Inman, D.L. and J.D. Frautschy, 1965, Littoral Processes and the Development of Shorelines, Coastal Eng. Specialty Conf, Amer. Soc. Civil Eng., p. 511-553. Inman, D.L. and C.E. Nordstrom, 1971, On the Tectonic and Morphologic Classification of Coasts, Jour. Geol., v. 79, n. 1, p. 1-21. Inman, D.L., 1983, Application of coastal dynamics to the reconstruction of paleocoastlines in the vicinity of La Jolla, California, p. 1-49, in P.M. Masters and N.C. Fleming (eds.), Quaternary Coastlines and Marine Archeology, Academic Press, London, 641 pp. Inman, D.L. and S.A. Jenkins, 1985, Oceanographic Report for Oceanside Beach Facilities, Prepared for the City of Oceanside, CA, 206 pp. 28 MARCH 1997 8-3 BEACH SAND TRANSPORT & SEDIMENTATION SOUTHWESNAVFACENGCOM FY 97 MCON PROJECT P-706 CHANNEL DREDGING BEACH SAND TRANSPORT AND SEDIMENTATION REPORT PHASE I: SOUTH OCEANSIDE AND SOLANA BEACH Inman, D.L. and S.A. Jenkins, 1985, Erosion and Accretion Waves from Oceanside Harbor, Conference record, Oceans 85: Ocean Engineering and the Environment. New York, Institute of Electrical and Electronic Engineers. Inman, D.L., S.S. Pawka and M.J. Shaw, 1989, The NSTS field experiment sites: Part A: Torrey Pines experiment, in: Seymour, RJ. (ed.) Nearshore Sediment Transport, Plenum, pp. 7-13. Inman, D.L. and P.M. Masters, 1991, Budget of Sediment and the Prediction of the Future State of the Coast, Chapter 9, in Coast of California Storm and Tidal Waves Study, San Diego Region, "State of the Coast" Report, U.S. Army Corps of Engineers, Los Angeles Dist. Kuhn, G.G. and P.P. Shepard, 1984, Sea Cliffs, Beaches and Coastal Valleys of San Diego County, Univ. of Calif. Press, 193 pp. Marine Board, 1987, Responding to Changes in Sea Level: Engineering Implications, National Research Council, National Academy Press, Washington D.C., 148 pp. Marine Advisers, 1960, Design Waves for Proposed Small Craft Harbor at Oceanside, California, prepared for the U.S. Army Corps of Engineers, Los Angeles District. Meteorology International Inc., 1977, Deep-water Wave Statistics for the California Coast, Stations 5 and 6, prepared for the Department of Navigation and Ocean Development, State of California. Mitch, W.J. and J.G. Gosselink, 1993, Wetlands, Van Norstrand Reinhold, New York, 722 pp. Munk, W.H. and F.E. Snodgrass, 1957, Measurements of southern swell at Guadalupe Island, Jour. Marine Res., v. 4, p. 272-286. Namias, J. and D.R. Cayan, 1984, El Ninos: Implications for Forecasting, Oceanus, v. 27, p. 41-47. National Research Council, 1992, Restoration of Aquatic Ecosystems - Science, Technology, and Public Policy, National Academy Press, Washington, D.C., 552 pp. National Research Council, 1995, Wetlands Characteristics and Boundaries, National Academy Press, Washington, D.C., 308 pp. O'Reilly, W.C. and R.T. Guza, 1991, A comparison of two spectral wave models in the Southern California Bight, Coastal Engineering, 19(3-4): 199-215. O'Reilly, W.C. and R.T. Guza, 1991, Comparison of spectral refraction-diffraction wave models, Jour. Waterway, Port. Coastal and Ocean Eng., Amer. Soc. Civil Eng., 117, n3, p 199-215. 28 MARCH 1997 8-4 BEACH SAND TRANSPORT & SEDIMENTATION SOUTHWESNAVFACENGCOM FY 97 MCON PROJECT P-706 CHANNEL DREDGING BEACH SAND TRANSPORT AND SEDIMENTATION REPORT PHASE I: SOUTH OCEANSIDE AND SOLANA BEACH O'Reilly, W.C. and R.T. Guza, 1993, A comparison of two spectral wave models in the Southern California Bight, Coastal Engineering, 19 (3-4): 263-282. O'Reilly, W.C., 1989, Modeling the Storm Waves of January 17-18, 1988, Shore and Beach, v. 57, n. 4. Pacific Weather Analysis, 1983, Preparation of Extratropical Storm Wave Hindcasts for Moffatt and Nichol, Engineers. Pacific Weather Analysis, 1987, Preparation of Tropical Storm and Southern Swell Hindcasts for Moffatt and Nichol, Engineers. Pawka, S.S., D.L. Inman, R.L. Lowe and L. Holmes, 1976, Wave Climate at Torrey Pines Beach, U.S. Army Corps of Engineers, Coastal Engineering Research Center, Tech. Paper 76-5, 372 pp. Pawka, S.S., and R.T. Guza, 1983, Coast of California Wave Study - Site Selection, Scripps Inst. of Oceanog., Ref. Series No. 83-12, 51 pp. Pawka, S.S., 1983, Island shadows in wave directional spectra, Jour. Geophys. Res., 88(C4): 2579-2591. Petterssen, S., 1958, Introduction to Meteorology, McGraw Hill, 327 pp. Pugh, D.T., 1987, Tides, Surges and Mean Sea Level, John Wiley and Sons, 472 pp. Reid, J.L. and A.W. Mantyla, 1976, The Effect of the Geostrophic Flow Upon Coastal Sea Elevations in the Northern North Pacific Ocean, Jour. Geophys. Res., v. 81, n. 18 p. 3100-3110. Revelle, R., 1983, Probable Future Changes in Sea Level Resulting from Increased Atmospheric Carbon Dioxide, in Changing Climate, Report of the Carbon Dioxide Assessment Committee, National Research Council, Washington, D.C., p. 433-448. San Diego Association of Governments (SANDAG), 1993, Shoreline Preservation Strategy for the San Diego Region, 43 pp. San Diego Association of Governments (SANDAG), 1996, Opportunistic Sand Projects - Year End Report, report to Shoreline Erosion Committee dated 26 November 1996. Seymour, R.J., D. Castel and J.O. Thomas, 1989, Coastal Data Information Program, Thirteenth Annual Report, 1988, IMR Reference 89-1, Scripps Institution of Oceanography, La Jolla, California. 28 MARCH 1997 8-5 BEACH SAND TRANSPORT & SEDIMENTATION SOUTHWESNAVFACENGCOM FY 97 MCON PROJECT P-706 CHANNEL DREDGING BEACH SAND TRANSPORT AND SEDIMENTATION REPORT PHASE I: SOUTH OCEANSIDE AND SOLANA BEACH Seymour, R.J., R.R. Strange III, D.R. Cayan and R.A. Nathan, 1984, Influence of El Ninos on California's Wave Climate, Proc. 19th Int. Conf. Coastal Eng., Amer. Soc. Civil Eng., p. 577-592. Soil Conservation Service, 1993, Escondido Creek Hydrologic Area, Project Report, San Diego County, California, Technical Report, 174 pp. Sumner, P.P., and J.W. Ross, 1930, Landslide Description, in Memorandum to Dr. T.W. Vaughan, Scripps Institution of Oceanography Archives, 1 p. Tekmarine, Inc. 1995. Semi-Annual Beach Profile Survey and Analysis October 1994. Prepared for the City of Carlsbad, California. Tekmarine, 1988, Sand Thickness Survey Report, October-November, 1987, USACOE, Los Angeles Dist, CCSTWS 88-5, 21 pp. U.S. Army Corps of Engineers, Los Angeles District, 1984, Sediment Sampling - Dana Point to Mexican Border (Task ID, Nov. 83 to Jan. 84) - Coast of California Storm and Tidal Waves Study CCSTWS 84-5. U.S. Army Corps of Engineers, 1984, Geomorphology Framework Report, Dana Point to the Mexican Border, USACOE, Los Angeles Dist., CCSTWS 84-4, 75 pp. U.S. Army Corps of Engineers, Los Angeles District, 1985, Littoral Zone Sediments San Diego Region Oct 83 - Jun 84 - Coast of California Storm and Tidal Waves Study, Prepared by USC Geological Sciences. U.S. Army Corps of Engineers, 1986, Southern California Coastal Processes Data Summary, USACOE, Los Angeles Dist, CCSTWS 86-1, 572 pp. U.S. Army Corps of Engineers, Los Angeles District. 1987. Oceanside Littoral Cell Preliminary Sediment Budget Report - Coast of California Storm and Tidal Waves Study CCSTWS 87-4. Prepared by Tekmarine, Inc. U.S. Army Corps of Engineers, Los Angeles District, 1988b, River Sediment Discharge Study San Diego Region- USACOE, Los Angeles District, CCSTWS 88-3. U.S. Army Corps of Engineers, Los Angeles District, 1988a, Coastal Cliff Sediments, San Diego County (1887-1947), USACOE, Los Angeles District, CCSTWS 88-8. U.S. Army Corps of Engineers, Waterways Experiment Station, Coastal Engineering Research Center, 1989, GENESIS: Generalized Model for Simulating Shoreline Change, CERC-89-19, prepared by J. Hanson and N.C. Kraus. 28 MARCH 1997 8-6 BEACH SAND TRANSPORT & SEDIMENTATION SOUTHWESNAVFACENGCOM FY 97 MCON PROJECT P-706 CHANNEL DREDGING BEACH SAND TRANSPORT AND SEDIMENTATION REPORT PHASE I: SOUTH OCEANSIDE AND SOLANA BEACH U.S. Army Corps of Engineers, Los Angeles District, 1989, Historic Wave and Seal Level Data Report (SDR) - Coast of California Storm and Tidal Waves Study, Prepared by Moffat & Nichol with Guza and Borgman. U.S. Army Corps of Engineers, 1990, Sediment Budget Report, Oceanside Littoral Cell, USACOE, Los Angeles Dist, CCSTWS 90-2. U.S. Army Corps of Engineers, Los Angeles District, 1991, State of the Coast Report San Diego Region - Main Report, Coast of California Storm and Tidal Waves Study (CCSTWS), v. 1 U.S. Army Corps of Engineers, Los Angeles District, 1991, State of the Coast Report San Diego Region - Appendices, Coast of California Storm and Tidal Waves Study, v. 2. U.S. Army Corps of Engineers, Waterways Experiment Station, Coastal Engineering Research Center, 1993, SBEACH: Numerical Model for Simulating Storm-Induced Beach Change - Report 3 User's Manual, Prepared by Rosati, J.D.,Wise, R.A. and Kraus, N.C. and Larson, M. U.S. Army Corps of Engineers, Waterways Experiment Station, Coastal Engineering Research Center, 1994, BMAP: Beach Fill Module Report 1 - User's Guide, Prepared by Sommerfeld,B.G., Mason, J.M., Kraus, N.C. and Larson, M. U.S. Army Corps of Engineers, Waterways Experiment Station, 1996, SBEACH: Numerical Model for Simulating Storm-Induced Beach Change. Coastal Engineering Research Program, Windows Version. Vanderhurst, W.L., R.J. McCarthy and D.L. Hannan, 1982, Black's Beach Landslide, Geologic Studies in San Diego, San Diego Association of Geologists, p 46-56. Zetler, B.D. and R.E. Flick, 1985, Predicted Extreme High Tides for California, 1983-2000, Jour. Waterway, Port, Coastal and Ocean Div., Amer. Soc. Civil Eng., v. 111(4), p. 758-765. 28 MARCH 1997 8-7 BEACH SAND TRANSPORT & SEDIMENTATION Appendices APPENDIX A TIDE AND SEA LEVEL CHANGES APPENDIX A TIDES AND SEA LEVEL CHANGES Tides and sea level changes together determine design water levels. The water level is important for coastal processes and engineering design since it determines how high and how far shoreward the effect of breaking waves can reach. For example, if sea levels are unusually high due to a combination of circumstances, as they were in the winter of 1982-83, large waves can be far more effective in causing beach erosion, cliff failure, coastal damage and flooding than under normal conditions. This section outlines the tide and sea level fluctuations and trends in the San Diego region. Many fluctuations other than the tide contribute to local sea level changes. Additional factors that are important in the San Diego region, and in southern California in general, include storm surges, large scale changes in water temperature and wind forcing, climate related fluctuations, and long term rise in relative sea level (Flick and Cayan, 1984). In addition, geologic processes such as local subsidence, tectonic uplift and earthquake movements can produce changes in relative sea level, but these are not important in the project area over the relatively short time scales of interest in this study. Tidal Datum Tide heights are referred to a common datum, usually mean lower low water (MLLW), defined as the average of the lowest water level readings of each day over a specified 19-year interval, or tidal epoch, currently set at 1960-78. Other tidal datums include mean sea level (MSL), mean higher high water (MHHW), etc. These are derived from the water level data by appropriate statistical means, and referenced to benchmarks and a fixed datum such as NGVD, as illustrated in Figure A-l. Tide The tide is the regular change of ocean water level caused by the astronomical forces of the moon and sun. The tide is the only component of sea level change that is predictable. It is also the largest, with open coast elevation changes of up to about 3 meter in the study area. The mean tidal range on the open coast of the study area is about 1.6 meter (Disney, 1955). The tide can be decomposed into a set of constituent frequencies near 1 and 2 cycles per lunar day (24 hours, 50 minutes), which each have a given amplitude and phase at any location. Longer period, 1 and 2 cycle per year oscillations caused by atmospheric and oceanographic factors are also usually included in tidal analyses and predictions. These annual and semiannual constituents represent average water level fluctuations at these periods, and do increase the accuracy of water level predictions. However, they are not true tides in the strict, astronomical sense. A-l 19.63 CO CD O) CM 11.92 9.48 8.73 6.86- 6.67- 4.11 0.00 + Benchmark Tidal 6 (1952) Highest Observed Sea Level (8 Aug 83) MHHW (1960-78) MHW (1960-78) MSL (1960-78) NGVD (formerly 'Sea Level Datum of 1929") MLLW (1960-78) Tidal Elevations Relative to MLLW Datum (FT) (M) -f 7.81 2.38 5.37 1.64 4.62 1.41 2.75 0.84 2.56 0.78 -- 0 Station Datum of Tabulation Figure A-l, Tidal Datum at La Jolla Tide Gage On the California coast, the tide is mixed with nearly equal semi-daily and daily components (Zetler and Flick, 1985). California's tide regime is distinctly different from the semi-diurnal conditions that dominate the east coast of the United States. The most important tidal fluctuations on this coast occur once and twice daily, twice monthly, twice yearly and every 4.4 years. The two high tides and two low tides that occur each day are, respectively, unequal in amplitude, as illustrated in Figure A-2. The lower-low tide of the day generally follows the higher-high after about 7 or 8 hours. The tide rises from lower-low to the next higher-high (through lower-high and higher- low) over the rest of the tidal day, or about 17 hours. The monthly tidal changes are dominated by the spring-neap cycle which is formed by the interference of semidiurnal constituents. This cycle produces two periods of relatively high tides (springs) around full and new moon, and two periods of lower ranges (neaps) around the times of half-moon. One spring tide range per month is usually higher than the other, because of changes in the moon's distance and declination. The declination dependence is called the tropic cycle and is caused by interference of diurnal constituents. Peak Tides The highest monthly tides in the winter and summer months are higher than those in the spring and fall as a result of lunar and solar declination effects (Figure A-2). Furthermore, the extreme monthly higher-high tides in the winter tend to occur in the morning, sometimes quite early. This is a disadvantage from a coastal flooding perspective, since preparations for storm waves must often be made at night, in anticipation of the high tide the next morning. Longer period variations also occur in the peak tides. On the California coast, there is a 4.4 year cycle caused by the precession of the lunar perigee that results in higher peak monthly tides of about 15 cm, compared with years in between (Figure A-3). This cycle crested in 1982-83, 1986-87, 1990-91, and 1995-96, and will peak again in 1999-2000. The 18.6 year regression of the lunar node causes an 8 cm variation in peak tide heights with a maximum in 1986-87 and a minimum in 1997 (Zetler and Flick, 1985). The highest predicted tide at San Diego during these extreme periods is 2.4 m above MLLW, and the lowest is 70 cm below MLLW (USACOE, 1988). The tide range on the open coast, including the project area, is about 93% of this value, or 2.2 m above and 65 cm below MLLW. Storm Surge Storm surge is the portion of the local, instantaneous sea level elevation that exceeds the predicted tide and is attributable to the effects of low barometric pressure and high wind associated with storms. Sometimes the super-elevation of sea level due to waves and wave-induced surges is included in design calculations of storm surge. A 1 mb drop in pressure causes an approximately 1 cm rise in water level (Pugh, 1987). Strong storms in southern California are typically associated with 10-15 mb pressure troughs, corresponding well to the observed 10 to 15 cm storm surges (USACOE, 1991). The wind usually makes a relatively minor contribution to storm surges in the San Diego region (Flick, 1986). A-3 SAN DIEGO TIDES 1983 II II27 JAN 12 It28 JAN 12 II29 JAN 4-- 2-- 0-- -2-- .4.. SPRING A A. A •EHW •MHHW •MSL •MLLW • ( 12 II 25 APR « 12 U i • 12 11 I 26 APR 27 APR SUMMER _EHW •MHHW MSL MLLW 12 II • • <» '• • « , " '« «9 JUL 10 JUL 11 JU. AUTUMN A --EHW --MHHW --MSL --MLLW _4 J. I 12 K f • 12 20 OCT 21 OCTTIOCS «e cut HOUR W«*T 11 i •12 II22 OCT Figure A-2, Daily and Seasonal Tidal Fluctuations PREDICTED EXTREME HIGH TIDES Tl!•—•OQ "tfI H ft above MLLW 9>0 r HUMBOLDT 8.0 7.0 L 80 _ 5/W FRANCISCO LOS ANGELES 6.0 L 7.0 6.0 8.0 r 7.0 6.0 L [iiiiiiiiiii|iiiiiiiiiii|iiMiiiiiii|iiiiiiiiiii|iuniiiiiijiiiiiiiiiiiiiiiiiiiiiiiillliiiiiiil|iillliiilll|llliiiiiiliiiiiiiiiiiii|iiiiiiiiiiiiiiiiiiiiiil|li iiii|iimiiiiiijin 1111111111111111111111111 1983 1984 1985 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 SAN DIEGO Weather systems in the San Diego area generally last 2 to 6 days. Longer storm surge episodes are possible due to bunching of successive storms. The average positive storm surge event is 6 days long at La Jolla, based upon analysis of the 1955 to 1984 tide gauge record (USACOE, 1991). Storm surge events exceeding 15 cm last about 2 days. Surges rarely exceed 30 cm, excluding the effect of waves (Flick and Badan-Dangon, 1989). The 10 highest water level residuals (defined essentially the same as Strom surge), is shown in Table A-l (USACOE, 1991). Also calculated are the return period of maximum sea level using data observed at La Jolla from 1926-1986 (Figure A-4). This suggests that the recurrence period for the coincidence of the maximum tide and the maximum observed surge (about 2.5 m, MLLW) is on the order of 5000 years. Based on joint occurrence statistics for La Jolla, the coincidence of extreme high tides and peak storm surge (1955-1984 record) and of extreme high tides and high waves (1976-1984 record) is expected to be very rare (USACOE, 1991). However, the vertical component of wave induced surge on a beach can be of the order of half the significant breaker height, and can exceed 2 m during large wave events. Table A-l - Ten largest Tidal Residual Events at La Jolla (1955-1984) Event 1 2 3 4 5 6 7 8 9 10 Date 2-3 Feb 1983 13-14 Feb 1980 15-17 Jan 1983 2-3 Mar 1983 28 Feb - 5 Mar 1978 4 Feb 1958 ll-12Sep 1984 8-9 Dec 1982 9-10Novl982 24 Dec 1959 Peak Height (ft) 1.06 0.96 0.95 0.94 0.93 0.91 0.89 0.88 0.86 0.84 Reference: USACOE, 1991 Seasonal Mean Sea Level Seasonal mean sea levels in the San Diego area tend to be highest in the fall and lowest in the spring, with differences of about 15 cm, as shown in Figure A-5. This results from the fact that water temperature in the upper layers is a minimum in March and reaches a maximum in about October. Local warming or cooling resulting from offshore shifts in water masses can alter the average sea level by several tenths of a foot over periods of several months (Reid and Mantyla, 1976). A-6 LA JOLLA MAXIMUM SEA LEVELS UJ O CQ (5 UJ X Sum of Maximum Tide and Maximum Anomaly 1955-1984 Maximum Observed Sea Laval 1925-1986 Maximum P adlctad Tide 6.9 10 10 10 10 RETURN PERIOD (years) Figure A-4, Maximum Sea Level-Frequency LA JOLLA-SIO PIER MONTHLY MEAN SEALEVEL 3.5 LJ > O CD UJ 3.0 2.5 2.0 I M M 1.0 0.9 COcc UJ\- Ul 0.8 0.7 0.6 S 0 N D Figure A-5, Seasonal Mean Sea Level Variation El Nino El Nino is a term that describes large scale changes in the atmospheric and oceanic circulation of the equatorial Pacific and Indian Oceans, accompanied by warming in the eastern tropical Pacific. Comparison of annual sea level anomalies with a chronology of past El Nino episodes shows a strong tendency for high sea level to occur off California during El Nino periods (Cayan and Flick, 1985). El Nino episodes may provide a background of elevated sea level for 1 to 2 years on the west coast (Chelton and Davis, 1980). Major El Nino episodes accompanied by large positive sea level anomalies appear to have an average return period of about 14 years, with departures from the trend on the order of 6 cm for durations of 2 to 4 years (Cayan and Flick, 1985). This was the case during the later half of 1982 and for most of 1983. The combination of El Nino effects and storm surges raised the average sea levels in southern California by up to 15 cm above normal during this time (Flick and Cayan, 1984). These factors, together with the peak in tidal heights corresponding to the summer-winter and 4.4 year cycles mentioned above, and the large wave heights set the stage for the wave caused flooding and erosion that marked that winter. Sea Level Rise There is much interest in the subject of sea level rise. In particular, it is important to consider the question of what future rates of rise are likely to be, and if these rates will be greater than in the past due to the greenhouse effect and global warming. Many studies of sea level rise (and fall) exist detailing the geological evidence on time scales of the glacial ages over the past several million years, and from the less dramatic changes over the past 100 years. Regular rise and fall in global sea level of about 150 m occurs on cycles of about 100,000 years. Smaller changes of about 50 m are superposed at periods of about 20,000 and 40,000 years. At present, we are in a "climatic optimum," where the earth is near its maximum temperature, the ice caps are near maximum retreat, and sea level is near its peak. The question now is whether the earth will enter into a greenhouse induced, "super inter-glacial," with unprecedented warming, before the natural, ice-age cycles once again bring global cooling. The shorter term trends are well documented because of the fairly large number of instrumental tide gauge records available (Hicks et al, 1983; Aubrey and Emery, 1983; Barnett, 1983). The first tide gauge operated in San Diego from 1853 to 1872, and a permanent gauge was installed in 1906 (Figure A-6). Tide measurements at Scripps Pier in La Jolla are continuous from 1924. Both gauges show a mean sea level rate of increase of about 20 cm per century over their respective records (USACOE, 1989). This is close to the value of about 15 cm widely accepted as representative of global sea level increase over the past 100 years (Revelle, 1983). While most scientists now believe future sea level rise will accelerate, many have cautioned against undue alarm. Because of its relatively steep open coast, the San Diego region and California in general, is much less vulnerable to sea level rise than the east or Gulf coasts of the United States. Peak high tides, storm surges and El Nino effects all can temporarily raise water levels by several centuries worth of mean sea level rise. It is these factors that pose the greatest potential for flooding A-9 and coastal erosion when coupled with high wave