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Home My WebLink AboutSDP 03-12; STORM WATER MANAGEMENT PLAN; 2004-05-05STORM WATER MANAGEMENT PLAN for 1265 CARLSBAD VILLAGE DRIVE Prepared for: Carlsbad Village Drive Investors, LLC 1241 Carlsbad Village Drive Suite 100 Carlsbad, California 92008 (760) 434-1400 lllp C /1f4: n Prepared by: BUCCOLA ENGINEERING. INC. 3142 Vista Way Suite 301 0 Oceanside, California 92056 (760) 721-2000 May 05, 2004 172-1 Purpose Introduction 1265 Carlsbad Village Drive Storm Water Management Plan SDP 03-12 Determination of Applicable Storm Water BMP Requirements Sight Description Criteria for Identification of Pollutants of Concern Criteria for Identification of Conditions of Concern Establishing Storm Water Best Management Practices (BMPs) Storm Water BMP Maintenance Summary & Conclusion Figures, Tables & Appendices TABLE OF CONTENTS 1.0 Purpose 2.0 Introduction 3.0 Determination of Applicable Storm Water BMP Requirements 4.0 Sight Description 4.1 Existing Drainage Patterns and Facilities 4.2 Proposed Site Development Drainage Patterns and Facilities 5.0 Criteria for Identification of Pollutants of Concern 5.1 Historical Sources of Pollutants From the. Project Area 5.2 Identification of Receiving Waters 5.3 ,.. Identification of 303(d) Impaired-Waters 5.4 Identification of Pollutants of Concern 6.0 Criteria for Identification of Conditions of Concern 6.1 Summary- Evaluation of the Final Hydrology Study 6.2 Identification of Conditions of Concern 7.0 Establishing Storm Water Best Management Practices (BMPs) 7.1 Site Design BMPs 7.2 Source Control BMPs 7.3. . BMPs for Individual Priority Project Categories 7.4 Selection of Treatment Control BMPs 7.5 Numeric Sizing Design 7.6 Location of Treatment Control BMPs 7.7 Infiltration BMPs - Use and Restrictions , 7.8 Wavier of Treatment Control BMP Requirements 8.0 Storm Water BMP Maintenance 8.1 Mai ntenance,Mechanisms 8.2 Verification Mechanisms 8.3 Maintenance Requirements 9.0 Summary & Conclusion Storm Water Management Plan Site Development Plan for 1265 Carlsbad Village Drive Buccola Engineering, Inc. Carlsbad Village Drive Investors, LLC TABLE OF CONTENTS (continued) 10.0 Figures, Tables & Appendices Figure - I Vicinity Map Figure —2 USGS Location Map Figure .3 85th Percentile Precipitation Isopluvial Map Figure —4 Existing Site Condition & Drainage Pattern Exhibit Figure - 5 Proposed Site Condition & Drainage Pattern Exhibit Figure —6 Post Construction Storm Water BMP Exhibit Figure —7 Treatment Control BMP - Grass-lined Swale Detail Table - I Storm Water BMP Requirements Matrix Table —2 Pollutants by Land Use Type Table —4 Treatment Control BMP Selection Matrix Appendix A - Storm Water Requirements Applicability Checklists Part A: Determine Priority Project Permanent Storm Water BMP Requirements Part B: Determine Standard Permanent Storm Water Requirements Part C: Determine Construction Phase Storm Water Requirements Part D: Determine Construction Site Priority Appendix B - LASUSMP BMP Design Criteria, B.13 Vegetative Swale Appendix C - Structural BMP Swale Calculations Appendix D Operations & Maintenance Plan Storm Water Management Plan Site Development Plan for 1265 Carlsbad Village Drive Buccola Engineering, Inc. Carlsbad Village Drive Investors, LLC 1.0 Purpose This report has been prepared to address storm water pollution control objectives as mandated by the Clean Water Act (CWA) and as regulated by the National Pollution Discharge Elimination System (NPDES), the California Regional Water Quality Control Board, San Diego Region (SDRWQCB), the Model Standard Urban Storm Water Mitigation Plan (MSUSMP) for San Diego County and the City of Carlsbad Standard Urban Storm Water Mitigation Plan, Storm Water Standards (SUSMP). This report identifies storm water quality concerns associated with the development of the 1265 Carlsbad Village Drive site. The discussion will include the identification of the Receiving Waters for each discharge point, the Conditions of Concern (COCs) and the Pollutants of Concern (POCs). The narrative will also include descriptions of the existing and proposed site drainage patterns and facilities. The plan will also address the objectives of employing Best Management Practices (BMPs), coupled with an effective monitoring and maintenance program as a means for providing long-term water quality, to the maximum extent practicable (MEP). The Storm Water Management Plan is submitted, as required, as part of the review process for discretionary permit application. As such, this report will not address construction related storm water concerns as provided for in the City of Carlsbad SUSMP. Identification of construction related sources of water pollution and the application of mitigating BMPs is typically discussed in the Storm Water Pollution Prevention Plan (SWPPP). The subject project will not be required to prepare a SWPPP, as the area of disturbance is less than 1 acre. However, the waiving of the SWPPP requirement does not release the developer from the responsibility of obtaining a grading permit and an approved erosion control plan. The specified BMPs shall be installed, monitored and maintained, in an acceptable manner, as determined by City Inspection Staff. Storm Water Management Plan Site Development Plan for 1265 Carlsbad Village Drive Buccola Engineering, Inc. Carlsbad Village Drive Investors, LLC 2.0 Introduction The Federal Water Pollution Control Act (also referred to as the Clean Water Act [CWA]) was amended in 1972 to make it unlawful to discharge pollutants to the waters of the United States from any point source, unless the discharge is in compliance with an NPDES permit. In 1990, the U.S. Environmental Protection Agency (USEPA) published final regulations that established storm water permit application requirements. The RWQCB has since elected to adopt one statewide General Permit. In response, the California Regional Water Quality Control Board, San Diego Region (SDRWQCB), has published Order No. 2001-01, NPDES No. CAS0108758 to administer the implementation of Federally mandated controls on a local level. The order divides the region into Watershed Management Areas (WMAs) and assigns Municipal Copermittees to regulate storm water related activities within a particular V4A. Each Copermittee owns or operates a municipal separate storm sewer system (MS4) through which it discharges urban runoff into waters of the United States within the San Diego Region. Each Copermittee is responsible for meeting the provisions contained in Division 7 of the California Water Code, the CWA and regulations adopted hereunder. In accordance with Section F. 1.b.(2) Order No. 2001-01, the Copermittees have approved a Model SUSMP for San Diego County, the Port of San Diego and Cities in San Diego County. The City of Carlsbad is identified as a Municipal Copermittee under Section 1 of SDRWQCB, Order No. 2001-01. As a Copermittee, under Section 10 of the aforementioned order, the City of Carlsbad is responsible for implementing an Urban Runoff Management Program (URMP) that is designed to reduce discharges of pollutants that flow into and from MS4s to the maximum extent practicable (MEP). Moreover, the City of Carlsbad, under Section D. 1 of said order, has authority to establish, maintain and enforce adequate legal authority to control pollutant discharges into and from its MS4 through ordinance, statute, permit, contract or similar means. Pursuant to Section D.1 of the previously cited SDRWQCB order, the City of Carlsbad has prepared a SUSMP to define Urban Runoff Requirements for Priority New Development and Redevelopment Projects. The requirements of the SUSMP are applicable to the 1265 Carlsbad Village Drive project as defined under Appendix A, Storm Water Requirements Applicability Checklist. Storm Water Management Plan Site Development Plan for 1265 Carlsbad Village Drive Buccola Engineering, Inc. Carlsbad Village Drive Investors, LLC 3.0 Determination of Applicable Storm Water BMP Requirements The City of Carlsbad SUSMP provides Appendix A as a mechanism to determine the Applicable Storm Water BMP Requirements. The SUSMP requires the completion of Section 1, Part A and Part B, as a component of the review process for application of discretionary permit review. The checklist is designed to provide a standard to define and identify the land use of Priority Projects. The completion of SUSMP Appendix A, Section 1, Part A; indicates that the proposed project development is defined under item 8 as Parking lots greater than or equal to 5,000 ft2 or with at least 15 parking spaces that are potentially exposed to urban runoff. The proposed development will include 36 parking spaces over an area of 10,430 square feet. The completion of SUSMP Appendix A, Section 1, Part B; identifies that the project proponent is cited as including the following elements as part of the proposed site development. Item 1 New impervious areas, such as rooftops, roads, parking lots, driveways, paths and sidewalks Item 2 New pervious landscape areas and irrigation systems Item 4 Trash storage areas Item 9 Any grading or ground disturbance during construction The SUSMP also provides Table 1 - Standard Development Project & Priority Project Storm Water BMP Requirements Matrix. A review of the matrix indicates that the project is required to incorporate site design BMPs, source control BMPs and treatment control BMPs. The project is also subject to BMPs applicable to individual Priority Project Categories. The completed checklists; Section 1, Part A: Determine Priority Project Permanent Storm Water BMP Requirements; Part B: Determine of Standard Permanent Storm Water Requirements; Section 2, Part C: Determine Construction Phase Storm Water Requirements; Part D: Determine Construction Site Priority, may be found in Appendix A. Storm Water Management Plan Site Development Plan for 1265 Carlsbad Village Drive Buccola Engineering, Inc. Carlsbad Village Drive Investors, LLC 4.0 Site Description The project is located in the northwestern portion of the City of Carlsbad, southeast of Carlsbad Village Drive west of Interstate 5 (Figure 1). .The property fronts a portion of Carlsbad Village Drive and contains 0.46 fallow acres. The parcel is bound to the north by an existing fire station and to the south by an existing office building. An existing residential development abuts the southern property line. The majority of the site contains slope grades of approximately 8%. Isolated areas containing slopes approaching 33% are located along the northern property line. Elevation ranges are between 120 feet Mean Sea Level (MSL) at the northeast site boundary to 111 feet MSL at the southwest project boundary. The project area does not contain any existing structures.. Storm Water Management Plan Site Development Plan for 1265 Carlsbad Village Drive Buccola Engineering Inc. Carlsbad Village Drive Investors, LLC 4.1 Existing Drainage• Patterns and Facilities The Master Drainage and Storm Water Quality Management Plan - City of Carlsbad, California March, 1994, indicates that the project site is located within the Agua Hedionda Watershed Basin Designation. However, the existing topography of the adjacent properties and the proposed site grading indicates that the site is actually part of the Buena Vista Watershed Basin Designation. The existing onsite topography drains from the northeast to the southwest. Offsite flows, from the fire station site, enter the property and sheet flow across the parcel in a southwesterly direction. The sheet flow continues in a southwest direction until it reaches an existing retaining wall located along the south parcel boundary. The flows drain across the retaining wall and enter the parking lot located west of the site. The runoff is conveyed northwesterly within the parking lot to an existing outfall location on Carlsbad Village Drive. Existing onsite drainage patterns and facilities are delineated on Figure - 4 Existing Site Condition & Drainage Pattern Exhibit. Storm Water Management Plan Site Development Plan for 1265 Carlsbad Village Drive Buccola Engineering, Inc. Carlsbad Village Drive Investors, LLC 4.2 Proposed Site Development Drainage Patterns and Facilities The proposed site development will consist of a multi-storied commercial building with supporting onsite parking. Approximately 30% of the parking area is covered and will not be exposed to rainfall. However, at the request of the City of.Carlsbad, the covered parking area has been included in the numeric sizing of the grass-lined swale. The site is designed to mimic the historic runoff patterns by allowing storm runoff to sheet flow across the parking lot in a southwesterly direction. The sheet flow passes directly into a proposed grass-lined swale structural BMP. The swale directs the treated runoff to a proposed concrete apron and D-25 curb outlet. The curb outlet is located at a historic outfall location on Carlsbad Village Drive. Proposed onsite drainage patterns and facilities are delineated on Figure 5 - Proposed Site Condition & Drainage Pattern Exhibit. Storm Water Management Plan Site Development Plan for 1265 Carlsbad Village Drive Buccola Engineering, Inc. Carlsbad Village Drive Investors, LLC 5.0 Criteria for Identification of Pollutants of Concern The City of Carlsbad SUSMP mandates that priority projects identify historical and anticipated sources of pollutants. Procedures are outlined and information is provided to aid in the identification of possible sources of pollution that may impair the beneficial uses of a receiving water. 