events. On the other hand, this is no time for complacency either. Coastal planners and engineers would be prudent to use at least the past century's pace of sea level rise for planning over periods up to about 25 years. The Marine Board (1987) suggests a value of 40 cm per century for 25 year design. A-10 APPENDIX B WAVE PROCESSES APPENDIX B WAVE PROCESSES Waves provide nearly all of the energy input that drives shoreline processes in southern California. In particular, waves provide the energy that moves sand both along the shore and across the shore. Another result of wave action is the generation of longer period motions that are amplified at the shoreline even as the waves that generate them are dissipated (Guza and Thornton, 1982, 1985). These "surf beat" oscillations can be quite high, especially during very energetic storm surf, and are the leading cause of beach berm overtopping, beach erosion and coastal flooding (Gourley, 1992). Sources of Wave Energy As illustrated in Figure B-l, incoming waves come from three main sources: 1) northern hemisphere swell, 2) southern hemisphere swell, and 3) shorter period sea waves from all offshore directions generated locally within the bight (USACOE, 1986). Waves in the swell categories originate in their respective hemispheres north and south of the equator, and arrive in southern California after traveling over impressive distances (Munk and Snodgrass, 1957). Measurements show that over 80% of the energy in the local wave climate is in the form of waves with periods of 5 seconds and longer, indicative of swell. During times of large waves, this fraction reaches 90%. This indicates that swell waves from distant sources are by far the most important influence on the local shoreline. Wave Climate Seasonal Summary The wave climate can be divided into three seasons (USACOE, 1991). Winter (October-March) is dominated by northwesterly waves generated by north Pacific extratropical storms with occasional contributions from seas associated with the passage of storm fronts. Maximum significant wave heights reach about 10m, and periods range from 12 to 21 seconds. Spring (April-June) is a transitional period from the energetic conditions of winter to the mild climate of summer. Local storm activity earlier in the period can generate 1 to 2 m high seas with periods in the range of 5 to 10 seconds (Pawka, 1976). Summer (July-September) is dominated by Southern Hemisphere swell (2 m maximum heights, periods 15 to 24 seconds), and north Pacific tropical storm swell (5 m maximum heights, periods 8 to 16 seconds). Relatively strong and persistent northwest winds offshore of the Channel Islands generate higher frequency waves that can be a significant portion of the energy at the coast in the summer. Wave heights can reach 6 m, with periods of 5 to 12 seconds (USACOE, 1988). B-l Santa Barbara Northern Hemisphere Swell 0 20 mi • Long Beach Dana Pt. Oceanside Southern Hemisphere Swell 34°N 33° 32° 121°W 120°119°118°117° Figure B-l, Sources of Wave Energy at Oceanside Cell Winter Waves Northern hemisphere winter swell waves are usually produced by a specific, remote meteorological disturbance, including Aleutian storms, sub-tropical storms north of Hawaii, Pacific typhoons, tropical hurricanes and strong winds in the eastern North Pacific. During the winter, a broad band of high cyclone activity extends across the Pacific from Asia to the Gulf of Alaska. The majority of these storms travel toward the Gulf of Alaska, but many of them reach as far south as southern California and even northwest Mexico (Petterssen, 1958). Northwesterly waves due to these extratropical storms are the dominant source of swell frequency energy in winter (USACOE, 1988; Inman et al, 1989). Winter waves under typical conditions in the Oceanside study area are about 1.4 m high with a period of 11 seconds. Aleutian storms move from west to east across the Pacific at high latitude and often stagnate in the Gulf of Alaska. These waves reach the southern California coast, but with diminished amplitude because of the shoreline orientation and blocking by Point Conception. During occasional winters and springs, such as in 1982-83, the storm tracks of these extra-tropical cyclones are displaced farther south than normal. This produces maximum wave heights in the range of 10 m and maximum wave periods of around 21 seconds in central and southern California, and is the most important source of extreme waves in the region. Storms generated near Hawaii move across the Pacific at mid-latitudes. These storms occur less frequently than the Aleutian storms. Some intense extratropical storms develop between Hawaii and California (Aldrich and Meadows, 1966), often producing large westerly ocean swells and waves. Summer Waves Southern hemisphere swell is generated in the South Pacific, Indian and Southern Ocean by high latitude Antarctic and Pacific storms during the southern fall, winter and spring. The swell reaches southern California after a travel time of about 8 to 10 days (USACOE, 1988). The distribution of south swell in southern California is bimodal, with more activity in late spring and early fall than in the summer. The coastal engineering importance of occasionally large southern swell was demonstrated by destructive waves that focused on the Long Beach breakwater in the 1950's. These waves also cause reversals in the predominantly southward flow of littoral sand, and push the material to the north. Although south swell rarely exceeds 2 m in height, during summer, these waves dominate the littoral processes of the region for the simple reason that not enough compensating northern hemisphere swell is generated at that time. Summer waves under typical conditions in the Oceanside study area are about 1 m high with a period of 13 seconds. During the summer and fall, Eastern Pacific tropical cyclones move into the Pacific from off the west coast of Mexico. For most of these storms, the largest waves have a deep water wave approach direction from east of south, and would not impact much of the San Diego region with west-facing beaches. However, these storms later in their life cycle, and storms that follow a northwesterly track generate swell that approaches the San Diego coast from a more south to southwest direction. The swell waves generated by these events usually do not exceed 2 m in height by the time they reach southern California. B-3 Between 1966 and 1989,197 of the 3 90 tropical cyclones that developed in the Eastern North Pacific reached hurricane strength (USACOE, 1991). Very few tropical storms have reached as far north as southern California. However, on rare occasions the offshore waters are warm enough to sustain a hurricane much farther north than normal. This happened in September 1939, when a hurricane passed directly over southern California, and the resulting waves caused widespread destruction. Typhoon generated swell in the western North Pacific generally does not reach southern California. Strong summer winds sometimes develop over the extreme eastern Pacific as a result of steep gradients in the atmospheric pressure around the Pacific high pressure cell. These strong and persistent north and northwest winds are an important feature of the summer weather pattern in California, and also generate moderately high waves. Island Sheltering The Southern California Bight is noted for its offshore islands, shallow banks, canyons and generally complicated bathymetry. The coastal orientation is nearly north-south (west facing) in most of the San Diego region. The coastline orientation and the islands and banks greatly influence the swell propagating toward shore by partially sheltering southern California, including the San Diego region. The islands and banks partially shelter the coastline from the deep ocean waves, leaving only a few windows from some sectors at most mainland locations. Refraction, diffraction, reflection and dissipation of the incident deep ocean waves by the islands and bathymetric features further complicate the wave patterns. As a result of the complicated bathymetry and the offshore islands, coastal wave energy varies drastically as a function of even relatively small changes in the incoming direction of the deep ocean waves (Pawka and Guza, 1983; O'Reilly and Guza 1993). Equally dramatic is how much the wave height from the same offshore source can change over a short distance on the beach. Numerical wave models have been developed to simulate the propagation of deep ocean swell waves through the entire region (O'Reilly and Guza, 1992). Extreme Waves Characterizing and understanding extreme wave heights in the study area is important because these waves are responsible for very rapid shoreline and beach sand volume changes. Extreme storm events have caused extensive damage along the southern California coast. A series of storms during the winter of 1982-83, and the high intensity storm of January 17-18, 1988 are examples of recent storms that seriously impacted beaches and coastal structures in southern California, including the San Diego study area. The largest waves arriving in southern California are normally generated by North Pacific extratropical storms, or by Eastern North Pacific tropical cyclones (USACOE, 1991). Table B-l summarizes the maximum significant wave heights (in feet) that can be expected as a function of their recurrence interval and location. B-4 TABLE B-l - DEEP WATER MAXIMUM SIGNIFICANT WAVE HEIGHT FREQUENCY (METERS) LOCATION Mission Bay Begg Rock Scripps Pier Mission Bay Del Mar Oceanside San Clemente METERS 192.0 110.0 7.9 10.0 10.7 9.1 10.0 MEANHS (meter) 2.3 3.7 1.5 2.1 1.9 1.6 1.6 5Yr 4.6 6.9 2.8 4.3 4.0 2.8 3.3 10 Yr 5.2 7.7 3.2 4.9 4.4 3.1 3.8 25 Yr 6.1 8.7 3.7 5.7 5.0 3.6 4.4 50 Yr 6.8 9.5 4.0 6.3 5.5 3.8 4.8 100 Yr 7.3 10.1 4.3 6.9 6.0 4.1 5.2 () = depth of wave gage Reference: USACOE, 1991 Wave Data Sources As part of the Coast of California Storm and Tidal Waves Study for the San Diego Region, hindcast and measured wave data sets were compiled and analyzed (Moffatt and Nichol, 1988, and USACOE, 1991). Historic extreme wave data for the San Diego region in deep and shallow water locations were determined using statistical procedures prepared by the U.S. Army Waterways Experiment Station. Deep water extreme wave hindcasts produced by Marine Advisors (1960), Meteorology International, Inc. (1977), Pacific Weather Analysis (1983, 1987), Fleet Numerical Oceanography Center (1987), and Waterways Experiment Station (1987) were analyzed and evaluated (Figure B-2). In addition, deepwater wave data from Buoy 46024, operated by the National Data Buoy Center, National Oceanic and Atmospheric Administration, as well as visual observation of wave characteristics reported by ships at sea archived at the National Climate Data Center, and shallow water gauges and arrays and deepwater wave gauges installed by the U.S. Army Corps of Engineers and the State of California Department of Boating and Waterways, operated as the Coastal Data Information Program (CDIP) by Scripps Institution of Oceanography, were analyzed (Figure B-3). It is important to emphasize that the wave statistics provided in these reports are only valid at the gauge locations where the data was recorded. B-5 PT. CONCEPTION Vi SAN MIGUEL ISLAND *£•£.:•"• V"1 SANTA BARBARA^L-:-~--.::»--.~.-" . . . • • Na to s o to .LOS ANGELES 20 30 a a GRAPHIC SCALE IN MILES SANTA ROSA ISLAND Mil 5 HINDCAST STATIONS STATION MA Mil 5 Mil 6 PWA 1 PWA 2 FNOC WES 1 WES 2 WES 3 WES 4 LATITUDE LONGITUDE OFFSHORE OCEANSIDE EXACTLOCATION UNKNOWN 33° 30' 31*30' 33*15' 32*40' 32° S31 32" 22' 32" 35' 32°47I 33° 00' 120*24' 118°24' 118*40' 118° 20' 117°53' 118*26' 118° 58' 11930' I SANTA BARBARA ISLAND d SAN NICOLAS ISLAND H-PWA i SAN CLEMENTE ISLAND WES 4 I FNOC WES -L. PWA 2 WES 2 WES PACIFIC OCEAN I Mil 6 POINT •OCEANSIDE I SAN /•'DIEGO 34*N 32* 121* W Source:USACOE 1991 120*119'118* 117' Figure B-2, Wave Hindcast Stations — 34* N : • SANTA BARBARAPT. CONCEPTION SANTA CRUZ ISLANDSAN MIGUEL ISLAND LOS .ANGELES SANTA ROSA ISLAND20 30 I GRAPHIC SCALE IN MILES SANTA BARBARA ISLAND 0 r .DANA POINT A. BEGG ROCK BUOY SAN CLEMENTE CbSAN NICOLAS ISLAND SANTA CATALINA ISLAND OCEANSIDE DEL MAR A'SAN CLEMENTE ISLAND SCRIPPS PIER A/tHEGOWAVE GAGE LOCATIONS MISSION BAY BUOY MISSION BAY ENTRANCENOAA 46024 MISSION BAY BEGG ROCK SHIPBOARD OBS DATA SQUARESCRIPPS PIER MISSION BAY ENTR. OCEANSIDE SAN CLEMENTE SHIPBOARD OBS - 32* 121*W Source:USACOE 1991 117° Figure B-3, Wave Gage Locations Wave Data Analysis Two different statistical methodologies were used to determine the probability distribution and the extrapolated wave heights. The first method used the Stratified Population Extremal Model (Borgman, 1987) for extreme event wave hindcast data sets consisting of extreme wave heights above a given threshold that can be separated into categories based on the wave source. The second method utilized the Seasonal Maxima Distribution Model (Borgman, 1987; Borgman and Gonzalez, 1987) to analyze data sets which were not easily separated into categories, in which the database was of short time extent, or the measurements were not continuous over the period of the record. This method was used for the data sets consisting of limited measured wave data (see USACOE, 1991, for details of methodologies and discussion of data sets). Recurrence intervals for significant wave heights were determined using both methods. Statistical analyses are presented for the maximum significant wave heights. Statistical analyses of wave period and wave approach direction were not conducted. Extreme Wave Recurrence Figure B-4 compares predicted recurrence intervals for significant wave heights of the hindcast data sets in a combined extratropical storm swell and sea category. The various wave height estimates as a function of recurrence interval differ by about a factor of 2, illustrating the complexity of wave processes in southern California, and the resulting uncertainty in estimating these statistics. Recurrence intervals for the NOAA buoy and the CDIP Begg Rock (deepwater) data are included. The Fleet Numerical Oceanography Center (FNOC) data set has some limitations and some data that appears to be in error. The Meteorological International Incorporated (Mil, the only data set for the seas category) and visual observation data sets were assessed as not suitable for statistical analysis. The NOAA and CDIP Begg Rock buoys provided intermittent data over a relatively short period of time, and caution is urged in extrapolation of these data beyond 5 to 10 years (Moffatt and Nichol, 1988). The Waterways Experiment Station (WES), Pacific Weather Analysis (PWA), and Marine Advisors (MA) appear to be reasonable data sets for this purpose (Moffatt and Nichol, 1988). The Waterways Experiment Station extreme events inventory data was not available for direct comparison because analysis was done by the Waterways Experiment Station (Corson et al, 1987). Extreme Wave Recurrence Synthesis In an attempt to produce a data set representing a longer time period, data sets from Marine Advisors, Pacific Weather Analysis, and the Begg Rock buoy were combined to form a data set covering 1904 to 1988. Recurrence intervals versus deepwater significant wave height were calculated for deepwater, tropical, extratropical, combined tropical and extratropical, and with the assumption of statistical independence and use of the convolution theorem, convoluted categories. Two shallow water stations were also analyzed. The results are shown in Figure B-5. The summary B-8 4) 0) g 01x tuI Ou. z oc UJI Q. UJUJ O 5 10 Source:USACOE 1991 25 RECURRENCE INTERVAL (Years) 100 Figure B-4, Comparison of Hindcast and Measured Deepwater Significant Wave Height Frequency Curve COMBINED TROPICAL AND EXTRATROPICAL STORMS 1.000 eo oD_ oDC 10 15 20 25 30 Significant Wave Height, ft. Date Sources: ^ 1904 to 1956 Marine Advisors (1960) * 1957 to 1983 Pacific Weather Analysis (1983) O 1984 to 1988 CDIP Begg Rock Buoy Figure B-5, Extreme Deepwater Wave Frequency Curve Extreme Wave Synthesis of nearshore wave statistics compiled by Scripps Institution of Oceanography (CDIP), and summarized in Table B-2, is recommended "as practical guidance for coastal planners and engineers." TABLE B-2 - WAVE HEIGHT STATISTICAL ANALYSIS Deep- Water Tropical Deep- Water Extratropical Deep-Water Combined Deep- Water Convoluted Shallow- Water Mission Bay Shallow- Water Oceanside Beach WAVE HEIGHT (METERS) 10 Yr 3.0 5.9 6.1 6.0 5.1 4.6 50 Yr 4.0 7.7 8.0 8.0 5.6 5.6 lOOYr 6.0 8.5 8.8 8.8 6.5 6.9 Reference: Scripps Institution of Oceanography B-ll APPENDIX C NUMERICAL MODELING INPUT/OUTPUT SOUTH OCEANSIDE GENESIS I/O Frederic R. Harris, Inc. SUBJEC/I - COMPUTED BY ---- --------- CHECKED BY SHEET NO — 4.... OF .../ JOB NO DATE . .-:•?.. I i i \ \ /Q- (x K (X = ±ro Tfte. fitetfr Csew-n+) 75 COASTAL ENGINEERING RESEARCH CENTER Sc LUND INSTITUTE OF TECHNOLOGY ** *•* ** ** ** ** *** ** ** ** ** ** *** ** * * ** *** ** ** ** **** ** ** •*•* ** **** ** ** •*•* *** ** ** ** *•** ** ** ** ** +* ** ** ** ** ** **** +* *+ ** ** ** * * ** ** *•* **** ** ++ +* ** I VERSION 3.0 | H h USER NO. 415 DECEMBER 1994 RUN: NAVY HOMEPORT BECH FILL STUDY AT SOUTH OCEANSIDE METRIC UNITS GROIN X-COORDINATES 7 DISTANCE TO GROIN TIPS FROM X-AXIS 240.00 GROIN PERMEABILITIES 0.00 DATES OR TIME STEPS WHEN FILLS START 970601 DATES OR TIME STEPS WHEN FILLS END 970620 X-COORDINATES WHERE FILLS START 21 X-COORDINATES WHERE FILLS END 41 DX = 10 NWAVES = HCNGF =1.0 270.00 252.11 266.27 278.64 268.73 267.62 301.70 385.00 475.00 530.00 810.00 SHORELINE CHANGE AFTER 1.YEARS = 2912 TIME STEPS. DATE IS 980531 i.O 1 ..0 DT = DCLOS 2CNGF 3.00 = 10.0 = 1.0 ; POSITION AFTER 267 252 268 278 267 269 306 395 480 550 850 .35 .22 .37 .47 .45 .53 .55 .00 .00 .00 .00 264 252. 270 278 266 271 311 400 490. 580 850. .75 .73 .36 .04 .31 .85 .69 .00 .00 .00 .00 ISSTART = ABH = ZCNGA = 1. YEARS = 262. 253. 272. 277 265. 274. 317, 410. 495. 605. 840. .22 .60 .22 .37 .35 .55 .17 .00 .00 .00 .00 259 254 273 276 264 277 323 420 480 640 830 1 1.7 3.0 N = DZ = Kl = 2912 TIME .80 .80 .89 .48 .64 .61 .07 .00 .00 .00 .00 257. 256 275 275 264. 281. 329. 430 482. 670. 825. .60 .30 .35 .41 .22 .00 .47 .00 .22 .00 .00 110 10.0 0.45 STEPS . 255 258 276 274 264 284 336 430 486 705 825 .74 .03 .55 .20 .13 .68 .31 .00 .67 .00 .00 DATE 254 259 277 272 264 288 343 440 492 745 815 NTS = D50 = K2 = IS .25 .96 .50 .88 .40 .61 .29 .00 .40 .00 .00 2912 0.18 0.25 980531 253. 262. 278. 271. 265. 292. 349. 450. 499. 770. 811. .14 .01 .16 .49 .06 .75 .78 .00 .37 .00 .44 252 264 278 270 266 297 355 470 510 800 810 .42 .14 .54 .09 .13 .11 .47 .00 .13 .00 .00 0 12. 6. 18. 13, 12. -8 0. 0, 0. 0, .00 .11 .27 .64 .73 .62 .30 .00 .00 .00 .00 2 17 8 18 12 14 -13 0 0 0 0 .35 .22 .37 .47 .45 .53 .45 .00 .00 .00 .00 4. 17. 10. 23. 11. 11. -18. 0. 0. 0. 0. .75 .73 .36 .04 .31 .85 .31 .00 .00 ,00 ,00 7 18 12. 27 10 19. -17 0. 0. 0, 0. .22 .60 .22 .37 .35 .55 .83 .00 .00 .00 .00 14. 9. 18. 26. 9. 17. -21. 0. 0. 0. 0. 80 80 89 48 64 61 93 00 00 00 00 12 11 20 25 9 16 -25. 0, 2. 0. 0. .60 .30 .35 .41 .22 .00 .53 .00 .22 .00 .00 10 8 21 19 9 14 -8 0 1. 0 0. .74 .03 .55 .20 .13 .68 .69 .00 .67 .00 .00 9 4 22 17 9 8 -6 0 2 0 0 .25 .96 .50 .88 .40 .61 .71 .00 .40 .00 .00 13 2 23 11 10 2 -20 0 9 0 1 .14 .01 .16 .49 .06 .75 .22 .00 .37 .00 .44 12. 4. 18. 15. 11. -2. -19. 0. 0. 0. 