5.1 Historical Sources of Pollutants From the Project Area A site reconnaissance was performed on May 29, 2003 to identify possible existing sources of pollution and conditions of concern. The site is accessed by a single driveway / dirt road and has been cleared of buildings and groundcover. The project area contains a sparse cover of weeds. Existing visible sources of pollutants appear to be denuded areas and small amounts of trash. The fire station, located upstream of the site appears to contribute untreated runoff from impervious building and patio areas. There is evidence of silt deposition from run off in the form of ruts and small alluvial fans in the denuded areas. However there is no apparent evidence of run off concentration points adjacent to the street or along the downstream property that would indicate the introduction of silt. Non-visible sources of pollutants from the site may include the introduction of pollutants from the upstream fire department site and deposition of airborne pollutants from vehicle use on Carlsbad Village Drive and nearby Interstate 5. Storm Water Management Plan Site Development Plan for 1265 Carlsbad Village Drive Buccola Engineering, Inc. Carlsbad Village Drive Investors, LLC 5.2 Identification of Receiving Waters The State Water Resources Control Board has adopted a Basin Plan that was initially developed in the early 1960s by the State Department of Water Resources (DWR). The purpose of the Basin Plan is to preserve water quality and protect the beneficial uses of all regional waters in California. The Basin Plan recognizes the regional differences in water quality and quantity, and is designed to facilitate administration of a water quality plan. Subsequently, in the early 1970s, the State Board enumerated the Basin Planning Areas, Hydrologic Units, Areas and Subareas of the State. In accordance with the early DWR definitions, Hydrologic Units are the entire watershed of one or more streams; hydrologic areas are major tributaries and/or major groundwater basin within the Hydrologic Unit; and Hydrologic Subareas are major subdivisions of the Hydrologic Areas including both water-bearing and nonwater-bearing formations. These boundaries should not be confused with the CWA 303(d) designation, which mandates the identification of impaired waters within the state and is discussed in Section 5.3 of this report. The 1265 Carlsbad Village Drive site is located within: Hydrologic Unit Basin Planning Area 9—San Diego Carlsbad Hydrologic Unit - Basin Number 904.00 Buena Vista Hydrologic Area - 904.20 El Salto Hydrologic Sub-Area - 904.21 The Carlsbad Hydrologic Unit is a roughly triangular-shaped area Of about 210 square miles, extending from Lake Wohlford on the east to the Pacific Ocean on the west, and from Vista on the north to Cardiff-by-the-Sea on the south. The unit includes the cities of Oceanside, Carlsbad, Leucadia, Encinitas, Cardiff-by-the Sea, Vista and Escondido. The unit is drained by the following creeks; Buena Vista, Agua Hedionda, San Marcos and Escondido. The Carlsbad Unit contains four major coastal lagoons; Buena Vista, Agua Hedionda, Batiquitos and San Elijo. Buena Vista Lagoon lies between the cities of Carlsbad and Oceanside, and is partially within each city. A sandbar occasionally forms across the mouth forming an ocean beach. The water level in the lagoon is maintained by an inflow rising groundwater and return irrigation water from the area upstream of Vista Creek. A portion of the lagoon has been designated as a bird sanctuary. Storm Water Management Plan Site Development Plan for 1265 Carlsbad Village Drive Buccola Engineering, Inc. Carlsbad Village Drive Investors, LLC 5.3 Identification of 303(d) Impaired Waters Section 303(d)(1)(A) of the CWA specifies that each State shall identify those waters within its boundaries for which the effluent limitations required by sections cited in the CWA "are not stringent enough to implement any water quality standard applicable to such waters. The State shall establish a priority ranking of such waters... taking into account the severity of the pollution and the uses to be made of such waters." In summary, the Clean Water Act Section 303(d) Water Body mandates that the State(s) list the impaired bodies of water in which water quality does not meet applicable water quality standards and/or is not expected to meet water quality standards, even after the application of technology based pollution controls required by the CWA. The discharge of urban runoff to these water bodies by the Copermittees is significant because these discharges can cause or contribute to violations of applicable water quality standards. The USEPA approved a list of Impaired Waters prepared by the SDRWQCB on 12 May 1999. The City of Carlsbad SUSMP requires the identification of all downstream Receiving and Impaired Waters. According to the SDRWQCB the Impaired Receiving Waters of the 1265 Carlsbad Village Drive project are defined as follows: Buena Vista Lagoon Regional —9 (San Diego) Water Body Type "E" - Estuaries Name - Buena Vista Lagoon Calwater Watershed - 90421000 Pollutant/Stressor - Bacteria Indicators Potential Sources - Nonpoint/Point Source TMDL Priority -Low Estimated Size Affected —202 acres Proposed TMDL Completion - Not Available/Unpublished Pollutant/Stressor - Nutrients Potential Sources - Nonpoint/Point Source TMDL Priority - Low Estimated Size Affected —202 acres Proposed TMDL Completion - Not Available/Unpublished Storm Water Management Plan Site Development Plan for 1265 Carlsbad Village Drive Buccola Engineering, Inc. Carlsbad Village Drive Investors, LLC 5.3 Identification of 303(d) Impaired Waters (continued) Buena Vista Lagoon Pollutant/Stressor - Sediment/Siltation Potential Sources - Nonpoint/Point Source TMDL Priority - Medium Estimated Size Affected - 202 acres Proposed TMDL Completion - Not Available/Unpublished Pacific Ocean Shoreline, Buena Vista Creek HA Regional —9 (San Diego) Water Body Type "C" - Coastal Shorelines/Beaches Name - Pacific Ocean Shoreline, Buena Vista Creek HA Caiwater Watershed - 90421000 Pollutant/Stressor - Bacteria Indicators Potential Sources - Nonpoint/Point Source TMDL Priority - Low Estimated Size Affected - 1.2 miles Proposed TMDL Completion - Not Available/Unpublished Storm Water Management Plan Site Development Plan for 1265 Carlsbad Village Drive Buccole Engineering, Inc. Carlsbad Village Drive Investors, LLC 5.4 Identification of Pollutants of Concern The City of Carlsbad SUSMP states that upon identifying the project's anticipated pollutants (Section III. LA, Table 2), the receiving waters for each discharge point and the pollutants identified in the 303(d) list, that a comparison be drawn to determine the pollutants of concern. The SUSMP contains Table 2, which provides a list of "Anticipated and Potential Pollutants Generated by Land Use Types". The listed pollutants reflect possible sources of pollution related to the post-development land use. The 1265 Carlsbad Village Drive project is a commercial development of less, than 100,000 square feet with a supporting parking lot. Table 2 lists the following Potential Pollutants Generated by Land Use Types: Parking Lots Sediments (if landscaping exists onsite) Nutrients (if landscaping exists onsite) Heavy Metals Trash & Debris Oxygen Demanding Substances (if landscaping exists onsite) Oil & Grease Pesticides (if landscaping exists onsite) As previously noted in Section 5.3, the 303(d) Impaired Waters, the pollutants/stressors identified as impairing the receiving waters are as follows: Buena Vista Lagoon Low Priority - Bacteria Indicators Low Priority . -Nutrients . Medium Priority - Sediment/Siltation Pacific Ocean Shoreline Low Priority - Bacteria Indicators Bacteria Indicators are analogous to bacteria and viruses that comprise the ubiquitous microorganisms that thrive under certain environmental conditions. The proliferation of bacteria and viruses is typically caused by the inclusion of animal or human fecal wastes to the watershed. Coliform is an example of bacteria associated with fecal wastes. Webster's Dictionary defines "coliform" .as, of or relating to, or like the colon bacillus, normally occurring in all vertebrate intestinal tracts. Escherichia coil. Water containing excessive levels of bacterial indicators can alter the aquatic habitat and create a harmful environment for humans and aquatic life. Storm Water Management Plan Site Development Plan for 1265 Carlsbad Village Drive Buccola Engineering, Inc. Carlsbad Village Drive Investors, LLC 5.4 Identification of Pollutants of Concern (continued) Eutrophic forms of water pollution are manifest in bodies of water in which the increase of mineral and organic nutrients has reduced the dissolved oxygen therefore, producing an environment that favors plant life over animal life. Concentrations of nutrients, such as nitrogen and phosphorus, in bodies of water can lead to excessive growth of aquatic plants and algae. Excessive growth may cause above normal decay of organic material and a subsequent reduction in dissolved oxygen in a process referred to as eutrophication. The Section 303(d) List identifies Bacteria Indicators as impairing the Buena Vista Lagoon and the Pacific Ocean Shoreline. However, Table 2 "Anticipated and Potential Pollutants Generated by Land Use Types" (Figure 6) specifically excludes Bacteria & Viruses from the General Pollutant Categories associated with the project development, therefore the SWMP for the 1265 Carlsbad Village Drive project shall not address Bacteria Indicators as a pollutant of concern. The Identified Pollutants of Concern which are the target of the Treatment Control BMP(s) are as follows: Sediments/Siltation Nutrients Heavy Metals Trash & Debris Oxygen Demanding Substances Oil & Grease Pesticides Storm Water Management Plan Site Development Plan for 1265 Carlsbad Village Drive Buccola Engineering, Inc. Carlsbad Village Drive Investors, LLC 6.0 Criteria for Identification of Conditions of Concern Changes to the hydrologic regime of a priority project would be considered a condition of concern if the change(s) were to impact the "integrity of downstream channels and habitat". To determine the Conditions of Concern, the SUSMP requires the following steps be followed for each priority project. Evaluate the projects COCs in a - drainage (hydrology) report prepared by a qualified registered civil engineer. Section 6.1 of this plan provides a Summary Evaluation of the Preliminary.. Hydrology Report. Perform a field reconnaissance of the project area to observe and report on down stream conditions. The existing site observations are discussed in Section 4 of this plan, while the relationship between the existing and developed conditions and the effect upon run off characteristics is discussed in Section .1 of the SWIVIP. Compute rainfall characteristics from the project area Predevelopment and post-development runoff characteristics are calculated as part of the Preliminary Hydrology Report. The findings thereof are discussed in Section 6.1 of the SWMP Storm Water Management Plan Site Development Plan for 1265 Carlsbad Village Drive Buccole Engineering, Inc. Carlsbad Village Drive Investors, LLC 6.1 Summary Evaluation of the Final Hydrology Report A site reconnaissance was performed and drainage study completed to analyze effects of the predevelopment and post development drainage impacts to the site. The existing site observations are discussed in Section 4 of this plan. This Section refers to information found in the "Final Hydrology Report for 1265 Carlsbad Village Drive". The Node locations cited in this Section are referenced from the above-mentioned report and are delineated on Figure 6— Post Construction Phase BMP Exhibit. The proposed project will consist of a multi-storied commercial building with a supporting parking lot. As previously mentioned, the proposed building will cover approximately 30% of the proposed parking lot. The existing hydrologic regime divides the site into two drainage basins. Approximatel'y 3/4 of the site drains to the northwest. The watershed generates 1.15 cfs at Node location 108 during a 100-year storm event. The remainder of the site drains south and west to an outfall location south of the site. This portion Of the site generates 0.05 cfs at Node 208 during a 100-year storm. The developed site runoff condition is also comprised of two drainage basins. The eastern portion of the site drains in a northwesterly direction. Runoff from the eastern basin is collected in a series of landscaped areas equipped with grated private drains. The treated flows are conveyed in a private drain to an outfall location on Carlsbad Village Drive adjacent to the eastern property line. The eastern basin develops 0.70 cfs during a 100-year storm event. The remaining western portion of the site drains in a northwesterly direction to a grass-lined swale BMP. The swale directs the flow in a northerly direction to a curb outlet located on Carlsbad Village Drive and adjacent to the western property line. The western portion of the site develops 2.15 cfs during a 100-year storm event at Node location 208. A complete "Final Hydrology Report for 1265 Carlsbad Village Drive" is included as part of the Review Process for Discretionary Actions. Storm Water Management Plan Site Development Plan for 1265 Carlsbad Village Drive Buccola Engineering, Inc. Carlsbad Village Drive Investors, LLC 6.2 Identification of Conditions of Concern Common impacts to the hydrologic regime resulting from development typically include increased runoff volume and velocity; reduced infiltration; increased flow frequency, duration and peaks; faster time to reach peak flow; and water quality degradation. These changes have the potential to permanently impact downstream channels and habitat integrity. A change to a priority project site's hydrologic regime would be considered a condition of concern if the change would impact downstream channels and habitat integrity. Possible COCs, as identified in the SUSMP, that are associated with the development of the 1265 Carlsbad Village Drive project include the following: An increase in runoff volume Reduced infiltration Water quality degradation The development of the 1265 Carlsbad Village Drive project will increase the site runoff by 1.65 cfs. The Master Drainage and Storm Water Quality Management Plan, dated March 1994 indicates that the. site is part of a larger watershed that contributes to an existing 66" RCP storm drain with a worse-case pipe slope of 0.50%. Assuming the depth of flow in the 66" pipe to be Y2 the pipe diameter, or 2.75 feet, the pipe would carry approximately 1,190 cfs. Employing this very conservative approach indicates that the increase in flow to the receiving water is a negligible 0.14 %. However, it is safe to assume that the storm drain facility is designed to carry flows approaching non-pressure flow capacity. Such a comparison would yield an increase in flow of 0.06 % to the entire downstream habitat and facilities. It is the determination of this report that such a minor increase in flow the overall watershed does not constitute a negative impact to downstream channels and habitat integrity. Reduced infiltration and water quality degradation concerns are addressed by employing site, source and treatment control BMPs. The site design BMPs are discussed in Section 7.1 while, source control BMPs are addressed in Section 7.2 of this report. The 1265 Carlsbad Village Drive project also proposes the construction of treatment control BMPs that will reduce or remove pollutants of concern. The selection and function the BMPs are discussed in Section 7.4 through 7.6 of the