0. .42 .14 .54 .09 .13 .89 .53 .00 .13 .00 ,00 OUTPUT LAST TIMESTEP NO.2912 DATE IS 980531 OFFSHORE WAVE DATA INPUT: HZ = 0.750000 T =5.00000 ZZ 5.00000 CALIBRATION/VERIFICATION ERROR 8.85175 CALCULATED VOLUMETRIC CHANGE = +7.4SE+05 (M3) SIGN CONVENTION: EROSION (-), ACCRETION (+) * INPUT FILE START.DAT TO GENESIS VERSION 3.0 * A MODEL SETUP --A A.I RUN TITLE NAVY HOMEPORT BECH FILL STUDY AT SOUTH OCEANSIDE A. 2 INPUT UNITS (METERS=1; FEET=2): ICONV 1 A. 3 TOTAL NUMBER OF CALCULATION CELLS AND CELL LENGTH: NN, DX 110 100 A.4 GRID CELL NUMBER WHERE SIMULATION STARTS AND NUMBER OF CALCULATION CELLS (N = -1 MEANS N = NN): ISSTART, N 1 110 A.5 VALUE OF TIME STEP IN HOURS: DT 3 A. 6 DATE WHEN SHORELINE SIMULATION STARTS (DATE FORMAT YYMMDD: 1 MAY 1992 = 920501): SIMDATS 970601 A. 7 DATE WHEN SHORELINE SIMULATION ENDS OR TOTAL NUMBER OF TIME STEPS (DATE FORMAT YYMMDD: 1 MAY 1992 = 920501) : SIMDATE 980531 A. 8 NUMBER OF INTERMEDIATE PRINT-OUTS WANTED: NOUT 2 A. 9 DATES OR TIME STEPS OF INTERMEDIATE PRINT-OUTS (DATE FORMAT YYMMDD: 1 MAY 1992 = 920501, NOUT VALUES) : TOUT(I) 970831 971130 A. 10 NUMBER OF CALCULATION CELLS IN OFFSHORE CONTOUR SMOOTHING WINDOW (ISMOOTH = 0 MEANS NO SMOOTHING, ISMOOTH = N MEANS STRAIGHT LINE. RECOMMENDED DEFAULT VALUE = 11) : ISMOOTH 11 A.11 REPEATED WARNING MESSAGES (YES=1; N0=0): IRWM 1 A.12 LONGSHORE SAND TRANSPORT CALIBRATION COEFFICIENTS: Kl, K2 0.45 0.25 A.13 PRINT-OUT OF TIME STEP NUMBERS? (YES=1, N0=0): IPRINT 0 B WAVES B B.I WAVE HEIGHT CHANGE FACTOR. WAVE ANGLE CHANGE FACTOR AND AMOUNT (DEG) (NO CHANGE: HCNGF=1, ZCNGF=1, ZCNGA=0): HCNGF, ZCNGF, ZCNGA 113 B.2 DEPTH OF OFFSHORE WAVE INPUT: DZ 10 B.3 IS AN EXTERNAL WAVE MODEL BEING USED (YES = 1; NO=0): NWD 0 B.4 COMMENT: IF AN EXTERNAL WAVE MODEL IS NOT BEING USED, CONTINUE TO B. 9 B.5 NUMBER OF SHORELINE CALCULATION CELLS PER WAVE MODEL ELEMENT: ISPW 0 B.6 NUMBER OF HEIGHT BANDS USED IN THE EXTERNAL WAVE MODEL TRANSFORMATIONS (MINIMUM IS 1, MAXIMUM IS 9) : NBANDS 1 B.7 COMMENT: IF ONLY ONE HEIGHT BAND WAS USED CONTINUE TO B. 9 B.8 MINIMUM WAVE HEIGHT AND BAND WIDTH OF HEIGHT BANDS: HBMIN, HBWIDTH 0 0 B.9 VALUE OF TIME STEP IN WAVE DATA FILE IN HOURS (MUST BE AN EVEN MULTIPLE OF, OR EQUAL TO DT): DTW 3 B.10 NUMBER OF WAVE COMPONENTS PER TIME STEP: NWAVES 1 B.ll DATE WHEN WAVE FILE STARTS (FORMAT YYMMDD: 1 MAY 1992 = 920501) : WDATS 970101 C BEACH C C.I EFFECTIVE GRAIN SIZE DIAMETER IN MILLIMETERS: D50 0.18 C.2 AVERAGE BERM HEIGHT FROM MEAN WATER LEVEL: ABH 1.7 C.3 CLOSURE DEPTH: DCLOS 10 C.4 ANY OPEN BOUNDARY? (N0=0, YES=1) : IOB 0 C.5 COMMENT: IF NO OPEN BOUNDARY, CONTINUE TO D. C.6 TIME BASE IN BOUNDAY MOVEMENT SPECIFICATION(S) ? (SIMULATION PERIOD = 1, DAY = 2, TIME STEP = 3) : ITB 1 C.I OPEN BOUNDARY ON LEFT-HAND SIDE? (N0=0, YES=1) : IOB1 0 C.8 COMMENT: IF A GROIN ON LEFT-HAND BOUNDARY, CONTINUE TO C.10 C.9 BOUNDARY MOVEMENT PER TIME BASE ON LEFT-HAND BOUNDARY, IN SYSTEM OF UNITS SPECIFIED IN A. 2 (PINNED BEACH => YC1 = 0) : YC1 0 C.10 OPEN BOUNDARY ON RIGHT-HAND SIDE? (N0=0, YES = 1> : IOBN 0 C.ll COMMENT: IF A GROIN ON RIGHT-HAND BOUNDARY, CONTINUE TO D. C.12 BOUNDARY MOVEMENT PER TIME BASE ON LEFT-HAND BOUNDARY, IN SYSTEM OF UNITS SPECIFIED IN A.2 (PINNED BEACH => YCN = 0) : YCN 0 D NON-DIFFRACTING GROINS D D.I ANY NON-DIFFRACTING GROINS? (N0=0, YES=1) : INDG 1 D.2 COMMENT: IF NO NON-DIFFRACTING GROINS, CONTINUE TO E. D.3 NUMBER OF NON-DIFFRACTING GROINS: NNDG 1 D.4 GRID CELL NUMBERS OF NON-DIFFFRACTING GROINS (NNDG VALUES): IXNDG(I) 7 D.5 LENGTHS OF NON-DIFFRACTING GROINS FROM X-AXIS (NNDG VALUES): YNDG(I) 240 E DIFFRACTING (LONG) GROINS AND JETTIES E E.I ANY DIFFRACTING GROINS OR JETTIES? (N0=0, YES=1) : IDG 0 E.2 COMMENT: IF NO DIFFRACTING GROINS, CONTINUE TO F. E.3 NUMBER OF DIFFRACTING GROINS/JETTIES : NDG 0 E.4 GRID CELL NUMBERS OF DIFFFRACTING GROINS/JETTIES (NDG VALUES): IXDG(I) E.5 LENGTHS OF DIFFRACTING GROINS/JETTIES FROM X-AXIS (NDG VALUES): YDG(I) E.6 DEPTHS AT SEAWARD END OF DIFFRACTING GROINS/JETTIES (NDG VALUES) : DDG(I) F- ALL GROINS/JETTIES F F.I COMMENT: IF NO GROINS OR JETTIES, CONTINUE TO G. F.2 PERMEABILITIES OF ALL GROINS AND JETTIES (NNDG+NDG VALUES): PERM(I) 0.0 F.3 IF GROIN OR JETTY ON LEFT-HAND BOUNDARY, DISTANCE FROM SHORELINE OUTSIDE GRID TO SEAWARD END OF GROIN OR JETTY: YG1 0 F.4 IF GROIN OR JETTY ON RIGHT-HAND BOUNDARY, DISTANCE FROM SHORELINE OUTSIDE GRID TO SEAWARD END OF GROIN OR JETTY: YGN 0 G DETACHED BREAKWATERS G G.I ANY DETACHED BREAKWATERS? (NO=0, YES=1) : IDE 0 G.2 COMMENT: IF NO DETACHED BREAKWATERS, CONTINUE TO H. G.3 NUMBER OF DETACHED BREAKWATERS: NDB 0 G.4 ANY DETACHED BREAKWATER ACROSS LEFT-HAND CALCULATION BOUNDARY (N0=0, YES=1): IDB1 0 G.5 ANY DETACHED BREAKWATER ACROSS RIGHT-HAND CALCULATION BOUNDARY (NO=0, YES=1): IDBN 0 G.6 GRID CELL NUMBERS OF TIPS OF DETACHED BREAKWATERS (2 * NDB - (IDB1+IDBN) VALUES): IXDB(I) G.7 DISTANCES FROM X-AXIS TO TIPS OF DETACHED BREAKWATERS (1 VALUE FOR EACH TIP SPECIFIED IN G.6) : YDB(I) G.8 DEPTHS AT DETACHED BREAKWATER TIPS (1 VALUE FOR EACH TIP SPECIFIED IN G.6): DDE(I) G.9 TRANSMISSION COEFFICIENTS FOR DETACHED BREAKWATERS (NDB VALUES): TRANDB(I) H SEAWALLS H H.I ANY SEAWALL ALONG THE SIMULATED SHORELINE? (YES=1; N0=0): ISW 1 H.2 COMMENT: IF NO SEAWALL, CONTINUE TO I. H.3 GRID CELL NUMBERS OF START AND END OF SEAWALL (ISWEND = -1 MEANS ISWEND = N) : ISWBEG, ISWEND 1 110 ! - BEACH FILLS 1 1.1 ANY BEACH FILLS DURING SIMULATION PERIOD? (N0=0, YES=1) : IBF 1 1.2 COMMENT: IF NO BEACH FILLS, CONTINUE TO K. 1.3 NUMBER OF BEACH FILLS DURING SIMULATION PERIOD: NBF 1 1.4 DATES OR TIME STEPS WHEN THE RESPECTIVE FILLS START (DATE FORMAT YYMMDD: 1 MAY 1992 = 920501, NBF VALUES) : BFDATS(I) 970601 1.5 DATES OR TIME STEPS WHEN THE RESPECTIVE FILLS END (DATE FORMAT YYMMDD: 1 MAY 1992 = 920501, NBF VALUES) : BFDATE(I) 970620 1.6 GRID CELL NUMBERS OF START OF RESPECTIVE FILLS (NBF VALUES) : IBFS(I) 21 1.7 GRID CELL NUMBERS OF END OF RESPECTIVE FILLS (NBF VALUES) : IBFE(I) 41 1.8 ADDED BERM WIDTHS AFTER ADJUSTMENT TO EQUILIBRIUM CONDITIONS (NBF VALUES): YADD(I) 25 j BYPASS ING J J.I ANY BYPASSING OPERATIONS DURING SIMULATION PERIOD? (NO=0, YES=1): IBP 0 J.2 COMMENT: IF NO BYPASSING OPERATIONS, CONTINUE TO K. J.3 READ BYPASSING RATES FROM A FILE OR SPECIFY BELOW? (FILE=1, BELOW=2): IBPF 1 J.4 COMMENT: IF BYPASSING OPERATIONS ARE SPECIFIED BELOW, CONTINUE TO J.8 -- BYPASSING OPERATIONS SPECIFIED IN SEPARATE DATA FILE -- J.5 DATE OR TIME STEP WHEN BYPASS DATA FILE STARTS AND ENDS, RESPECTIVELY (FORMAT YYMMDD: 1 MAY 1992 = 920501) : QQDATS QQDATE 0 0 J.6 CELL NOS. WHERE BYPASS FILE STARTS AND ENDS, RESPECTIVELY: IQQS, IQQE 0 0 J.7 COMMENT: END OF BYPASS DATA FILE SECTION. CONTINUE TO K. -- BYPASSING OPERATIONS SPECIFIED IN THIS FILE -- J.8 NUMBER OF BYPASSING OPERATIONS DURING SIMULATION PERIOD: NBP 0 J.9 DATES OR TIME STEPS WHEN THE RESPECTIVE OPERATIONS START (DATE FORMAT YYMMDD: 1 MAY 1992 = 920501, NBP VALUES) : BPDATS(I) J.10 DATES OR TIME STEPS WHEN THE RESPECTIVE OPERATIONS END (DATE FORMAT YYMMDD: 1 MAY 1992 = 920501, NBP VALUES) : BPDATE(I) J.ll GRID CELL NUMBERS OF START OF RESPECTIVE OPERATIONS (NBP VALUES): IBPS (I) J.12 GRID CELL NUMBERS OF END OF RESPECTIVE OPERATIONS (NBP VALUES) : IBPE(I) J.13 BYPASSING RATES AS TOTAL AVERAGE VOLUME PER HOUR (CY/HR OR M3/HR, ACCORDING TO UNITS GIVEN IN A. 2) FOR RESPECTIVE OPERATIONS (NBP VALUES): QBP(I) K COMMENTS K * ALL COORDINATES MUST BE GIVEN IN THE "TOTAL" GRID SYSTEM * ONE VALUE FOR EACH STRUCTURE, TIP ETC. ESPECIALLY IMPORTANT FOR COMBINED STRUCTURES, E.G., TWO DEW'S WHERE THE LOCATION WHERE THEY MEET HAS TO BE TREATED AS TWO TIPS. * ANY GROIN CONNECTED TO A DETACHED BREAKWATER MUST BE REGARDED AS DIFFRACTING * CONNECTED STRUCTURES MUST BE GIVEN THE SAME Y AND D VALUES WHERE THEY CONNECT * IF DOING REAL CASES, THE WAVE.DAT FILE MUST CONTAIN FULL YEARS DATA * DATA FOR START OF BEACH FILL IN SPACE AND TIME SHOULD BE GIVEN IN INCREASING/CHRONOLOGICAL ORDER. DATA FOR END OF BEACH FILL MUST CORRESPOND TO THESE VALUES, AND NOT NECESSARILY BE IN INCREASING ORDER. * DON'T CHANGE THE LABELS OF THE LINES SINCE THEY ARE USED TO IDENTIFY THE LINES BY GENESIS. END RUN:NAVY HOMEPORT BECH FILL STUDY AT SOUTH OCEANSIDE INITIAL SHORELINE POSITION (M) 270.00 240.00 260.00 260.00 255.00 255.00 310.00 385.00 475.00 530.00 810.00 265.00 235.00 260.00 260.00 255.00 255.00 320.00 395.00 480.00 550.00 850.00 260 235 260 255 255 260 330 400 490 580 850 SHORELINE POSITION 270.00 241.22 270.24 282.95 269.14 256.70 307.22 385.00 475.00 530.00 810.00 265.67 241.55 273.80 282.51 266.43 258.43 314.66 395.00 480.00 550.00 850.00 261 242 276 281 263 260 321 400 490 580 850 SHORELINE POSITION 270.00 244.23 268.42 282.62 268.51 259.54 305.14 385.00 475.00 530.00 810.00 LAST TIME BREAKING 0.91 0.90 0.90 0.90 0.90 0.90 0.90 0.90 0.90 0.90 0.90 0.90 BREAKING 2.85 3.49 4.11 3.65 3.31 266.14 244.62 271.48 282.20 266.32 261.54 311.00 395.00 480.00 550.00 850.00 262 245 274 281 264 264 316 400 490 580 850 .00 255. .00 235. .00 260. .00 250. .00 255. .00 255. .00 335. .00 410. .00 495. .00 605. .00 840. 00 00 00 00 00 00 00 00 00 00 00 (M) AFTER .42 257. .62 244. .80 279. .94 281. .77 261. .90 264. .81 328. .00 410. .00 495. .00 605. .00 843. (M) AFTER .32 258. .65 247. .23 276. .53 280. .20 262. .24 267. .52 321. .00 410. .00 495. .00 605. .00 840. 30 43 19 23 30 19 44 00 00 00 30 62 28 63 63 23 66 54 00 00 00 00 STEP. DIFFRACTED WAVES WAVE HEIGHT 0.91 0.91 0.91 0. 0.90 0.90 0.90 0.90 0.90 0.90 0.90 0.90 0.90 0.90 0.90 0.90 0.90 0.90 0.90 0.90 0.90 0.90 0.90 0.90 0.90 0.90 0.90 0.90 0.90 0.90 0.90 0.90 0.90 0.90 0. 0. 0. 0. 0. 0. 0. 0. 0. 0. 245 245 255 250 255 260 345 420 480 640 830 729 253 246 280 280 259. 268 334. 420. 485. 640. 837. 1457 255. 249. 278. 279. 260. 271. 325. 420. 481. 640. 833. .00 245.00 .00 245.00 .00 255.00 .00 250.00 .00 255.00 .00 265.00 .00 355.00 .00 430.00 .00 480.00 .00 670.00 .00 825.00 TIME STEPS. .37 249.82 .94 250.09 .97 282.18 .36 279.26 .15 257.42 .33 273.31 .32 339.22 .00 430.00 .17 480.16 .00 670.00 .65 831.69 TIME STEPS. .07 251.84 ,46 252.11 .62 280.21 .49 278.12 .49 259.08 .75 276.47 .90 329.55 .00 430.00 .51 482.03 .00 670.00 .52 830.19 ALONGSHORE 91 0.91 0.91 90 90 90 90 90 90 90 90 90 90 0.90 0.90 0.90 0.90 0.90 0.90 0.90 0.90 0.90 0.90 0.90 0.90 0.90 0.90 0.90 0.90 0.90 0.90 0.90 0.90 245 250 255 255 255 270 345 430 485 705 825 .00 .00 .00 .00 .00 .00 .00 .00 .00 .00 .00 DATE IS 246 253 282 277. 256. 279. 342. 430. 485. 705. 825. .85 .76 .94 .87 .17 .08 .97 .00 .00 .00 .87 DATE IS 249. 255. 281. 276. 258. 281. 332. 430. 485. 705. 826. 0. 0. 0. 0. 0. 0. 0. 0. 0. 0. 0. .14 .11 .39 .53 08 70 .67 .00 20 00 13 90 90 90 90 90 90 90 90 90 90 90 245.00 255.00 255.00 255.00 255.00 280.00 350.00 440.00 490.00 745.00 815.00 970831 244.49 257.82 283.31 276.17 255.45 285.53 345.35 440.00 490.00 745.00 820.45 971130 247.01 258.37 282.19 274.75 257.56 287.32 335.69 440.00 490.07 745.00 821.24 0.90 0.90 0.90 0.90 0.90 0.90 0.90 0.90 0.90 0.90 0.90 240.00 260.00 255.00 260.00 255.00 290.00 370.00 450.00 490.00 770.00 810.00 242.73 262.05 283.39 274.11 255.27 292.48 345.87 450.00 490.00 770.00 815.19 245.46 261.75 282.64 272.78 257.59 293.18 338.98 450.00 495.56 770.00 815.73 0.90 0.90 0.90 0.90 0.90 0.90 0.90 0.90 0.90 0.90 0.90 240.00 260.00 260.00 255.00 255.00 300.00 375.00 470.00 510.00 800.00 810.00 241.62 266.27 283.25 271.74 255.68 299.76 343.47 470.00 510.00 800.00 810.00 244.52 265.14 282.78 270.69 258.24 299.15 341.62 470.00 510.00 800.00 810.00 WAVE ANGLE TO X-AXIS 2.85 3.59 4.10 3.58 3.34 2.85 3.68 4.09 3.52 3.38 2.85 3.77 4.06 3.46 3 .44 2. 3. 4. 3. 3. 85 85 02 41 50 2.89 3.02 3.93 3.99 3.97 3.91 3.36 3.33 3.58 3.66 3. 4. 3. 3. 3. 18 04 85 31 76 3.30 4.07 3.78 3.30 3.86 3.39 4.10 3.72 3.30 3.96 4.07 5.13 6.51 5.78 8.89 8.58 3 .51 4.17 5.28 6.56 5.69 4.28 5.42 6.57 5.68 4.39 5.57 6.55 5.74 9.51 10.05 10.46 7.73 GROSS TRANSPORT 459 459 459 460 493 460 453 457 501 1254 462 608 452 430 481 461 455 457 498 509 463 577 1468 6.85 VOLUME 459 462 471 464 451 • 459 493 455 533 882 487 6.01 4.49 5.72 6.49 5.90 10.72 5.01 4.60 5.86 6.39 6.19 4.70 5.99 6.27 6.60 4.80 6.12 6.16 7.10 10.82 10.73 10.45 4.02 (M3/1000) FROM 970601 460 461 459 466 473 476 463 466 453 463 485 504 460 679 710 459 467 456 468 478 507 844 1038 641 NET TRANSPORT VOLUME (M3/1000) FROM 52 -49 -173 -55 14 -78 -213 -25 -25 -44 -44 -45 TRANSPORT -203 -254 -333 -258 -219 -267 -357 -1251 -292 -566 -291 - -182 TRANSPORT 256 204 160 202 234 189 143 2 170 42 161 248 52 -63 -149 -46 29 -93 -203 -25 -25 -44 -44 VOLUME -203 -262 -315 -254 -212 -275 -351 -407 -294 -542 1468 VOLUME 256 198 165 207 242 182 147 101 168 35 0 49 -83 -128 -37 15 -110 -188 -25 -25 -44 -44 TO THE -204 -273 -300 -250 -218 -285 -340 -253 -451 -878 -133 TO THE 254 189 171 213 233 174 152 201 82 4 354 44 -104 -110 -33 1 -124 -166 -25 -25 -44 -44 LEFT -208 -285 -287 -249 -225 -293 -326 -399 -285 -663 -44 RIGHT 252 181 176 216 227 169 159 104 174 15 666 35 -126 -93 -34 -10 -147 -145 -25 -25 -44 -44 456 468 458 475 466 508 446 841 489 3.61 3.61 TO 980531 460 459 481 485 456 470 459 483 455 475 438 1045 429 457 467 459 491 434 514 446 1257 578 4.89 6.25 6.05 7.66 9.99 3.61 459 487 458 464 458 497 411 523 403 723 477 5.00 6.40 5.92 8.26 9.36 3.61 459 490 461 458 457 501 351 839 570 960 430 970601 TO 980531 18 -137 -85 -34 -21 -167 -120 -25 -25 -44 -44 (M3/1000) FROM -212 -300 -276 -250 -233 -307 -311 -404 -27 -1038 -81 -220 -306 -270 -251 -240 -321 -293 -406 -123 -837 - -126 (M3/1000) FROM 248 173 182 216 223 160 166 102 817 0 560 239 169 185 217 218 153 173 101 322 4 363 3 -150 -78 -33 -32 -186 -90 -25 -28 -44 -44 970601 -228 -316 -267 -252 -246 -334 -272 -151 -213 1045 - -198 970601 231 165 189 218 213 148 182 324 225 0 231 -8 -160 -72 -25 -42 -203 -80 -25 -30 -44 -44 -19 -166 -68 -15 -53 -213 -72 -25 -33 -44 -44 -34 -168 -64 1 -65 -217 -48 -25 -44 -44 -45 TO 980531 -234 -322 -264 -246 -251 -347 -257 -419 -218 1257 -115 -239 -327 -263 -239 -256 -355 -242 -434 -149 -710 -149 -246 -329 -262 -228 -261 -359 -204 -829 -504 -958 -182 TO 980531 225 162 192 221 208 144 177 95 227 0 462 220 160 195 224 202 142 169 88 253 12 327 212 160 198 230 195 142 146 9 66 2 248 OUTPUT OF BREAKING WAVE STATISTICS FOR SELECTED LOCATIONS N.B. WAVE DIFFRACTION IS NOT ACCOUNTED FOR! GRID CELL NUMBERS 1 22 44 66 88 AVERAGE 1.26 1.26 1.26 1.26 1.26 AVERAGE 0.84 -1.48 0.27 -1.05 0.35 AVERAGE 0.17 -0.47 0.01 -0.38 0.02 2 24 46 68 90 4 26 48 70 92 UNDIFFRACTED 1.26 1.26 1.26 1.26 1.26 1.26 1.26 1.26 1.26 1.25 UNDIFFRACTED 0.84 -1.00 - 0.00 - -0.48 - -4.98 - 0.74 0.70 0.24 0.14 5.51 6 28 50 72 94 8 30 52 74 96 11 13 33 35 55 57 77 79 99 101 15 37 59 81 103 17 39 61 83 105 19 41 63 85 107 BREAKING WAVE HEIGHTS (M) . 1.26 1.26 1.26 1.26 1.25 1.26 1. 1.26 1. 1.26 1. 1.26 1. 1.25 1. 26 1.26 26 1.26 26 1.26 26 1.26 25 1.26 1. 1. 1. 1. 1. 26 26 26 26 26 1.26 1.26 1.26 1.26 1.26 1.26 1.26 1.26 1.26 1.26 BREAKING WAVE ANGLE TO SHORELINE (DEG) 0.39 -0.56 -0.49 -3.12 -7.15 LONGSHORE TRANSPORT 0.17 -0.35 - -0.07 - -0.26 - -1.41 - 0.14 0.27 0.14 0.14 1.60 LONGSHORE TRANSPORT 0.46 0.37 0.30 0.37 0.42 0.33 0.26 0.00 0.00 0.00 0.00 0.45 0.46 0.36 0.30 0.38 0.42 0.32 0.26 0.00 0.00 0.00 0.00 CALCULATED FINAL 270.00 252.11 266.27 278.64 268.73 267.62 301.70 385.00 475.00 530.00 810.00 267.35 252.22 268.37 278.47 267.45 269.53 306.55 395.00 480.00 550.00 850.00 0.46 0.35 0.30 0.39 0.41 0.30 0.26 0.00 0.00 0.00 0.00 0.04 -0.23 -0.21 -0.95 -2.04 FOR LAST 0.45 0.34 0.31 0.39 0.41 0.29 0.25 0.00 0.00 0.00 0.00 0.13 -0. -0.48 -0. -0.80 -1. -3.09 2. -9.39 -7. RATE BASED -0.03 -0. -0.20 -0. -0.30 -0. -0.94 0. -2.62 -2. TIME STEP 0.45 0. 0.32 0. 0.31 0. 0.40 0. 0.40 0. 0.28 0. 0.24 0. 0.00 0. 0.00 0. 0.00 0. 0.00 0. 32 -0.72 19 -0.17 43 -1.90 34 -3.59 63 -0.87 -1. -0. -2. -1. 2. 20 16 23 04 98 -1.50 0.05 -2.25 -4.00 5.78 -1.68 0.42 -1.93 9.56 0.78 ON UNDIFFRACTED WAVES *100 (M3/SEC) 16 -0.27 12 -0.11 47 -0.59 58 -1.08 17 -0.33 -0. -0. -0. -0. 0. 40 11 68 37 75 -0.48 -0.05 -0.68 -1.19 1.60 -0.53 0.05 -0.60 2.55 0.09 *100 (M3/SEC) 44 0.44 31 0.31 32 0.33 41 0.41 39 0.38 27 0.27 23 0.21 00 0.00 00 0.42 00 0.00 00 0.00 0. 0. 0. 0. 0. 0. 0. 0. 0. 0. 0. 42 30 34 42 37 26 22 00 39 00 00 0.40 0.30 0.35 0.42 0.36 0.26 0.26 0.00 0.38 0.00 0.00 0.39 0.30 0.36 0.42 0.34 0.26 0.32 0.00 0.22 0.00 0.45 SHORELINE POSITION (M) 264 252 270 278 266 271 311 400 490 580 850 .75 262 .73 253 .36 272 .04 277 .31 265 .85 274 .69 317 .00 410 .00 495 .00 605 .00 840 .22 259.80 .60 254.80 .22 273.89 .37 276.48 .35 264.64 .55 277.61 .17 323.07 .00 420.00 .00 480.00 .00 640.00 .00 830.00 257.60 256.30 275.35 275.41 264.22 281.00 329.47 430.00 482.22 670.00 825.00 255. 258. 276. 274. 264. 284. 336. 430. 486. 705. 825. 74 03 55 20 13 68 31 00 67 00 00 254.25 259.96 277.50 272.88 264.40 288.61 343.29 440.00 492.40 745.00 815.00 253.14 262.01 278.16 271.49 265.06 292.75 349.78 450.00 499.37 770.00 811.44 252. 264. 278. 270. 266. 297. 355. 470. 510. 800. 810. .42 .14 .54 .09 .13 .11 .47 .00 .13 .00 .00 CALCULATED SEAWARDMOST SHORELINE POSITION (M) 270.00 252.11 277.22 283.48 273.53 267.62 310.00 267.35 252.22 282.48 282.66 267.45 269.53 320.00 264 252 284 281 266 271 330 .75 262 .73 253 .23 284 .94 281 .31 265 .85 274 .00 336 .22 259.80 .60 254.80 .23 283.56 .27 280.59 .35 264.64 .55 277.61 .16 345.00 257.60 256.30 283.35 280.02 264.22 281.00 355.00 255. 258. 283. 280. 264. 284. 352. 74 03 43 08 13 68 53 254.25 259.96 283.47 280.77 264.40 288.61 358.23 253.14 262.13 283.41 280.65 265.06 293.20 370.00 252. 267. 283. 278. 266. 300. 375. .42 .70 .56 .72 .13 .00 .04 385.00 475.00 532.49 810.05 395.00 480.00 554.23 850.00 400 490 580 850. .01 .00 .00 .00 410.00 495.00 606.94 844.69 420.00 487.09 640.00 839.52 430.00 485.74 670.14 833.86 430.47 487.05 705.05 827.68 440 492 745 821. .05 .58 .00 .68 450.51 500.91 770.00 815.82 470.00 514.70 800.00 810.00 CALCULATED LANDWARDMOST SHORELINE POSITION (M) 270.00 238.25 260.00 260.00 255.00 254.99 301.70 385.00 475.00 530.00 810.00 264.80 235.00 260.00 260.00 255.00 255.00 306.54 395.00 480.00 550.00 850.00 259 235. 260 255. 255. 257. 311. 400. 490. 580. 850, .55 .00 .00 .00 .00 .09 .61 .00 .00 .00 .00 CALCULATED REPRESENTATIVE 570.00 555.78 565.97 576.15 569.60 571.46 604.69 678.29 763.43 568.08 555.77 567.59 576.11 568.80 573.30 610.02 687.72 769.96 566. 556. 569. 575. 568. 575. 615. 697. 776. .15 .06 .15 .86 .13 .47 .81 .16 .54 253.99 235.00 260.00 250.00 254.99 255.00 316.86 410.00 495.00 605.00 840.00 245.00 242.35 255.00 250.00 254.98 259.99 322.23 420.00 480.00 640.00 830.00 244.99 245.00 255.00 250.00 254.92 264.99 327.57 430.00 480.00 670.00 825.00 244.46 250.00 255.00 255.00 254.79 270.00 332.39 430.00 485.00 705.00 825.00 242, 254. 255 255 254. 279. 335 440. 490. 745. 815. .70 .27 .00 .00 .53 .99 .11 .00 .00 .00 .00 240.00 258.00 255.00 260.00 254.48 289.94 336.10 450.00 490.00 770.00 810.00 239.59 260.00 260.00 255.00 254.77 297.10 335.35 470 .00 510.00 800.00 810.00 OFFSHORE CONTOUR POSITION (M) 564.23 556.63 570.63 575.43 567.62 577.98 622.06 706.61 783.28 562.30 557.46 571.97 574.84 567.33 580.83 628.79 715.83 790.44 560.38 558.53 573.16 574.11 567.27 584.01 636.00 724.72 798.58 558.93 559.79 574.18 573.28 567.48 587.50 643.61 733.18 808.06 557. 561. 574. 572. 567. 591. 651. 741. 819. .72 .20 .99 .37 ,99 .31 .62 .34 .20 556.78 562.73 575.59 571.43 568.82 595.43 660.03 749.12 832.12 556.12 564.34 575.98 570.49 569.97 599.83 668.93 756.52 847.03 863.92 882.97 903.87 926.09 949.23 972.69 995.87 1018.11 1038.77 1057.46 1073.41 1086.63 1096.94 1104.51 1109.68 1109.74 1109.81 1109.87 1109.94 1110.00 CALIBRATION/VERIFICATION ERROR = 8.85175 CALCULATED VOLUMETRIC CHANGE = +7.45E+05 (M3) SIGN CONVENTION: EROSION (-), ACCRETION ( + ) NAVY HONEPORT BECH FILL STUDY AT SOUTH OCEANSIDE 04-04-1997 O-c Ed Cd CO 1000-- 800-- 600-- 400-- 200-- 0- Initial Shoreline Calculated Shoreline Mon-Diffracting Groin Seauall Beach Fill 0 20 40 60 80 100 ALONGSHORE COORDINATE (cell spacing = 100 n) 120 SOUTH OCEANSIDE SBEACH I/O 10 c.g'<&to 9 LU -5 -10 -15 ^V- v^ ^C^~^•.-y ^V ^ ^^ ------ ^ - - ^••V v---^-X~ Summer Variation at South Oceanside Transect OS 0930 -^^:^ " L~'-^'r.'^^'-— -^^, - — -" - :-\--^-~ 1990 1991 1992 1993 1994 ^-— -'"^-'"~------ -_— -— - . 0 100 200 300 400 500 600 700 800 900 1000 1100 1200 Distance from Range (m) Elevation MSL (m)L. 1* , -*01 o 01 o 01 o% ^/•-., \-v x^^\... \ ''V Winter Variation at South Oceanside Transect OS 0930 \ <* } 100 200 300 >.; -V~' ';":-.-- ""•-•>.--";>-, '- -^~\'---^:.;--'--. ~""~ — ~ - -— ~ 400 500 600 700 800 Distance from Range (m) —"--.'." 900 -"~-~ i -1 i 1990 1991 1992 1993 1994 1996 . - ... _ 1000 1100 1200 10 5 1 o COE c,o "ic 35 "5 UJ •10 -15 ( "" ""\\...\\ Beach Fill Profile at South Oceanside Transect OS 0930 ""•-- - --••... ) 100 ^*x X """---... 200 300 400 Distance from Range (m) Initial Profile Nourished Profile — 500 600 S.Oceanside Beach Fill Profile Cut and Fill Report Profiirn Profile 2: XOn: XOff: Volume Change: Above Datum: Below Datum: Total Volume: Shoreline Change: From: To: Cell Changes: Cell* 1 2 Average Nourished Profile 0.00m 1265.00 m 89.626 cu. m/m 73.879 cu.m/m 163.605 cu.m/m 55.83 m 53.17 m 109.00 m Ending Distance(m) Ending Elevation(m) 24.06 2.17 1265.00 -15.00 Cell Volume(cu. m/m) 0.000 163.505 Cell Thickness(m) 0.00 0.13 Cumulative Volumefcu. m/m) 0.000 163.505 Gross Volume(cu. m/m) 0.000 163.505 -Page 1- 10 5 I 0 V) 0 Q> -5 LJJ -10 ( ^ ^ x \ vx . \ \^\ \^ South Oceanside - Case 1 Transect OS 0930 "^~\ ^~^^-^-^_^ • — -J- — • — , Initial Profile — Nourished Profile 180 Days 1 — ___ ) 100 200 300 400 500 600 700 800 900 Distance from Range (m) — _— _• — • — _~~-*• — 1000 1100 1200 Report for run: Reach: Initial Design Beach Fill Storm: Report Project: South Oceanside - Case 1 Reach: Initial Design Beach Fill Storm: Oct87-Dec87 MODEL CONFIGURATION INPUT UNITS (SI=1, AMERICAN CUST =2): 1 NUMBER OF CALCULATION CELLS: 240 GRID TYPE (CONSTANTS, VARIABLES): 0 CONSTANT CELL WIDTH: 5.0 NUMBER OF TIME STEPS AND VALUE OF TIME STEP IN MINUTES: 2190, 60.0 TIME STEP INTERVAL OF INTERMEDIATE OUTPUT: 500 NO COMPARSION WITH MEASURED PROFILE. PROFILE ELEVATION CONTOUR 1: 1.50 PROFILE ELEVATION CONTOUR 2: .00 PROFILE ELEVATION CONTOUR 3: -5.00 PROFILE EROSION DEPTH 1: .50 PROFILE EROSION DEPTH 2: 1.00 PROFILE EROSION DEPTH 3: 1.50 REFERENCE ELEVATION: .00 TRANSPORT RATE COEFFICIENT (mA4/N): .25E-6 COEFFICIENT FOR SLOPE DEPENDENT TERM (mA2/s): .0050 TRANSPORT RATE DECAY COEFFICIENT MULTIPLIER: .50 WATER TEMPERATURE IN DEGREES C : 20.0 WAVE TYPE (MONOCHROMATIC=1, IRREGULAR=2): 2 WAVE HEIGHT AND PERIOD INPUT (CONSTANTS, VARIABLES): 1 TIME STEP OF VARIABLE WAVE HEIGHT AND PERIOD INPUT IN MINUTES: 480.0 WAVE ANGLE INPUT (CONSTANTS, VARIABLES): 0 CONSTANT WAVE ANGLE: .0 WATER DEPTH OF INPUT WAVES (DEEP WATER = 0.0): .0 SEED VALUE FOR WAVE HEIGHT RANDOMIZER AND % VARIABILITY: 4567, 20.0 TOTAL WATER ELEVATION INPUT (CONSTANTS, VARIABLES): 1 TIME STEP OF VARIABLE TOTAL WATER ELEVATION INPUT IN MINUTES: 720.0 WIND SPEED AND ANGLE INPUT (CONSTANTS, VARIABLES): 0 CONSTANT WIND SPEED AND ANGLE: .0, .0 TYPE OF INPUT PROFILE (ARBITRARY=1, SCHEMATIZED=2): 1 DEPTH CORRESPONDING TO LANDWARD END OF SURF ZONE: .15 EFFECTIVE GRAIN SIZE DIAMETER IN MILLIMETERS: .26 MAXIMUM PROFILE SLOPE PRIOR TO AVALANCHING IN DEGREES: 15.0 BEACH FILL IS PRESENT. POSITION OF SEAWALL RELATIVE TO INITIAL PROFILE: 30.0 SEAWALL FAILURE IS NOT ALLOWED. NO HARD BOTTOM IS PRESENT. COMPUTED RESULTS DIFFERENCE IN TOTAL VOLUME BETWEEN FINAL AND INITIAL PROFILES: 4.8 mA3/m MAXIMUM VALUE OF WATER ELEVATION + SETUP FOR SIMULATION 1.49m TIME STEP AND POSITION ON PROFILE AT WHICH MAXIMUM VALUE OF WATER ELEVATION + SETUP OCCURRED 848, 60.0 m MAXIMUM ESTIMATED RUNUP ELEVATION: 4.37 m (REFERENCED TO VERTICAL DATUM) POSITION OF LANDWARD MOST OCCURRENCE OF A .50 m EROSION DEPTH: 30.0m DISTANCE FROM POSITION OF REFERENCE ELEVATION ON INITIAL PROFILE TO POSITION OF LANDWARD MOST OCCURRENCE OF A .50 m EROSION DEPTH: 51.0m POSITION OF LANDWARD MOST OCCURRENCE OF A 1.00 m EROSION DEPTH: 30.0m DISTANCE FROM POSITION OF REFERENCE ELEVATION ON INITIAL PROFILE TO POSITION OF LANDWARD MOST OCCURRENCE OF A 1.00 m EROSION DEPTH: 51.0m POSITION OF LANDWARD MOST OCCURRENCE OF A 1.50 m EROSION DEPTH: 35.0m DISTANCE FROM POSITION OF REFERENCE ELEVATION ON INITIAL PROFILE TO POSITION OF LANDWARD MOST OCCURRENCE OF A 1.50m EROSION DEPTH: 46.0m MAXIMUM RECESSION OF THE 1.50 m ELEVATION CONTOUR: 36.25 m MAXIMUM RECESSION OF THE .00 m ELEVATION CONTOUR: 44.52 m THE -5.00m CONTOUR DID NOT RECEDE Report for run: Reach: Final Design Beach Storm: Report Project: South Oceanside - Case 1 Reach: Final Design Beach Storm: Jan87-Sep87 MODEL CONFIGURATION INPUT UNITS (SI=1, AMERICAN CUST =2): 1 NUMBER OF CALCULATION CELLS: 238 GRID TYPE (CONSTANTS, VARIABLES): 0 CONSTANT CELL WIDTH: 5.0 NUMBER OF TIME STEPS AND VALUE OF TIME STEP IN MINUTES: 6570, 60.0 TIME STEP INTERVAL OF INTERMEDIATE OUTPUT: 2078 PROFILE ELEVATION CONTOUR 1: 1.50 PROFILE ELEVATION CONTOUR 2: .00 PROFILE ELEVATION CONTOUR 3: -5.00 PROFILE EROSION DEPTH 1: .50 PROFILE EROSION DEPTH 2: 1.00 PROFILE EROSION DEPTH 3: 1.50 REFERENCE ELEVATION: .00 TRANSPORT RATE COEFFICIENT (mA4/N): .25E-6 COEFFICIENT FOR SLOPE DEPENDENT TERM (mA2/s): .0050 TRANSPORT RATE DECAY COEFFICIENT MULTIPLIER: .50 WATER TEMPERATURE IN DEGREES C : 20.0 WAVE TYPE (MONOCHROMATIC=1, IRREGULAR=2): 2 WAVE HEIGHT AND PERIOD INPUT (CONSTANTS, VARIABLES): 1 TIME STEP OF VARIABLE WAVE HEIGHT AND PERIOD INPUT IN MINUTES: 480.0 WAVE ANGLE INPUT (CONSTANTS, VARIABLES): 0 CONSTANT WAVE ANGLE: .0 WATER DEPTH OF INPUT WAVES (DEEP WATER = 0.0): .0 SEED VALUE FOR WAVE HEIGHT RANDOMIZER AND % VARIABILITY: 4567, 20.0 TOTAL WATER ELEVATION INPUT (CONSTANTS, VARIABLES): 1 TIME STEP OF VARIABLE TOTAL WATER ELEVATION INPUT IN MINUTES: 720.0 WIND SPEED AND ANGLE INPUT (CONSTANTS, VARIABLES): 0 CONSTANT WIND SPEED AND ANGLE: .0, .0 TYPE OF INPUT PROFILE (ARBITRARY=1, SCHEMATIZED=2): 1 DEPTH CORRESPONDING TO LANDWARD END OF SURF ZONE: .15 EFFECTIVE GRAIN SIZE DIAMETER IN MILLIMETERS: .26 MAXIMUM PROFILE SLOPE PRIOR TO AVALANCHING IN DEGREES: 15.0 BEACH FILL IS PRESENT. POSITION OF SEAWALL RELATIVE TO INITIAL PROFILE: 30.0 SEAWALL FAILURE IS NOT ALLOWED. NO HARD BOTTOM IS PRESENT. COMPUTED RESULTS DIFFERENCE IN TOTAL VOLUME BETWEEN FINAL AND INITIAL PROFILES: .7 mA3/m MAXIMUM VALUE OF WATER ELEVATION + SETUP FOR SIMULATION 1.22m TIME STEP AND POSITION ON PROFILE AT WHICH MAXIMUM VALUE OF WATER ELEVATION + SETUP OCCURRED 2053, 75.0m MAXIMUM ESTIMATED RUNUP ELEVATION: 2.88 m (REFERENCED TO VERTICAL DATUM) POSITION OF LANDWARD MOST OCCURRENCE OF A .50 m EROSION DEPTH: 70.0m DISTANCE FROM POSITION OF REFERENCE ELEVATION ON INITIAL PROFILE TO POSITION OF LANDWARD MOST OCCURRENCE OF A .50 m EROSION DEPTH: 39.0 rn POSITION OF LANDWARD MOST OCCURRENCE OF A 1.00 m EROSION DEPTH: 75.0m DISTANCE FROM POSITION OF REFERENCE ELEVATION ON INITIAL PROFILE TO POSITION OF LANDWARD MOST OCCURRENCE OF A 1.00 m EROSION DEPTH: 34.0m POSITION OF LANDWARD MOST OCCURRENCE OF A 1.50m EROSION DEPTH: 85.0m DISTANCE FROM POSITION OF REFERENCE ELEVATION ON INITIAL PROFILE TO POSITION OF LANDWARD MOST OCCURRENCE OF A 1.50m EROSION DEPTH: 24.0m MAXIMUM RECESSION OF THE 1.50 m ELEVATION CONTOUR: 15.95m MAXIMUM RECESSION OF THE .00 m ELEVATION CONTOUR: 28.30 m THE -5.00 m CONTOUR DID NOT RECEDE 10 5 1 0 CO 2 ,o'£«re 35 -5 m -10 -15 c AV '^\Y\ x^\ "XN \ \ \ X^v \\^ South Oceanside - Case 2 Transect OS 0930 ^~- ^ ^ ^"^^-^^ — - —— " — ~ r Initial Profile — Nourished Profile 1 80 Days — -_ ) 100 200 300 400 500 600 700 800 900 Distance from Range (m) — — _^_• — — —,— • — ^_,— ^_ 1000 1100 1200 Report for run: Reach: Initial Design Beach Fill Storm: Report Project: South Oceanside Reach: Initial Design Beach Fill Storm: Oct93-Dec93 MODEL CONFIGURATION INPUT UNITS (SI=1, AMERICAN CUST =2): 1 NUMBER OF CALCULATION CELLS: 240 GRID TYPE (CONSTANTS, VARIABLES): 0 CONSTANT CELL WIDTH: 5.0 NUMBER OF TIME STEPS AND VALUE OF TIME STEP IN MINUTES: 1776, 60.0 TIME STEP INTERVAL OF INTERMEDIATE OUTPUT: 500 NO COMPARSION WITH MEASURED PROFILE. PROFILE ELEVATION CONTOUR 1: 1.50 PROFILE ELEVATION CONTOUR 2: .00 PROFILE ELEVATION CONTOUR 3: -5.00 PROFILE EROSION DEPTH 1: .50 PROFILE EROSION DEPTH 2: 1.00 PROFILE EROSION DEPTH 3: 1.50 REFERENCE ELEVATION: .00 TRANSPORT RATE COEFFICIENT (mA4/N): .25E-6 COEFFICIENT FOR SLOPE DEPENDENT TERM (mA2/s): .0050 TRANSPORT RATE DECAY COEFFICIENT MULTIPLIER: .50 WATER TEMPERATURE IN DEGREES C : 20.0 WAVE TYPE (MONOCHROMATIC=1, IRREGULAR=2): 2 WAVE HEIGHT AND PERIOD INPUT (CONSTANTS, VARIABLES): 1 TIME STEP OF VARIABLE WAVE HEIGHT AND PERIOD INPUT IN MINUTES: 180.0 WAVE ANGLE INPUT (CONSTANTS, VARIABLE^!): 0 CONSTANT WAVE ANGLE: .0 WATER DEPTH OF INPUT WAVES (DEEP WATER = 0.0): .0 SEED VALUE FOR WAVE HEIGHT RANDOMIZER AND % VARIABILITY: 4567, 20.0 TOTAL WATER ELEVATION INPUT (CONSTANTS, VARIABLES): 1 TIME STEP OF VARIABLE TOTAL WATER ELEVATION INPUT IN MINUTES: 60.0 WIND SPEED AND ANGLE INPUT (CONSTANTS, VARIABLES): 0 CONSTANT WIND SPEED AND ANGLE: .0, .0 TYPE OF INPUT PROFILE (ARBITRARY=1, SCHEMATIZED=2): 1 DEPTH CORRESPONDING TO LANDWARD END OF SURF ZONE: .15 EFFECTIVE GRAIN SIZE DIAMETER IN MILLIMETERS: .26 MAXIMUM PROFILE SLOPE PRIOR TO AVALANCHING IN DEGREES: 15.0 BEACH FILL IS PRESENT. POSITION OF SEAWALL RELATIVE TO INITIAL PROFILE: 30.0 SEAWALL FAILURE IS NOT ALLOWED. NO HARD BOTTOM IS PRESENT. COMPUTED RESULTS DIFFERENCE IN TOTAL VOLUME BETWEEN FINAL AND INITIAL PROFILES: 1.2mA3/m MAXIMUM VALUE OF WATER ELEVATION + SETUP FOR SIMULATION 1.60m TIME STEP AND POSITION ON PROFILE AT WHICH MAXIMUM VALUE OF WATER ELEVATION + SETUP OCCURRED 1089, 80.0m MAXIMUM ESTIMATED RUNUP ELEVATION: 2.72 m (REFERENCED TO VERTICAL DATUM) POSITION OF LANDWARD MOST OCCURRENCE OF A .50 m EROSION DEPTH: 75.0m DISTANCE FROM POSITION OF REFERENCE ELEVATION ON INITIAL PROFILE TO POSITION OF LANDWARD MOST OCCURRENCE OF A .50 m EROSION DEPTH: 34.0m POSITION OF LANDWARD MOST OCCURRENCE OF A 1.00 m EROSION DEPTH: 85.0m DISTANCE FROM POSITION OF REFERENCE ELEVATION ON INITIAL PROFILE TO POSITION OF LANDWARD MOST OCCURRENCE OF A 1.00 m EROSION DEPTH: 24.0m A 1.50m EROSION DEPTH DID NOT OCCUR ANYWHERE ON THE PROFILE. MAXIMUM RECESSION OF THE 1.50 m ELEVATION CONTOUR: 10.62m MAXIMUM RECESSION OF THE .00 m ELEVATION CONTOUR: 20.90 m THE -5.00m CONTOUR DID NOT RECEDE Report for run: Reach: 1988 Design Beach Storm: 1988 Report Project: South Oceanside Reach: 1988 Design Beach Storm: 1988 MODEL CONFIGURATION INPUT UNITS (SI=1, AMERICAN CUST =2): 1 NUMBER OF CALCULATION CELLS: 239 GRID TYPE (CONSTANTS, VARIABLES): 0 CONSTANT CELL WIDTH: 5.0 NUMBER OF TIME STEPS AND VALUE OF TIME STEP IN MINUTES: 7776, 60.0 TIME STEP INTERVAL OF INTERMEDIATE OUTPUT: 2078 NO COMPARSION WITH MEASURED PROFILE. PROFILE ELEVATION CONTOUR 1: 1.50 PROFILE ELEVATION CONTOUR 2: .00 PROFILE ELEVATION CONTOUR 3: -5.00 PROFILE EROSION DEPTH 1: .50 PROFILE EROSION DEPTH 2: 1.00 PROFILE EROSION DEPTH 3: 1.50 REFERENCE ELEVATION: .00 TRANSPORT RATE COEFFICIENT (mA4/N): .25E-6 COEFFICIENT FOR SLOPE DEPENDENT TERM (mA2/s): .0050 TRANSPORT RATE DECAY COEFFICIENT MULTIPLIER: .50 WATER TEMPERATURE IN DEGREES C : 20.0 WAVE TYPE (MONOCHROMATIC=1, IRREGULAR=2): 2 WAVE HEIGHT AND PERIOD INPUT (CONSTANTS), VARIABLES): 1 TIME STEP OF VARIABLE WAVE HEIGHT AND PERIOD INPUT IN MINUTES: 360.0 WAVE ANGLE INPUT (CONSTANTS, VARIABLES): 0 CONSTANT WAVE ANGLE: .0 WATER DEPTH OF INPUT WAVES (DEEP WATER = 0.0): .0 SEED VALUE FOR WAVE HEIGHT RANDOMIZER AND % VARIABILITY: 4567, 20.0 TOTAL WATER ELEVATION INPUT (CONSTANTS, VARIABLES): 1 TIME STEP OF VARIABLE TOTAL WATER ELEVATION INPUT IN MINUTES: 720.0 WIND SPEED AND ANGLE INPUT (CONSTANTS, VARIABLES): 0 CONSTANT WIND SPEED AND ANGLE: .0, .0 TYPE OF INPUT PROFILE (ARBITRARY=1, SCHEMATIZED=2): 1 DEPTH CORRESPONDING TO LANDWARD END OF SURF ZONE: .15 EFFECTIVE GRAIN SIZE DIAMETER IN MILLIMETERS: .26 MAXIMUM PROFILE SLOPE PRIOR TO AVALANCHING IN DEGREES: 15.0 BEACH FILL IS PRESENT. POSITION OF SEAWALL RELATIVE TO INITIAL PROFILE: 30.0 SEAWALL FAILURE IS NOT ALLOWED. NO HARD BOTTOM IS PRESENT. COMPUTED RESULTS DIFFERENCE IN TOTAL VOLUME BETWEEN FINAL AND INITIAL PROFILES: 1.5mA3/m MAXIMUM VALUE OF WATER ELEVATION + SETUP FOR SIMULATION 1.07m TIME STEP AND POSITION ON PROFILE AT WHICH MAXIMUM VALUE OF WATER ELEVATION + SETUP OCCURRED 4405, 60.0 m MAXIMUM ESTIMATED RUNUP ELEVATION: 3.55 m (REFERENCED TO VERTICAL DATUM) POSITION OF LANDWARD MOST OCCURRENCE OF A .50 m EROSION DEPTH: 50.0m DISTANCE FROM POSITION OF REFERENCE ELEVATION ON INITIAL PROFILE TO POSITION OF LANDWARD MOST OCCURRENCE OF A .50 m EROSION DEPTH: 38.1 m POSITION OF LANDWARD MOST OCCURRENCE OF A 1.00 m EROSION DEPTH: 50.0m DISTANCE FROM POSITION OF REFERENCE ELEVATION ON INITIAL PROFILE TO POSITION OF LANDWARD MOST OCCURRENCE OF A 1.00 m EROSION DEPTH: 38.1m POSITION OF LANDWARD MOST OCCURRENCE OF A 1.50m EROSION DEPTH: 55.0m DISTANCE FROM POSITION OF REFERENCE ELEVATION ON INITIAL PROFILE TO POSITION OF LANDWARD MOST OCCURRENCE OF A 1.50m EROSION DEPTH: 33.1m MAXIMUM RECESSION OF THE 1.50 m ELEVATION CONTOUR: 25.47 m MAXIMUM RECESSION OF THE .00 m ELEVATION CONTOUR: 36.66 m THE -5.00 m CONTOUR DID NOT RECEDE SOLANA BEACH GENESIS I/O Frederic R. Harris, Inc. SUBJECJ COMPUTED BY CHECKED BY . SHEET NO. OF . JOB NO. DATE . . A—/- -<:—." ^ / / .' ' ' ' ' ' >;((/ -- (X = COASTAL ENGINEERING RESEARCH CENTER & LUND INSTITUTE OF TECHNOLOGY ** ** ** ** ** ** *** ** ** ** ** ** *** ** ** ** *** ** *•* + * *•*••*•+ it* ** ** *-*• ***•*- •*•* ** ** *** ** * * *+ +*+ ** *•*• ** ** •** ** ** it-* ** ** ** *•* ** ** **• ** it* ** * * **• ** + **+ *•*• *•* ** ** VERSION 3.0 | + USER NO. 415 DECEMBER 1994 RUN: NAVY HOMEPORT BECH FILL STUDY AT SOLANA BEACH METRIC UNITS DATES OR TIME STEPS WHEN FILLS START 970701 970716 DATES OR TIME STEPS WHEN FILLS END 970715 970731 X-COORDINATES WHERE FILLS START 21 42 X-COORDINATES WHERE FILLS END 31 49 DX = 100 NWAVES = HCNGF = 1 SHORELINE 550 380, 173. 115. 117. 84 120 118 .00 .00 .23 .46 .67 .67 .00 .68 SHORELINE 0 0 33 -4 37 19 0 28 .00 .00 .23 .54 .67 .67 .00 .68 .0 1 .0 DT = DCLOS ZCNGF 3.00 = 10.0 = 1.0 ISSTART = 1 ABH = 1.7 ZCNGA = 0.0 POSITION AFTER 1. YEARS = 532 355 162 145 113 83 105 124 .49 .00 .19 .00 .03 .35 .11 .20 CHANGE 2 0 32 0 43 13 5 24 .49 .00 .19 .00 .03 .35 .11 .20 515 330 152 160 108 81 102 130 .05 .00 .44 .00 .59 .46 .76 .49 AFTER -4 0 42 0 38 6 7 30 .95 .00 .44 .00 .59 .46 .76 .49 497 310. 144. 180. 104. 79 101. 137, .75 .00 .10 .00 .21 .25 .48 .50 480 262 137 185 99 95 101 145 1 . YEARS = -2 0. 49. 0. 34. -5. 11 27 .25 .00 .10 .00 .21 .75 .48 .50 10 2 57 0 29 0 16 25 N = DZ = Kl = 2912 TIME .63 .17 .24 .00 .98 .00 .61 .24 2912 .63 .17 .24 .00 .98 .00 .61 .24 463. 244. 131. 190. 96. 115. 102. 153. TIME 3. -10. 51. 0. 36. 0. 17. 23. 60 47 80 00 07 00 65 65 STEPS 446. 227. 127. 170. 92. 120. 104. 162. STEPS . 60 53 80 00 07 00 65 65 21. -7. 47. 0. 37. 0. 19. 22. 10 0. 41 92 56 00 66 00 42 48 80 .0 45 DATE 429. 212. 124. 150. 89. 125. 106. 171. NTS = D50 = K2 = IS 00 71 23 00 85 00 88 52 DATE IS 41 08 56 00 66 00 42 48 19. 2. 44. 0. 39. 0. 21. 21. 00 71 23 00 85 00 88 52 2912 0.18 0 .25 980630 411. 198. 121. 128. 87. 120. 110. 180. 980630 21. 13. 31. -1. 37. 0. 25. 15. 14 58 40 70 66 00 04 72 14 58 40 30 66 00 04 72 392. 185. 118. 123. 86. 120. 113. 190. 17 25. 18. 33. 31. 0. 23 0 .80 .41 .43 .00 .00 .00 .97 .00 .80 .41 .43 .00 .00 .00 .97 .00 OUTPUT LAST TIMESTEP NO. 2912 DATE IS 980630 OFFSHORE WAVE DATA INPUT: HZ = 1.04000 T = 7.00000 ZZ = 17.0000 CALIBRATION/VERIFICATION ERROR = 17.4444 CALCULATED VOLUMETRIC CHANGE = +1.54E+06 (M3) SIGN CONVENTION: EROSION (-), ACCRETION (+) INPUT FILE START.DAT TO GENESIS VERSION 3.0 A MODEL SETUP -- - A A.I RUN TITLE NAVY HOMEPORT BECH FILL STUDY AT SOLANA BEACH A.2 INPUT UNITS (METERS=1; FEET=2): ICONV 1 A. 3 TOTAL NUMBER OF CALCULATION CELLS AND CELL LENGTH: NN, DX 80 100 A. 4 GRID CELL NUMBER WHERE SIMULATION STARTS AND NUMBER OF CALCULATION CELLS (N = -1 MEANS N = NN) : ISSTART, N 1 80 A. 5 VALUE OF TIME STEP IN HOURS: DT 3 A. 6 DATE WHEN SHORELINE SIMULATION STARTS (DATE FORMAT YYMMDD: 1 MAY 1992 = 920501) : SIMDATS 970701 A. 7 DATE WHEN SHORELINE SIMULATION ENDS OR TOTAL NUMBER OF TIME STEPS (DATE FORMAT YYMMDD: 1 MAY 1992 = 920501) : SIMDATE 980S30 A. 8 NUMBER OF INTERMEDIATE PRINT-OUTS WANTED: NOUT 2 A. 9 DATES OR TIME STEPS OF INTERMEDIATE PRINT-OUTS (DATE FORMAT YYMMDD: 1 MAY 1992 = 920501, NOUT VALUES) : TOUT(I) 970930 971231 A. 10 NUMBER OF CALCULATION CELLS IN OFFSHORE CONTOUR SMOOTHING WINDOW (ISMOOTH = 0 MEANS NO SMOOTHING, ISMOOTH = N MEANS STRAIGHT LINE. RECOMMENDED DEFAULT VALUE = 11) : ISMOOTH 11 A. 11 REPEATED WARNING MESSAGES (YES=1; NO=0): IRWM 1 A. 12 LONGSHORE SAND TRANSPORT CALIBRATION COEFFICIENTS: Kl, K2 0.45 0.25 A.13 PRINT-OUT OF TIME STEP NUMBERS? (YES = 1, NO=0) : IPRINT 0 B WAVE S B B.I WAVE HEIGHT CHANGE FACTOR. WAVE ANGLE CHANGE FACTOR AND AMOUNT (DEC) (NO CHANGE: HCNGF=1, ZCNGF=1, ZCNGA=0) : HCNGF, ZCNGF, ZCNGA 110 B.2 DEPTH OF OFFSHORE WAVE INPUT: DZ 10 B.3 IS AN EXTERNAL WAVE MODEL BEING USED (YES=1; N0=0) : NWD 0 B.4 COMMENT: IF AN EXTERNAL WAVE MODEL IS NOT BEING USED, CONTINUE TO B. 9 B.5 NUMBER OF SHORELINE CALCULATION CELLS PER WAVE MODEL ELEMENT: ISPW 0 B.6 NUMBER OF HEIGHT BANDS USED IN THE EXTERNAL WAVE MODEL TRANSFORMATIONS (MINIMUM IS 1, MAXIMUM IS 9) : NBANDS 1 B.7 COMMENT: IF ONLY ONE HEIGHT BAND WAS USED CONTINUE TO B.9 B.8 MINIMUM WAVE HEIGHT AND BAND WIDTH OF HEIGHT BANDS: HBMIN, HBWIDTH 0 0 B.9 VALUE OF TIME STEP IN WAVE DATA FILE IN HOURS (MUST BE AN EVEN MULTIPLE OF, OR EQUAL TO DT): DTW 3 B.10 NUMBER OF WAVE COMPONENTS PER TIME STEP: NWAVES 1 B.ll DATE WHEN WAVE FILE STARTS (FORMAT YYMMDD: 1 MAY 1992 = 920501): WDATS 970101 C --- BEACH - - C C.I EFFECTIVE GRAIN SIZE DIAMETER IN MILLIMETERS: D50 0.18 C.2 AVERAGE BERM HEIGHT FROM MEAN WATER LEVEL: ABH 1.7 C.3 CLOSURE DEPTH: DCLOS 10 C.4 ANY OPEN BOUNDARY? (N0=0, YES=1): IOB 0 C.5 COMMENT: IF NO OPEN BOUNDARY, CONTINUE TO D. C.6 TIME BASE IN BOUNDAY MOVEMENT SPECIFICATION(S) ? (SIMULATION PERIOD = 1, DAY = 2, TIME STEP = 3): ITB 1 C.7 OPEN BOUNDARY ON LEFT-HAND SIDE? (N0=0, YES=1) : IOB1 0 C.8 COMMENT: IF A GROIN ON LEFT-HAND BOUNDARY, CONTINUE TO C.10 C.9 BOUNDARY MOVEMENT PER TIME BASE ON LEFT-HAND BOUNDARY, IN SYSTEM OF UNITS SPECIFIED IN A. 2 (PINNED BEACH => YC1 = 0) : YC1 0 C.10 OPEN BOUNDARY ON RIGHT-HAND SIDE? (N0=0, YES=1) : IOBN 0 C.ll COMMENT: IF A GROIN ON RIGHT-HAND BOUNDARY, CONTINUE TO D. C.12 BOUNDARY MOVEMENT PER TIME BASE ON LEFT-HAND BOUNDARY, IN SYSTEM OF UNITS SPECIFIED IN A.2 (PINNED BEACH => YCN = 0) : YCN 0 D NON-DIFFRACTING GROINS - - D D.I ANY NON-DIFFRACTING GROINS? (N0=0, YES=1) : INDG 0 D.2 COMMENT: IF NO NON-DIFFRACTING GROINS, CONTINUE TO E. D.3 NUMBER OF NON-DIFFRACTING GROINS: NNDG 0 D.4 GRID CELL NUMBERS OF NON-DIFFFRACTING GROINS (NNDG VALUES): IXNDG(I) D.5 LENGTHS OF NON-DIFFRACTING GROINS FROM X-AXIS (NNDG VALUES): YNDG(I) E DIFFRACTING (LONG) GROINS AND JETTIES E E.I ANY DIFFRACTING GROINS OR JETTIES? (NO=0, YES=1) : IDG 0 E.2 COMMENT: IF NO DIFFRACTING GROINS, CONTINUE TO F. E.3 NUMBER OF DIFFRACTING GROINS/JETTIES: NDG 0 E.4 GRID CELL NUMBERS OF DIFFFRACTING GROINS/JETTIES (NDG VALUES) : IXDG(I) E.5 LENGTHS OF DIFFRACTING GROINS/JETTIES FROM X-AXIS (NDG VALUES) : YDG(I) E.6 DEPTHS AT SEAWARD END OF DIFFRACTING GROINS/JETTIES (NDG VALUES) : DDG(I) F --- ALL GROINS/JETTIES F F.I COMMENT: IF NO GROINS OR JETTIES, CONTINUE TO G. F.2 PERMEABILITIES OF ALL GROINS AND JETTIES (NNDG+NDG VALUES): PERM (I) F.3 IF GROIN OR JETTY ON LEFT-HAND BOUNDARY, DISTANCE FROM SHORELINE OUTSIDE GRID TO SEAWARD END OF GROIN OR JETTY: YG1 0 F.4 IF GROIN OR JETTY ON RIGHT-HAND BOUNDARY, DISTANCE FROM SHORELINE OUTSIDE GRID TO SEAWARD END OF GROIN OR JETTY: YGN 0 G DETACHED BREAKWATERS - G G.I ANY DETACHED BREAKWATERS? (N0=0, YES=1) : IDE 0 G.2 COMMENT: IF NO DETACHED BREAKWATERS, CONTINUE TO H. G.3 NUMBER OF DETACHED BREAKWATERS: NDB 0 G.4 ANY DETACHED BREAKWATER ACROSS LEFT-HAND CALCULATION BOUNDARY (N0=0, YES=1): IDB1 0 G.5 ANY DETACHED BREAKWATER ACROSS RIGHT-HAND CALCULATION BOUNDARY (N0=0, YES=1): IDBN 0 G.6 GRID CELL NUMBERS OF TIPS OF DETACHED BREAKWATERS (2 * NDB - (IDB1+IDBN) VALUES): IXDB(I) G.7 DISTANCES FROM X-AXIS TO TIPS OF DETACHED BREAKWATERS (1 VALUE FOR EACH TIP SPECIFIED IN G.6) : YDB(I) G.8 DEPTHS AT DETACHED BREAKWATER TIPS (1 VALUE FOR EACH TIP SPECIFIED IN G.6): DDB(I) G.9 TRANSMISSION COEFFICIENTS FOR DETACHED BREAKWATERS (NDB VALUES): TRANDB(I) H SEAWALLS H H.I ANY SEAWALL ALONG THE SIMULATED SHORELINE? (YES=1; N0=0) : ISW 1 H.2 COMMENT: IF NO SEAWALL, CONTINUE TO I. H.3 GRID CELL NUMBERS OF START AND END OF SEAWALL (ISWEND = -1 MEANS ISWEND = N): ISWBEG, ISWEND 1 80 I BEACH FILLS - 1 1.1 ANY BEACH FILLS DURING SIMULATION PERIOD? (NO=0, YES=1) : IBF 1 1.2 COMMENT: IF NO BEACH FILLS, CONTINUE TO K. 1.3 NUMBER OF BEACH FILLS DURING SIMULATION PERIOD: NBF 2 1.4 DATES OR TIME STEPS WHEN THE RESPECTIVE FILLS START (DATE FORMAT YYMMDD: 1 MAY 1992 = 920501, NBF VALUES) : BFDATS(I) 970701 970716 1.5 DATES OR TIME STEPS WHEN THE RESPECTIVE FILLS END (DATE FORMAT YYMMDD: 1 MAY 1992 = 920501, NBF VALUES) : BFDATE(I) 970715 970731 1.6 GRID CELL NUMBERS OF START OF RESPECTIVE FILLS (NBF VALUES): IBFS(I) 21 42 1.7 GRID CELL NUMBERS OF END OF RESPECTIVE FILLS (NBF VALUES) : IBFE(I) 31 49 1.8 ADDED BERM WIDTHS AFTER ADJUSTMENT TO EQUILIBRIUM CONDITIONS (NBF VALUES) : YADD(I) 25 45 j BYPASSING J J.I ANY BYPASSING OPERATIONS DURING SIMULATION PERIOD? (NO=0, YES=1): IBP 0 J.2 COMMENT: IF NO BYPASSING OPERATIONS, CONTINUE TO K. J.3 READ BYPASSING RATES FROM A FILE OR SPECIFY BELOW? (FILE=1, BELOW=2): IBPF 1 J.4 COMMENT: IF BYPASSING OPERATIONS ARE SPECIFIED BELOW, CONTINUE TO J.8 -- BYPASSING OPERATIONS SPECIFIED IN SEPARATE DATA FILE -- J.5 DATE OR TIME STEP WHEN BYPASS DATA FILE STARTS AND ENDS, RESPECTIVELY (FORMAT YYMMDD: 1 MAY 1992 = 920501) : QQDATS QQDATE 0 0 J.6 CELL NOS. WHERE BYPASS FILE STARTS AND ENDS, RESPECTIVELY: IQQS, IQQE 0 0 J.7 COMMENT: END OF BYPASS DATA FILE SECTION. CONTINUE TO K. -- BYPASSING OPERATIONS SPECIFIED IN THIS FILE -- J.8 NUMBER OF BYPASSING OPERATIONS DURING SIMULATION PERIOD: NBP 0 J.9 DATES OR TIME STEPS WHEN THE RESPECTIVE OPERATIONS START (DATE FORMAT YYMMDD: 1 MAY 1992 = 920501, NBP VALUES) : BPDATS(I) J.10 DATES OR TIME STEPS WHEN THE RESPECTIVE OPERATIONS END (DATE FORMAT YYMMDD: 1 MAY 1992 = 920501, NBP VALUES): BPDATE(I) J.ll GRID CELL NUMBERS OF START OF RESPECTIVE OPERATIONS (NBP VALUES) : IBPS(I) J.12 GRID CELL NUMBERS OF END OF RESPECTIVE OPERATIONS (NBP VALUES) : IBPE(I) J.13 BYPASSING RATES AS TOTAL AVERAGE VOLUME PER HOUR (CY/HR OR M3/HR, ACCORDING TO UNITS GIVEN IN A. 2) FOR RESPECTIVE OPERATIONS (NBP VALUES): QBP(I) K - COMMENTS K * ALL COORDINATES MUST BE GIVEN IN THE "TOTAL" GRID SYSTEM * ONE VALUE FOR EACH STRUCTURE, TIP ETC. ESPECIALLY IMPORTANT FOR COMBINED STRUCTURES, E.G., TWO DBW S WHERE THE LOCATION WHERE THEY MEET HAS TO BE TREATED AS TWO TIPS. * ANY GROIN CONNECTED TO A DETACHED BREAKWATER MUST BE REGARDED AS DIFFRACTING * CONNECTED STRUCTURES MUST BE GIVEN THE SAME Y AND D VALUES WHERE THEY CONNECT * IF DOING REAL CASES, THE WAVE.DAT FILE MUST CONTAIN FULL YEARS DATA * DATA FOR START OF BEACH FILL IN SPACE AND TIME SHOULD BE GIVEN IN INCREASING/CHRONOLOGICAL ORDER. DATA FOR END OF BEACH FILL MUST CORRESPOND TO THESE VALUES, AND NOT NECESSARILY BE IN INCREASING ORDER. * DON'T CHANGE THE LABELS OF THE LINES SINCE THEY ARE USED TO IDENTIFY THE LINES BY GENESIS. END RON:NAVY HOMEPORT BECH FILL STUDY AT SOLANA BEACH INITIAL SHORELINE POSITION (M) 550.00 380.00 140.00 120.00 80.00 65.00 120.00 90.00 530.00 355.00 130.00 145.00 70.00 70.00 100.00 100.00 520 330 110 160 70 75 95 100 SHORELINE POSITION 550.00 380.00 166.14 91.13 126.46 71.53 120.00 97.04 530.46 355.00 152.78 145.00 120.55 65.90 112.37 102.09 510 330 141 160 115 60 106 108 SHORELINE POSITION 550.00 380.00 170.60 116.67 124.01 76.10 120.00 105.25 530.08 355.00 157.49 145.00 121.13 76.21 88.79 110.29 510 330 145 160 116 78 93 116 .00 500. .00 310. .00 95. .00 180. .00 70. .00 85. .00 90. .00 110. 00 470. 00 260. 00 80. 00 185. 00 70. 00 95. 00 85. 00 120. (M) AFTER 729 .82 491. .00 310. .32 131. .00 180. .38 110. .82 56. .89 102. .65 116. 01 470. 00 275. 81 124. 00 185. 53 105. 05 95. 09 97. 68 126. (M) AFTER 1465 .23 490. .00 310. .55 135. .00 180. .32 110. .84 84. .61 96. .72 124. 59 471. 00 260. 01 126. 00 185. 35 103. 16 95. 56 97. 42 133. 00 00 00 00 00 00 00 00 460.00 255.00 80.00 190.00 60.00 115.00 85.00 130.00 TIME STEPS. 96 00 13 00 67 00 82 34 TIME 38 00 06 00 91 00 86 41 450.64 253.77 117.99 190.00 100.61 115.00 94.37 137.62 STEPS . 452.86 237.44 118.81 190.00 97.51 115.00 98.10 143.65 LAST TIME STEP. DIFFRACTED WAVES ALONGSHORE BREAKING WAVE HEIGHT 1.31 1.31 1.31 1.31 1.31 1.31 1.30 1.30 1.31 1.33 1.32 1.33 1.33 1.34 1.34 BREAKING 2.03 1.32 3.77 8.12 6.39 7.96 8.11 9.27 10.34 1.30 1.31 1.33 1.32 1.33 1.33 1.34 1.30 1.31 1.33 1.32 1.33 1.33 1.34 1.30 1.32 1.33 1.32 1.33 1.33 1.34 1.30 1.32 1.33 1.32 1.33 1.33 1.34 1.30 1.32 1.33 1.32 1.33 1.33 1.34 1.31 1.33 1.33 1.33 1.33 1.33 1.34 425.00 235.00 80.00 170.00 55.00 120.00 85.00 140.00 DATE IS 430.06 234.07 112.90 170.00 95.22 120.00 92.06 149.94 DATE IS 435.33 225.35 113.39 170.00 91.49 120.00 98.02 154.71 1.30 1.30 1.33 1.33 1.33 1.33 1.33 1.34 410.00 210.00 80.00 150.00 50.00 125.00 85.00 150.00 970930 409.27 215.29 108.25 152.73 89.51 125.00 91.10 162.89 971231 419.24 212.37 110.10 150.00 86.09 125.00 98.28 166.22 1.30 1.30 1.33 1.32 1.33 1.33 1.34 1.34 390.00 185.00 90.00 130.00 50.00 120.00 85.00 165.00 388.32 197.60 103.49 142.10 83.55 120.00 91.57 176.32 404.82 198.61 109.37 122.18 81.51 120.00 99.39 178.03 1.30 1.30 1.33 1.32 1.33 1.33 1.34 1.34 375 160 100 90 55 120 90 190 366 181 98 133 77 120 93 190 391 184 111 124 78 120 101 190 .00 .00 .00 .00 .00 .00 .00 .00 .48 .16 .12 .55 .48 .00 .54 .00 .93 ;50 .57 .39 .04 .00 .65 .00 WAVE ANGLE TO X-AXIS 2.03 1.26 4.27 8.25 6.30 8.12 8.05 9.51 GROSS TRANSPORT 510 510 822 609 474 376 468 1670 2.03 1.24 4.83 8.25 6.24 8.26 8.05 9.72 2.03 1.28 5.42 8.11 6.26 8.39 8.08 9.90 2.03 1.40 6.01 7.85 6.39 8.50 8.14 1.95 1.65 6.56 7.52 6.62 8.54 8.23 10.09 10.27 VOLUME (M3/1000) FROM 508 500 493 611 512 1289 464 875 462 1086 467 554 1.76 1.96 7.02 7.16 6.91 8.50 8.37 10.34 970701 TO 483 476 474 429 476 563 481 801 1.60 2.38 7.38 6.85 7.22 8.40 8.56 10.34 980630 462 441 481 769 1.49 2.89 7.67 6.64 7.51 8.29 8.78 10.34 447 449 473 790 1.40 3.35 7.91 6.49 7.76 8.19 9.02 10.34 407 459 444 369 423 453 471 485 606 481 449 788 494 489 428 361 500 NET TRANSPORT VOLUME 240 136 105 -57 -58 -36 -76 -250 -507 TRANSPORT -135 -683 -184 -222 - -240 -245 -312 -367 -557 TRANSPORT 375 138 290 153 182 208 158 117 49 240 136 98 -21 -102 -60 -76 -284 VOLUME -135 -59 -185 1670 -291 -254 -77 -389 VOLUME 375 550 283 0 189 194 711 105 237 136 91 -21 -96 -75 -82 -312 TO -135 -58 -186 -868 -293 -252 -218 -406 TO 372 553 277 6 196 176 142 93 490 377 408 513 (M3/1000) 243 136 73 -21 -85 -83 -91 -348 484 1152 433 526 FROM 245 136 47 -21 -69 -76 -104 -380 473 1064 451 539 464 531 462 554 457 532 469 571 451 464 474 591 453 467 480 606 970701 TO 980630 233 . 133 11 -21 -48 -76 -124 -409 THE LEFT (M3/1000) FROM -128 -120 -194 -1084 -288 -234 - -250 -430 THE RIGHT 371 392 268 1 202 142 158 82 -124 -2 -209 -484 -277 1153 -269 -453 -125 -111 -232 -495 -260 -1063 -287 -474 (M3/1000) FROM 369 1287 257 70 207 9 164 72 358 363 243 67 212 1 163 64 229 146 -17 -21 -34 -76 -145 -437 970701 -123 -140 -249 -25 -249 -451 -303 -496 970701 352 288 232 775 215 79 158 58 204 154 -41 -21 -22 -76 -167 -463 181 151 -62 -21 -12 -76 -193 -489 157 135 -67 -19 0 -76 -222 -507 TO 980630 -129 -143 -261 -32 -240 -451 -318 -517 -132 -149 -268 -57 -232 -178 -333 -540 -127 -162 -256 -191 -227 -307 -351 -557 TO 980630 333 298 219 736 217 80 150 54 314 300 205 732 219 285 140 50 279 297 188 177 226 159 129 49 OUTPUT OF BREAKING WAVE STATISTICS FOR SELECTED LOCATIONS N.B. WAVE DIFFRACTION IS NOT ACCOUNTED FOR! GRID CELL NUMBERS 1 16 32 48 64 AVERAGE 1.26 1.26 1.26 1.26 1.26 AVERAGE 2.89 2.77 -21.66 0.03 -0.63 1 17 33 49 65 3 19 35 51 67 UNDIFFRACTED 1.26 1.26 1.26 1.26 1.26 1.26 1.26 1.26 1.26 1.26 UNDIFFRACTED 2.89 1.94 -9.50 0.20 -0.79 2.85 2.01 -4.32 -0.01 -1.33 4 20 36 52 68 BREAKING 1. 1. 1. 1. 1. .26 .26 .26 .26 .26 BREAKING 2. 1. -4. -0. -I. .94 .81 .71 .28 .60 6 22 38 54 70 WAVE 1.26 1.26 1.26 1.26 1.26 WAVE 2.89 1.31 8.22 -0.64 -2.26 8 24 40 56 72 HEIGHTS 1 1 1 1 1 .26 .26 .26 .26 .26 ANGLE TO 2 1 0 -12 -2 .60 .02 .11 .18 .97 9 25 41 57 73 (M) . 