SWIvIP. Storm Water Management Plan Site Development Plan for 1265 Carlsbad Village Drive Buccola Engineering, Inc. Carlsbad Village Drive Investors, LLC 7.0 Establishing Storm Water Best Management Practices (BMPs) The SUSMP dictates that all priority projects shall implement storm water BMPs to mitigate the identified pollutants and conditions of concern. BMPs shall follow the requirements outlined in the SUSMP and shall be designed as to remove pollutants to the maximum extent practicable. All priority projects shall incorporate the applicable storm water BMPs into the project design. Table 1 - "Priority Project Storm Water BMP Requirements Matrix" specifies the application of Site Design, Source Control and Treatment Control BMPs based upon land use. Storm Water Management Plan Site Development Plan for 1265 Carlsbad Village Drive Carlsbad Village Drive Investors, LLC Buccola Engineering', Inc. 7.1 Site Design BMPs Site Control BMPs shall minimize the introduction of pollutants to the maximum extent possible (MEP). Priority projects will provide hydrologic project design that "attempts to mimic" the natural hydrology. The 1265 Carlsbad Village Drive project is a commercial development of less than 100,000 square feet with a supporting parking lot. Table 1 lists the requirements for the application of Site Design BMPs. Section III (2)A —Maintain Pre-development Rainfall Runoff Characteristics, provides examples of site design BMPs. The 1265 Carlsbad Village Drive project employs the following Site Design BMPs: Minimize impervious area Incorporate landscape buffer areas Drive aisles designed with minimal pavement width Increased building density, minimized building footprint Increase Rainfall Infiltration Direct rooftop runoff to pervious (landscape) areas Maximize Rainfall Interception . Maximized canopy interception by the planting of trees and large shrubs Minimize Directly Connected Impervious Areas (DCIAs) Draining rooftops into adjacent landscaping prior to discharging to the storm drain . Parking areas into adjacent landscaping Slope protection Planting and irrigating slope groundcover and canopy The site layout has been designed to maintain pre-development runoff characteristics by producing a modest increase of 1.65 cfs in total site runoff and by returning storm runoff to historic outfall locations. Drive aisle widths have been minimized. Lot landscaping will provide filtration for roof drains and lot runoff while, grated private drains will capture debris and silt before flows outfall to the street. Runoff from slopes will be conveyed across vegetated areas to minimize the possibility of introducing silt to the runoff. Storm Water Management Plan Site Development Plan for 1265 Carlsbad Village Drive Buccola Engineering, Inc. Carlsbad Village Drive Investors, LLC 7.2 Source Control BMPs Source Control BMPs are designed to prevent storm water pollution at the source. These BMPs shall be used in concert with Site Design BMPs to minimize the introduction of pollutants to the maximum extent possible (MEP). Reference is made to Section III (2)B - Source Control BMPs, which lists the requirements for the application of Source Control BMPs. The 1265 Carlsbad Village Drive project will employ the following Source Control BMPs: Post signs and prohibitive language that prohibits illegal dumping at public access points Maintain legibility of stencils and signs Use of efficient irrigation systems and landscape design Irrigation systems are designed to address specific water requirements Covered Trash Enclosures To further reduce the sources of pollutants, the parking lot shall receive regularly scheduled sweeping. CCRs will specify that outdoor or uncovered storage of materials is not acceptable. The landscape plan is designed to maximize canopy interception by providing a generous number and varied palette of trees and shrubs. In addition, ground-coverings have been selected to create areas for storm water treatment. Moreover, the specific irrigation requirements for each landscape area have been considered and addressed during the landscape design process. Storm Water Management Plan Site Development Plan for 1.265 Carlsbad Village Drive Buccole Engineering, inc. Carlsbad. Village Drive Investors, LLC 7.3 BMPs for Individual Priority Project Categories The City of Carlsbad SUSMP requires that storm water BMPs shall be selected during the design process for applicable priority projects. The following is a listing of Individual Priority Project Categories as cited in Section III (2)C that are a part of the proposed development and are addressed in the site design: Surface Parking Areas The remaining list of Individual Priority Project Categories are contained herein, however are not applicable to the 1265 Carlsbad Village Drive project: Private Roads : Residential Driveways & Guest Parking Dock Areas Maintenance Bays Vehicle & Equipment Wash Areas Outdoor Processing Areas Non-retail Fueling Areas Hillside Landscaping Storm Water Management Plan Site Development Plan for 1265 Carlsbad Village Drive Buccola Engineering, Inc. Carlsbad Village Drive Investors, LLC 7.4 Selection of Treatment Control BMPs The SUSMP states that projects shall be designed to remove pollutants of concern from the storm water conveyance system to the maximum extent practicable (MEP) through the incorporation of treatment control BMPs. Treatment control BMPs must be implemented unless, a wavier is granted to the project by the City Engineer, which indicates the lack of a feasible treatment control BUT. Priority projects shall be designed to remove pollutants of concern from the storm water conveyance system to the MEP through the use of treatment control BMPs. The selection process also requires the comparison of the list of pollutants for which the downstream receiving waters are impaired, with the anticipated pollutants generated by land use. Refer to Section 5.1 of this report, Identification of Pollutants of Concern, for a complete list of Primary and Secondary Pollutants of Concern. Where a site generates• both primary and secondary pollutants of concern, as is the case with 1265 Carlsbad Village Drive, the primary pollutants of concern shall receive priority for BMP selection. The SUSMP provides a Treatment Control BMP Selection Matrix as a reference in determining the appropriate treatment control BMP(s). The 1265 Carlsbad Village Drive project employs a combination of vegetated areas and swales that perform as biofiltration treatment BMPs to reduce the Pollutants of Concern. The selection of grass-lined swales as biofilter treatment BMPs is based upon the physical constraints posed by the size of the site and the required number of parking spaces. A comparison between the efficiency of the treatment control BMPs, as listed in Figure 8, and the pollutant priority (low or medium, per Section 4.1) of the impaired receiving waters indicate that the selected Treatment Control BMP efficiency is equal to or exceeds the impaired water pollutant priority. Storm Water Management Plan Ste Development Plan for 1265 Carlsbad Village Drive Buccole Engineering, Inc. Carlsbad Village Drive Investors, LLC 7.5 Numeric Sizing Design The SUSMP provides criteria for the Numeric Sizing Design of treatment control BMPs. The sizing of treatment control BMPs may be based upon flow or volume calculations. The calculation provided in this report is based upon the flow rate of runoff produced from a rainfall intensity of 0.2 inch of rainfall per hour for each hour of a storm event as described in Section III (2) D, Table 3 - Numeric Sizing Treatment Standards of the SUSMP. Calculation of the 85th percentile runoff is as follows: Q = C I A where C = Runoff Coefficient, San Diego County criteria I = 0.2 inches A = Basin Area, in acres The 1265 Carlsbad Village Drive site contains two storm water drainage basins. The Node locations are delineated on Figure 6. The flow based calculation for the eastern storm water drainage basin, vegetated strip treatment BMP is as follows: Node 108 where C = 0.85 1= 0.2 A =0.12 Q =0.02cfs The flow based calculation at the western storm water drainage basin, grass-lined swale treatment BMP is as follows: Node 208 where C=0.85 1=0.2 A=0.39 Q =0.07cfs Calculations indicating the flow characteristics of each grass-lined swale are contained on the following two pages. Channel calculations are based upon a trapezoidal channel 6 feet wide with side slopes of 4:1 (horizontal:vertical) and a base width of 4 feet, a longitudinal slope of 1% (respectively) and a Manning's n value of 0.024 (Handbook of Hydraulics, Brater & King, 6' edition). Storm Water Management Plan Site Development Plan for 1265 Carlsbad Village Drive Buccole Engineering, Inc. Carlsbad Village Drive Investors, LLC 7.5 Numeric Sizing Design (cont.) The City and County of Los Angeles have created a Manual for the Standard Urban Stormwater Mitigation Plan (SUSMP). The manual provides an introduction, permitting and inspection procedures, the body of the SUSMP, tables and appendices. Appendix B, of the manual, provides criteria for the design of treatment control BMPs. Since the City of Carlsbad SUSMP does not provide treatment BMP design criteria, this plan refers to the design criteria outlined in Appendix B, B.13 Vegetative Swale, of the Los Angeles SUSMP Manual. As outlined in the LASUSMP, Appendix B.13, Table 1, the criteria for swale performance is listed by parameter, optimal and minimum criteria, and is summarized as follows: Criteria Optimal - Minimum Hydraulic residence time 9 minutes - 5 minutes Average flow velocity 0.9 fps - not available, not published Swale width 8 feet - 2 feet Swale length 200 feet - 100 feet Swale slope 2-6%-l% Side slope ratio (horiz:vert) 4:1 - 2:1 Swale Performance Data at Node 108 is as follows: Flow rate of system = 0.02 cfs. Longitudinal slope of system = 1.0% Swale shape = trapezoidal Channel base width =4 feet Side slope ration = 4:1 Depth of Flow (Normal Depth) = 0.01 feet Velocity of channel flow = 0.35 fps Swale Performance Data at Node 208 is as follows: Flow rate of system = 0.07 cfs Longitudinal slope of system = 1.0% Swale shape = trapezoidal Channel base width =4 feet Side slope ration = 4:1 Depth of Flow (Normal Depth) = 0.03 feet Velocity of channel flow = 0.58 fps Storm Water Management Plan S.e Development Plan for 1265 Carlsbad Village Drive Buccole Engineering, Inc. Carlsbad Village Drive Investors, LLC 7.6 Location of Treatment Control BMPs According to the SUSMP treatment control BMPs should be implemented close to pollution sources to minimize costs and maximize pollutant removal prior to runoff entering receiving waters and may be combined with flood control structures. The treatment control BMPs are located adjacent to the source of runoff. The BMP locations are delineated on Figure 6 of this plan. Storm Water Management Plan Site Development Plan for 1265 Carlsbad Village Drive Carlsbad Village Drive Investors, LLC Buccola Engineering, Inc. 7.7 Infiltration BMPs - Use and Restrictions BMPs that are designed to function primarily as infiltration devices, such as infiltration basins and trenches, are subject to restrictions as outlined in the SUSMP. As groundwater basin data becomes available, the City Engineer may develop restrictions on the use of incidental infiltration devices such as grassy swales, vegetated buffer strips, detention basins or constructed wetlands. Three factors significantly influence the potential for urban runoff infiltration devices to contaminate ground water basins. They are (i) pollutant mobility, (ii) pollutant abundance in urban runoff and (iii) soluble fraction of pollutant. The risk of contamination of groundwater may be reduced by pretreatment of urban runoff. A discussion of the limitations and guidance for the application of infiltration practices is containedin the Environmental Protection .Agenc Report Number EPA/600/R-94/051, Potential Groundwater Contamination from Intentional and Nonintentional Stormwater Infiltration, USEPA (1994). To protect groundwater quality, the City Engineer may apply restrictions to the use of any BMPs that are designed to primarily function as infiltration devices. As additional groundwater basin data is obtained, the City Engineer may develop additional restrictions on the use of any BMPs that allow for incidental infiltration. At present, the City Engineer has not imposed specific restrictions on the use of incidental infiltration devices. However, the use of structural treatment control BMPs that are designed to primarily function as infiltration devices shall meet the following conditions. Applicable Restrictions Pollution prevention and source control BMPs shall be implemented at a level appropriate to protect groundwater quality at sites where infiltration structural treatment control BMPs are used. As cited in Section 7.4 of the SWMP, the 1265 Carlsbad Village Drive .site contains landscape areas that provide filtration. Non-Applicable Restrictions All dry weather flows shall be diverted from infiltration devices Urban runoff from commercial developments Storm Water Management Plan Site Development Plan for 1265 Carlsbad Village Drive Buccola Engineering, Inc. Carlsbad Village Drive Investors, LLC 7.7 Infiltration BMPs - Use and Restrictions (cont.) Non-Applicable Restrictions Vertical distance from the base of an infiltration device the seasonal high groundwater mark shall be at least 10 feet, or as determined by the City Engineer The soil through which infiltration is to occur shall have physical characteristics that are adequate for proper infiltration and for the protection of groundwater for beneficial uses Infiltration structural treatment control BMPs shall not be used in areas of. industrial or light industrial activity , The horizontal distance between the base of any infiltration BMP and water supply wells shall be 100 feet or as determined by the City Engineer. 100 feet or as determined by the City Engineer. Storm Water Management Plan Site Development Plan for 1265 Cailsbad Village Drive Buccola Engineering, Inc. Carlsbad Village Drive Investors, LLC 7.8 Wavier of Treatment Control BMP Requirements The City Engineer may provide for a project to be waived from the requirement of implementing structural treatment control BMPs (discussed in Section 3.2.4) if infeasibility can be established. Waivers may only be granted from structural treatment control BMP and structural treatment control BMP sizing requirements. Priority development projects, whether or not granted a waiver may not cause or contribute to an exceedance of water quality objectives. Pollutants in runoff from projects granted a waiver must still be reduced to the maximum extent practicable. The City must notify the Regional Board within 5 days of each waiver issued and shall include the name of the person granting each waiver. A, SUSMP waiver impact, fee program may be established by the City. As an alternative to implementing structural treatment control BMPs on site, the City may also implement the Local Equivalent Area Drainage (LEAD) Method pursuant to the requirements set forth in the SUSMP. Storm Water Management Plan Site Development Plan for 1265 Carlsbad Village Drive Duccola Engineering, Inc. Carlsbad Village Drive Investors, LLC 8.0 Storm Water BMP Maintenance The City Engineer will not consider structural BMPs "effective", and therefore will not accept storm water BMPs as meeting the MEP standard, unless a mechanism is in place that will insure ongoing long-term maintenance of all structural BMPs. This mechanism shall be proposed by the project proponent as part of the SWMP and will be refined through the City review process until satisfactory verification of maintenance is provided to the City Engineer. Such verification may include but is limited to covenants, legal agreements, maintenance agreements and / or conditional use permits. 8.1 Maintenance Mechanisms • The SUSMP suggests several mechahisms for providing long-term maintenance. The 1265 Carlsbad Village Drive project proposes to entering into a "Project proponent agreement to maintain storm water BMPs" as cited under Section V.4 of the SUSMP. The project proponent proposes to provide funding for reimbursement of maintenance costs as cited in the "Statement of Designated Responsible Party", attached hereto as a part, of Appendix "D", Operations and Maintenance Plan for 1265 Carlsbad Village Drive. This option was selected from the list of potential maintenance mechanisms because of the use of a grass-lined swale treatment control BMPs that are an integral part of the site design and landscape plan. Since the BMPs are not separate from the landscape, but rather are a part of the whole, the 1265 Carlsbad Village Drive project proposes to assign long-term maintenance-funding responsibility to the project proponent, with the knowledge that City staff may verify BMP maintenance. As such, the BMPs will be maintained and would not be neglected or fall into disrepair. 8.2 Verification Mechanisms For discretionary projects, the City approved method of storm water BMP maintenance shall be incorporated into the projects permit, and shall be consistent with permits issued by resource agencies, before City approval of discretionary permits. For projects only ministerial permits, the City-approved method of storm water BMP maintenance shall be incorporated into the permit conditions before the issuance of any ministerial permits. In all instances, the project proponent shall provide proof of execution of a City-approved method of maintenance repair and replacement before the issuance of construction approvals. For public projects that are not required to obtain permits, the City shall be responsible for ensuring that an approved method of storm water BMP maintenance repair and replacement is executed prior to the commencement of construction. For all properties, the verification mechanism will include the project proponent's signed statement, a part of the project application, accepting responsibility for all structural BMP maintenance, repair and replacement, until a City approved entity agrees to assume responsibility for structural BMP maintenance, repair and replacement. Storm Water Management Plan Site Development Plan for 1265 Carlsbad Village Drive Buccola Engineering, Inc. Carlsbad Village Drive Investors, LLC 8.3 Maintenance Requirements Operation & Maintenance (0 & M) Plan - The City requires that a copy of an Operation & Maintenance (0 & M) Plan, prepared by the project proponent satisfactory to the City Engineer, is attached to the approved maintenance agreement, which describes the designated responsible part to manage the storm water BMP(s), employee's training program and duties, operating schedule, maintenance frequency, routine service schedule, specific maintenance activities, copies of resource agency permits, and any other necessary activities. At a minimum, maintenance agreements shall require the inspection and servicing of all structural BMPs on an annual basis. The project proponent or City- approved maintenance entity shall complete and maintain 0 & M forms to document all maintenance requirements. Parties responsible for the 0 & M plan shall retain records for at least 5 years. These documents shall be made available to the City for inspection upon request at any time. Access Easement/Agreement: As part of the maintenance mechanism selected above, the City requires the inclusion of a copy of an executed access easement that shall be binding on the land throughout the life of the project, until such time that the storm water BMP requiring access is replaced, satisfactory to the City Engineer. Storm Water Management Plan Site Development Plan for 1265 Carlsbad Village Drive Buccola Engineering, Inc. Carlsbad Village Drive Investors, LLC 9.0 Summary and Conclusion This, report has been prepared in accordance with the City of Carlsbad SUSMP. The SWMP has identified sources of potential pollutants for the historic condition and has also identified the receiving and impaired waters below the project site. The plan identifies potential sources of pollution associated with the development of the 1265 Carlsbad Village Drive project and cites the implementation of mitigating BMPs for the post-construction condition. The plan also makes provision the long-term funding of a maintenance program that will protect water quality to the maximum extent practicable. Storm Water Management Plan Se Development Plan for 1265 Carlsbad Village Drive Buccole Engineering, Inc. Carlsbad Village Drive Investors, LLC 10.0 Figures, Tables & Appendices Figure - I Vicinity Map Figure— 2 USGS Location Map Figure - 5th Percentile Precipitation Isopluvial Map Figure —4 Existing Site Condition & Drainage Pattern Exhibit Figure —5 Proposed Site Condition & Drainage Pattern Exhibit Figure —6 Post Construction Storm Water BMP Exhibit Figure —7 Treatment Control BMP - Grass-lined Swale Detail Table - I Storm Water BMP Requirements Matrix Table —2 Pollutants by Land Use Type Table —4 Treatment Control BMP Selection Matrix Storm Water Management Plan Site Development Plan for 1265 Carlsbad Village Drive Buccola Engineering, Inc. Carlsbad Village Drive Investors, LLC CITY OF OCEANSIDE HIGHWAY Z8 44 PACIFIC c OCEAN ç,O CITY OF VISTA CITY OF SAN MARCOS P<,vI1. CITY OF ENCINITAS PREPARED IN THE OFFICE OF: B kX17.L24 760/721-2000 ENGINEERING, inc 3142 Vista Way, Suite 301, Oceanside, CA 92056 NOT TO SCALE 1265 CARLS6.40 WAGE DRIVE STORM WATER MIMGEMENT PLAN FIGURE 1 ViCINITY M4P PREPARED IN THE OFFICE OF: 1265 CARLS84D WAGE DRIVE L J 1(7f,4 760/721-2000 STORM WATER M4V4GEMENT PLAN ENGINEERING, inc FIGURE 2 3142 Vista Way, Suite 301, Oceanside, CA 92056 NOT TO SCALE USGS LOCATiON MAP ti \\ \ X11 )?J LJ /4UEN4 " JV r , S IT - / \ wl - 111 : : \Zv Iy \ , '- :: I AGUA 'HEOIOVDA ~~l 1 41 LAGOON SOLJRC COUNTY OF SW INErJO, DR4FT 6127101 PREPARED IN THE OFFICE OF: 1265 C4RLSBAD WAGE DRflf B UCCOLA 760/721-2000 STORM WATER M4N4GEMENT PLAN FIGURE 3 ENGINEERING, 120tYIDffA71flM ICflDI 1MM MAP 3142 Vista Way, Suite 301, Oceanside, CA 92056 OQLfl rrirl.,rJY,,I-c ri,iriuiiijiv IlJ#I rw-_ ivy -ON II- F' d el op + I I _-1 y I I I EXISTING LEGEND LIRECTJON OF SHEET FLOW WATERSHED BOUNDARY PREPARED IN THE OFF/CE OF: 1265 (24RL5840 I'7LLACE DR/If STORM WAlER MIN4NC&I1ENT PLAN B ircjl QJ.j4 760/721-2000 ENGINEERING, inc FI GURE 4 3142 Vista Way, Suite 301, Oceanside, CA 92056 SCALE 1 = 30 EXIST/NC SITE CONDITION AND DPAINACE PATTERN EXHIBIT LEGEND DIRECT/ON OF SHEET FLOW WATERSHED BOUNDARY DIRECT/ON OF FLOW, STORM DRAIN = PREPARED IN THE OFFICE OF: B LT1OLA 760/721-2000 ENGINEERING, inc 3142 Vista Way, Suite 301, Oceanside, CA 92056 7265 C4RLSB4O fr7LLACE DRIVE STORM WATER M4N4G9IENT PLAN FIGURE 5 SCALE- t" = o' PROPOSED SITE DEVELOPMENT AND DRAJN4GE PA71ERN EXHIBIT 5 LEGEND GRASS-LINED S WALE TREATEMENT BMP— LANDSCAPE ARM NOTES MAINTENANCE PERSONNEL SHALL RECEIVE TRAINING REGARD/NC THE INTENT IMPLEMENTATION AND MAINTENANCE OF BMPs. LANDSCAPE AND IRRICA liON SHALL BE MAINTAINED IN SUCH A MANNER AS TO INSURE IRRIGATION RUNOFF PLANT DEBRIS AND SOIL OR SILT DO NOT ENTER THE STORM bRAIN. 3 PLANT MATERIAL SHALL BE MAINTAINED OR REPLACED AS NECESSARY TO PROViDE ADEQUATE GROUND COVER AND SILT CONTAINMENT PAVED AREAS SHALL RECEIVE REGULARLY SCHEDULED SWEEPING. STORM DRAIN INLETS SHALL RECEIVE PROHIBITiVE STENCILING AND/OR SIGN4GE TO THE S4 17SFACT10N OF THE C/fl' ENGINEER, PER' SECTiON ZY OF THE SWMP. 6. THE ARCHITECT SHALL DESIGN ROOF-DRAIN DOWNSPOUTS IN L0CA170NS THAT ALLOW FOR FLOW ACROSS LANDSCAPE AREAS PRIOR TO ENTERING THE PRIVATE DRAIN SYSTEM. Z PLANTiNG AND IRRIGA liON SPECIFiCATiONS PER LANDSCAPE PLAN. PREPARED IN THE OFFICE OF: 760/7212000 BUCCOLA ENGINEERING, inc u = 3142 Vista: Way, Suite 301, Oceanside, CA 92056 SCALE: l 30' 1265 CP4RLSB4D WAGE DRIVE STORM WATER 94t4GEMENT PLAN FIGURE 6 POST CONSTRUCTiON PH4SE BMP EXHIBIT CURB OPENING , 4 ACPAV/IENT i , DIRECTION OF 211. --a.- I lJIIJI Il_IIF1IIT# - I-, VEGEAT1ON DETAIL GRASS-LINED SWALE STRUCTURAL BMP NOT TO SCALE PREPARED IN THE OFFICE OF: 1265 C.4RL5840 ITLLACE DRII'E 1? c1''12L1 760/721-2000 STORM JIATER U4NAGEMENT PLAI ENGINEERING, inc FIGURE 7 3142 Vista Way, Suite 301, Oceanside, CA 92056 STRUCfl/PAL BUP DETAiL] Tahlo 1. Standard Develanment Pmiect & Priority Protect Storm Water BMP Reouirements Matrix Ms Appffcable to Individual Priotiy Project Cotegories(3) E CJ 0 . 0 . .' ZRZ Site Source Treatment Design Bmps(') Control Brnps(2) 4 3 0 ' . . Contto] p(4) Standard Projects R R 0 0 0 0 0 0 0 0 0 0 0 Frioriy Projects: Detached Residential Development R R R R R S Attached Residential R R R s Development Commercial Development R R R R ioo,000 it 2 Automotive Repair Shop R R R R R R R S Restaurants R R R R - S Hillside Development R R R ?5,000 ft2 Parking Lots Street. Highways & R R Freeways = Required; select one or more applicable and appropriate BMPs from the applicable steps in Section 111.2.A—D, or equivalent as identified in Appendix C. 0 = Optional/or may be required by City staff. As Appropriate, applicants are encouraged to incorporate treatment the control BMPs and BMPs applicable to individual priority project categories into the project design. City staff may require one or more of these BMPs, where applicable. S = Select one or more applicable and appropriate treatment control BliPs from C. Refer to Section 111.2.A. Refer to Section 111.2.8. Priority project categories must apply specific storm water SUP requirements, where applicable. Priority projects ore subject to the requirements of all prioirity project categories that apply. Refer to Section llL2,D. Applies if the paved area totals )5,000 square feet or with >15 parking spaces and is potentially exposed to urban runoff. Source: City of Carlsbad SUSMP I I INDICATES PROJECT CATEGORY I IDENTIFIED AS POSSIBLE APPLICABLE BMP FOR PRIOR/fl' PROJECT CATEGORY PREPARED IN THE OFFICE OF: 1265 C4RLSB4O WLLAQE DRIVE B UCCOLA 760'7212000 STORM WATER M4N4GDIENT PLAN ENGINEERING, -inc TABLE 1 3142 Vista Way, Suite 301, Oceanside, CA 92056 STORM WATER. L9MP REQUIREMENTS MATRIX PREPARED IN THE OFFICE OF: .1? LTc.7c.VOLA 760/721-2000 ENGINEERING, inc 3142 Vista Way, Suite 301, Oceanside, CA 92056 1265 CARLSB4D $4/lACE DRIVE STORM WATER MAN'ICEMENT PLAN TABLE 2 POLLUTANYS BY LAND USE TYPE Table 2. Anticipated and Potential Pollutants by Land Use Types General Pollutant Categories Project Trash Oxygen Oil Bacteria categories Heavy Organic & Demanding & & Sediments Nutrients Metals Compounds Debris Substances Crease Viruses Pesticides Detached Residential X X X X X X X Development Attached Residential X X X p (1) p (2) p (') x Development 1 S Commercial Development P0 P (1) - p (2) x P (5) x p P (5) ?i0O,000112 Automotive Repair x x x Restaurants X X X X Hillside Development X X X X X x )5000ft2 Parking Lots p (!) Highways & x p Nx x x (4) X P 5 X &eewoys X = Anticipated P = Potential A potential pollutant if landscaping exits on—site. A potential pollutant if the project includes uncovered parking areas. J. A potential pollutant if land use involves food or animal waste products. Including petroleum hydrocarbons. Including solvents. Source: City of Carlsbad SUSMP INDICATES PROJECT CATEGORY IDENTIFIED AS AN ANTiC/PA TED/PO TENTI4L POLLUTANT BY PROJECT CATEGORY Ttyhfp 4 471niet,im1 TrnIment Control BMP Selection Matrix. Pollutant of Concern Treatment Control BMP Categories Detention Infiltration Wet Ponds Drainage . uI,uLiOfl Hydrodysamic 2 Separator Systems ) Basins .Bosins() or Wetlands Sediment IM H H H L H U_____ Nutrients J:L U Al U L U L______ Heavy Metals U U H L H L______ Crganic Compounds $U U U U ___ U L______ Trash & Debris L H - U U 'U H U Oxygen Demanding U U U L N L Substances Bacteria U H U L U L Oil & Grease :M U U U L H L Pesticides .'9U U U U L U L Including trenches and porous pavement Also known as hydrodynamic devices and baffle boxes. L Low removal efficiency Y. Medium removal efficiency H: High removal efficiency U. Unknown removal efficiency Sources: Guidance Specifying Management Measuras for Soqrces of Nonpo/nt Pollution in CoastalWaters National Stormwater Best Alanagement Practices Database (2001) and Guide for BMP Selection in (1q93) Urban Developed keas (2001). C/fr of Carlsbad SUSUP. I I IDENTIFIED AS A POLLUTANT OF CONCERN SELECTED STRUCTURAL TREATMENT CONTROL BMP & REMOVAL EFFICIENCY PREPARED IN THE OFFICE OF: B T TCCOLA 760/721-2000 ENGINEERING, inc 3142 Vista Way, Suite 301, Oceanside, CA 92056 1265 CARLSBAD 1LLACE DRIVE STORM WATER M44N4CEMENT PLAN TABLE 4 77?EATh1E7VT CONTROL BMP SELEC17ON MATRIX Appendices Appendix A - Storm Water Requirements Applicability ChecklistE Part A: Determine Priority Project Permanent Storm Water BMP Requirements Part B: Determine Standard Permanent Storm Water Requirements Part C: Determine Construction Phase Storm Water Requirements Part D: Determine Construction Site Priority Appendix B - LASUSMP BMP Design Criteria, B.13 Vegetative Swale Appendix C - Structural BMP Swale Calculations Appendix D - Operation & Maintenance Plan Storm Water Management Plan Ste Development Plan for 1265 Carlsbad Village Drive Carlsbad Village Drive Investors, LLC Buccola Engineering, Inc. Storm Water Standards 4/03/03 VI. RESOURCES & REFERENCES APPENDIX A STORM WATER REQUIREMENTS APPLICABILITY CHECKLIST Complete Sections 1 and 2 of the following checklist to determine your project's permanent and construction storm water best management practices requirements. This form must be completed and submitted with your permit application. Section 1. Permanent Storm Water BMP Requirements: If any answers to Part A are answered "Yes," your project is subject to the "Priority Project Permanent Storm Water BMP Requirements," and "Standard Permanent Storm Water BMP Requirements" in Section III, "Permanent Storm Water BMP Selection Procedure" in the Storm Water Standards manual. If all answers to Part A are "No," and any answers to Part B are "Yes," your project is only subject to the "Standard Permanent Storm Water BMP Requirements". If every question in Part A and B is answered "No," your project is exempt from permanent storm water requirements. Part A: Determine Priority Project Permanent Storm Water BMP Reauirements. Does the project meet the definition of one or more of the priority project Yes No categories?