1.26 1.26 1.26 1.26 1.26 11 27 43 59 75 1.26 1.26 1.26 1.26 1.26 12 28 44 60 76 1.26 1.26 1.26 1.26 1.26 14 30 46 62 78 1.26 1.26 1.26 1.26 1.26 SHORELINE (DEC) 2.35 0.72 -0.36 -3.85 -3.27 -7.22 0.03 -0.96 1.58 -4.18 5.87 -0.20 -0.83 -1.43 -4.32 3 .11 -0.38 -0.36 7.48 -5.10 AVERAGE LONGSHORE TRANSPORT RATE BASED ON UNDIFFRACTED WAVES *100 (M3/SEC) 0.76 ' 0.76 0.75 0.77 0.75 0.65 0.58 -1.78 1.59 0.82 0.77 0.46 0.48 0.43 0.31 0.23 0.15 -0.05 -0.13 -0.22 -5.37 -2.70 -1.29 -1.39 -0.07 -0.04 -0.12 -0.19 -0.29 -0.34 -0.47 -0.54 LONGSHORE TRANSPORT FOR LAST 3.11 3.11 3.10 3.08 2.26 2.26 2.26 2.26 2.78 2.76 2.74 2.70 2.69 0.00 0.00 0.00 2.56 2.43 2.39 2.38 2.40 2.45 2.58 2.67 0.00 0.00 2.59 2.44 1.84 1.79 1.73 1.67 1.44 CALCULATED FINAL 550.00 380.00 173.23 115.46 117.67 84.67 120.00 118.68 532.49 355.00 162.19 145.00 113.03 83.35 105.11 124.20 2.24 -0.07 -0.19 -0.32 -0.25 -3.39 -1.15 0.37 -0.71 -0.91 -0.99 -1.24 TIME STEP *100 (M3/SEC) 3.06 3.03 3.00 2.98 2.26 3.01 2.95 2.89 2.66 2.61 2.57 2.54 0.00 0.00 0.00 0.00 2.39 2.41 2.42 2.41 0.00 0.00 0.00 0.00 2.24 2.12 2.05 1.99 1.60 1.55 1.51 1.47 -0.28 -0.48 -1.27 3 .01 2.85 2.55 0.00 2.41 0.00 1.95 1.45 -0.16 2.06 -1.48 3.04 2.81 2.64 2.65 2.40 0.00 1.90 1.44 SHORELINE POSITION (M) 515.05 330.00 152.44 160.00 108.59 81.46 102.76 130.49 CALCULATED SEAWARDMOST 550.00 380.00 173.23 127.39 132.08 84.84 120.00 118.68 532.81 355.00 162.19 145.00 125.18 84.66 113.92 124.20 520.00 330.00 152.44 160.00 118.95 86.09 108.82 130.49 CALCULATED LANDWARDMOST 550.00 380.00 140.00 85.22 80.00 62.72 120.00 90.00 530.00 355.00 130.00 145.00 70.00 64.34 87.29 97.28 510.02 330.00 110.00 160.00 69.99 60.41 92.78 100.00 497 310 144 180 104 79 101 137, .75 .00 .10 .00 .21 .25 .48 .50 SHORELINE 500 310. 144 180 115. 90. 104 137. .00 .00 .10 .00 .50 .42 .47 .50 480.63 262.17 137.24 185.00 99.98 95.00 101.61 145.24 463 .60 244.47 131.80 190.00 96.07 115.00 102.65 153.65 446.41 227.92 127.56 170.00 92.66 120.00 104.42 162.48 429 212. 124. 150. 89 125. 106. 171. .00 .71 .23 .00 .85 .00 .88 .52 411.14 198.58 121.40 128.70 87.66 120.00 110.04 180.72 392.80 185.41 118.43 123.00 86.00 120.00 113.97 190.00 POSITION (M) 480.63 278.59 137.24 185.00 111.29 98.17 102.09 145.24 463.60 256.00 131.80 190.00 107.39 115.00 102.65 153.65 446.41 236.41 127.56 171.62 103.85 120.00 104.42 162.48 429. 217. 124. 158. 99. 125. 106. 171. .12 .96 .24 .11 .51 ,00 .88 .52 412.10 200.93 121.86 148.25 91.05 120.00 110.04 180.72 395.60 185.41 122.18 139.78 86.01 120.00 113.97 190.00 SHORELINE POSITION (M) 489 310. 95. 180. 67. 54. 90. 109. .99 .00 .00 .00 .87 .80 .00 .96 469.86 260.00 80.00 185.00 63.78 95.00 85.00 119.66 449.54 237.15 80.00 190.00 59.70 115.00 84.99 129.88 425.00 224.77 80.00 170.00 54.95 120.00 84.86 140.00 408. 208. 80. ISO. 50. 125. 84. 150. .15 .39 .00 .00 .00 .00 .95 .00 386.82 184.95 90.00 115.29 50.00 120.00 85.00 165.00 363.31 160.00 92.65 90.00 55.00 120.00 88.79 190.00 CALCULATED REPRESENTATIVE OFFSHORE CONTOUR POSITION (M) 850.00 664.73 487.53 443.84 426.49 394.91 408.76 426.21 832.29 644.59 475.96 445.12 421.37 395.60 409.16 431.38 814.57 624.39 466.17 446.33 416.02 396.74 409.60 437.28 796. 604. 458. 447. 410, 398. 410. 443. .86 .32 .28 .10 .72 .30 .16 .73 779.14 584.52 452.27 446.98 405.80 400.30 410.92 450.65 761.43 565.59 448.13 445.79 401.67 402.43 411.93 458.52 742.74 547.65 445.37 443.35 398.48 404.35 413.36 466.39 723. 530. 443. 439. 396. 405. 415. 474. .70 .79 .77 .94 .35 .97 .44 .26 704.32 515.11 443.06 435.83 395.14 407.19 418.24 482.13 684.65 500.68 443.12 431.32 394.71 408.11 421.82 490.00 CALIBRATION/VERIFICATION ERROR =17.4444 CALCULATED VOLUMETRIC CHANGE = +1.54E+06 (M3) SIGN CONVENTION: EROSION (-), ACCRETION ( + ) NAUY HOMEPORT BECH FILL STUM AT SOLANA BEACH 04-04-1997 oB-, u I—I -3 CO 600- - 500-- 400-- 300-- 200- 100-- Initial Shoreline Calculated Shoreline Seauall Beach Fill 10 20 30 40 50 60 70 ALONGSHORE COORDINATE (cell spacing = 100 n) 80 SOLANA BEACH SBEACH I/O CARDIFF - SOLANA 10 5 1 0 (/) 2 c 03s -5 UJ -10 -15 ( \ \ \ \ v. _..-., 7s"- ^\^>T-.X7*";-,, Summer Variation at Cardiff - Solana Transect SD 0630 X ) 100 200 300 ""•<~-^>r ••'->-. \ "•-«*. "^ ;;iii^v !=<!'^, "^ •"-'--::- "">"li^.-^. 400 500 600 700 800 Distance from Range (m) 1986 1987 1988 — 1989 900 1000 1100 1200 10 5 1 „ (/> O3 S -5 UJ -10 -15 ( .A vi \\ \s, /'" " •^;\~---x^.. V. -'' "\ ~"\ Winter Variation at Cardiff - Solana Transect SD 0630 'V \ } 100 200 300 \• v\ \;.,_->.,^ -^^~ ""-•--,.,. '""-^... 7":>-:^ "•--- 400 500 600 700 800 Distance from Range (m) 1986 1987 1996 900 1000 1100 1200 10 IUl -5 -10 -15 _/l \\\ ^ \ v/ •x\,\ vx\ ""-- Cardiff Solana - Beach Fill Profile Transect SD 0630 ""\-~...^ ~""\"---- Initial Profile Nourished Profile — 1 0 100 200 300 400 500 600 700 800 900 1000 1100 Distance from Range (m) 1200 Cardiff Seasonal Variation Cut and Fill Report Profile 1: Profile 2: XOn: XOff i Volume Change: Above Datum: Below Datum: Total Volume: Shoreline Change: 63.88 m From: 25.12 m To: 89.00 m Average n 0.00 m 830.00 m 87.782 cu. m/m 107.638 cu.m/m 195.420 cu.m/m Cell Changes: Cell # 1 2 3 Ending Distance(m) Ending Elevation(m) Cell Volume (cu. m/m) Cell Thickness (m) Cumulative Volume (cu. m/m) Gross Volume (cu. m/m) 14.95 2.59 0.000 0.00 0.000 0.000 150.33 -3.07 196.031 1.45 196.031 196.031 830.00 -13.97 -0.611 -0.00 195.420 196.642 -Page 1- 10 5 1 o </> 2 o « S -5 UJ -10 -15 ( A \ \ \\ \ X \ \ v / -'•'- ^\ XX \ Cardiff Solana - Case 1 Transect SD 0630 ) 100 200 300 400 •••-.... 500 600 700 Distance from Range (m) "-•-- Initial Profile — Nourished P 180 Days 800 900 1 rofile 1000 1100 1200 Report for run: Reach: Alt.l - Oct87-Dec87 Storm: Report Project: Cardiff- Case 1 Reach: Alt.l - Oct87-Dec87 Storm: Oct87-Dec87 MODEL CONFIGURATION INPUT UNITS (SI=1, AMERICAN CUST.=2): 1 NUMBER OF CALCULATION CELLS: 166 GRID TYPE (CONSTANTS, VARIABLES): 0 CONSTANT CELL WIDTH: 5.0 NUMBER OF TIME STEPS AND VALUE OF TIME STEP IN MINUTES: 2848, 60.0 TIME STEP INTERVAL OF INTERMEDIATE OUTPUT: 500 NO COMPARSION WITH MEASURED PROFILE. PROFILE ELEVATION CONTOUR 1: 1.50 PROFILE ELEVATION CONTOUR 2: .00 PROFILE ELEVATION CONTOUR 3: -5.00 PROFILE EROSION DEPTH 1: .50 PROFILE EROSION DEPTH 2: 1.00 PROFILE EROSION DEPTH 3: 1.50 REFERENCE ELEVATION: .00 TRANSPORT RATE COEFFICIENT (mA4/N): .25E-6 COEFFICIENT FOR SLOPE DEPENDENT TERM (mA2/s): .0010 TRANSPORT RATE DECAY COEFFICIENT MULTIPLIER: .50 WATER TEMPERATURE IN DEGREES C : 20.0 WAVE TYPE (MONOCHROMATIC=1, IRREGULARS): 2 WAVE HEIGHT AND PERIOD INPUT (CONSTANTS, VARIABLES): 1 TIME STEP OF VARIABLE WAVE HEIGHT AND PERIOD INPUT IN MINUTES: 480.0 WAVE ANGLE INPUT (CONSTANTS, VARIABLES): 0 CONSTANT WAVE ANGLE: .0 WATER DEPTH OF INPUT WAVES (DEEP WATER = 0.0): .0 SEED VALUE FOR WAVE HEIGHT RANDOMIZER AND % VARIABILITY: 4567, 20.0 TOTAL WATER ELEVATION INPUT (CONSTANTS, VARIABLES): 1 TIME STEP OF VARIABLE TOTAL WATER ELEVATION INPUT IN MINUTES: 720.0 WIND SPEED AND ANGLE INPUT (CONSTANTS, VARIABLES): 0 CONSTANT WIND SPEED AND ANGLE: .0, .0 TYPE OF INPUT PROFILE (ARBITRARY=1, SCHEMATIZED=2): 1 DEPTH CORRESPONDING TO LANDWARD END OF SURF ZONE: .50 EFFECTIVE GRAIN SIZE DIAMETER IN MILLIMETERS: .28 MAXIMUM PROFILE SLOPE PRIOR TO AVALANCHING IN DEGREES: 15.0 BEACH FILL IS PRESENT. POSITION OF SEAWALL RELATIVE TO INITIAL PROFILE: 20.0 SEAWALL FAILURE IS NOT ALLOWED. NO HARD BOTTOM IS PRESENT. COMPUTED RESULTS DIFFERENCE IN TOTAL VOLUME BETWEEN FINAL AND INITIAL PROFILES: .6 mA3/m MAXIMUM VALUE OF WATER ELEVATION + SETUP FOR SIMULATION 1.31m TIME STEP AND POSITION ON PROFILE AT WHICH MAXIMUM VALUE OF WATER ELEVATION + SETUP OCCURRED 2053, 60.0m MAXIMUM ESTIMATED RUNUP ELEVATION: 2.72 m (REFERENCED TO VERTICAL DATUM) POSITION OF LANDWARD MOST OCCURRENCE OF A .50 m EROSION DEPTH: 55.0m DISTANCE FROM POSITION OF REFERENCE ELEVATION ON INITIAL PROFILE TO POSITION OF LANDWARD MOST OCCURRENCE OF A .50 m EROSION DEPTH: 39.0m POSITION OF LANDWARD MOST OCCURRENCE OF A 1.00 m EROSION DEPTH: 55.0m DISTANCE FROM POSITION OF REFERENCE ELEVATION ON INITIAL PROFILE TO POSITION OF LANDWARD MOST OCCURRENCE OF A 1.00 m EROSION DEPTH: 39.0m POSITION OF LANDWARD MOST OCCURRENCE OF A 1.50m EROSION DEPTH: 60.0m DISTANCE FROM POSITION OF REFERENCE ELEVATION ON INITIAL PROFILE TO POSITION OF LANDWARD MOST OCCURRENCE OF A 1.50m EROSION DEPTH: 34.0m MAXIMUM RECESSION OF THE 1.50 m ELEVATION CONTOUR: 19.45 m MAXIMUM RECESSION OF THE .00 m ELEVATION CONTOUR: 35.85m MAXIMUM RECESSION OF THE -5.00 m ELEVATION CONTOUR: .64m Report for run: Reach: Alt. 1-1993 Storm: 1993 Report Project: Cardiff- Case 1 Reach: Alt. 1-1993 Storm: 1993 MODEL CONFIGURATION INPUT UNITS (SI=1, AMERICAN CUST.=2): 1 NUMBER OF CALCULATION CELLS: 165 GRID TYPE (CONSTANTS, VARIABLES): 0 CONSTANT CELL WIDTH: 5.0 NUMBER OF TIME STEPS AND VALUE OF TIME STEP IN MINUTES: 8310, 60.0 TIME STEP INTERVAL OF INTERMEDIATE OUTPUT: 2078 NO COMPARSION WITH MEASURED PROFILE. PROFILE ELEVATION CONTOUR 1: 1.50 PROFILE ELEVATION CONTOUR 2: .00 PROFILE ELEVATION CONTOUR 3: -5.00 PROFILE EROSION DEPTH 1: .50 PROFILE EROSION DEPTH 2: 1.00 PROFILE EROSION DEPTH 3: 1.50 REFERENCE ELEVATION: .00 TRANSPORT RATE COEFFICIENT (mA4/N): .25E-6 COEFFICIENT FOR SLOPE DEPENDENT TERM (mA2/s): .0010 TRANSPORT RATE DECAY COEFFICIENT MULTIPLIER: .50 WATER TEMPERATURE IN DEGREES C : 20.0 WAVE TYPE (MONOCHROMATIC=1, IRREGULAR-2): 2 WAVE HEIGHT AND PERIOD INPUT (CONSTANTS, VARIABLES): 1 TIME STEP OF VARIABLE WAVE HEIGHT AND PERIOD INPUT IN MINUTES: 180.0 WAVE ANGLE INPUT (CONSTANTS), VARIABLES): 0 CONSTANT WAVE ANGLE: .0 WATER DEPTH OF INPUT WAVES (DEEP WATER = 0.0): .0 SEED VALUE FOR WAVE HEIGHT RANDOMIZER AND % VARIABILITY: 4567, 20.0 TOTAL WATER ELEVATION INPUT (CONSTANTS, VARIABLES): 1 TIME STEP OF VARIABLE TOTAL WATER ELEVATION INPUT IN MINUTES: 60.0 WIND SPEED AND ANGLE INPUT (CONSTANTS, VARIABLES): 0 CONSTANT WIND SPEED AND ANGLE: .0, .0 TYPE OF INPUT PROFILE (ARBITRARY=1, SCHEMATIZED=2): 1 DEPTH CORRESPONDING TO LANDWARD END OF SURF ZONE: .50 EFFECTIVE GRAIN SIZE DIAMETER IN MILLIMETERS: .28 MAXIMUM PROFILE SLOPE PRIOR TO AVALANCHING IN DEGREES: 15.0 BEACH FILL IS PRESENT. POSITION OF SEAWALL RELATIVE TO INITIAL PROFILE: 20.0 SEAWALL FAILURE IS NOT ALLOWED. NO HARD BOTTOM IS PRESENT. COMPUTED RESULTS DIFFERENCE IN TOTAL VOLUME BETWEEN FINAL AND INITIAL PROFILES: 3.4 mA3/m MAXIMUM VALUE OF WATER ELEVATION + SETUP FOR SIMULATION 1.63m TIME STEP AND POSITION ON PROFILE AT WHICH MAXIMUM VALUE OF WATER ELEVATION + SETUP OCCURRED 848, 35.0 m MAXIMUM ESTIMATED RUNUP ELEVATION: 5.37 m (REFERENCED TO VERTICAL DATUM) POSITION OF LANDWARD MOST OCCURRENCE OF A .50 m EROSION DEPTH: 25.0m DISTANCE FROM POSITION OF REFERENCE ELEVATION ON INITIAL PROFILE TO POSITION OF LANDWARD MOST OCCURRENCE OF A .50 m EROSION DEPTH: 33.2m POSITION OF LANDWARD MOST OCCURRENCE OF A 1.00 m EROSION DEPTH: 25.0m DISTANCE FROM POSITION OF REFERENCE ELEVATION ON INITIAL PROFILE TO POSITION OF LANDWARD MOST OCCURRENCE OF A 1.00 m EROSION DEPTH: 33.2m POSITION OF LANDWARD MOST OCCURRENCE OF A 1.50 m EROSION DEPTH: 25.0m DISTANCE FROM POSITION OF REFERENCE ELEVATION ON INITIAL PROFILE TO POSITION OF LANDWARD MOST OCCURRENCE OF A 1.50 m EROSION DEPTH: 33.2m MAXIMUM RECESSION OF THE 1.50 m ELEVATION CONTOUR: 25.43 m MAXIMUM RECESSION OF THE .00 m ELEVATION CONTOUR: 30.72 m MAXIMUM RECESSION OF THE -5.00 m ELEVATION CONTOUR: .16m (0^ oI £ LLJ -Ao,tfii_ko-15 A v^\ \ \\\ \\lv X '\ """••--• - -^ Cardiff Solana - Case 2 Transect SD 0630 \... ... _. — 1 1 1 Initial Profile Nourished Profile 1 80 Days 100 200 300 400 500 600 700 Distance from Range (m) 800 900 1000 1100 1200 Report for run: Reach: Initial Design Beach Fill Storm: Oct93-Dec93 Report Project: Cardiff-Solana Beach - Case 2 Reach: Initial Design Beach Fill Storm: Oct93-Dec93 MODEL CONFIGURATION INPUT UNITS (SI=1, AMERICAN CUST.=2): 1 NUMBER OF CALCULATION CELLS: 166 GRID TYPE (CONSTANTS, VARIABLES): 0 CONSTANT CELL WIDTH: 5.0 NUMBER OF TIME STEPS AND VALUE OF TIME STEP IN MINUTES: 1776, 60.0 TIME STEP INTERVAL OF INTERMEDIATE OUTPUT: 500 NO COMPARSION WITH MEASURED PROFILE. PROFILE ELEVATION CONTOUR 1: 1.50 PROFILE ELEVATION CONTOUR 2: .00 PROFILE ELEVATION CONTOUR 3: -5.00 PROFILE EROSION DEPTH 1: .50 PROFILE EROSION DEPTH 2: 1.00 PROFILE EROSION DEPTH 3: 1.50 REFERENCE ELEVATION: .00 TRANSPORT RATE COEFFICIENT (mA4/N): .25E-6 COEFFICIENT FOR SLOPE DEPENDENT TERM (mA2/s): .0010 TRANSPORT RATE DECAY COEFFICIENT MULTIPLIER: .50 WATER TEMPERATURE IN DEGREES C : 20.0 WAVE TYPE (MONOCHROMATIC=1, IRREGULAR=2): 2 WAVE HEIGHT AND PERIOD INPUT (CONSTANTS, VARIABLES): 1 TIME STEP OF VARIABLE WAVE HEIGHT AND PERIOD INPUT IN MINUTES: 180.0 WAVE ANGLE INPUT (CONSTANTS, VARIABLES): 0 CONSTANT WAVE ANGLE: .0 WATER DEPTH OF INPUT WAVES (DEEP WATER = 0.0): .0 SEED VALUE FOR WAVE HEIGHT RANDOMIZER AND % VARIABILITY: 4567, 20.0 TOTAL WATER ELEVATION INPUT (CONSTANTS, VARIABLES): 1 TIME STEP OF VARIABLE TOTAL WATER ELEVATION INPUT IN MINUTES: 60.0 WIND SPEED AND ANGLE INPUT (CONSTANTS, VARIABLES): 0 CONSTANT WIND SPEED AND ANGLE: .0, .0 TYPE OF INPUT PROFILE (ARBITRARY=1, SCHEMATIZED=2): 1 DEPTH CORRESPONDING TO LANDWARD END OF SURF ZONE: .50 EFFECTIVE GRAIN SIZE DIAMETER IN MILLIMETERS: .26 MAXIMUM PROFILE SLOPE PRIOR TO AVALANCHING IN DEGREES: 15.0 BEACH FILL IS PRESENT. POSITION OF SEAWALL RELATIVE TO INITIAL PROFILE: 20.0 SEAWALL FAILURE IS NOT ALLOWED. NO HARD BOTTOM IS PRESENT. COMPUTED RESULTS DIFFERENCE IN TOTAL VOLUME BETWEEN FINAL AND INITIAL PROFILES: -4.5 mA3/m MAXIMUM VALUE OF WATER ELEVATION + SETUP FOR SIMULATION 1.60m TIME STEP AND POSITION ON PROFILE AT WHICH MAXIMUM VALUE OF WATER ELEVATION + SETUP OCCURRED 1040, 65.0 m MAXIMUM ESTIMATED RUNUP ELEVATION: 3.08 m (REFERENCED TO VERTICAL DATUM) POSITION OF LANDWARD MOST OCCURRENCE OF A .50 m EROSION DEPTH: 50.0m DISTANCE FROM POSITION OF REFERENCE ELEVATION ON INITIAL PROFILE TO POSITION OF LANDWARD MOST OCCURRENCE OF A .50 m EROSION DEPTH: 44.0m POSITION OF LANDWARD MOST OCCURRENCE OF A 1.00 m EROSION DEPTH: 60.0m DISTANCE FROM POSITION OF REFERENCE ELEVATION ON INITIAL PROFILE TO POSITION OF LANDWARD MOST OCCURRENCE OF A 1.00 m EROSION DEPTH: 34.0m A 1.50m EROSION DEPTH DID NOT OCCUR ANYWHERE ON THE PROFILE. MAXIMUM RECESSION OF THE 1.50m ELEVATION CONTOUR: 19.42 m MAXIMUM RECESSION OF THE .00 m ELEVATION CONTOUR: 25.07m MAXIMUM RECESSION OF THE -5.00 m ELEVATION CONTOUR: .10m Report for run: Reach: 1988 Design Beach Storm: Report Project: Cardiff-Solana Beach - Case 2 Reach: 1988 Design Beach Storm: 1988 MODEL CONFIGURATION INPUT UNITS (SI=1, AMERICAN CUST.=2): 1 NUMBER OF CALCULATION CELLS: 165 GRID TYPE (CONSTANTS, VARIABLES): 0 CONSTANT CELL WIDTH: 5.0 NUMBER OF TIME STEPS AND VALUE OF TIME STEP IN MINUTES: 7776, 60.0 TIME STEP INTERVAL OF INTERMEDIATE OUTPUT: 2078 NO COMPARSION WITH MEASURED PROFILE. PROFILE ELEVATION CONTOUR 1: 1.50 PROFILE ELEVATION CONTOUR 2: .00 PROFILE ELEVATION CONTOUR 3: -5.00 PROFILE EROSION DEPTH 1: .50 PROFILE EROSION DEPTH 2: 1.00 PROFILE EROSION DEPTH 3: 1.50 REFERENCE ELEVATION: .00 TRANSPORT RATE COEFFICIENT (mA4/N): .25E-6 COEFFICIENT FOR SLOPE DEPENDENT TERM (mA2/s): .0010 TRANSPORT RATE DECAY COEFFICIENT MULTIPLIER: .50 WATER TEMPERATURE IN DEGREES C : 20.0 WAVE TYPE (MONOCHROMATIC=1, IRREGULAR=2): 2 WAVE HEIGHT AND PERIOD INPUT (CONSTANTS, VARIABLES): 1 TIME STEP OF VARIABLE WAVE HEIGHT AND PERIOD INPUT IN MINUTES: 360.0 WAVE ANGLE INPUT (CONSTANTS, VARIABLES): 0 CONSTANT WAVE ANGLE: .0 WATER DEPTH OF INPUT WAVES (DEEP WATER = 0.0): .0 SEED VALUE FOR WAVE HEIGHT RANDOMIZER AND % VARIABILITY: 4567, 20.0 TOTAL WATER ELEVATION INPUT (CONSTANTS, VARIABLES): 1 TIME STEP OF VARIABLE TOTAL WATER ELEVATION INPUT IN MINUTES: 720.0 WIND SPEED AND ANGLE INPUT (CONSTANTS, VARIABLES): 0 CONSTANT WIND SPEED AND ANGLE: .0, .0 TYPE OF INPUT PROFILE (ARBITRARY=1, SCHEMATIZED=2): 1 DEPTH CORRESPONDING TO LANDWARD END OF SURF ZONE: .50 EFFECTIVE GRAIN SIZE DIAMETER IN MILLIMETERS: .26 MAXIMUM PROFILE SLOPE PRIOR TO AVALANCHING IN DEGREES: 15.0 BEACH FILL IS PRESENT. POSITION OF SEAWALL RELATIVE TO INITIAL PROFILE: 20.0 SEAWALL FAILURE IS NOT ALLOWED. NO HARD BOTTOM IS PRESENT. COMPUTED RESULTS DIFFERENCE IN TOTAL VOLUME BETWEEN FINAL AND INITIAL PROFILES: .5 mA3/m MAXIMUM VALUE OF WATER ELEVATION + SETUP FOR SIMULATION 1.09m TIME STEP AND POSITION ON PROFILE AT WHICH MAXIMUM VALUE OF WATER ELEVATION + SETUP OCCURRED 5809, 40.0 m MAXIMUM ESTIMATED RUNUP ELEVATION: 4.10 m (REFERENCED TO VERTICAL DATUM) POSITION OF LANDWARD MOST OCCURRENCE OF A .50 m EROSION DEPTH: 30.0m DISTANCE FROM POSITION OF REFERENCE ELEVATION ON INITIAL PROFILE TO POSITION OF LANDWARD MOST OCCURRENCE OF A .50 m EROSION DEPTH: 38.9m POSITION OF LANDWARD MOST OCCURRENCE OF A 1.00 m EROSION DEPTH: 30.0m DISTANCE FROM POSITION OF REFERENCE ELEVATION ON INITIAL PROFILE TO POSITION OF LANDWARD MOST OCCURRENCE OF A 1.00 m EROSION DEPTH: 38.9m POSITION OF LANDWARD MOST OCCURRENCE OF A 1.50m EROSION DEPTH: 35.0m DISTANCE FROM POSITION OF REFERENCE ELEVATION ON INITIAL PROFILE TO POSITION OF LANDWARD MOST OCCURRENCE OF A 1.50m EROSION DEPTH: 33.9m MAXIMUM RECESSION OF THE 1.50m ELEVATION CONTOUR: 18.26m MAXIMUM RECESSION OF THE .00 m ELEVATION CONTOUR: 33.29m MAXIMUM RECESSION OF THE -5.00 m ELEVATION CONTOUR: 3.41m FLETCHER COVE 10 § °(02 .o"•P 3 -5 LU -10 -15 :! ^^ " N V v " :-x--^.': Summer Variation at Fletcher - Solana Beach Transect SD 0600 ^i~, ^:>~,.. "-'^-.-, ~--t:,:^. "'•":-;;.;--- c>,. '^T;v?r. ' "^-'"""- 1996 1987 1988 - 1989 0 100 200 300 400 500 600 700 800 900 1000 1100 1200 Distance from Range (m) 10 5 1 o </> co 1§; -5 01 -10 -15 e \,XK \ ^..--:'^-. -O^- --. X J^>- \ v Winter Variation at Fletcher - Solana Beach Transect SD 0600 --^x ) 100 200 ' ••>••--.:""»... ^::~--^ -7;~-.., ""'->..^ 1986 1987 1996 ^ 300 400 500 600 700 800 900 Distance from Range (m) 1000 1100 1200 to c i UJ 10 5 0 -5 -10 -15 ( , V \ ^, >-X. ^ \ X Beach Fill Profile at Fletcher - Solana Beach Transect SD 0600 X *^> ^X ^\«^^"^>"^^>^ ''^X ^^V,^fc.^ ^^^^^>.•^ ) 100 200 300 400 500 600 700 800 900 ^^•m-Initial Profile Nourished Profile 1000 1100 12 Distance from Range (m) Fletcher - Solana Beach Cut and Fill Report Profile 1: Profile 2i XOn; XOff: Volume Changei Above Datum: Below Datum: Total Volume: Shoreline Change: From: To: Cell Changes: Cell # 1 2 3 Average Nourished Profile 0.00 m 915.00 m 118.397 cu. m/m 94.318 cu.m/m 212.715 cu.m/m 72.36 m 28.64 m 101.00 m Ending Distance(m) Ending Klevation(m) Cell Volume (cu. m/m) Cell Thickness (m) Cumulative Volume (cu. m/m) Gross Volume (cu. m/m) 4.58 2.34 0.000 0.00 0.000 0.000 140.01 -1.95 212.725 1.57 212.725 212.725 915.00 -13.62 -0.010 -0.00 212.715 212.735 -Page 1- Elevation MSL (m)i iUl O O1 O Ul O\ /\ \ \\ i,\ >^ \ A ^•-•-, 'X'""""\X Fletcher Solana - Case 1 Transect SD 0600 -.-.. Initial Profile — Nourished Profile 180 Days -- ) 100 200 300 400 500 600 700 800 900 1000 1100 Distance from Range (m) 1200 Report for run: Reach: Initial Design Beach Fill Storm: Oct87-Dec87 Report Project: Fletcher -Solana Beach - Casel Reach: Initial Design Beach Fill Storm: Oct87-Dec87 MODEL CONFIGURATION INPUT UNITS (SI=1, AMERICAN CUST.=2): 1 NUMBER OF CALCULATION CELLS: 183 GRID TYPE (CONSTANTS), VARIABLES): 0 CONSTANT CELL WIDTH: 5.0 NUMBER OF TIME STEPS AND VALUE OF TIME STEP IN MINUTES: 2848, 60.0 TIME STEP INTERVAL OF INTERMEDIATE OUTPUT: 500 NO COMPARSION WITH MEASURED PROFILE. PROFILE ELEVATION CONTOUR 1: 1.50 PROFILE ELEVATION CONTOUR 2: .00 PROFILE ELEVATION CONTOUR 3: -5.00 PROFILE EROSION DEPTH 1: .50 PROFILE EROSION DEPTH 2: 1.00 PROFILE EROSION DEPTH 3: 1.50 REFERENCE ELEVATION: .00 TRANSPORT RATE COEFFICIENT (mA4/N): .25E-6 COEFFICIENT FOR SLOPE DEPENDENT TERM (mA2/s): .0010 TRANSPORT RATE DECAY COEFFICIENT MULTIPLIER: .50 WATER TEMPERATURE IN DEGREES C : 20.0 WAVE TYPE (MONOCHROMATIC^, IRREGULAR=2): 2 WAVE HEIGHT AND PERIOD INPUT (CONSTANTS, VARIABLES): 1 TIME STEP OF VARIABLE WAVE HEIGHT AND PERIOD INPUT IN MINUTES: 480.0 WAVE ANGLE INPUT (CONSTANTS, VARIABLES): 0 CONSTANT WAVE ANGLE: .0 WATER DEPTH OF INPUT WAVES (DEEP WATER = 0.0): .0 SEED VALUE FOR WAVE HEIGHT RANDOMIZER AND % VARIABILITY: 4567, 20.0 TOTAL WATER ELEVATION INPUT (CONSTANTS, VARIABLES): 1 TIME STEP OF VARIABLE TOTAL WATER ELEVATION INPUT IN MINUTES: 720.0 WIND SPEED AND ANGLE INPUT (CONSTANTS, VARIABLES): 0 CONSTANT WIND SPEED AND ANGLE: .0, .0 TYPE OF INPUT PROFILE (ARBITRARY=1, SCHEMATIZED=2): 1 DEPTH CORRESPONDING TO LANDWARD END OF SURF ZONE: .50 EFFECTIVE GRAIN SIZE DIAMETER IN MILLIMETERS: .25 MAXIMUM PROFILE SLOPE PRIOR TO AVALANCHING IN DEGREES: 15.0 BEACH FILL IS PRESENT. POSITION OF SEAWALL RELATIVE TO INITIAL PROFILE: 15.0 SEAWALL FAILURE IS NOT ALLOWED. NO HARD BOTTOM IS PRESENT. COMPUTED RESULTS DIFFERENCE IN TOTAL VOLUME BETWEEN FINAL AND INITIAL PROFILES: -2.1 mA3/m MAXIMUM VALUE OF WATER ELEVATION + SETUP FOR SIMULATION 1.22m TIME STEP AND POSITION ON PROFILE AT WHICH MAXIMUM VALUE OF WATER ELEVATION + SETUP OCCURRED 2053, 60.0m MAXIMUM ESTIMATED RUNUP ELEVATION: 3.43 m (REFERENCED TO VERTICAL DATUM) POSITION OF LANDWARD MOST OCCURRENCE OF A .50 m EROSION DEPTH: 55.0m DISTANCE FROM POSITION OF REFERENCE ELEVATION ON INITIAL PROFILE TO POSITION OF LANDWARD MOST OCCURRENCE OF A .50 m EROSION DEPTH: 46.0m POSITION OF LANDWARD MOST OCCURRENCE OF A 1.00 m EROSION DEPTH: 55.0m DISTANCE FROM POSITION OF REFERENCE ELEVATION ON INITIAL PROFILE TO POSITION OF LANDWARD MOST OCCURRENCE OF A 1.00 m EROSION DEPTH: 46.0m POSITION OF LANDWARD MOST OCCURRENCE OF A 1.50m EROSION DEPTH: 60.0m DISTANCE FROM POSITION OF REFERENCE ELEVATION ON INITIAL PROFILE TO POSITION OF LANDWARD MOST OCCURRENCE OF A 1.50 m EROSION DEPTH: 41.0m MAXIMUM RECESSION OF THE 1.50m ELEVATION CONTOUR: 22.03 m MAXIMUM RECESSION OF THE .00 m ELEVATION CONTOUR: 41.54m THE -5.00m CONTOUR DID NOT RECEDE Report for run: Reach: 1993 Design Beach Storm: 1993 Report Project: Fletcher -Solana Beach - Casel Reach: 1993 Design Beach Storm: 1993 MODEL CONFIGURATION INPUT UNITS (SI=1, AMERICAN CUST.