* Detached residential development of 10 or more units - Attached residential development of 10 or more units - I-,- Commercial development greater than 100,000 square feet i.- Automotive repair shop - Restaurant Steep hillside development greater than 5,000 square feet Project discharging to receiving waters within Environmentally Sensitive Areas - a..- Parking lots greater than or equal to 5,000 ft' or with at least 15 parking spaces, and potentially exposed to urban runoff - - Streets, roads, highways, and freeways which would create a new paved surface that is 5,000 square feet or greater - - * Refer to the definitions section in the Storm Water Standards for expanded definitions of the priority project categories. Limited Exclusion: Trenching and resurfacing work associated with utility projects are not considered priority projects. Parking lots, buildings and other structures associated with utility projects are priority projects if one or more of the criteria in Part A is met. If all answers to Part A are "No", continue to Part B. 30 Storm Water Standards 4/03/03 Part' B: Determine Standard Permanent Storm Water Reauirements. Does the project propose: Yes No New impervious areas, such as rooftops, roads, parking lots, driveways, paths and sidewalks? New pervious landscape areas and irrigation systems? Permanent structures within 100 feet of any natural water body? Trash storage areas? - Liquid or solid material loading and unloading areas? - - Vehicle or equipment fueling, washing, or maintenance areas? - Require a General NPDES Permit for Storm Water Discharges Associated with Industrial Activities (Except construction)?* Commercial or industrial waste handling or storage, excluding typical office or household waste?- - Any grading or ground disturbance during constructiOn? '-.- Any new storm drains, or alteration to existing storm drains? - *10 find out if your project is required to obtain an individual General NPDES Permit for Storm Water Discharges Associated with Industrial Activities, visit the State Water Resources Control Board web site at, ww.swrcb.ca.gov/stormwtr/industrial.html Section 2. Construction Storm Water BMP Requirements: If the answer to question I of Part C is answered "Yes," your project is subject to Section IV, "Construc:ion Storm Water BMP Performance Standards," and must prepare a Storm Water Pollution Prevention Plan (SWPPP). If the answer to question I is "No," but the answer to any of the remaining questions is "Yes," your project is subject to Section IV, "Construction Storm Water BMP Performance Standards," and must prepare a Water Pollution Control Plan (WPCP). If every question in Part C is answered "No," your project is exempt from any construction storm water BMP requirements. If any of the answers to the questions in Part C are "Yes," complete the construction site prioritization in Part C', below. Part C: Determine Construction Phase Storm Water Reauirements. Would the project meet any of these criteria during construction? Yes No Is the project subject to California's statewide General NPDES Permit for Storm Water - Discharges Associated With Construction Activities? 5vr L6 L5 TH*N f A. - - Does the project propose grading or soil disturbance? Would storm water or urban runoff have the potential to contact any portion of the construction area, including washing and staging areas? - - Would the project use any construction materials that could negatively affect water quality if discharged from the site (such as, paints, solvents, concrete, and stucco)? - 31 Storm Water Standards 4103/03 Part 0: Determine Construction Site Priority In accordance with the Municipal Permit, each construction site with construction storm Water BMP requirements must be designated with a priority: high, medium or low. This prioritization must be completed with this form, noted on the plans, and included in the SWPPP or WPCP. Indicate the project's priority in one of the check boxes using the criteria below, and existing and surrounding conditions of the project, the type of activities necessary to complete the construction and any other extenuating circumstances that may pose a threat to water quality. The City reserves the right to adjust the priority of the projects both before and during construction. [Note: The construction priority does NOT change construction BMP requirements that apply to projects; all construction BMP _, requirements must be identified on a case-by-case basis. The construction priority does affect the frequency of inspections that will be conducted by City staff. See Section IV.1 for more details on construction BMP requirements.] U A) High Priority Projects where the site is 50 acres or more and grading will occur during the rainy season Projects 5 acres or more. 3) Projects 5 acres or more within or directly adjacent to or discharging directly to a coastal lagoon or other receiving water within an environmentally sensitive area Projects, active or inactive, adjacent or tributary to sensitive water bodies B) Medium Priority Capital Improvement Projects where grading occurs, however a Storm Water Pollution Prevention Plan (SWPPP) is not required under the State General Construction Permit (i.e., water and sewer replacement projects, intersection and street re-alignments, widening, comfort stations, etc.) Permit projects in the public right-of-way where grading occurs, such as installation of sidewalk, substantial retaining walls, curb and gutter for an entire street frontage, etc. ,.however SWPPPs are not required. 3) Permit projects on private property where grading permits are required, however, Notice Of Intents (NOls) and SWPPPs are not required. £J C) Low Priority Capital Projects where minimal to no grading occurs, such as signal light and loop installations, street light installations, etc. Permit projects in the public right-of-way where minimal to no grading occurs, such as pedestrian ramps, driveway additions, small retaining walls, etc. Permit projects on private property where grading permits are not required,, such as small retaining walls, single-family homes, small tenant improvements, etc. 32 APPENDIX B BMP DESIGN CRITERIA B.13 VEGETATIVE SWALE DESCRIPTION Vegetated swales are shallow vegetated channels to convey stormwater where pollutants are removed by filtration through grass and infiltration through soil. They look similar to, but are wider than, a ditch that is sized only to transport flow. They require shallow slopes and soils that drain well. Grassed swale designs have achieved mixed performance in pollutant removal efficiency. Moderate removal rates have been reported for suspended solids and metals associated with particulates such as lead and zinc. Runoff waters are typically not detained long enough to effectively, remove ,very fine suspended solids, and swales are generally unable, to remov significant amounts of dissolved nutrients. Pollutant removal capability is related to channel dimensions, longitudinal slope, and type of vegetation. Optimum design of these components will increase contact time of runoff through the swale and improve pollutant removal rates. Vegetated swales are primarily stormwater conveyance systems. They can provide sufficient control under light to moderate runoff conditions, but their ability to control large storms is limited. Therefore, they are most applicable in low to moderate sloped areas as an alternative to ditches and curb and gutter drainage. Their performance diminishes sharply in highly urbanized settings. Vegetated swales are often used as a pretreatment measure for other downstream BMPs, particularly infiltration devices. Enhanced vegetative swales utilize check dams and wide depressions to increase runoff storage and promote greater settling of pollutants. ADVANTAGES Relatively easy to design, install and maintain. Vegetated areas that would normally be included in the site layout, if designed for appropriate flow patterns, may be used as a vegetated swale. Relatively inexpensive. . . . Vegetation is usually pleasing to residents. LIMITATIONS Irrigation may be necessary to maintain vegetative cover. Potential for mosquito breeding areas. Possibility of erosion and channelization over time. Requires dry soils with good drainage and high infiltration rates for better pollutant removal. . May 17, 2000 B-65 APPENDIX B BMP DESIGN CRITERIA Not appropriate for pollutants toxic to vegetation. Large area requirements may make this BMP infeasible for some sites. Used to serve sites less than 10 acres in size, with slopes no greater than 5 percent. The seasonal high water table should be at least 2 feet below the surface. Buildings should be at least 10 feet from the site. DESIGN CRITERIA Several criteria should be kept in mind when beginning swale design. These provisions, presented in Table 1, have been developed through a series of evaluative research, conducted on swale performance. Table 1. Criteria for optimum swale performance (Homer, 1993). Parameter ' Optimal Criteria Minimum Criteria* Hydraulic Residence Time 9 min 5 mm Average Flow Velocity 0.9 ft/s Swale Width 8 ft 2 It Swale Length 200 ft 100 ft Swale Slope • 2 -6% ' 1% Side Slope Ratio (horizontal:vertical) 4: 1 2 :1 * Criteria at or below minimum values can be used when compensatory adjustments are made to the standard design. Specific guidance on implementing these adjustments will be discussed in the design section. The procedures described below were set forth by Homer, and unless otherwise cited, are set forth in Blo filtration for Stormwater Runoff Quality Control, published in 1993. The following steps are recommended to be conducted in order to complete a swale design: Determine the flow rate to the system. Determine the slope of the system. Select a swale shape (skip if filter strip design). Determine required channel width. Calculate the cross-sectional area of flow for the channel. Calculate the velocity of channel flow. Calculate swale length. Select swale location based on the design parameters. Select a vegetation cover for the swale. Check for swale stability. May 17, 2000 , B-66 APPENDIX B BMP DESIGN CRITERIA Recommended procedures for each task are discussed in detail below. Determine Flow Rate to the System. Calculate the flow rate of stormwater to be mitigated by the vegetated swale using the Los Angeles County Department of Public Works Method for Calculating Standard Urban Storm water Mitigation Plan (SUSMP) Flow Rates and Volumes Based on 0.75-inches of Rainfall. Runoff from larger events should be designed to bypass the swale, consideration must be given to the control of channel erosion and destruction of vegetation. • A stability analysis for larger flows (up to the 100-yr 24-hour) must be performed. If the flow rate approaches or exceeds I ft3ls, one or more of the design criteria in Table imay be violated, and the swale system may, notfUnction correctly (Washington State Department of Transportation, 1995).. Altemative measures to lower the design flow should be investigated. Possibilities include dividing the flow among several swales, installing detention to control release rate upstream, and reducing developed surface area to reduce runoff coefficient value and gain space for biofiltration (Homer, 1993). Determine the Slope of the System. The slope of the swale will be somewhat dependent on where the swale is placed, but should be between the stated criteria of one and six percent. Select a Swale Shape. Normally, swales are designed and constructed in a trapezoidal shape, although alternative designs can be parabolic, rectangular, and triangular. Trapezoidal cross-sections are preferred because of relatively wider vegetative areas and ease of maintenance (Khan, 1993). They also avoid the sharp corners present in V- shaped and rectangular swales, and offer better stability than the vertical walls of rectangular swales. Determine Required Channel Width. Estimates for channel width for the selected shape can be obtained by applying Manning's: 1.486ARh0667S 0.5 n Where: Q = Flow (ft3ls). A = Cross-sectional area of flow (ft2). Rh = Hydraulic radius of flow cross section (ft). S = Longitudinal slope of biofilter (ft/ft). n = Manning's roughness coefficient. May 17, 2000 6-67 APPENDIX B BMP DESIGN CRITERIA A Manning's n value of 0.02 is used for routine swales that will be mowed with some regularity. For swales that are infrequently mowed, use a Manning's n value of 0.024. A higher n value can be selected if it is known that vegetation will be very dense (Khan, 1993). Figure 1 presents channel geometry and equations for a trapezoidal swale, the most frequently used shape. WT JH Y Z elff Figure 1. Channel geometry for a trapezoid swaie. Cross Sectional Area(A)' by' zy 2 Width(w)' b' 2yz Hydraulic Radius (Rh)' by. 2y by' 2ys/z2. 