=2): 1 NUMBER OF CALCULATION CELLS: 182 GRID TYPE (CONSTANTS), VARIABLES): 0 CONSTANT CELL WIDTH: 5.0 NUMBER OF TIME STEPS AND VALUE OF TIME STEP IN MINUTES: 8310, 60.0 TIME STEP INTERVAL OF INTERMEDIATE OUTPUT: 2078 NO COMPARSION WITH MEASURED PROFILE. PROFILE ELEVATION CONTOUR 1: 1.50 PROFILE ELEVATION CONTOUR 2: .00 PROFILE ELEVATION CONTOUR 3: -5.00 PROFILE EROSION DEPTH 1: .50 PROFILE EROSION DEPTH 2: 1.00 PROFILE EROSION DEPTH 3: 1.50 REFERENCE ELEVATION: .00 TRANSPORT RATE COEFFICIENT (mA4/N): .25E-6 COEFFICIENT FOR SLOPE DEPENDENT TERM (mA2/s): .0010 TRANSPORT RATE DECAY COEFFICIENT MULTIPLIER: .50 WATER TEMPERATURE IN DEGREES C : 20.0 WAVE TYPE (MONOCHROMATIC=1, IRREGULAR=2): 2 WAVE HEIGHT AND PERIOD INPUT (CONSTANTS, VARIABLES): 1 TIME STEP OF VARIABLE WAVE HEIGHT AND PERIOD INPUT IN MINUTES: 180.0 WAVE ANGLE INPUT (CONSTANTS), VARIABLE^!): 0 CONSTANT WAVE ANGLE: .0 WATER DEPTH OF INPUT WAVES (DEEP WATER = 0.0): .0 SEED VALUE FOR WAVE HEIGHT RANDOMIZER AND % VARIABILITY: 4567, 20.0 TOTAL WATER ELEVATION INPUT (CONSTANTS, VARIABLES): 1 TIME STEP OF VARIABLE TOTAL WATER ELEVATION INPUT IN MINUTES: 60.0 WIND SPEED AND ANGLE INPUT (CONSTANTS, VARIABLES): 0 CONSTANT WIND SPEED AND ANGLE: .0, .0 TYPE OF INPUT PROFILE (ARBITRARY=1, SCHEMATIZED=2): 1 DEPTH CORRESPONDING TO LANDWARD END OF SURF ZONE: .50 EFFECTIVE GRAIN SIZE DIAMETER IN MILLIMETERS: .25 MAXIMUM PROFILE SLOPE PRIOR TO AVALANCHING IN DEGREES: 15.0 BEACH FILL IS PRESENT. POSITION OF SEAWALL RELATIVE TO INITIAL PROFILE: 15.0 SEAWALL FAILURE IS NOT ALLOWED. NO HARD BOTTOM IS PRESENT. COMPUTED RESULTS DIFFERENCE IN TOTAL VOLUME BETWEEN FINAL AND INITIAL PROFILES: -1.7mA3/m MAXIMUM VALUE OF WATER ELEVATION + SETUP FOR SIMULATION 1.57m TIME STEP AND POSITION ON PROFILE AT WHICH MAXIMUM VALUE OF WATER ELEVATION + SETUP OCCURRED 873, 40.0 m MAXIMUM ESTIMATED RUNUP ELEVATION: 3.61 m (REFERENCED TO VERTICAL DATUM) POSITION OF LANDWARD MOST OCCURRENCE OF A .50 m EROSION DEPTH: 15.0m DISTANCE FROM POSITION OF REFERENCE ELEVATION ON INITIAL PROFILE TO POSITION OF LANDWARD MOST OCCURRENCE OF A .50 m EROSION DEPTH: 48.2m POSITION OF LANDWARD MOST OCCURRENCE OF A 1.00 m EROSION DEPTH: 20.0m DISTANCE FROM POSITION OF REFERENCE ELEVATION ON INITIAL PROFILE TO POSITION OF LANDWARD MOST OCCURRENCE OF A 1.00 m EROSION DEPTH: 43.2m POSITION OF LANDWARD MOST OCCURRENCE OF A 1.50m EROSION DEPTH: 25.0m DISTANCE FROM POSITION OF REFERENCE ELEVATION ON INITIAL PROFILE TO POSITION OF LANDWARD MOST OCCURRENCE OF A 1.50m EROSION DEPTH: 38.2m MAXIMUM RECESSION OF THE 1.50 m ELEVATION CONTOUR: 36.40m MAXIMUM RECESSION OF THE .00 m ELEVATION CONTOUR: 35.78m THE -5.00 m CONTOUR DID NOT RECEDE Elevation MSL (m)i iUl O Ul O Ul O\ \ X ;T\ " X K'"x XV -v \ :^to,_ **""• ^ V"\.. Fletcher Solana - Case 2 Transect SD 0600 ""•••-.._ Initial Profile — Nourished Profile 180 Days ) 100 200 300 400 500 600 700 800 900 Distance from Range (m) — 1000 1100 1200 Report for run: Reach: Initial Design Beach Fill Storm: Oct93-Dec93 Report Project: Fletcher-Solana Beach - Case 2 Reach: Initial Design Beach Fill Storm: Oct93-Dec93 MODEL CONFIGURATION INPUT UNITS (SI=1, AMERICAN CUST.=2): 1 NUMBER OF CALCULATION CELLS: 183 GRID TYPE (CONSTANTS, VARIABLES): 0 CONSTANT CELL WIDTH: 5.0 NUMBER OF TIME STEPS AND VALUE OF TIME STEP IN MINUTES: 1776, 60.0 TIME STEP INTERVAL OF INTERMEDIATE OUTPUT: 500 NO COMPARSION WITH MEASURED PROFILE. PROFILE ELEVATION CONTOUR 1: 1.50 PROFILE ELEVATION CONTOUR 2: .00 PROFILE ELEVATION CONTOUR 3: -5.00 PROFILE EROSION DEPTH 1: .50 PROFILE EROSION DEPTH 2: 1.00 PROFILE EROSION DEPTH 3: 1.50 REFERENCE ELEVATION: .00 TRANSPORT RATE COEFFICIENT (mA4/N): .25E-6 COEFFICIENT FOR SLOPE DEPENDENT TERM (mA2/s): .0010 TRANSPORT RATE DECAY COEFFICIENT MULTIPLIER: .50 WATER TEMPERATURE IN DEGREES C : 20.0 WAVE TYPE (MONOCHROMATIC^, IRREGULARS): 2 WAVE HEIGHT AND PERIOD INPUT (CONSTANTS), VARIABLES): 1 TIME STEP OF VARIABLE WAVE HEIGHT AND PERIOD INPUT IN MINUTES: 180.0 WAVE ANGLE INPUT (CONSTANTS, VARIABLES): 0 CONSTANT WAVE ANGLE: .0 WATER DEPTH OF INPUT WAVES (DEEP WATER = 0.0): .0 SEED VALUE FOR WAVE HEIGHT RANDOMIZER AND % VARIABILITY: 4567, 20.0 TOTAL WATER ELEVATION INPUT (CONSTANTS, VARIABLES): 1 TIME STEP OF VARIABLE TOTAL WATER ELEVATION INPUT IN MINUTES: 60.0 WIND SPEED AND ANGLE INPUT (CONSTANTS, VARIABLES): 0 CONSTANT WIND SPEED AND ANGLE: .0, .0 TYPE OF INPUT PROFILE (ARBITRARY=1, SCHEMATIZED=2): 1 DEPTH CORRESPONDING TO LANDWARD END OF SURF ZONE: .50 EFFECTIVE GRAIN SIZE DIAMETER IN MILLIMETERS: .25 MAXIMUM PROFILE SLOPE PRIOR TO AVALANCHING IN DEGREES: 15.0 BEACH FILL IS PRESENT. POSITION OF SEAWALL RELATIVE TO INITIAL PROFILE: 15.0 SEAWALL FAILURE IS NOT ALLOWED. NO HARD BOTTOM IS PRESENT. COMPUTED RESULTS DIFFERENCE IN TOTAL VOLUME BETWEEN FINAL AND INITIAL PROFILES: 1.7mA3/m MAXIMUM VALUE OF WATER ELEVATION + SETUP FOR SIMULATION 1.54m TIME STEP AND POSITION ON PROFILE AT WHICH MAXIMUM VALUE OF WATER ELEVATION + SETUP OCCURRED 1040, 75.0m MAXIMUM ESTIMATED RUNUP ELEVATION: 2.78 m (REFERENCED TO VERTICAL DATUM) POSITION OF LANDWARD MOST OCCURRENCE OF A .50 m EROSION DEPTH: 65.0m DISTANCE FROM POSITION OF REFERENCE ELEVATION ON INITIAL PROFILE TO POSITION OF LANDWARD MOST OCCURRENCE OF A .50 m EROSION DEPTH: 36.0m POSITION OF LANDWARD MOST OCCURRENCE OF A 1.00 m EROSION DEPTH: 75.0m DISTANCE FROM POSITION OF REFERENCE ELEVATION ON INITIAL PROFILE TO POSITION OF LANDWARD MOST OCCURRENCE OF A 1.00 m EROSION DEPTH: 26.0m A 1.50 m EROSION DEPTH DID NOT OCCUR ANYWHERE ON THE PROFILE. MAXIMUM RECESSION OF THE 1.50 m ELEVATION CONTOUR: 9.63m MAXIMUM RECESSION OF THE .00 m ELEVATION CONTOUR: 22.56 m THE -5.00m CONTOUR DID NOT RECEDE Report for run: Reach: 1988 Design Beach Storm: 1988 Report Project: Fletcher-Solana Beach - Case 2 Reach: 1988 Design Beach Storm: 1988 MODEL CONFIGURATION INPUT UNITS (SI=1, AMERICAN CUST =2): 1 NUMBER OF CALCULATION CELLS: 182 GRID TYPE (CONSTANTS, VARIABLES): 0 CONSTANT CELL WIDTH: 5.0 NUMBER OF TIME STEPS AND VALUE OF TIME STEP IN MINUTES: 7776, 60.0 TIME STEP INTERVAL OF INTERMEDIATE OUTPUT: 2078 NO COMPARSION WITH MEASURED PROFILE. PROFILE ELEVATION CONTOUR 1: 1.50 PROFILE ELEVATION CONTOUR 2: .00 PROFILE ELEVATION CONTOUR 3: -5.00 PROFILE EROSION DEPTH 1: .50 PROFILE EROSION DEPTH 2: 1.00 PROFILE EROSION DEPTH 3: 1.50 REFERENCE ELEVATION: .00 TRANSPORT RATE COEFFICIENT (mA4/N): .25E-6 COEFFICIENT FOR SLOPE DEPENDENT TERM (mA2/s): .0010 TRANSPORT RATE DECAY COEFFICIENT MULTIPLIER: .50 WATER TEMPERATURE IN DEGREES C : 20.0 WAVE TYPE (MONOCHROMATIC=1, IRREGULAR=2): 2 WAVE HEIGHT AND PERIOD INPUT (CONSTANTS, VARIABLES): 1 TIME STEP OF VARIABLE WAVE HEIGHT AND PERIOD INPUT IN MINUTES: 360.0 WAVE ANGLE INPUT (CONSTANTS, VARIABLES): 0 CONSTANT WAVE ANGLE: .0 WATER DEPTH OF INPUT WAVES (DEEP WATER = 0.0): .0 SEED VALUE FOR WAVE HEIGHT RANDOMIZER AND % VARIABILITY: 4567, 20.0 TOTAL WATER ELEVATION INPUT (CONSTANTS, VARIABLES): 1 TIME STEP OF VARIABLE TOTAL WATER ELEVATION INPUT IN MINUTES: 720.0 WIND SPEED AND ANGLE INPUT (CONSTANTS, VARIABLES): 0 CONSTANT WIND SPEED AND ANGLE: .0, .0 TYPE OF INPUT PROFILE (ARBITRARY^, SCHEMATIZED=2): 1 DEPTH CORRESPONDING TO LANDWARD END OF SURF ZONE: .50 EFFECTIVE GRAIN SIZE DIAMETER IN MILLIMETERS: .25 MAXIMUM PROFILE SLOPE PRIOR TO AVALANCHING IN DEGREES: 15.0 BEACH FILL IS PRESENT. POSITION OF SEAWALL RELATIVE TO INITIAL PROFILE: 15.0 SEAWALL FAILURE IS NOT ALLOWED. NO HARD BOTTOM IS PRESENT. COMPUTED RESULTS DIFFERENCE IN TOTAL VOLUME BETWEEN FINAL AND INITIAL PROFILES: 1.4mA3/m MAXIMUM VALUE OF WATER ELEVATION + SETUP FOR SIMULATION 1.15m TIME STEP AND POSITION ON PROFILE AT WHICH MAXIMUM VALUE OF WATER ELEVATION + SETUP OCCURRED 6937, 45.0 m MAXIMUM ESTIMATED RUNUP ELEVATION: 3.93 m (REFERENCED TO VERTICAL DATUM) POSITION OF LANDWARD MOST OCCURRENCE OF A .50 m EROSION DEPTH: 40.0m DISTANCE FROM POSITION OF REFERENCE ELEVATION ON INITIAL PROFILE TO POSITION OF LANDWARD MOST OCCURRENCE OF A .50 m EROSION DEPTH: 38.4m POSITION OF LANDWARD MOST OCCURRENCE OF A 1.00 m EROSION DEPTH: 45.0m DISTANCE FROM POSITION OF REFERENCE ELEVATION ON INITIAL PROFILE TO POSITION OF LANDWARD MOST OCCURRENCE OF A 1.00 m EROSION DEPTH: 33.4m POSITION OF LANDWARD MOST OCCURRENCE OF A 1.50m EROSION DEPTH: 50.0m DISTANCE FROM POSITION OF REFERENCE ELEVATION ON INITIAL PROFILE TO POSITION OF LANDWARD MOST OCCURRENCE OF A 1.50m EROSION DEPTH: 28.4m MAXIMUM RECESSION OF THE 1.50 m ELEVATION CONTOUR: 24.42 m MAXIMUM RECESSION OF THE .00 m ELEVATION CONTOUR: 28.57m MAXIMUM RECESSION OF THE -5.00 m ELEVATION CONTOUR: 1.34m BATIQUITOS SBEACH I/O 10 5 1 „ V)2 .0'a > 50) -5 ID -10 -15 ( *VVvV*i, ^/^d\ -^., \\\• v \\-. \ M \ ^l "\ \ Batiquitos Fill Transect CB 0760 ^^•\ "^x ~"-\ I Initial Profile — Nourished Measured 1 80 Days 360 Days — 540 Days ) 100 200 300 400 500 600 700 800 900 1000 1100 1200 Distance from Range (m) Report for run: Reach: Beach Fill - 0.2mm Storm: Oct93-Dec93 Report Project: Batiquitos Reach: Beach Fill - 0.2mm Storm: Oct93-Dec93 MODEL CONFIGURATION INPUT UNITS (SI=1, AMERICAN CUST.=2): 1 NUMBER OF CALCULATION CELLS: 144 GRID TYPE (CONSTANTS, VARIABLES): 0 CONSTANT CELL WIDTH: 5.0 NUMBER OF TIME STEPS AND VALUE OF TIME STEP IN MINUTES: 1776, 60.0 TIME STEP(S) OF INTERMEDIATE OUTPUT 1: 200 TIME STEP(S) OF INTERMEDIATE OUTPUT 2: 400 PROFILE ELEVATION CONTOUR 1: 1.50 PROFILE ELEVATION CONTOUR 2: .00 PROFILE ELEVATION CONTOUR 3: -5.00 PROFILE EROSION DEPTH 1: .50 PROFILE EROSION DEPTH 2: 1.00 PROFILE EROSION DEPTH 3: 1.50 REFERENCE ELEVATION: .00 TRANSPORT RATE COEFFICIENT (mA4/N): .25E-6 COEFFICIENT FOR SLOPE DEPENDENT TERM (mA2/s): .0010 TRANSPORT RATE DECAY COEFFICIENT MULTIPLIER: .50 WATER TEMPERATURE IN DEGREES C : 20.0 WAVE TYPE (MONOCHROMATIC=1, IRREGULAR=2): 2 WAVE HEIGHT AND PERIOD INPUT (CONSTANTS, VARIABLES): 1 TIME STEP OF VARIABLE WAVE HEIGHT AND PERIOD INPUT IN MINUTES: 180.0 WAVE ANGLE INPUT (CONSTANTS, VARIABLES): 0 CONSTANT WAVE ANGLE: .0 WATER DEPTH OF INPUT WAVES (DEEP WATER = 0.0): .0 SEED VALUE FOR WAVE HEIGHT RANDOMIZER AND % VARIABILITY: 4567, 20.0 TOTAL WATER ELEVATION INPUT (CONSTANTS, VARIABLES): 1 TIME STEP OF VARIABLE TOTAL WATER ELEVATION INPUT IN MINUTES: 60.0 WIND SPEED AND ANGLE INPUT (CONSTANTS, VARIABLES): 0 CONSTANT WIND SPEED AND ANGLE: .0, .0 TYPE OF INPUT PROFILE (ARBrTRARY=l, SCHEMATIZED=2): 1 DEPTH CORRESPONDING TO LANDWARD END OF SURF ZONE: .50 EFFECTIVE GRAIN SIZE DIAMETER IN MILLIMETERS: .20 MAXIMUM PROFILE SLOPE PRIOR TO AVALANCHING IN DEGREES: 15.0 BEACH FILL IS PRESENT. NO SEAWALL IS PRESENT. NO HARD BOTTOM IS PRESENT. COMPUTED RESULTS DIFFERENCE IN TOTAL VOLUME BETWEEN FINAL AND INITIAL PROFILES: 3.7 mA3/m DIFFERENCE IN TOTAL VOLUME BETWEEN MEASURED AND INITIAL PROIFLES -261.8 mA3/m SUM OF SQUARES OF DIFFERENCES BETWEEN MEASURED AND FINAL PROFILES: 127.0 mA2 MAXIMUM VALUE OF WATER ELEVATION + SETUP FOR SIMULATION 1.48m TIME STEP AND POSITION ON PROFILE AT WHICH MAXIMUM VALUE OF WATER ELEVATION + SETUP OCCURRED 1089, 100.0 m MAXIMUM ESTIMATED RUNUP ELEVATION: 3.93 m (REFERENCED TO VERTICAL DATUM) POSITION OF LANDWARD MOST OCCURRENCE OF A .50 m EROSION DEPTH: 75.0m DISTANCE FROM POSITION OF REFERENCE ELEVATION ON INITIAL PROFILE TO POSITION OF LANDWARD MOST OCCURRENCE OF A .50 m EROSION DEPTH: 33.1m POSITION OF LANDWARD MOST OCCURRENCE OF A 1.00 m EROSION DEPTH: 80.0m DISTANCE FROM POSITION OF REFERENCE ELEVATION ON INITIAL PROFILE TO POSITION OF LANDWARD MOST OCCURRENCE OF A 1.00 m EROSION DEPTH: 28.1 m POSITION OF LANDWARD MOST OCCURRENCE OF A 1.50 m EROSION DEPTH: 85.0m DISTANCE FROM POSITION OF REFERENCE ELEVATION ON INITIAL PROFILE TO POSITION OF LANDWARD MOST OCCURRENCE OF A 1.50 m EROSION DEPTH: 23.1m MAXIMUM RECESSION OF THE 1.50 m ELEVATION CONTOUR: 12.34m MAXIMUM RECESSION OF THE .00 m ELEVATION CONTOUR: 8.43m THE -5.00 m CONTOUR DID NOT RECEDE Report for run: Reach: Second Storm: Jan93-May93 Report Project: Batiquitos Reach: New Reach Storm: Jan93-May93 MODEL CONFIGURATION INPUT UNITS (SI=1, AMERICAN CUST =2): 1 NUMBER OF CALCULATION CELLS: 143 GRID TYPE (CONSTANTS, VARIABLES): 0 CONSTANT CELL WIDTH: 5.0 NUMBER OF TIME STEPS AND VALUE OF TIME STEP IN MINUTES: 8310, 60.0 TIME STEP INTERVAL OF INTERMEDIATE OUTPUT: 2077 PROFILE ELEVATION CONTOUR 1: 1.50 PROFILE ELEVATION CONTOUR 2: .00 PROFILE ELEVATION CONTOUR 3: -5.00 PROFILE EROSION DEPTH 1: .50 PROFILE EROSION DEPTH 2: 1.00 PROFILE EROSION DEPTH 3: 1.50 REFERENCE ELEVATION: .00 TRANSPORT RATE COEFFICIENT (mA4/N): .25E-6 COEFFICIENT FOR SLOPE DEPENDENT TERM (mA2/s): .0010 TRANSPORT RATE DECAY COEFFICIENT MULTIPLIER: .50 WATER TEMPERATURE IN DEGREES C : 20.0 WAVE TYPE (MONOCHROMATIC=1, IRREGULAR=2): 2 WAVE HEIGHT AND PERIOD INPUT (CONSTANTS, VARIABLES): 1 TIME STEP OF VARIABLE WAVE HEIGHT AND PERIOD INPUT IN MINUTES: 180.0 WAVE ANGLE INPUT (CONSTANTS, VARIABLES): 0 CONSTANT WAVE ANGLE: .0 WATER DEPTH OF INPUT WAVES (DEEP WATER = 0.0): .0 SEED VALUE FOR WAVE HEIGHT RANDOMIZER AND % VARIABILITY: 4567, 20.0 TOTAL WATER ELEVATION INPUT (CONSTANTS, VARIABLES): 1 TIME STEP OF VARIABLE TOTAL WATER ELEVATION INPUT IN MINUTES: 60.0 WIND SPEED AND ANGLE INPUT (CONSTANTS, VARIABLES): 0 CONSTANT WIND SPEED AND ANGLE: .0, .0 TYPE OF INPUT PROFILE (ARBITRARY=1, SCHEMATIZED=2): 1 DEPTH CORRESPONDING TO LANDWARD END OF SURF ZONE: .50 EFFECTIVE GRAIN SIZE DIAMETER IN MILLIMETERS: .20 MAXIMUM PROFILE SLOPE PRIOR TO AVALANCHING IN DEGREES: 15.0 BEACH FILL IS PRESENT. NO SEAWALL IS PRESENT. NO HARD BOTTOM IS PRESENT. COMPUTED RESULTS DIFFERENCE IN TOTAL VOLUME BETWEEN FINAL AND INITIAL PROFILES: 10.5 mA3/m DIFFERENCE IN TOTAL VOLUME BETWEEN MEASURED AND INITIAL PROIFLES -261.4mA3/m SUM OF SQUARES OF DIFFERENCES BETWEEN MEASURED AND FINAL PROFILES: 25.3 mA2 MAXIMUM VALUE OF WATER ELEVATION + SETUP FOR SIMULATION 1.64m TIME STEP AND POSITION ON PROFILE AT WHICH MAXIMUM VALUE OF WATER ELEVATION + SETUP OCCURRED 4773, 70.0 m MAXIMUM ESTIMATED RUNUP ELEVATION: 4.58 m (REFERENCED TO VERTICAL DATUM) POSITION OF LANDWARD MOST OCCURRENCE OF A .50 m EROSION DEPTH: 35.0m DISTANCE FROM POSITION OF REFERENCE ELEVATION ON INITIAL PROFILE TO POSITION OF LANDWARD MOST OCCURRENCE OF A .50 m EROSION DEPTH: 71.4m POSITION OF LANDWARD MOST OCCURRENCE OF A 1.00 m EROSION DEPTH: 45.0m DISTANCE FROM POSITION OF REFERENCE ELEVATION ON INITIAL PROFILE TO POSITION OF LANDWARD MOST OCCURRENCE OF A 1.00 m EROSION DEPTH: 61.4m POSITION OF LANDWARD MOST OCCURRENCE OF A 1.50m EROSION DEPTH: 50.0m DISTANCE FROM POSITION OF REFERENCE ELEVATION ON INITIAL PROFILE TO POSITION OF LANDWARD MOST OCCURRENCE OF A 1.50m EROSION DEPTH: 56.4m MAXIMUM RECESSION OF THE 1.50 m ELEVATION CONTOUR: 34.22 m MAXIMUM RECESSION OF THE .00 m ELEVATION CONTOUR: 38.88m THE -5.00 m CONTOUR DID NOT RECEDE Report for run: Reach: 1996 Storm: Jan93-Apr93 Report Project: Batiquitos Reach: 1996 Storm: Jan93-Apr93 MODEL CONFIGURATION INPUT UNITS (SI=1, AMERICAN CUST.=2): 1 NUMBER OF CALCULATION CELLS: 142 GRID TYPE (CONSTANTS, VARIABLES): 0 CONSTANT CELL WIDTH: 5.0 NUMBER OF TIME STEPS AND VALUE OF TIME STEP IN MINUTES: 2160, 60.0 TIME STEP INTERVAL OF INTERMEDIATE OUTPUT: 2077 PROFILE ELEVATION CONTOUR 1: 1.50 PROFILE ELEVATION CONTOUR 2: .00 PROFILE ELEVATION CONTOUR 3: -5.00 PROFILE EROSION DEPTH 1: .50 PROFILE EROSION DEPTH 2: 1.00 PROFILE EROSION DEPTH 3: 1.50 REFERENCE ELEVATION: .00 TRANSPORT RATE COEFFICIENT (mM/N): .25E-6 COEFFICIENT FOR SLOPE DEPENDENT TERM (mA2/s): .0010 TRANSPORT RATE DECAY COEFFICIENT MULTIPLIER: .50 WATER TEMPERATURE IN DEGREES C : 20.0 WAVE TYPE (MONOCHROMATIC=1, IRREGULAR=2): 2 WAVE HEIGHT AND PERIOD INPUT (CONSTANTS, VARIABLES): 1 TIME STEP OF VARIABLE WAVE HEIGHT AND PERIOD INPUT IN MINUTES: 180.0 WAVE ANGLE INPUT (CONSTANTS, VARIABLES): 0 CONSTANT WAVE ANGLE: .0 WATER DEPTH OF INPUT WAVES (DEEP WATER = 0.0): .0 SEED VALUE FOR WAVE HEIGHT RANDOMIZER AND % VARIABILITY: 4567, 20.0 TOTAL WATER ELEVATION INPUT (CONSTANTS, VARIABLES): 1 TIME STEP OF VARIABLE TOTAL WATER ELEVATION INPUT IN MINUTES: 60.0 WIND SPEED AND ANGLE INPUT (CONSTANTS, VARIABLES): 0 CONSTANT WIND SPEED AND ANGLE: .0, .0 TYPE OF INPUT PROFILE (ARBITRARY=1, SCHEMATIZED=2): 1 DEPTH CORRESPONDING TO LANDWARD END OF SURF ZONE: .50 EFFECTIVE GRAIN SIZE DIAMETER IN MILLIMETERS: .20 MAXIMUM PROFILE SLOPE PRIOR TO AVALANCHING IN DEGREES: 15.0 BEACH FILL IS PRESENT. NO SEAWALL IS PRESENT. NO HARD BOTTOM IS PRESENT. COMPUTED RESULTS DIFFERENCE IN TOTAL VOLUME BETWEEN FINAL AND INITIAL PROFILES: 1.4mA3/m DIFFERENCE IN TOTAL VOLUME BETWEEN MEASURED AND INITIAL PROIFLES -121.3 mA3/m SUM OF SQUARES OF DIFFERENCES BETWEEN MEASURED AND FINAL PROFILES: 19.6mA2 MAXIMUM VALUE OF WATER ELEVATION + SETUP FOR SIMULATION 1.47m TIME STEP AND POSITION ON PROFILE AT WHICH MAXIMUM VALUE OF WATER ELEVATION + SETUP OCCURRED 848, 60.0 m MAXIMUM ESTIMATED RUNUP ELEVATION: 3.58 m (REFERENCED TO VERTICAL DATUM) POSITION OF LANDWARD MOST OCCURRENCE OF A .50 m EROSION DEPTH: 30.0m DISTANCE FROM POSITION OF REFERENCE ELEVATION ON INITIAL PROFILE TO POSITION OF LANDWARD MOST OCCURRENCE OF A .50 m EROSION DEPTH: 39.6m POSITION OF LANDWARD MOST OCCURRENCE OF A 1.00 m EROSION DEPTH: 55.0m DISTANCE FROM POSITION OF REFERENCE ELEVATION ON INITIAL PROFILE TO POSITION OF LANDWARD MOST OCCURRENCE OF A 1.00 m EROSION DEPTH: 14.6m POSITION OF LANDWARD MOST OCCURRENCE OF A 1.50m EROSION DEPTH: 55.0m DISTANCE FROM POSITION OF REFERENCE ELEVATION ON INITIAL PROFILE TO POSITION OF LANDWARD MOST OCCURRENCE OF A 1.50 m EROSION DEPTH: 14.6m MAXIMUM RECESSION OF THE 1.50 m ELEVATION CONTOUR: 7.21m MAXIMUM RECESSION OF THE .00 m ELEVATION CONTOUR: 8.18m THE -5.00 m CONTOUR DID NOT RECEDE APPENDIX D PHOTOGRAPHS I I SOUTHWESNAVFACENGCOM FY 97 MCON PROJECT P-706 CHANNEL DREDGING BEACH SAND TRANSPORT AND SEDIMENTATION REPORT PHASE I: SOUTH OCEANSIDE AND SOLANA BEACH I I I I I I I SO-1. From 122 m south of Oceanside Pier looking north - Approx. Tide = 1.13m tn SO-1 A. From Mission Avenue looking north - Approx. Tide = 1.80 m 28 MARCH !997 D-l BEACH SAND TRANSPORT & SEDIMENTATION SOUTHWESNAVFACENGCOM FY 97 MCON PROJECT P-706 CHANNEL DREDGING SEACH SAND TRANSPORT AND SEDIMENTATION7 REPORT PHASE I: SOUTH OCEANSIDE AND SOLANA BEACH SO-2. From 122 m south of Oceanside Pier looking south - Approx. Tide = 1.13 m SO-2A. From Mission Avenue looking south - Approx. Tide = 1.80 m 28 MARCH 1997 D-2 BEACH SAND TRANSPORT & SEDIMENTATION I I I I I I I I I I SOUTHWESNAVFACENGCOM FY 97 MCON PROJE<5&&706 CHANNEL DREDGING BEACH SAND TRANSPORT AND SEDIMENTATION REPORT PHASE I: SOUTH OCEANSIDE AND SOLANA BEACH SO-3. From Tyson St. looking north towards Oceanside Pier - Approx. Tide = 1.13m SO-3A. From south of Tyson St. Park looking north - Approx. Tide = 1.71 m 28 MARCH 1997 D-3 BEACH SAND TRANSPORT & SEDIMENTATION SOUTHWESNAVFACENGCOM FY 97 MCON PROJECT P-706 CHANNEL DREDGING BEACH SAND TRANSPORT AND SEDIMENTATION REPORT PHASE I: SOUTH OCEANSIDE AND SOLANA BEACH From Tyson St. looking east, 2-45 cm rep storm drain outlets, south of public access Approx. Tide = 1.12m SO-5. From Tyson St. looking west, 45 cm rep storm drain outlet - Approx. Tide = 1.15m 28 MARCH 1997 BEACH SAND TRANSPORT & SEDIMENTATION I I I I I I I I I I I I SOUTHWESNAVFACENGCOM FY 97 MCON PROJECT P-706 CHANNEL DREDGING BEACH SAND TRANSPORT AND SEDIMENTATION REPORT PHASE I: SOUTH OCEANSIDE AND SOLANA BEACH SO-6. From 15 m south of Ash St. public beach access stairs looking north towards Oceanside Pier - Approx. Tide = I.i5m SO-7. From 15 m north of Wisconsin Ave. looking south at public access ramp - Approx. Tide = 1.21 m 28 MARCH 199"D-5 BEACH SAND TRANSPORT & SEDIMENTATION SOUTHWESNAVFACENGCOM FY 97 MCON PROJECT P-706 CHANNEL DREDGING BEACH SAND TRANSPORT AND SEDIMENTATION REPORT PHASE I: SOUTH OCEANSIDE AND SOLANA BEACH SO-8. From Wisconsin Ave. looking south - Approx. Tide = 1.27 m SO-9. From Wisconsin Ave. looking north - Approx. Tide = 1.27 m 28 MARCH 1997 D-6 BEACH SAND TRANSPORT &. SEDIMENTATION I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I SOUTHWESNAVFACENGCOM FY 97 MCON PROJECT P-706 CHANNEL DREDGING BEACH SAND TRANSPORT .AND SEDIMENTATION REPORT PHASE I: SOUTH OCEANSIDE AND SOLANA BEACH SO-9A. From Wisconsin Ave. looking north - Approx. Tide = 1.61 m SO-10. From Hayes St. looking south - Approx. Tide - 1.27 m 28 MARCH 1997 D-7 BEACH SAND TRANSPORT & SEDIMENTATION SOUTHWESNAVFACENGCOM FY 97 MCON PROJECT P-706 CHANNEL DREDGING BEACH SAND TRANSPORT AND SEDIMENTATION REPORT PHASE I: SOUTH OCEANSIDE AND SOLANA BEACH SO-10A. From Wisconsin Ave. looking south - Approx. Tide = 1,61 m SO-11. From Wisconsin Ave. looking north - Approx. Tide = 1.27 m 28 MARCH 1997 BEACH SAND TRANSPORT & SEDIMENTATION I I I I I I I I I I I I I SOUTHWESNAVFACENGCOM FY 97 MCON PROTEST P-706 CHANNEL DREDGING BEACH SAND TRANSPORT AND SEDIMENTATION REPORT PHASE I: SOUTH OCEANSIDE AND SOLANA BEACH SO-12. From south of Wisconsin Ave. looking north - Approx. Tide = 1.27 m SO-13. From Marron St. looking south - Approx. Tide = 1.27 m 28 MARCH 1997 D-9 BEACH SAND TRANSPORT & SEDIMENTATION SOUTHWESNAVFACENGCOM FY 97 MCON PROJECT P-706 CHANNEL DREDGING BEACH SAND TRANSPORT AND SEDIMENTATION REPORT PHASE I: SOUTH OCEANS IDE AND SOL ANA BEACH . • SO-14. From Marron St. looking at public access - Approx. Tide = 1.27 m SO-15. From Marron St. looking north - Approx. Tide = 1.27 m 28 MARCH 1997 D-!0 BEACH SAND TRANSPORT & SEDIMENTATION I I I I I I I I I I SOUTHWESNAVFACENGCOM FY 97 MCON PROJECT P-706 CHANNEL DREDGING BEACH SAND TRANSPORT AND SEDIMENTATION REPORT PHASE !: SOUTH OCEANSIDE AND SOLANA BEACH SO-1-6. From Marron St. looking south - Approx. Tide = 1.33 m SO-16A. From Marron St. looking at 2-90 cm rep - Approx. Tide = 1.33 m 28 MARCH !997 D-I!BEACH SAND TRANSPORT & SEDIMENTATION SOUTHWESNAVFACENGCOM FY 97 MCON PROJECT P-706 CHANNEL DREDGING BEACH SAND TRANSPORT AND SEDIMENTATION REPORT PHASE I: SOUTH OCEANSIDE AND SOLANA BEACH SO-17. From beach looking at Foster St. west end cul-de-sac, 45 cm rep storm drain outlet Approx. Tide = 1.33 m SO-18. From Foster St. looking south towards Oceanside Blvd. at ramp for public access Approx. Tide = 1.33 m 28 MARCH 1997 D-I2 BEACH SAND TRANSPORT & SEDIMENTATION I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I SOUTHWESNAVFACENGCOM FY 97 MCON PROJECT P-706 CHANNEL DREDGING BEACH SAND TRANSPORT AND SEDIMENTATION REPORT PHASE I: SOUTH OCEANSIDE AND SOLANA BEACH SO-19. From Foster St. looking north - Approx. Tide = 1.33 m SO-20. From Foster St. cul-de-sac looking west - Approx. Tide = 1.33 m 28 MARCH 1997 D-13 BEACH SAND TRANSPORT & SEDIMENTATION SOUTHWESNAVFACENGCOM FY 97 MCON PROJECT P-706 CHANNEL DREDGING BEACH SAND TRANSPORT AND SEDIMENTATION REPORT PHASE I: SOUTH OCEANSIDE AND SOLAN A BEACH SO-2I. Looking west along and on top of 90 cm city sewer outfall - Approx. Tide = 1.6 m SO-22. From 300 m south of Crosswaithe St. looking between rocks at house and vacant lot where 90 cm sewer outfall alignment occurs - Approx. Tide = 1.6 m 28 MARCH 1997 D-14 BEACH SAND TRANSPORT & SEDIMENTATION I I I I I I I I I I I I I I I I I I I 1 I I I I I I I I I I I I I I I SOUTHWESNAVFACENGCOM FY 97 MCON PROJECT P-706 CHANNEL DREDGING BEACH SAND TRANSPORT AND SEDIMENTATION REPORT PHASE I: SOUTH OCEANSIDE AND SOLAN A BEACH SO-23. From Witherby St. looking south - Approx. Tide = 1.51 m • •.