1 Substituting the geometric equations presented in Figure 1 into Manning's equation, the bottom width (Wb) and the top width (Wt) for the trapezoid swale can be computed using the following equations: w ' Qn •zH ' y 167 s05 W' Wb' 2zH (3) May 17, 2000 B-68 APPENDIX B BMP DESIGN CRITERIA Where: Q = Flow rate in ft3/s. n = Manning's roughness coefficient. Y Depth of flow. H = The side slope in the form of z: 1. For trapezoidal and the limited case of V-shapes, the side slope (z) used should be at least 3:1 (horizontal:vertical). V-shaped swales should be double checked after computation of wt to make sure that z = 2w is at least 3. If a slope steeper than 2:1 must be used, additional stabilization measures (i.e., lining the swale with riprap) may be needed. Typically, the depth of flow in the channel (H) is set at to 4 inches. Flow depth can also be determined by subtracting 2 inches from the expected grass height, if the grass type and the height it will be maintained is known. Values lower than 3 to 4 inches can be used, but doing so will increase the computed width (wt or Wb) of the swale (Washington State Department of Transportation, 1995). Swale width computed should be between 2 to 8 feet. Relatively wide swales (those wider than 8 feet are more susceptible to flow channelization and are less likely to have uniform sheet flow across the swale bottom for the entire swale length. The maximum widths for swales is on the order of 10 feet, however widths greater than 8 feet should be evaluated to consider the effectiveness of the flow spreading design used and the likelihood of maintaining evenness in the swale bottom. Since length may be used to compensate for width reduction (and vice versa) so that area is maintained, the swale width can be arbitrarily set to 8 feet to continue with the analysis. If b is less than 2 feet, set b = 2 feet and continue. Narrower widths can be used if space is very constrained. Sometimes when the flow rate is very low, the equation above can generate a negative value for Wb. Since this is not possible, the bottom width should be set to 1 feet when this occurs. Calculate Cross-Sectional Area. Compute the cross-sectional area (A) for the swale, using the following equation: Ax • (wb . 2zH)yH (4) Calculate the Velocity of the Channel Flow. Channel flow velocity (U) can be computed using the continuity equation: May 17, 2000 B-69 APPENDIX B BMP DESIGN CRITERIA U.. AX (5) This velocity should be less than 0.9 ftfs,a velocity that was found to cause grasses to be flattened, reducing filtration. A velocity lower than this maximum value is recommended to achieve the 9-minute hydraulic residence time criterion,: particularly in shorterswales (at U = 0.9 ft/s. a 485-ft swale is needed for a 9-min residence time and a 269-ft swale for a 5-mm. residence time). if the value of U suggests that a longer swale will be needed than space permits, investigate how the design flow Q can be reduced, or increase flow depth (H) and/or swale width (wt) up to the maximum allowable values and repeat the analysis. 7. Calculate Swale Length. Compute the swale length (L) using the following equation: L • Utr (60 s/mm) (6) Where: tr = Hydraulic residence time (in minutes). Use tr = 9 min for this calculation. If a swale length greater than the space will permit results, investigate how the design flow Q can be reduced. Increase flow depth (H) and/or swale width (Wb) up to the maximum allowable values and repeat the analysis. If all of these possibilities are checked and space is still insufficient, t can be reduced, but to no less than 5 minutes. If the computation results in L less than 100 ft, set L = 100 ft and investigate possibilities in width reduction. This is possible through recalculating U at the 100-ft length, recomputing cross-sectional area, and ultimately adjusting the swale width Wb using the appropriate equation. 8. Select Swale Location. Swale geometry should be maximized by the designer, using the above equations, and given the area to be utilized. If the location has not yet been chosen, it is advantageous to compute the required swale dimensions and then select a location where the calculated width and length will fit. If locations available cannot accommodate a linear swale, a wide-radius curved path can be used to gain length. Sharp bends should be avoided to reduce erosion potential. Regardless of when and May 17, 2000 B-70 APPENDIX B BMP DESIGN CRITERIA how site selection is performed, consideration should be given to the following site criteria: Soil Type. Soil characteristics in the swale bottom should be conducive to grass growth. Soils that contain large amounts of clay cause relatively low permeability and result in standing water, and may cause grass to die. Where the potential for leaching into groundwater exists, the swale bottom may need to be sealed with clay to protect from infiltration into the resource. Compacted soils will need to be tilled before seeding or planting. If topsoil is required to facilitate grass seeding and growth, use 6 inches of the following recommended topsoil mix: 50 to 80 percent sandy loam, 10 to 20 percent clay, and 10 to 20 percent composted organic matter (exclude animal waste). Slope. The natural slope of the potential location will determine the nature and amount of regrading, or if additional measures to reduce erosion and/or increase pollutant removal are required. Swales should be graded carefully to attain uniform longitudinal and lateral slopes and to eliminate high and low spots. If needed, grade control checks should be provided to maintain the computed longitudinal slope and limit maximum flow velocity (Urbonas, 1992). Natural Vegetation. The presence and composition of existing vegetation can provide valuable information on soil and hydrology. If wetland vegetation is present, inundated conditions may exist at the site. The presence of larger plants, trees and shrubs, may provide additional stabilization along the swale slopes, but also may shade any grass cover established. Most grasses grow best in full sunlight, and prolonged shading should be avoided. It is preferable that vegetation species be native to the region of application, where establishment and survival have been demonstrated. 9. Select Vegetative Cover. A dense planting of grass provides the filtering mechanism responsible for water quality treatment in swales. In addition, grass has the ability to grow through thin deposits of sediment and sand, stabilizing the deposited sediment and preventing it from being resuspended in runoff waters. Few other herbaceous plant species provide the same density and surface per unit area. Grass is by far the most effebtive choice of plant material in swales, however not all grass species provide optimum vegetative cover for use in swale systems. Dense turf grasses are best for vegetative cover. Table 2 lists several turf grasses, and their suitability in terms of cold tolerance, heat tolerance, mowing height adaptation, drought tolerance, and maintenance cost and effort. In areas of poor drainage, wetlands species can be planted for increased, vegetative cover. Use wetland species that are finely divided like grass and relatively resilient. Invasive species, such as cattails, should be avoided to eliminate proliferation in the May 17, 2000 B-71 APPENDIX B BMP DESIGN CRITERIA swale and downstream. Woody or shrubby plantings can be used for landscaping on the edge of side slopes, but not in the swale treatment area. Trees and shrubs can provide some additional stabilization, but also mature and shade the grass. In addition, leaf or needle drop can contribute unwanted nutrients, create debris jams, or interfere with waterfiow through the system. If landscape plantings are to be used, selection and planting processes should be carefully planned and carried out to avoid these potential problems. Cold Tolerance Heat Tolerance Mowing Height Drought Tolerance Maintenance Creeping bentgrass Zovsia grass Tall f Hybrid bermuda Creeping bentgrass Dichondra Zoysia grass Kentucky bluegrass Hybrid ocr Common bermuda grass k. ILLt,a 5taaa ntgrass Xrass Red fescue St Augustine grass Highland Kentucky bluegrass Perennial zyegrass Weeping alkali grass Tall fescue Dichondra Creeping bentgrass St. Augustinegrass Common bermudagrass Kentucky bluegrass Hybrid bermuda grass Kentucky bluegrass Colonial bentgrass Perennial iyegrass Highland bentgrass Tall fescue Perennial iyegrass Weeping alkali grass Colonial bentgrass Dichondra Tall fescue Kikuy grass Red fescue Colonial bentgrass Highland bentgrass Zoysiagrass St. Augustine grass Highland bentgrass Zoysia grass Hybrid bermudagrass Dichondra Weeping alkaligrass Creeping bentgrass Kentuckf bluegrass Tall fescue Zoysia grass Red fescue Perennialryegrass Common bermuda grass Common bermuda grass Highland bentgrass j(jj grass Hybrid bermuda grass Creeping bentgrass Kikuyu grass Colonial bentgrass St. Augustine grass Weeping alkaligrass Dichondra Table 2. Criteria for turf grass cover (Camp, Dresser and McKee, 1993.) May 17, 2000 B-72 High Low I APPENDIX B BMP DESIGN CRITERIA 10. Check Swale Stability. The stability check is performed for the combination of highest expected flow and least vegetation coverage and height. Stability is normally checked for flow rate (Q) for the 100-yr1 24-h storm unless runoff from larger such events will bypass the swale. Q can be determined using the same methods mentioned for the initial design, storm computation. The maximum velocity (U) in ft/s, that is permissible for the vegetation type,,' slope, and soil conditions should be obtained. Table 3 provides maximum velocity data for a variety of vegetative covers and slopes. Table 3. Guide for selecting maximum permissible swale velocities for stability (adapted from Chow [1959], Livingston, 0 al., [1984], and Goldman, eta]., [1986] from Homer [1993]). Maximum Velocity (ftls) Cover Type Slope (%) Erosion-resistant soils Easily eroded soils Kentucky bluegrass Tall fescue 0 -5 6 5 Kentucky bluegrass Ryegrasses Western wheat-grass 5-10 5 4 Grass-legume 0 -5 5 4 Mixture 5-10 4 3 Red fescue 0-5 3 2.5 The estimated degree of retardance for different grass coverage ("good" or "fair") should be obtained for the selected vegetation height. Estimation should be based on coverage and height will first receive flow, or whenever coverage and height are at their lowest. Table 4 provides qualitative degree of retardance for coverage and grass height. Table 4. Grass height, and degree of retardance (Homer, I Average Grass Height (mm [inches)) Degree of Retardance - Coverage = "Good" > 760 (30) Very high 280-610(11-24)' High 150- 270 (6- 10) Moderate 50- 150 (2 - 6) Low > 50 (>2) Very low Coverage = "Fair" > 760 (30) B. High May 17. 2000 B73 APPENDIX B BMP DESIGN CRITERIA Table 4. Grass coverage, height, and degree of retardance (Homer, 1993). Average Grass Height (mm finches)) Degree of Retardance 280- 610 (11 -24) Moderate 150- 270 (6 - 10) Low 50 - 150 (2 - 6) D. Low > 50 (>2) Very low Select a trial Manning's n value for poor vegetation cover and low height. A good initial choice is n = 0.04. Using the alphabetic code assigned for the degree of retardance and the chosen n value, consult the following graph to obtain a first approximation for URh (velocity x hydraulic radius). The graph in Figure 2 was derived based on English units. Compute the hydraulic radius, using the t4 determined for vegetation type and slope, by applying the following equation: URh 0 URh (7) max Use Manning's equation to solve for the actual URh: VR • .1 RL67 NO.5 (8) May 17, 2000 B-74 APPENDIX B BMP DESIGN CRITERIA uuuii -imllfll__ IIIIIu! !gIE __ •uii ii I me •I!II I -- . - __ IIIUI — 111111__1 E_..iulii _ Once the actual URh is determined, compare this value with the first approximation for URh obtained through Figure 2. If they do not agree within five percent, adjust Manning's n value and repeat the process until acceptable agreement is reached. If n < 0.033 is needed to get agreement, set n = 0.033, solve URh again using Manning's equation above, and proceed. The actual velocity for the final design conditions should be computed using the following equation: URh (9) The actual velocity U should be less than the U=x value obtained from Table 3. The area (Ax) required for stability should be computed from the following equation: May 17, 2000 B-75 APPENDIX B BMP DESIGN CRITERIA AX 0 U (10) The area value obtained in this procedure should be compared with the area (Ar) value obtained in the capacity analysis. If less area is required for stability than is provided for capacity, the design is acceptable. If more area is required for stability, use the area (Ax) value obtained in the stability analysis to recalculate channel dimensions. The depth of flow at the stability check design flow rate then needs to be computed for the final dimensions of the swale by solving for yin the area equations provided on Figure 2. Compare this flow depth to the depth used in the capacity design. The larger of the two values should be used, plus 1 ft of freeboard, to obtain the total depth of the swale. The top width for the full depth of the swale should than be recalculated. As a final check for capacity should be performed based on the stability check design storm, maximum vegetation height and cover to ensure that capacity is adequate if the largest expected event coincides with the greatest retardance. Using Manning's equation, the Manning's n value used for capacity design, and the calculated channel dimension (including freeboard) to compute the flow capacity of the channel. If the flow capacity is less than the stability check design storm flow rate, increase the channel cross-sectional area as needed for this conveyance, and specify the new channel dimensions. REFERENCES Camp, Dresser and McKee, Inc., Larry Walker Associates, 1993. California Best Management Practices - Municipal, California State Water Resources Council Board, Alameda, CA. Colorado Department of Transportation, 1992, Erosion Control and Storm water Quality Guide, Colorado Department of Transportation. DEQ Storm Water Management Guidelines, Department of Environmental Quality, State - of Oregon. http://wate6ualily.deg.state.or.us/wqLciroundwa/Swmqmtauide.htm GKY and Associates, Inc. June 1996. Evaluation and Management of Highway Runoff Water Quality, Publication No. FHWA-PD-96-032. Prepared for: US Department of Transportation, Federal Highway Administration. Washington, DC. May 17, 2000 B-76 APPENDIX B BMP DESIGN CRITERIA R. R. Homer, 1993. Biofiltration for Storm Runoff Water Quality Control, prepared for the Washington State Department of Ecology, Center for Urban Water Resources Management, University of Washington, Seattle, WA. Z. Khan, C. Thrush, P. Cohen, L. Kuzier, R. Franklin, D. Field, J. Koon, and R. Homer, 1993. Bio filtration Swale Performance Recommendations andDesign Considerations, Washington Department of Ecology, University of Washington, Seattle, WA. K. H. Lichten, June 1997. Compilation of New Development Stormwater Treatment Controls in the San Francisco Bay Area, Bay Area Stormwater Management Agencies Association, San Francisco, CA. Low-Impact Development Design Manual, November 1997. Department of Environmental Resources, Prince George's County, MD. T. R. Schueler, P. Kumble, and M. Heraty, 1992. A Current Assessment of Urban Best Management Practices: Techniques for Reducing Nonpoint Source Pollution in the Coastal Zone, Anacostia Research Team, Metropolitan Washington Council of Governments, Washington, DC. B. R. Urbonas, J. T. Doerfer, J. Sorenson, J. T. Wulliman, and T. Fairley, 1992. Urban Storm Drainage Criteria Manual, Volume 3- Best Management Practices, Stormwater Quality, Urban Drainage and Flood Control District, Denver, CO. Ventura Countywide Stormwater Quality Management Program, Draft BMP BF: Bio filters, June 1999 Ventura, CA. Washington State Department of Transportation, .1995. Highway Runoff Manual, Washington State Department of Transportation. May 17, 2000 B-77 APPENDIX B BMP DESIGN CRITERIA The following is a list of known locations where a Vegetated Swale was installed. The design of the installed swale in each location may vary from what is recommended in this SUSMP due to its specific circumstances. Los Angeles County does not endorse nor warranty any design used in the locations herein. Each individual case may require that the design be tailored to perform properly. Installed Location (City/Address) Brand/Manufacturer Owner/Client Cerritos Maintenance Station N/A Caltrans 1-605/Del Amo Ave. N/A Caltrans May 17, 2000 B-78 Appendix C - Structural BMP Swale Calculation Node 108 Given Input Data: Shape Trapezoidal Solving for Depth of Flow Flowrate 0.02 cfs Slope 0.01 ft/ft Manning's n 0.0240 Height 4.00 in Bottom width 4.00 ft Left slope 0.25 ft/ft (V/H) Right slope 0.25 ft/ft (V/H) Computed Results: Depth 0.014 in Velocity 0.35 fps Full Flowrate 4.44 cfs Flow area 0.05 ft2 Flow perimeter 4.11 in Hydraulic radius 0.01 in Top width 4.11 in Area 1.76 ft2 Perimeter 6.72 in Percent full 4.21% Storm Water Management Plan Site Development Plan for 1265 Carlsbad Village Drive Buccola Engineering, Inc. Carlsbad Village Drive Investors, LLC Appendix C - Structural BMP Swale Calculation Node 208 Given Input Data: Shape Solving for Flowrate Slope Manning's n Height Bottom width Left slope Right slope Computed Results: Depth Velocity Full Flowrate Flow area Flow perimeter Hydraulic radius Top width Area Perimeter Percent full Trapezoidal Depth of Flow 0.07 cfs 0.01 ft/ft 0.0240 4.00 in 4.00 ft 0.25 ft/ft (V/H) 0.25 ft/ft (V/H). 