-••***S- '-'- - - -*—- SO-23 A. From Morse St. looking south - Approx. Tide = 1.55 m 28 MARCH 1997 D-I5 BEACH SAND TRANSPORT & SEDIMENTATION SOUTHWESNAVFACENGCOM FY 97 MCON PROJECT P-706 CHANNEL DREDGING BEACH SAND TRANSPORT AND SEDIMENTATION REPORT PHASE I: SOUTH OCEANSIDE AND SOLANA BEACH SO-24. From Witherby St. looking north - Approx. Tide = 1.51 m SO-25. Looking south from 90 cm sewer outfall looking at private "stairs" above sand - Approx. Tide = 1.39 m 28 MARCH 1997 D-I6 BEACH SAND TRANSPORT & SEDIMENTATION I I I I I I I I I I I I I I I SOUTHWESNAVFACENGCOM FY 97 MCON PROJECT P-7G6 CHANNEL DREDGING BEACH SAND TRANSPORT AND SEDIMENTATION REPORT PHASE I: SOUTH OCEANSIDE AND SOLANA BEACH SO-25A. Looking west along Lorna Alta Creek at Buccaneer Beach - Approx. Tide = 1.51 m SO-25B. From Loma Alta Creek looking north - Approx. Tide = 1.51 m 28 MARCH 1997 D-17 BEACH SAND TRANSPORT & SEDIMENTATION SOUTHWESNAVFACENGCOM FY 97 MCON PROJECT P-706 CHANNEL DREDGING BEACH SAND TRANSPORT AND SEDIMENTATION REPORT PHASE I: SOUTH OCEANSIDE AND SOL ANA BEACH SO-25C From LomaAltaCreek looking south - Approx. Tide- 1.51 m 28 MARCH 1997 D-l BEACH SAND TRANSPORT & SEDIMENTATION I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I SOUTHWESNAVFACENGCOM FY 97 MCON PROJECT P-706 CHANNEL DREDGING BEACH SAND TRANSPORT AND SEDIMENTATION REPORT PHASE I: SOUTH OCEANSIDE AND SOL AN A BEACH SB-26. From west end of Solana Vista Dr. looking north- Approx. Tide = 0.82 m " SB-26A. From Plaza St. looking north - Approx. Tide = 0.91 m 28 MARCH 1997 D-!9 BEACH SAND TRANSPORT & SEDIMENTATION SOUTHWESNAVFACENGCOM FY 97 MCON PROJECT P-706 CHANNEL DREDGING BEACH SAND TRANSPORT AND SEDIMENTATION REPORT PHASE I: SOUTH OCEANSIDE AND SOLANA BEACH SB-27. From west end of Solana Vista Dr. looking south - Approx. Tide = 0.82 m SB-27A. From Plaza St. looking south - Approx. Tide = 0.91 m 28 MARCH 1997 D-20 BEACH SAND TRANSPORT & SEDIMENTATION I I I I I I I I I I I I I I SOUTHWESNAVFACENGCOM FY 97 MCON PROJECT P-7G6 CHANNEL DREDGING BEACH SAND TRANSPORT AND SEDIMENTATION REPORT PHASE I: SOUTH OCEANSIDE AND SOLANA BEACH SB-28. From Cardiff State Beach parking lot looking north - Approx. Tide = 0.64 rn f3&~.-m?^&•-'•- *^**^- SB-29. From Cardiff State Beach parking lot looking south - Approx. Tide = 0.64 m 28 MARCH S997 D-21 BEACH SAND TRANSPORT & SEDIMENTATION SOUTHWESNAVFACENGCOM FY 97 MCON PROJECT P-706 CHANNEL DREDGING BEACH SAND TRANSPORT AND SEDIMENTATION REPORT PHASE I: SOUTH OCEANSIDE AND SOLANA BEACH SB-30. From San Elijo Lagoon inlet looking north - Approx. Tide = 0.64 m SB-31. From San Elijo Lagoon inlet looking south - Approx. Tide = 0.64 m 28 MARCH 1997 D-22 BEACH SAND TRANSPORT & SEDIMENTATION I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I SOUTHWESNAVFACENGCOM FY 97 MCON PROJECT P-706 CHANNEL DREDGING BEACH SAND TRANSPORT AND SEDIMENTATION REPORT PHASE I: SOUTH OCEANSIDE AND SOLANA BEACH SB-32. From San Elijo Lagoon inlet looking west - Approx. Tide = 0.57 m SB-33. Looking east towards bridge over inlet of San Elijo Lagoon - Approx. Tide = 0.57 m 28 MARCH E997 D-23 BEACH SAND TRANSPORT & SEDIMENTATION SOUTHWESNAVFACENGCOM FY 97 MCON PROJECT P-706 CHANNEL DREDGING BEACH SAND TRANSPORT .AND SEDIMENTATION REPORT PHASE I: SOUTH OCEANSIDE AND SOLANA BEACH ^'i*-*-'''--i. ,V'"- "~-r - •'...;;•." ':'-.'.;.-—T^r ~r*.~;;'-'~.-^jr "'i*' " .•.•-.•-•" ."•- SB-34. From beach parking lots between Cardiff & San Elijo looking south - Approx. Tide = 0.57 m SB-35. From parking lots between Cardiff & San Elijo looking north - Approx. Tide = 0.55 m 28 MARCH 1997 D-24 BEACH SAND TRANSPORT & SEDIMENTATION I I I I I I I I 1 I I I I I I I 1 I I I I I I I I I I I I I I I I ' .•' - SOUTHWESNAVFACENGCOM FV 97 MCON PROJECT P-706 CHANNEL DREDGING BEACH SAND TRANSPORT AND SEDIMENTATION REPORT PHASE I: SOUTH OCEANSIDE AND SOLANA BEACH SB-36. From parking lot for restaurants between Cardiff & San Elijo looking north - Approx. Tide = 0.45m SB-37. From parking lot for restaurants between Cardiff & San Elijo looking south Approx. Tide = 0.45m 28 MARCH 1997 BEACH SAND TRANSPORT & SEDIMENTATION SOUTHWESNAVFACENGCOM FY 97 MCON PROJECT P-706 CHANNEL DREDGING BEACH SAND TRANSPORT AND SEDIMENTATION REPORT PHASE I: SOUTH OCEANSIDE AND SOLANA BEACH SB-38. From south end of Cardiff State Beach parking lot looking south towards tide pools Approx. Tide = 0.36m I I I I I I 1 I i i i SB-39. Looking south at concrete sea wall south of Cardiff State Beach parking lot - Approx. Tide = 0.33 m 28 MARCH !997 D-26 BEACH SAND TRANSPORT & SEDIMENTATION I I I I I I I I I I I I I I I SOUTHWESNAVFACENGCOM FY 97 MCON PROJECT P-706 CHANNEL DREDGING BEACH SAND TRANSPORT AND SEDIMENTATION REPORT PHASE I: SOUTH OCEANSIDE AND SOLAN A BEACH SB-40. From 30-60 m south of south end of Cardiff State Beach parking lot looking south at southern end of Approx. Tide pools - Approx. Tide - 0.33 m SB-41. From 30-60 m south of south end of Cardiff State Beach parking lot looking north at north end of Approx. Tide pools - Approx. Tide = 0.33 m 28 MARCH 1997 BEACH SAND TRANSPORT & SEDIMENTATION SOUTHWESNAVFACENGCOM FY 97 MCON PROJECT P-706 CHANNEL DREDGING BEACH SAND TRANSPORT AND SEDIMENTATION REPORT PHASE I: SOUTH OCEANSIDE AND SOLANA BEACH SB-42. From west end of Solana Vista Dr. looking south towards 40 cm cmp down drain & weep holes in sandbag slope retaining wail - Approx. Tide = 0.27 m SB-43. From south end of Cardiff State Beach parking lot looking south - Approx. Tide = 0.13 m 28 MARCH 1997 D-2S BEACH SAND TRANSPORT & SEDIMENTATION I I I I I I I 1 I I I I I I I I I I 1 1 I I I SOUTHWESNAVFACENGCOM FY 97 MCON PROJECT P-706 CHANNEL DREDGING BEACH SAND TRANSPORT AND SEDIMENTATION REPORT PHASE I: SOUTH OCEANSIDE AND SOLANA BEACH SB-44. From south of stairs at west end of Solana Vista Dr. looking south Approx. Tide = 0.06 m "v^""r--"-^Tv r-/.^'•w-^—.:"Jg^j-_J^.:L',-, Z "•* SB-44A. From Clark St. looking north - Approx. Tide = 0.33 m 28 MARCH 1997 D-29 BEACH SAND TRANSPORT & SEDIMENTATION SOUTHWESNAVFACENGCOM FY 97 MCON PROJECT P-706 CHANNEL DREDGING BEACH SAND TRANSPORT AND SEDIMENTATION REPORT PHASE I: SOUTH OCEANSIDE AND SOLANA BEACH Approx. Tide = 0.06 m I I I I I I I 1 i I i i SB-45A. From Clark St. looking south - Approx. Tide = 0.33 m 28 MARCH 1997 D-30 BEACH SAND TRANSPORT & SEDIMENTATION I I I I I SOUTHWESNAVFACENGCOM I I I I I I I FY 97 MCON PROJECT P-706 CHANNEL DREDGING BEACH SAND TRANSPORT AND SEDIMENTATION REPORT PHASE I: SOUTH OCEANSIDE AND SOLANA BEACH SB-46, From west end of Plaza St. looking at existing 80 cm dia. rep storm drain outlet, new 130 cm dia. rep under construction to left of ramp - Approx. Tide = 1.3 m SB-47. From west end of Plaza St. looking down ramp for public access - Approx. Tide = 1.24 m 28 MARCH 1997 D-31 BEACH SAND TRANSPORT & SEDIMENTATION SOUTHWESNAVFACENGCOM FY 97 MCON PROJECT P-706 CHANNEL DREDGING BEACH SAND TRANSPORT AND SEDIMENTATION REPORT PHASE I: SOUTH OCEANSIDE AND SOLAN A BEACH 53-48. From west end of Plaza St. !ooking south from bottom of public access concrete ramp Approx. Tide = 1.24 m SB-49. From west end of Plaza St. looking north at site of 130 cm storm drain rep ocean outfall under construction - Approx. Tide = 1.18m 2S MARCH 1997 D-32 BEACH SAND TRANSPORT & SEDIMENTATION I I I I I I I I I I I M SOUTHWESNAVFACENGCOM FY 97 MCON PROJECT P-706 CHANNEL DREDGING BEACH SAND TRANSPORT AND SEDIMENTATION REPORT PHASE I: SOUTH OCEANSIDE AND SOLANA BEACH SB-50. Looking south at new 130 cm dia. rep storm drain outfall under construction Approx. Tide = 0.91 m iZr^^ij**-'^1-*'"^ •"""'•**9t'v~iT^I "- -v-.'*"" l-._u-;;:,'*4-s3 ••«"---*' -V - ?i^*3$p%r=%a+i -~:.-.' - -^ . -V-~- •^HJ.^J-^.^ ,-r^ - .',' ^'^,—., "--^ - --, . " ^^"* •-i_^ "^ -'^fc">"' - " ~ , ^5*»&iWy SB-51. From 30 m south of public access ramp on west end of Plaza St. looking north towards 130 cm rep storm drain outfall - Approx. Tide = 0.91 m 28 MARCH !997 D-33 BEACH SAND TRANSPORT & SEDIMENTATION SOUTHWESNAVFACENGCOM FY 97 MCON PROJECT P-706 CHANNEL DREDGING BEACH SAND TRANSPORT AND SEDIMENTATION REPORT PHASE i: SOUTH OCEANSIDE AND SOLANA BEACH SB-52. From 30 m south of public access ramp on west end of Plaza St. looking south towards shore - Approx. Tide = 0.93 m I I I I I 1 I I I 1 i I i SB-53. Looking east at range marker locating alignment of Cardiff Sanitation District Outfall - Approx. Tide = 1.42 m ft 28 MARCH 1997 BEACH SAND TRANSPORT & SEDIMENTATION SOUTHWESNAVFACENGCOM FY 97 MCON PROJECT P-706 CHANNEL DREDGING BEACH SAND TRANSPORT AND SEDIMENTATION REPORT PHASE I: SOUTH OCEANSIDE AND SOLANA BEACH PHOTOGRAPH LEGEND SO - South Oceanside Beach Fill Site SB - Solatia Beach Fill Site All So and SB photographs taken on 11 March 97, except as follows: SO: 1 A, 2A, 9A, 10A, 23A taken on 22 January 96 SB: 26A, 27A, 44A, 45A taken on 23 January 96 All tide elevations are referenced to Mean Lower Low Water (MLLW). 28 MARCH 1997 D-35 BEACH SAND TRANSPORT & SEDIMENTATION APPENDIX E DREDGE AREA AND BEACH GRAIN SIZE DATA REACH 1 Boring Number 19 VC-31 TH 86-1 TH 86-2 TH 86-3 TH 86-4 TH 86-5 TH 86-6 TH 86-7 TH 86-8 TH 86-9 TH 86-10 TH 86-1 1 TH86-12 TH86-14 TH86-15 TH86-16 TH86-17 TH86-18 TH 86-19 TH 86-20 TH 86-21 TH 86-22 TH 86-23 TH 86-24 20 21 22 VC-36 VC-36 VC-37 23 VC-38 VC-38 VC-39 P-53C P-57G P-65C P-66C P-67C P-68C P-71G P-74C P-75C P-76C P-77G P-78G P-79C P-80G P-81G P-82G P-83G P-84G P-85G Median Average U.S. Standard Sieve #/ Particle Size (mm) 7 2.800 96 95 100 100 100 100 100 100 100 100 100 100 100 93 98 100 100 100 98 99 98 100 98 100 99 100 98 100 100 100 95 100 99 99 100 100 88 100 100 100 100 100 100 100 100 100 100 100 100 99 94 84 84 98 100.0 98.4 10 2.000 95.3 93 100 100 100 100 100 100 100 100 100 100 100 92 98 100 100 100 97 99 98 100 98 100 99 99.8 98 99.8 100 100 94.6 99.7 97.9 98.7 100 99 84 100 100 100 100 100 100 100 100 100 100 100 100 99 90 82 82 95 100.0 97.9 18 1.000 92.9 90 100 99 99 99 100 100 100 100 100 100 100 90 98 100 100 100 96 98 96 100 97 100 97 99.7 97.3 99.7 100 100 94.5 99.5 96 97.4 99.5 98 74 100 99 100 100 100 100 99 99 100 99 99 99 96 80 77 74 79 99.0 96.4 35 0.500 88.8 86 98 98 98 99 100 100 100 99 99 100 100 88 96 99 98 99 93 95 93 99 95 98 91 97.8 96 99.2 99.5 99.7 94 98.3 90 92 99 97 62 100 99 99 100 100 100 99 99 99 98 99 98 89 67 70 51 37 98.0 93.3 60 0.250 74.4 52.1 95 95 93 71 91 92 94 96 93 90 93 71 91 98 93 94 76 81 77 63 81 82 56 77.7 87.2 95.2 99.1 99.2 88 94 82 83.6 92.9 91 40 98 98 99 99 99 99 99 99 96 95 99 93 63 50 56 19 5 92.5 83.1 80 0.180 45 35 79 75 58 18 37 34 36 63 50 34 32 44 58 77 52 65 41 38 36 15 35 32 15 45 65 60 65 65 61 66 58 60 70 86 20 81 87 92 94 94 98 96 97 90 91 96 89 53 45 49 14 2 58.0 57.3 120 0.125 3.74 15 21 13 12 3 7 6 5 14 9 4 6 26 14 22 11 20 17 9 13 4 7 7 4 4.33 34.1 16.9 30 30 33 28.9 29 30 40 66 7 27 28 40 38 44 40 46 36 39 45 43 45 27 22 27 9 1 20.5 21.8 200 0.075 1.9 4.1 3 3 3 1 1 1 1 4 4 2 2 8 3 3 5 4 4 3 5 2 2 3 2 1.8 8 5 4.4 4.4 3.4 7 4.2 5.2 6.7 14 3 3 3 4 5 5 5 5 5 3 4 5 10 2 2 3 1 1 3.2 3.9 270 0.053 1.7 2.5 3 3 3 4 1 1 1 4 4 2 2 4 3 3 4 4 4 3 4 2 2 3 2 1.66 4.7 3.32 2.9 2.8 1.3 3.48 1.9 2.2 5.7 10 2 2 2 3 4 3 3 3 3 2 2 3 8 2 2 2 1 1 3.0 2.9 450 0.032 1.7 2 2 2 2 3 1 1 1 3 3 2 2 3 3 3 3 3 3 3 3 2 2 2 2 1.66 J3.34 3.32 2.4 2 1 3.48 1.8 2 5.5 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 2.0 1.6 635 0.020 1.7 1 2 2 2 3 0 0 0 3 3 1 1 2 2 2 3 3 3 2 3 1 1 2 1 1.66 3.34 3.32 2 1.8 1 3.48 1.6 2 5.5 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1.0 1.3 De (Ft) 6 1.97 2 5 3 3.5 3 4 4 4 pth <m) 1.83 0.6 0.61 1.52 0.91 1.07 0.91 1.22 1.22 1.22 6 J1.83 4 2 4.5 1.5 3 1.5 3 3 4.3 3 3 3 4 3.5 5 8 6 0.66 2.95 0.98 6 0.33 0.98 0.33 0 0 0 0 0 0 1.22 0.61 1.37 0.46 0.91 0.46 0.91 0.91 1.31 0.91 0.91 0.91 1.22 1.07 1.52 2.44 1.83 0.2 0.9 0.3 1.83 0.1 0.3 0.1 0 0 0 0 0 0 0 ; 0 0 0 0 0 0 0 0 0 0 0 0 0 2.0 2.2 0 0 0 0 0 0 0 0 0 0 0 0 0.6 0.7 Soil Class SP SP-SM SP SP SP SP SP SP SP SP SP SP-SC SP SP SP-SM SP SP SP SP-SC SP SP SP SP 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0.0 0.0 Elevation (Ft) -49.5 -48.9 -43.9 -45.9 -42.3 -33.3 -34.2 -35.7 -34.2 -44.2 -45 (m) -15.1 -14.9 -13.4 -14 -12.9 -10.1 -10.4 -10.9 -10.4 -13.5 -13.7 -40.5; -12.3 -37.5 -45 -41.5 -43.1 -41.5 -42 -41 -42.8 -43.4 -43.6 -38.2 -47 -47.5 -46.1 -50 -51.4 -49.2 -51.5 -48.6 -54.7 -51.2 -51.8 -52.8 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 -41.3 -28.9 -11.4 -13.7 -12.6 -13.1 -12.6 -12.8 -12.5 -13 -13.2 -13.3 -11.6 -14.3 -14.5 -14.1 -15.2 -15.7 -15 -15.7 -14.8 -16.7 -15.6 -15.8 -16.1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 -12.6 -8.8 Dredae Area #1 - Particle Size Distribution Curves zmuDClitQ. 1.00 0.10 PARTICLE SIZE (mm) 0.01 REACH 2 Boring Number P-32G P-33G VC-22 VC-22 P-35C B-12 P-36C P-37G P-38G P-40C 17 P-41G P-42G P-43G 18 P-45C P-46G P-47G P-48G P-49G P-50G P-51G P-52G Median Average U.S. Standard Sieve #/ Particle Size mm) 7 2.800 99 100 100 100 91 85.9 100 93 99 97 100 96 100 100 94 88 87 99 100 97 89 99 99 99.0 96.2 10 2.000 99 100 99.8 99.7 89 82.9 100 87 98 96 98 94 100 99 92.3 84 78 98 100 96 86 99 98 98.0 94.5 18 1.000 95 96 99 99 84 73 100 79 94 92 96.8 87 99 93 85.8 75 64 93 100 94 76 94 96 94.0 89.8 35 0.500 80 52 77 72 68 57.8 98 66 74 74 88.3 71 93 64 71.2 64 49 79 98 87 62 86 89 74.0 74.8 60 0.250 25 5 16.7 11.8 25 24.5 83 25 18 29 31.3 26 19 22 26.3 21 15 29 32 43 29 32 51 25.0 27.8 80 0.180 9 2 8 4 9 16.2 65 7 5 17 16 6 4 7 13 6 5 6 6 20 8 9 15 8.0 11.4 120 0.125 4 1 4 2 4 10.8 40 2 2 13 4.76 2 1 3 1.96 2 2 2 2 11 2 3 4 2.0 5.4 200 0.075 3 1 1.7 1.4 2 6.9 24 1 2 10 4.65 1 1 1 1.69 1 1 1 1 2 1 1 2 1.4 3.1 270 0.053 3 1 1 1 2 5.4 22 1 2 10 4.3 1 1 1 1.63 1 1 1 1 1 1 1 2 1.0 2.9 450 0.032 0 0 1 1 0 4.4 0 0 0 0 3.07 0 0 0 1.63 0 0 0 0 0 0 0 0 0.0 0.5 635 0.020 0 0 1 1 0 4 0 0 0 0 3.07 0 0 0 1.63 0 0 0 0 0 0 0 0 0.0 0.5 Depth (Ft) 0 0 0.33 4.59 0 0 0 0 0 0 6 0 0 0 4 0 0 0 0 0 0 0 0 0.0 0.6 (m) 0 0 0.1 1.4 0 0 0 0 0 0 1.83 0 0 0 1.22 0 0 0 0 0 0 0 0 0.0 0.2 Soil Class Elevation (Ft) 0 0 -44 -48.2 0 -44 0 0 0 0 -46.9 0 0 0 -47.7 0 0 0 0 0 0 0 0 0.0 -10.0 <m) 0 0 -13.4 -14.7 0 -13.4 0 0 0 0 -14.3 0 0 0 -14.5 0 0 0 0 0 0 0 0 0.0 -3.1 Dredae Area #2 - Particle Size Distribution Curves o 100 90 80 70 60 50 40 30 20 10 0 I— 10.00 1.00 0.10 PARTICLE SIZE (mm) 0.01 Sample Oceanside Carlsbad San Dieguito Del Mar Torrey Pines .a Jolla Bay Mission Beach OS- 1770 A OS-1770B OS-1770C OS-1770D OS-1770E OS-1770F OS-1000A OS-1000B OS-1000C OS-1000D OS-1000E OS-1000F OS-0930A OS-0930B OS-0930C OS-0930D OS-0930E OS-0930F CB-0820A CB-0820B CB-0820C CB-0820D CB-0820E CB-0820F CB-0720A CB-0720B CB-0720C CB-0720D SD-0630A SD-0630B DM-0580A DM-0580B DM-0580C DM-0580D DM-0580E TP-0520A TP-0520B TP-0520C TP-0520D LJ-0460A LJ-0460B LJ-0460C LJ-0460D PB-0408A PB-0408B PB-0408C PB-0408D PB-0408E JPB-0408F mperial Beach OB-0230A OB-0230B OB-0230C OB-0230D SS-0035A SS-0035B SS-0035C SS-0035D Median Median U.S. Standard Sieve #/ Particle Size (mm) 7 2.800 100.00 100.00 100.00 100.00 100.00 100.00 100.00 100.00 100.00 100.00 100.00 100.00 100.00 100.00 100.00 100.00 100.00 100.00 100.00 100.00 100.00 100.00 100.00 100.00 100.00 100.00 100.00 100.00 100.00 100.00 100.00 100.00 100.00 100.00 100.00 100.00 100.00 100.00 100.00 100.00 100.00 100.00 100.00 100.00 100.00 100.00 100.00 100.00 100.00 100.00 100.00 100.00 100.00 100.00 100.00 100.00 100.00 100.00 10 2.000 100.00 100.00 100.00 99.00 100.00 100.00 100.00 100.00 100.00 100.00 100.00 100.00 100.00 100.00 100.00 100.00 100.00 100.00 100.00 100.00 100.00 100.00 100.00 100.00 100.00 100.00 100.00 100.00 100.00 100.00 100.00 100.00 100.00 100.00 100.00 100.00 100.00 100.00 100.00 99.00 100.00 100.00 100.00 100.00 100.00 100.00 100.00 100.00 100.00 100.00 100.00 100.00 100.00 100.00 100.00 100.00 100.00 100.00 18 1.000 98.00 100.00 100.00 97.00 100.00 100.00 99.00 100.00 100.00 99.00 97.00 100.00 100.00 97.00 95.00 99.00 98.00 100.00 97.00 100.00 100.00 100.00 100.00 100.00 100.00 97.00 100.00 100.00 100.00 100.00 98.00 99.00 100.00 100.00 100.00 100.00 100.00 100.00 98.00 98.00 97.00 100.00 100.00 100.00 100.00 100.00 100.00 100.00 100.00 100.00 100.00 100.00 100.00 97.00 100.00 98.00 100.00 100.00 25 0.710 97.00 100.00 99.00 96.00 100.00 100.00 97.00 100.00 100.00 98.00 96.00 100.00 98.00 95.00 89.00 98.00 97.00 100.00 70.00 99.00 99.00 98.00 98.00 100.00 100.00 97.00 100.00 100.00 98.00 98.00 97.00 100.00 100.00 100.00 100.00 100.00 100.00 100.00 100.00 98.00 100.00 100.00 100.00 100.00 100.00 100.00 100.00 100.00 100.00 100.00 100.00 100.00 100.00 94.00 100.00 98.00 100.00 100.00 35 0.500 97.00 98.00 95.00 95.00 100.00 100.00 95.00 100.00 99.00 97.00 95.00 100.00 97.00 91.00 86.00 97.00 97.00 100.00 55.00 98.00 98.00 98.00 97.00 100.00 100.00 97.00 100.00 99.00 97.00 98.00 97.00 100.00 97.00 97.00 99.00 100.00 100.00 100.00 100.00 98.00 97.00 96.00 100.00 99.00 100.00 98.00 100.00 99.00 98.00 99.00 97.00 98.00 99.00 65.00 98.00 98.00 98.00 98.00 45 0.355 95.00 95.00 78.00 90.00 99.00 98.00 75.00 98.00 98.00 97.00 93.00 99.00 94.00 84.00 85.00 95.00 96.00 98.00 35.00 95.00 95.00 97.00 95.00 97.00 99.00 90.00 98.00 98.00 90.00 91.00 95.00 99.00 96.00 96.00 96.00 98.00 99.00 99.00 99.00 97.00 96.00 96.00 100.00 97.00 97.00 96.00 98.00 98.00 97.00 95.00 91.00 97.00 97.00 52.00 96.00 96.00 98.00 97.00 60 0.250 72.00 70.00 38.00 78.00 98.00 97.00 33.00 95.00 87.00 88.00 88.00 97.00 55.00 67.00 81.00 87.00 91.00 97.00 16.00 45.00 71.00 96.00 82.00 90.00 84.00 68.00 85.00 93.00 60.00 69.00 72.00 97.00 84.00 84.00 83.00 94.00 97.00 96.00 96.00 95.00 72.00 90.00 100.00 75.00 84.00 76.00 95.00 78.00 89.00 50.00 80.00 90.00 95.00 25.00 75.00 85.00 97.00 84.00 80 0.180 30.00 25.00 14.00 58.00 96.00 92.00 7.00 62.00 67.00 55.00 70.00 94.00 16.00 30.00 65.00 75.00 75.00 86.00 7.00 10.00 31.00 80.00 55.00 80.00 27.00 41.00 64.00 57.00 23.00 45.00 30.00 70.00 50.00 51.00 52.00 53.00 66.00 72.00 82.00 61.00 42.00 70.00 90.00 33.00 57.00 51.00 72.00 53.00 73.00 10.00 60.00 77.00 84.00 9.00 31.00 53.00 92.00 53.00 120 0.125 10.00 7.00 3.00 30.00 85.00 70.00 3.00 18.00 18.00 21.00 60.00 73.00 3.00 5.00 35.00 50.00 50.00 60.00 2.00 2.00 10.00 44.00 27.00 50.00 4.00 14.00 30.00 30.00 7.00 25.00 10.00 30.00 20.00 25.00 26.00 16.00 22.00 25.00 50.00 21.00 10.00 37.00 67.00 5.00 23.00 16.00 30.00 29.00 47.00 2.00 30.00 61.00 61.00 2.00 7.00 21.00 72.00 25.00 170 0.090 2.00 1.00 0.00 11.00 31.00 35.00 0.00 2.00 3.00 3.00 30.00 16.00 0.00 0.00 10.00 13.00 16.00 28.00 0.00 0.00 2.00 7.00 10.00 21.00 0.00 3.00 10.00 5.00 0.00 10.00 3.00 3.00 2.00 10.00 9.00 2.00 1.00 5.00 10.00 2.00 2.00 11.00 17.00 0.00 6.00 2.00 2.00 12.00 13.00 0.00 5.00 20.00 21.00 0.00 1.00 3.00 40.00 3.00 200 0.075 0.00 0.00 0.00 2.00 17.00 9.00 0.00 0.00 0.00 0.00 16.00 7.00 0.00 0.00 0.00 5.00 5.00 6.00 0.00 0.00 0.00 2.00 2.00 7.00 0.00 1.00 3.00 0.00 0.00 3.00 0.00 0.00 0.00 2.00 4.00 0.00 0.00 0.00 3.00 0.00 1.00 2.00 5.00 0.00 0.00 0.00 0.00 4.00 8.00 0.00 0.00 4.00 7.00 0.00 0.00 0.00 18.00 0.00 Dep (m) 2.1 1.0 0.0 -1.0 -3.0 -6.0 2.1 1.0 0.0 -1.0 -3.0 -6.0 3.0 1.0 0.0 -1.0 -3.0 -6.0 3.0 1.0 0.0 -1.0 -3.0 -6.0 3.0 0.0 -3.0 -6.0 -3.0 -6.0 1.0 0.0 -1.0 -3.0 -6.0 3.0 0.0 -3.0 -6.0 2.0 0.0 -3.0 -6.0 3.0 1.0 0.0 -1.0 -3.0 -6.0 3.0 0.0 -3.0 -6.0 3.0 0.0 -3.0 -6.0 -1.0 All Data per CCSTWS, 83-84 Sediment Sampling Dana Point to Mexican Border Oceanside - Particle Size Distribution Curves 0.01 - -D- - OS-1770A _ <>_ OS-1770B - -£r - OS-1770C —X- OS-1770D —X- - OS-1770E — OS-1770F! : —— - OS-1000A j — O- OS-1000B i | - H- - OS-1000C : — •- OS-1000D - -*- - OS-1000E —A- OS-1000F —•- - OS-0930A :—Q- OS-0930B • - -o- ~ OS-093DC - -a - OS-0930D ! - -X - OS-0930E ! — X- OS-0930F I ' ' "Median Carlsbad Beach-Particle Size Distribution Curves Solana-Encinitas Beach - Particle Size Distribution Curves PARTICLE SIZE (mm) - -O- -SD-0630A -<• SD-0630B A -DM-0580A -X- -DM-0580B —X- -DM-0580C DM-0580D - DM-0580E Medan " • • Average 100 Torrey Pines Beach - Particle Size Distribution Curves 0.01 rTP-0520A -TP-0520B •A- -TP-0520C —X- -TP-0520D •Median • • " Average La Jolla - Particle Size Distribution Curves 100 10 10.00 1.00 -Q- - LJ-0460A O- LJ-D460B A- - LJ-0460C X - LJ-0460D PARTICLE SIZE (mm) Mission Beach • Particle Size Distribution Curves 100 20 10 10-00 1.00 0.01 PB-0408A O- PB-0408B -A- - PB-0408C -X- PB-0408D —X- - PB-0408E __- PB-0408F - OB-0230A ; — O- OB-0230B - OB-0230C — •- OB-0230D •Median PARTICLE SIZE (mm) Imperial Beach - Particle Size Distribution Curves 10 1.00 0.10 PARTICLE SIZE (mm) - -O- - SS-0035A — O- SS-0035B - -i - SS-0035C i—X- SS-0035D APPENDIX F EVERTS COASTAL TECHNICAL MEMORANDUM RECEIVEDEVERTS COASTAL CONSULTING IN SHORELINE PRESERVATION AND SEDIMENTATION IN COASTAL WATERS MAR 5* fi 1QQ7 3802 Stevely Avenue R Y Long Beach, CA 90808 ° * phone (310) 425-2377 fax (as above, please call first) email: 70663,572@CompuServe.com 24 March 1997 Mr. Kevin Pierce Frederic R. Harris, Inc. 222 West Sixth Street, Suite 950 San Pedro, CA 90731 Subject: Solana Beach, Cardiff-by-the-Sea, and Oceanside beach enhancements; revised comments (EC 97004). Dear Mr. Pierce: This letter is a revision of the five technical topics I discussed in a 15 March 1997 letter report. The subject of that letter was the proposed US Navy beachfill projects at the subject sites. 1. Objectives and Project Benefits. The main objectives of these enhancement projects is to provide a larger recreational beach and increased protection against the forces of breaking waves at the backbeach line. Beach enhancement also reduces the probability of marine related flooding. Recreational potential is a function of mean beach width; protective capacity is a function of the sediment volume, placement profile, and type of material in the beach above mean sea level prior to a storm. 2. Beachfill Considerations. Important considerations in a beach enhancement project are: (1) to maximize recreational potential, meaning the area of new dry beach that is created, (2) to maximize the protective capacity of the enhanced beach, primarily the volume of sediment above msl during the storm season that can be anticipated from approximately November through April, (3) to reduce post-enhancement beachfill losses to a minimum, and (4) to reduce adverse impacts to a minimum. Options in San Diego County are constrained by the SANDAG-specified volumes to be placed, the designated sites where the material is scheduled to be placed, and the character of the beachfill that is being made available. 