0.029 in 0.58 fps 4.44 cfs 0.12 ft2 4.24 in 0.03 in 4.24 in 1.76 ft2 6.72 in 8.91 % Storm Water Management Plan Site Development Plan for 1265 Carlsbad Village Drive Buccota Engineering, Inc. Carlsbad Village Drive Investors, LLC APPENDIX "D" Operations & Maintenance Plan for 1265 Carlsbad Village Drive Prepared for: Carlsbad Village Drive Investors, LLC 1241 Carlsbad Village Drive Suite 100 Carlsbad, California 92008 (760)434-1400 • Prepared by: Buccola Engineering, Inc. 3142 Vista Way Suite 301 Oceanside, California 92056 May 05, 2004 172-1 Operation & Maintenance Plan for: 1265 Carlsbad Village Drive Buccola Engineering, Inc. TABLE OF CONTENTS Statement of Designated Responsible Party 1.0 Introduction 2.0 Purpose 3.0 Designated Responsible Party 4.0: Permanent Treatment Control (Structural) Control BMPs 5.0 Operation & Maintenance 5.1 Training 5.2 Inspections 5.3 Maintenance 6.0 Summary and Conclusion Figures Figure 1 - Permanent Structural BMP Location Exhibit Appendices Appendix I - Training Records Appendix II - Routine Maintenance Activities Appendix Ill - Inspection Checklists Operation & Maintenance Plan for: 265 Carlsbad Village Drive Buccola Engineering, Inc. Statement of Designated Responsible Party The undersigned "Designated Responsible Party" accepts responsibility for the inspection, maintenance, repair and replacement of the "permanent treatment" storm watàr' BMP(s); pursuant to the approved "Storm Water Management Plan for 1265 Carlsbad Village Drive" and in accordance with "Section V- Implementation & Maintenance of Requirements" of the Standard Urban Storm Water Mitigation Plan. The undersigned acknowledges that the City has the authority to submit a warning or a citation should a permanent treatment BMP fall into disrepair as a result of poor maintenance practices. The undersigned also acknowledges that upon receipt of repeated warning or citation and with prior written notification, that the "City has the right, but not the obligation, to perform maintenance" on the permanent treatment BMP. -. - Therefore, upon prior written notification, the undersigned grants access to the permanent. treatment BMP in favor of the City of Carlsbad, for the purpose of corrective maintenance to the permanent treatment BMP. In addition, and pursuant to Section V.4.1 of the City of Carlsbad Standard Urban Storm Water Mitigation Plan, the undersigned further agrees to reimburse the City for costs incurred as a result of maintenance to the site permanent treatment BMP. The undersigned also acknowledges that there are significant penalties for submitting false information, including the possibility of fine and imprisonment for knowing violations. Project Proponent: Frank Violi Signature Date Operation & Maintenance Plan for.- 1265 Carlsbad Village Drive Buccola Engineering, Inc. 1.0 Introduction The City of Carlsbad is identified as a Municipal Copermittee under Section 1 of the California Regional Water Quality Control Board, San Diego Region (SDRWQCB), Order No. 2001-01. Asa Copermittee, under Section 10 of the aforementioned order, the City of Carlsbad is responsible for implementing an Urban Runoff Management Program (URMP) that is designed to reduce discharges of pollutants that flow into and from MS4s to the maximum extent practicable (MEP). Moreover, the City of Carlsbad, under Section D. 1 of said order, has authority to establish, maintain and enforce adequate legal authority to control pollutant discharges into and from its MS4 through ordinance, statute, permit, contract or similar means. Pursuant to Section D.1 of SDRWQCB Order No. 2001-01, the City of Carlsbad his prepared and adopted a SUSMP to define Urban Runoff Requirements for Priority New Development and Redevelopment Projects. The 1265 Carlsbad Village Drive is a "discretionary action" project and is therefore subject to the requirements of the SUSMP. Operation & Maintenance Plan for: 1265 Cadsbad Village Drive Buccola Engineering, Inc. 2.0 Purpose The purpose of this 0 & M Plan is to comply with the terms of the City of Carlsbad - Standard Urban Storm Water Mitigation Plan (SUSMP) and to provide a set of guidelines directed toward the implementation of an inspection and maintenance program that will ensure the intended, long-term function, of the project's "permanent treatment" BMPs. Section V.4.1 of the SUSMP,.states the following: "The maintenance agreement shall include the following: Operations & Maintenance (O&M) Plan. The applicant shall include an Operation & Maintenance (O&M) plan, prepared satisfactory to the City, with the approved maintenance agreement, which describes the designated responsible party to manage the storm water BMP(s), employee's training program and duties, operating schedule, maintenance frequency, routine service schedule, specific maintenance activities (including maintenance of storm water conveyance system stamps), copies of resource agency permits, and any other necessary activities. At a minimum, maintenance agreements shall require the applicant to provide inspection and servicing of all permanent treatment BMPs on an annual basis. The project proponent or City-approved maintenance entity shall complete and maintain O&M forms to document all maintenance requirements. Parties responsible for the O&M plan shall retain records for at least 5 years. These documents shall be made available to the City for inspection upon request at any time. Access Easement/Agreement: If a permanent BMP requires access for maintenance, as part of the O&M plan, the applicant shall execute and record an access easement or agreemerit that shall be binding on the under lying land throughout the life of the project in favor of the party responsible for maintenance, until such time that the permanent treatment BMP requiring access for maintenance is removed or replaced. The City shall approve any changes to permanent BMP's, O&M Plans or access agreements. The agreement shall include a provision that gives the City the right, but not the obligation to perform the maintenance. The party responsible for BMP maintenance will pay the City for any and all costs incurred by the City for maintaining any BMP's. The agreement will provide a cost recovery provision in favor of the City satisfactory to the City Attorney." Note that access to the permanent treatment BMP for maintenance purposes is granted to the City as noted in the "Statement of Designated Responsible Party". The 1265 Carlsbad Village Drive project is also subject to conditions cited in Planning Resolution No. 5506. The conditions relevant to storm water concerns are as follows: Operation & Maintenance Plan for: 265 Cafisbad Village Drive Buccola Engineering, Inc. 2.0 Purpose (cont.) (28.) Prior to issuance of grading permit or building permit, whichever occurs first, Developer shall submit for City. approval a "Storm Water Management Plan (SWMP)." The SWMP shall demonstrate compliance with the City of Carlsbad Standard Urban Runoff Mitigation Plan (SUSMP), Order 2001-01 issued by the San Diego Region of the California Regional Water Quality Control Board and the City of Carlsbad Municipal Code. The SWMP shall address measures to avoid contact or filter said pollutants from storm water, to the maximum extent practicable, for the post-construction stage of the project. At a minimum, the SWMP shall: Identify existing and post-development on-site pollutants-of- concern; Identify the hydrologic unit this project contributes to and impaired bodies that could be impacted by this project; C. Recommended source controls and treatment controls that will be implemented with this project to avoid contact or filter said pollutants from the storm water to the maximum extent practicable before discharging to City right-of-way; Establish specific procedures for handling spills and routine cleanup. Special considerations and effort shall be applied to resident education on the proper procedures for handling clean up and disposal of pollutants; ensure long-term maintenance of all post construction BMPs in perpetuity; f, identify how post-development runoff rates and velocities from the site will not exceed the pre-development runoff rates and velocities to the maximum extent practicable. Operation & Maintenance Plan for: 1265 Carlsbad Village Drive Buccola Engineering, Inc. 3.0 Designated Responsible Party Section V.4.1 - Operation & Maintenance (O&M) Plan of the SUSMP, states that the Plan shall describe the "Designated Responsible Party" to manage the storm water BMPs, employee's training program and duties, operating schedule, maintenance frequency, routine service schedule, specific maintenance activities (including maintenance of storm water conveyance system stamps), copies of resource agency permits and any other necessary activities.. .the project proponent or City approved maintenance entity shall complete and maintain O&M forms to document all maintenance requirements. Operation & Maintenance Plan for: 1265 Carlsbad Village Drive Buccola Engineering, Inc. 4.0 Permanent Treatment Control (Structural) BMPs Treatment Control (Structural) control BMPs are defined in the SUSMP - Appendix I - Definitions, as "any engineered system designed and constructed to remove pollutants from urban runoff. Pollutant removal is achieved by simple gravity settling of particulate pollutants, filtration, biological uptake, media absorption or any other physical, biological, or chemical process." Treatment BMPs may be further be categorized as volume or flow-based BMPs. An example of a flow-based BMP is a grass-lined swale, while a detention pond is an example of a volume-based BMP. Whether categorized as a volume or a flow-based, the BMPs are designed to treat the "first flush" of storm runoff. The first flush may be described as the runoff, which accumulates on a watershed during - the initial phase of a storm (rainfall) event. The anticipated volume of runoff is 16w however, tends to contain higher concentrations of pollutants. The 1265 Carlsbad Village Drive' employs a single, flow-based, grass-lined swale BMP and landscape areas to treat the site storm runoff. The BMP was selected on basis of pollutant removal efficiency, site constraints and the relative ease of maintenance. The location of the permanent treatment control BMP is delineated on Figure 1 - Permanent Treatment BMP Location Exhibit. Operation & Maintenance Plan for: 1265 Carlsbad Village Drive Buccola Engineering, Inc. 5.0. Operations & Maintenance For the structural BMPs to function as designed, it is necessary to implement a comprehensive O&M Plan. Key elements of a sound O&M Plan include training, inspection and maintenance. 