3. Maximize Benefits and Minimize Losses. Trade-offs must be made in the design process because ail potential benefits of an enhanced beach cannot be optimized. Recreational potential is maximized when the design berm is low. The most recreational area per unit volume of beachfill is initially provided in this situation. A low beach, however, may suffer slightly for at least two reasons. First, for a specified length, a low enhanced beach of fixed volume will project further offshore than a high beach. Compared to a higher berm elevation, this could result in a somewhat amplified beachfill spreading rate. The comparative difference in the rates could be quantified using a methodology such as the Corps of Engineers' GENESIS one-line model. The second problem may be nuisance ponding behind an accretional berm that forms at the seaward edge of the low beach. For the same specified length, a high berm will probably provide more protection against flooding. The amount placed at the back of the beach may last longer as well, and consequently provide protection against property damage caused by breaking waves for a somewhat longer period. A trade-off between optimizing the recreational and protective benefits would be to place the beachfill at the natural berm elevations shown in Table 1. Table 1. Natural berm elevations, Oceanside Littoral Cell* Location Solana Beach Cardiff-by-the-Sea Oceanside Berm Elevation, meters above mean sea level 2.8 2.8 3.4 Remarks Fletchers Cove south end near restaurants south part of city * from "Sediment Budget Report, Oceanside Littoral Cell" Corps of Engineers Report No. CCSTWS 90-2, Nov 92 (ref is USACE-LAD, 1992). Natural sandy beach berms tend to be nearly horizontal. This is also a realistic situation for artificially-created berms as well. It is not too important to expend a great deal of effort in designing and constructing a superior seaward slope for the placed beachfill. Waves and wave runup will soon rework the material and shape it to a slope that is more in equilibrium with nature. A steep placement slope should be avoided for recreational-user safety reasons. The 20:1 (run/rise) slopes you intend to use is reasonable. A 10:1 slope is near or milder than the natural slope of the foreshore and is not unrealistic if practical, beneficial to the contractor, and conducive to the construction of the berm. Scarping is also a consideration in the designation of a placement slope, with scarps more likely to form and more likely to be higher when the slope is steep than when it is mild. If the beachfill is similar in size distribution to the native material on the foreshore, the probability of a scarp forming in the placed material at a 10:1 slope will probably only be increased over that ofthepre-fill slope (where a berm is present) because the beachfill bulk density is lower, i.e., the deposit is not as densely packed as it would be if it was formed by wave action. Most losses of beachfill occur as a result of shore-parallel transport. Shore-normal losses from the littoral sediment lens are typically much smaller on long beaches, such as those under consideration. The littoral sediment lens is the active body of coastal sediment within which a change in mean beach width is proportional to a change in sediment volume. The upper limit of the lens is the backbeach line; the lower limit is the shorebase or the so-called "pinch-out" depth. The pinch-out location is at the seaward limit of reversible seasonal sediment transport in the littoral sediment lens. Post-placement spreading, or alongshore, losses from the project sites are going to be difficult to forecast. Yet, at each of the sites this irreversible loss is likely to be significant from the perspective of lost dry beach per unit time. Beachfill spreading losses will likely be greater than pre-fill losses of native material. The largest project-life cost of a deterministic beach enhancement (the subject Oceanside Cell enhancements are opportunistic) is often associated with the periodic nourishments required to maintain the design mean beach width and volume as the beachfill spreads from the project site. All else being equal, long and narrow enhanced beaches lose sediment at a lower rate by spreading than short, wide enhanced beaches of the same artificial volume. The alongshore ends of the beach should be tapered to avoid a rapid spreading away from the sharp corners. 4. Possible Adverse Impacts. Adverse impacts, if they occur, will be caused by beachfill that creates a hazard on the project site, or migrates out of the project area, either in an alongshore or offshore direction, resulting in adverse impacts outside the limits of the beachfill. On-site hazards are probably limited to scarps that form following a period of erosion. The creation of a scarp cannot be avoided, but by placing the beachfill on a 20:1 (run/rise) or even a 10:1 slope, the height of the scarp can be limited. A scarp usually forms above about msl. For a given amount of sediment eroded, the scarp height will be inversely proportional to the slope above that elevation. In most cases, the foreshore on an enhanced beach equilibrates within a year or two, so the formation of abnormally high scarps associated with the project should be limited to that time interval. Adverse impacts caused by shore-normal transport could occur if there is silt and mud- sized material in the beachfill and it reaches habitat that might suffer if covered. Silt and mud will pass across the shorebase at the depths shown in Table 2. The quantity of fines expelled from the beachfill as it is reworked will be proportional to the difference between the percent of fines (< 0.062 mm diameter) in the beachfill and the percent fines in the littoral sediment lens. Thus, if the composite size distribution by volume in the natural lens is 5% less than in the beachfill, and 300,000 cubic meters (cum) of beachfill are placed, less than 15,000 cum of fines will be released in 1 or 2 years. In a severe storm event, when the most will be released, one might expect a 10 to 20% mobilization, or 1500 to 3000 cum (a severe storm will temporarily erode perhaps 50-100 cum/m of beach material above msl). This estimated single event release of beachfill fines to the continental shelf is an order of magnitude less than the quantity of suspended solids discharged from some of the larger watersheds in coastal San Diego County during high flow events. Most investigators estimate 80-90% of the material discharged in San Diego streams is wash load, or suspended material. It is worthwhile noting silt and mud-sized material is in transit across the shorebase and the continental shelf at all times under natural conditions. The sources of these fines are uplands with the material transported in streams that discharge directly across the littoral zone, lagoons that only pass suspended upland material during high flow events, lagoons that discharge organic material that originates within them, and seacliff-source material that is mobilized during wave storms. Uplands are the largest contributor and the fines are most likely to reach the littoral zone at lagoon mouths. Currents that move this silt and mud tend to distribute it over the entire continental shelf. Table 2. Depth of shorebase*. Location Soiana Beach Cardiff-by-the-Sea Qceanside Depth of Shorebase, meters below mean sea level 9 9 8.5 Remarks very little sand in littoral sediment lens very little sand in ] illo ral sediment lens greater amount of sand in littoral sediment lens * from "Sediment Budget Report, Oceanside Littoral Cell" Corps of Engineers Report No. CCSTWS 90-2, Nov 92 (ref is USACE-LAD, 1992). Beachfill sand may cause adverse impacts if rocky substrate is exposed landward of the shorebase. The amount of sand cover that results could be large, depending on the depth of the substrate and the amount of beachfill placed per unit length of shoreline. A calculation can be made to estimate the cover thickness if those variables are provided. A potential adverse impact you mentioned is the plugging of storm sewer outlets. If the outfalls are above the planned berm elevation there should be little problem. The natural berm elevation is the upper limit of runup-caused deposition on the foreshore under normal conditions. If the outlet is below the natural berm elevation, it could be plugged if wave runup reaches it. Adverse impacts caused by spreading will vary from one location to another. There is considerable previous experience to draw upon concerning the shoaling or closure of lagoons and shoaling in the Oceanside Harbor entrance caused by the longshore movement of beachfill. Consider comparing the volume of sediment placed in previous projects and the documented impacts versus the amount the Navy is planning to place. In the past, Oceanside Harbor has been impacted by sand delivered to the proposed south Oceanside placement area. Some moved north into the lee of the south jetty at the harbor and subsequently into the harbor entrance. A portion of the proposed Oceanside beachfill will likely do the same. However, since there is precedent for this impact, I doubt it will be a problem. At least for the Corps of Engineers, the responsible party for most of the historical placements in south Oceanside, it should not be a problem. Beachfill placed at Oceanside will also spread to the south. This southward movement will reach the outlet of Buena Vista Lagoon and possibly and Agua Hedionda Lagoon. The increased amount passing into Agua Hedionda will be a function of the distance the shoreline is advanced out along the north jetty due to project beachfill. Since the advance of the beach declines proportional to distance from the placement site, the amount that will enter Agua Hedionda Lagoon will probably be slight. Buena Vista Lagoon could be affected to a greater extent because of its proximity to the placement site. Longshore spreading from the south Cardiff site and Fletchers Cove should not greatly exacerbate problems at either the entrance to San Elijo or Penasquitos Lagoons. These are natural features that open and close depending on: (I) the freshwater flows from their respective watersheds, (2) the width of the beach at their outlets, (3) the daily longshore sediment transport rate and the tide range. Optimum conditions for closure are no freshwater flow, a wide beach, and high longshore sediment transport at the time of neap tide (neap tide because then the tidal prism to counter the closure effect of the material moving along the foreshore is a minimum). As project beachfill spreads, the beaches at these lagoons will widen somewhat, but probably not a great deal. The other variables are more important controls on the closure process than an expected increase in mean beach width due to the proposed projects. Should either of these lagoons close it would not be difficult to open it. It is routinely done to release freshwater that has ponded during the winter rainy season. 5. Realistic Expectations of Beachfill Behavior. The enhanced beaches will be wider at the time sediment is placed than after the beachfill has been reworked. The establishment of a dynamic equilibrium profile will be at the expense of sediment from the upper part of the littoral sediment lens. The mean width of the enhanced beach will decline over a longer time interval as the beachfill spreads laterally. Beachfill reworking results in the establishment of a dynamic equilibrium profile as sediment is transported in an offshore direction. As previously noted, this typically occurs in one or two years. The resulting profile should be thought of as the design profile when forecasting the mean enhanced width because the displaced beachfill remains within the limits of the project. The mean width of the adjusted beach can be estimated by adding the mean width of the added effective beachfill to the mean width of the existing natural beach. The beachfill addition to the mean width may be estimated by subtracting the beachfill fraction that will not contribute to a wider beach and then adjusting the remaining beachfill volume to a dynamic equilibrium profile shape. Silt and mud, if present in the beachfill in a greater proportion than in the native littoral sediment lens, will likely move offshore beyond the shoreface in the 1 to 2-year equilibrating period. In almost all situations where sediment is obtained from deep sites, such as an estuary channel, there is a small or not so small component of silt and mud- sized material in it. Some of these fines will be carried seaward when the fill deposit is reworked. The result will be a net loss to the littoral sediment lens. Almost all sediment in the littoral sediment lens in south Oceanside and in the Solana Beach and Cardiff areas is sand-sized or larger (USACE-LAD, 1990). A conservative approach would be to subtract the amount of beachfill with a diameter of less than 62 microns from the placement volume for equilibrium design beach width calculations. From the size distributions I saw in the office the other day, this will be about 5% of the total, thereby reducing the effective amount that will remain in the littoral sediment lens by that portion. Some fines may be lost between the San Diego Bay source area and the project beaches. In the late 1970's Richard Hobson researched this topic and published at least one paper in the CERC series on the percent fines lost in transfer. It is not unreasonable to be conservative and assume no transfer losses will occur. It is similarly not unreasonable, as a first approximation, to assume the shape of the dynamic equilibrium profile will be similar to the existing profile, only that will be displaced seaward a distance commensurate to the volume placed per unit length of beach (adjusted as described above for silt and mud fractions that will be lost). The displacement distance will be the incremental distance the mean width of the beach will be enhanced. An approximation of this mean width increase, Aw , is Vba hi which Vba= adjusted volume of beachfill placed at the site (such as volumes listed in preceding paragraph), / = length of project, hb = elevation of berm (Table 1), and zs = elevation of shorebase (Table 2). Analyses should consider the differing size distributions of the native beach sand and beachfill sediment. Beachfill fractions that are finer than the native fractions may cause the profile to equilibrate at a milder slope. Some of the fine sands may even be lost offshore the shorebase. Another expectation should be that the beachfill will spread along the coast north and south of the placement sites. This spreading results in a time-progressive net loss at the project site. The mean width of the enhanced beach will be progressively reduced as a result. As previously noted, in the absence of beach stabilization structures, long, narrow enhanced beaches tend to retain their beachfill longer than short, wide enhanced beaches because the planform disequilibrium imposed by the beachfill is greater in the latter situation. A longshore sediment transport analysis could be made to estimate the statistical probability of a given percentage of the beachfill being lost from a specific site in a specified time interval. I hope these comments help. Thank you for the opportunity to assist in this project. Sincerely, OASTAL APPENDIX G CORRESPONDENCE Inlet Maintenance in the Northern San Diego Region March 26,1997 Submitted by: San Diego Association of Governments General The opening of inlets in the San Diego region occurs under a U.S. Army Corps of Engineers general permit. San Luis Rev River Maintained by: City of Oceanside The City of Oceanside Streets Division maintains this inlet as needed for flood control. Loma Alta Creek Maintained by: City of Oceanside The City of Oceanside Streets Division clears silt east of the railroad tracks at the beginning of each flooding season (late fall/early winter), and continues to clear sediment as necessary throughout the rainy season. (Clearing occurs 1-3 times per season.) During the summer (Memorial Day through end of Sept.), the city pushes sand at the creek mouth inland, creating a berm and blocking creek drainage to the beach. Water is directed one block north to a sewer effluent out-flow pipe which pumps the discharge into the ocean one mile north of the creek. Buena Vista Lagoon Maintained by: City of Oceanside & City of Carlsbad The City of Oceanside has primary responsibility for the maintenance of this lagoon. The City of Carlsbad shares responsibility on a limited basis. (Provides access, is notified of activities.) The City of Oceanside maintains a weir blocking the lagoon's ocean outlet. The city excavates the eastern side of the lagoon to keep channels open for upstream flow. Excavation occurs 2-3 times per winter to ensure that the nearby residential area is protected from flooding. Note: This is not a tidal lagoon. It is permanently closed to the ocean. Sand replenishment will have no impact on this "inlet." Agua Hedionda Lagoon Maintained by: SDG&E SDG&E dredges the outer basin approximately once every two years to ensure sufficient water flow for the cooling of power operations. The last project occurred winter 95-96 and the next project is scheduled to occur winter 97-98. SDG&E has constructed jetties to promote the flow of water into and out of the lagoon. Encinas Creek Maintained by: City of Carlsbad The City of Carsbad maintains the opening as needed. Batiquitos Lagoon Maintained by: US Fish & Wildlife Service, National Marine Fisheries Service, California State Lands Commission, California Dept. of Fish and Game, Port of Los Angeles, City of Carlsbad The Batiquitos Lagoon Enhancement Project (94-96) was a joint project completed last year. Dredging occurred to maintain the natural tidal flow and keep the channel entrance open. Jetties were designed to ensure the lagoon mouth is kept open and sand allowed to pass throught the inlet. San Elijo Lagoon Maintained by: CA Dept. of Fish & Game, County of San Diego The lagoon mouth is opened as needed (approximately once per year) to maintain a tidal flow which enhances the health and biological productivity of the lagoon. San Dieguito River Maintained by: District 22 Agricultural Association, City of Del Mar Dredging occurs as needed to keep the inlet open. The San Dieguito River J.P.A. and Southern California Edison are developing a wetlands restoration program in this area, which will include inlet maintenence. Los Penasquitos Lagoon Information will be provided prior to April 1, 1997. FROM :COMMUNITY-SER^ICES G19 966 8S6T 1937,04-02 8SS3 P. 02/03 CITY OF OCEAIMSIOE COMMUNITY SERVICES DEPARTMENT April 2, 1997 Carmen Gendusa Frederic R. Harris, Inc 222 West Sixth Street Suite 950 San Pedro, CA 90731 Dear Mr. Gendusa: This letter is in responsf: to your request for information regarding the practices employed in the maintenance of flood control facilities along the coastline within the City of Oceanside. The information below attei apts to answer your questions: 1. All storm water discharge points within the City limits are inspected immediately prior to or during peri ods of rainfall. This effort generally entails clearing obstructions within the pipes or chat inels and providing a clear path between the discharge point and the tidal zone. These functions are shared between the City's Community Services Department and the Beach and Harbor Department. The specific locations are: San Luij Key River Storm dain pipe located at west end of Surfrider Street Storm d ain pipe located at west end of Civic Center Drive Storm d.-ain pipe located at west end of Tyson Street Storm d ain pipe located at west end of Wisconsin Street Storm d .-arn located at west end of Marron Street Loma ALta Channel - 1500 block S. Pacific Street Storm drain pipe located at west end of Cassidy Street Buena Msta Creek - south City limits The Communit y Services Department is responsible for the maintenance of all City owned storm dain facilities. 300 NORTH COAST HIGHWAY • OCEANSIDE, CA 92054-2885 • TELEPHONE 619-965-4500 or 619-966-4530 • FAX 619-966-8867 966 8667 Carmen Gendusa Frederic R. Harris, Inc. April 2, 1997, page 2 ; 3. Ail storm draii facilities are inspected prior to the storm season commencing in November, and the appropriate maintenance work is performed. Additional work is performed throughout the storm season as required. 4. Loma Alta Cro;k was the last channel cleaned this year. 5. The last major t laintenance to the flood control facilities was performed during February, 1997. If you have further questions, I may be contacted at (760) 966-4507. Sincerely, W^ James D. Stillman Public Services Divisi ?n Manager JDS:ws T ur CITY OF ENCINITAS MEMORANDUM Date: AttrilZ 1997 TO: Carmen Gendusa Frederic R. Harris FROM: Hans Carl Jensen Senior Qvil Engineer SUBJECT: Navy Sand F21 Beaches Responding to your inquiry dated March 25, 1997, we have keyed our answers with the numbers corresponding to your questions. 1. Maintenance to dear the flow to the ocean over the beaches has not been needed at any storm drain outfall The lagoon mouth at San Hijo Lagoon has been kept open on and off by the Lagoon Conservancy, woikingwith the San Diego County Parks. "Die Giy has not been involved in that activity . Z Storm drain attention if needed is the responsibility of Gty of Encimtas Public Works Department 3. Seel above . Replacement of headwall for Moonlight Beach drain was required in 1994 after high flows and high waves destroyed the old outfall wall Frederic R* Harris, Inc. 222 West Sixth Street Suire 950 San Pedro, CA 90731 3tQ/S33-I002 i_i*»»n«Fax: 3IO/S33-J236 HARRIS FACSIMILE COYERSHEET 0ate: MjoeMS, 1997 Job; 163070-01 File: Fax #: (619)755-1782 Serial: To: ^ City of Solana Beach RCOCI\/irr\ Attn: Brad Nguyen, Engineering Dept ™ CV*CI v t;y From:" "" Carmen Gcndusa RE: Navy Sand FiU Number of pages (including cover sheet).!, As you are aware, the Navy is currently preparing plan for the placement of sand fill along various portions of your city's beaches. We are aware of various lagoon inlets/outlets, sewer ocean outfalls,. stoira drain outfalls/outlets and various creek outlets within the project area, which includes the cities of Oceanside, Carlsbad, Encinitas, Solana Beach and San Diego (Torrey Pines). Please provide the following information, specific to each area, i.e., lagoons, storm drain pipes, storm drain outfalls, sewer ocean outfalls and creeks outlets: !. Please describe your maintaaance practices that help insure the unimpeded flow at and beyond the outlet(s) -(and Jagooo inlets) C/f£tnti**j 0«~t~ $far/n cfr&f'r»./*kfa, c*fct>i *6fl<^<x 2. \Vho performs these maintenance activities? <?«*- &<£>* &4>r£s Pcpf* f f*"*f *//?%« 2 3. How often is routine maintenance performed? /**,//** ^/^ ^rc^^/7*"r''*rftotl// 4. What was the last major maintenance performed? *?*&€.- c /•*****.$ o£ &+£*<* 5. When was the last major maintenance activity performed? f, 5" yea r-s 4y , If you have any questions, please call me at your earliest convenience. If this message is illegible or incomplete, please call 310/833-1002. This facsimile is privileged and confidential. It is solely for the addressee. Any unauthorized disclosure, reproducdoa, distribution, or raking of any action in reliance on ttoe contents of this mformatioa is prohibited. If you icccive this facsimile in error, please notify us Immediately.