5.1 Training It is essential that the Owner/Designated Responsible Party and maintenance forces receive specific training to enable the intended function of the structural BMPs. Storm water pollution control seminars are available, to the public, through City, County and private organizations such as the Building Industry Association (BIA). The courses are tailored to address specific topics. Topics generally covered include National Pollution Discharge Elimination System (NPDES) Regulations and Best Management Practices. It is the responsibility of the Owner to obtain training specifically tailored to address inspection, operation and maintenance of the site treatment BMPs. Owner training shall be verified by providing a certificate of attendance. Maintenance activities are often subcontracted to outside sources. In the event of such occurrence, proof of contractor training shall be provided to the Owner in the form of a certificate of attendance and/or affidavit, from the contractor, to that effect. This manual recommends that-the Owner and maintenance personnel receive training at least once every five years, or as notified by the City of Oceanside. Owner/Designated Responsible Party and Employee/Contractor training records shall be maintained for a period of no less than five (5) years. Training records shall be filed in Appendix I. Operation & Maintenance Plan for: 1265 Carlsbad Village Drive Buccola Engineering, Inc. 5.2 Inspections The routine inspection component of the O&M Plan serves as a mechanism to proactively identify potential and existing problems that may impair the intended function of a source control or structural BMP. The inspector must assess the condition and effectiveness of each element of a source control or structural BMP. The findings of such inspections will subsequently affect maintenance activities. Section V.4.1, of the SUSMP, recommends that inspections be performed on an annual basis. This manual recommends that inspections be conducted in September and May of each year. This schedule coincides with the "official rainy season" that begins October 1St and ends April 30th of each year. Adoption of this schedule will provide ample time to perform corrective maintenance to structural BMPs, before and after the rainy season. All corrective maintenance shall be completed by October ls, to coincide with the official beginning of the rainy season. Additional inspections shall be performed after storm events producing greater than 1" of rainfall as reported by the National Weather Service. Source Control BMPs The 1265 Carlsbad Village Drive has source control BMPs located on or in the vicinity of the Treatment BMP as delineated on Figure 1 of this Plan. The inspection of the source control BMPs shall include: Condition of signage Check for unobstructed view of signage Condition of inlet stenciling (if applicable) Check for unobstructed view of stenciling The 1265 Carlsbad Village Drive landscape and irrigation system is laid out in such a manner as to provide groundcover and canopy landscape that requires a minimum amount of irrigation. To ensure the proper operation of the irrigation system and to reduce the introduction of non-storm water flows to the storm drain system; the inspection of landscape and irrigation shall include the following: General condition of landscape ground cover and canopy Check for areas of bare soil within the landscape/slope areas Check condition or private drain within landscape areas,. note obstructions Check irrigation system for function, coverage & damage Operation & Maintenance Plan for: 1265 Carlsbad Village Drive Buccola Engineering, Inc. 6.2 Inspections (continued) Structural (Treatment) Control BMPs The 1265 Carlsbad Village Drive site employs a grass-lined swale and landscape areas to function as the site treatment BMPs. The location of the source control BMP and the treatment BMP watershed area are delineated on Figure 1 - Permanent Structural BMP Location Exhibit. Common maintenance problems associated with vegetated swales are; erosion, weed growth, maintaining grass, sedimentation and bank deterioration. Additional problems may include the presence of animal burrows the accumulation of trash or debris and inlet failure due to blockage. Grass-lined Swale Presence of trash and/or plant debris Presence of holes, ruts or animal burrows Condition of low-flow outfall locations Condition of filtering grass / groundcover Condition of swale bed and embankments Level of captured sediment (less than '/2") Condition of concrete apron Check irrigation system for function, coverage & overspray Sweep interior drive aisles, parking stalls and flatwork It is the responsibility of the Owner/Designated Responsible Party to complete the inspection checklist by performing field observations that will determine the condition of the checklist items and to assign directed corrective maintenance. Maintenance items that arise but do not appear on the list of routine maintenance activities shall be categorized as Non-routine maintenance operations. A written description of non-routine activities shall be completed at the bottom of the Inspection Checklist or as an attachment thereof. In addition, the inspecting party shall confirm, by field observation, that all corrective maintenance directives have been completed in a timely fashion, and in particular, prior to October 1st, the official start of the rainy season and shall indicate, by signature, the satisfactory completion thereof. The completed and signed checklist shall constitute an inspection record. Inspection records shall be maintained for a period of at least 5 years. An inspection check list is included as part of this plan as Appendix III. Operation & Maintenance Plan for: 1265 Catlsbad Village Drive Buccola Engineering, Inc. 5.3 Maintenance Structural BMP maintenance may be categorized as routine and non-routine maintenance operations. Routine maintenance operations are generally preventative measures, while non-routine maintenance activities tend to be corrective in nature. Routine maintenance may be characterized as "good housekeeping" and to a great extent is simply the removal of debris before it has an opportunity to enter the storm drain system. The Darwin Glentreatment BMPs are an integral part of the site landscape and therefore, shall receive regularly scheduled maintenance (every 2-4 weeks) as part of the overall landscape upkeep. Maintenance crews must pay particular attention to the use of fertilizers and pesticides to avoid excessive application and/or possible introduction to runoff. Routine maintenance of the structural BMPs will consist of the following: Grass-lined Swale Weed, debris & trash removal Check for holes, ruts or animal burrows Check condition of low-flow outfall location Trim/mow filtering grass/groundcover Check condition swale bed and embankments Check condition of Gravel Outfall, downstream of weir Remove captured sediment greater than 'A" deep Maintain clear low-flow inlet openings Replant/reseed as necessary to maintain coverage Check irrigation system for function, coverage and overspray Drive Aisle, Parking Stalls & Interior Sidewalks Weed, debris & trash removal Sweeping Landscape and Irrigation Weed, debris & trash removal Replant/reseed as necessary to maintain coverage Check irrigation for function, coverage and overspray A list of routine maintenance activities is included as part of this Plan and may be found in Appendix II. The list itemizes specific activities and the frequency thereof. It is the responsibility of the Owner to provide the maintenance contractor with the list of routine maintenance activities. The Owner and contractor shall sign the list of routine maintenance activity as an acknowledgement of receipt. Contractor billing activity shall provide a record of scheduled maintenance frequency. Maintenance records shall be kept on file for 5 years. Operation & Maintenance Plan for: 1265 Carlsbad Village Drive Buccola Engineering, Inc. 5.3 Maintenance (continued) The results of an inspection may deem that one or more the features of a structural BMP may require refitting, rehabilitation or replacement to maintain correct operation. These types of corrective action are not part of regularly scheduled maintenance and are categorized as non-routine maintenance activities. Specific examples of non-routine maintenance activities associated with the selected BMPs include: Aeration of filtering grass Removal of sod, tilling of topsoil and replacement of grass Repair of low-flow inlet structures . Cleaning of low-flow pipe(s) Reconstruction of swale bed and/or embankments Reconstruction or repair to swale irrigation system Repair or replacement of signage/stencils Non-routine maintenance operations are not specifically itemized on the inspection checklist or in Section 5.2. Provision is made for recordation of non-routine maintenance operations on the bottom of the inspection record located in Appendix III. Records of non-routine maintenance activities shall be maintained for a period of at least 5 years. Should the Owner encounter site conditions that require corrective action, which appear to be beyond his or her level of training or expertise, it is the recommendation of this manual that the Owner contact the City of Carlsbad, Engineering Department at (760) 602-2720. Operation & Maintenance Plan for: 1265 Cafisbad Village Drive Buccola Engineering, Inc. 6.0 Summary and Conclusion This O&M Plan has been prepared in accordance with the City of Carlsbad SUSMP and is intended to provide the Designated Responsible Party with minimum guidelines to establish an effective O&M schedule and system for recording such activities. This Plan recommends that the Designate Responsible Party become familiar with the approved SWMP for the subject project. The SWMP describes the intent, structure and function of the site design, source control and structural BMPs and is the basis for the development of this O&M Plan. A copy of the approved SWMP is available for review at the City of Carlsbad, Engineering counter. This plan also suggests that the Designated Responsible Party refer to the City of Carlsbad SUSMP for information regarding BMPs, definitions, general categories of water pollution and additional information resources. Copies of the SUSMP are available at the City of Carlsbad Engineering counter or on the web at www.ci.carlsbad.ca.us/cseerv/4susmp.html. It is possible that as Best Available Technologies (BATs) improve and the Regional Water Quality Control Board enacts more stringent water quality standards, that the structural BMPs may require upgrades or other improvements to improve pollutant removal efficiency. The proper and diligent implementation of an effective O&M Plan will help to keep maintenance costs in check, insure the proper function of the structural BMPs and protect water quality to the maximum extent practicable. Operation & Maintenance Plan for: 1265 Carlsbad Village Drive Buccola Engineering, Inc. FIGURES Operation & Maintenance Plan for: 1,265 Carlsbad Village Drive Buccola Engineering, Inc. E 1ST/Nc? FIR _SIAT1cJN I N SYSTEM W _____ 11GRA TED LOW—FLOW! L - SUBDIVISION BOUNDARY ROOF DRAINS TO 21 / LANDSCAPE (TYP) WILL ffMf vj t U] - -- -- ----_-----I __ CANOPY INTERCEPT/yE & COVERED TRASH I J FIL TRA TING LANDSCAPE (r,'P) r ENCLOSURE z C4 I -•• cn PROHIBITIVE SIcLAGk 3fl RAS_LI)YED cwA4E—j 7 0-25 CURB OUTLET. Ji flj 10MA 4LL] E APRON CONCRET III > 0 Pr. •.. -- .d__- - --. -- - —_.4- ----.•--•, -- -I C SUBDIVISION BOUNDARY C 80> PROHIBITiVE STENCILING A I J EXISTING_OfficEI B1/ILD'NG . I O LEGEND GRASS—LINED SWALE STRUCTURAL BMP - LANDSCAPE _____ NOT TO SCALE APPENDICES Operation & Maintenance Plan for: 1265 Carlsbad Village Drive Buccola Engineering, Inc. Appendix I - Training Records Operation & Maintenance Plan for: 1265 Carlsbad Village Drive Buccola Engineering, Inc. Insert Owner & Maintenance Personnel Training Records Operation & Maintenance Plan for: 1265 Carlsbad Village Drive Buccola Engineering., Inc. Appendix II - Routine Maintenance Activities Operation & Maintenance Plan for: 1265 Carlsbad Village Drive Buccola Engineering, Inc. ROU77NE MAIN NCE ACTMTiES FOR O&M I TRUCTL/RAL BUPs Note to the Maintenance Contractor: the following notes define a "Scope of Work" and does not constitute a between the Owner and Maintenance Contractor. The items contained in this list of Maintenance Activities shall be performed on the Structural BMPs as part of the regularly scheduled landscape maintenance. The Maintenance Contractor shall oversee the completion of non—routine maintenance directives that result from periodic structural BMP inspection. The following Structural BUP maintenance activities shall be performed as part of routine landscape maintenance: 1 - Collect and remove trash & plant, debris .. 2 - Remove & dispose of weeds from grass—lined swale 3 - Mow or trim swale bed & embankment ground cover 4 - Re—seed / re—sod swale bed & embankment ground cover 5 - Check for standing water or "soggy" swale bed or embankment 6 - Check for ruts, holes or animal burrows in and around grass—lined swale 7 - Check for accumulation of sediment within grass—lined swole 8 - Check condition of concrete apron (undermining, cracking) 9 - Maintain clear low—flow grated inlet openings Check condition of source control BMPs (signage & stenciling) Check irrigation system for function, coverage & overspray Sweep interior drive 'aisles, parking stalls and flatwork Minimize fertilizer and pesticide use Other: (Print & Initial) General Notes: 1 - The contractor shall remove & dispose of trash, plant debris and silt. Refuse shall not be allowed to enter any storm drainage structure. 2 - The contractor shall periodically operate the automatic irrigation system(s) and monitor the effectiveness thereof. Sprinklers found to place ,water outside of landscape ores shall be adjusted to eliminate non— storm wafer introduction of runoff to streets and storm drain. 3 - Signature of this document acknowledges receipt of Appendix II - Routine Maintenance Activities. Signature of this document does not constitute a contract between owner and. contractor. Billing records of scheduled maintenance activities shall serve as a record of satisfactory completion of Routine MaintenanceActivities for the Operation & Maintenance of structural BMPs. "Owner' wner Date Maintenance Contractor Date PREPARED IN THE OFFICE OF: ]3 (J 1G.LI4 760/721-2000 ENGINEERING, inc 3142 Vista Way, Suite 301, Oceanside, CA 92056 OPERATIONS & MAINTENANCE PLAN FOR 1265 CARLSBAD VILLAGE DRIVE APPENDIX II ROUTINE MAINTENANCE' ACTIVITIES Appendix Ill - Inspection Checklists Operation & Maintenance Plan for: 1265 Cafisbad Village Drive Buccola Engineering, Inc. INSPECTiON REV - O&M STRUCTURAL BMP PEC liON CHECKUST Structural B/vIP: _____________________________ Date of Inspection: Inspected by: Title. Note to Inspecting Party: Inspections shall be performed during September and May of each year and after storm events as described in section 5.2 of this Plan. The inspector shall determine the condition of the BMP item based upon field observation. Check "yes "/f the condition of the item is acceptable. Check "no" if the condition of the item is unacceptable. Determine and record an appropriate corrective maintenance directive. Record completion date of maintenance directive. Maintenance items that ore not contained on this checklist are considered to be "non—routine" items as defined in Section 53 of this Plan. Provide a written explanation of all the non—routine maintenance activit'ies in the space provided on this form. Attach additional pages as necessary. The Owner shall retain this document for five years. /TEM/CONDl71OW YES NO MAINTENANCE DIRECTIVE COMPLE77ON DATE Trash, plant debris & weed removal General landscape coverage & condition Grass—lined swale bed & embankment stability Grass—lined swale bed & embankment coverage Sediment in swale & landscape areas (1/2"or less) - Inflow locations / private grated inlet condition - Concrete arpon condition & stability Source control BMPs (signage & stenciling) Irrigation system (function, coverage & overspray) - Non—routine maintenance operations (attach additional pages as necessary,): Signature of Inspector Date PREPARED IN THE OFFICE OF: OPERATIONS & MAINTENANCE PLAN T) U' 760/721-2000 FOR D U U Q T A Lii'1 1265 CARLSBAD VILLAGE DRIVE ENGINEERING, inc APPENDIX III 3142 Vista Way, Suite 301, Oceanside, CA 92056 INSPECTION CHECKLIST