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Home My WebLink About; Carlsbad Blvd. Seawall; Environmental Impact Report (Final); 1985-10-01FINAL ENVIRONMENTAL IMPACT REPORT CARLSBAD BOULEVARD BLUFF STABILIZATION PROJECT CITY OF CARLSBAD SCH #84091201 Prepared FOP: City of Carlsbad 1200 Elm Avenue Carlsbad, CA 92008 Prepared By: Inc. f211 Fifth Avenue San Diego, CA 92103 Project No. 30270/35084001 October 1985 RESPONSES TO COMMENTS CARLSBAD BOULEVARD BLUFF STABILIZATION PROJECT Section 15088 of the State CEQA Guidelines requires that the lead agency respond to letters of comment received as a result of public review of the Draft EIR. The City of Carlsbad received letters of comment from the agencies and individuals listed below in chronological order. The comments appear on the following pages, with responses provided adjacent to each comment. The letters of comment and accompanying res- ponses, bound together with the "Draft EIR, comprise the Final EIR for the proposed project. »1. County of San Diego, Department of Health Services, April 23, 1985. 2. State of California, Department of Boating and Waterways, May 15, 1985. 3. State of California, State Lands Commission, May 17, 1985. 4. State of California, Department of Parks and Recreation, May 22, 1985. 5. State of California, Office of Planning and Research, May 28, 1985. 6. Surfrider Foundation, May 31, 1985. 7. State of California, California Coastal Commission, June 4, 1985. COUNTY OF SAN DIEGO DEPARTMENT OF HIALTH .SERVICES 1700 Pacific Hltftwtr. San Dtogo.'CA 92101 JAMES A. FOROE, Director DIVISION OF ENVIRONMENTAL HEALTH PROTECTION 236-2243 April 23. 1985 City of Carljbad 1200 Elm Ave. Carlsbad. CA 92008 RE: DRAFT EIR-C'USBAD BOULEVARD BLUFF STABILIZATION PROJECT Dear Sir: This 1s In response to your request for our department'i comments regarding the above draft Environmental Impact Report. Staff of the Dlvlson of Environmental Health Protection has reviewed the reporttrtd MC have no concerns at thts time regarding this project. If you have any questions regarding this matter, please call me at 236-2243. Very truly yours 1 County of San Diego. Depejtmant of Cornmtnti 8Uff of the Division of Environmental Health Protection have no concerns regarding the project. _—- Response! No response IB necessary. RICHARD J. RAMIREZ. Ass1stant"Ch1efDivision of Environmental, Health Protection RJR:dmc cc: H, DevlneK. He (1 man (with attachment) J»e*e •< Celfctermta Memorond um Te , (i) Dr. Gordon t. Snow The Resources Agency (2) Hr. Hike How*a city of Carlsbad 1200 Elm Avenue . Carlsbad, CA 92008 he* > D*e«rtm*nt •« tooting and W«terwoyi TlM DeMurcee Afe*My of California DON MAY 1 5 1985 Subject* SCH 1840912011 Carlsbad Boulevard Seawall The Departnent of Boating and waterways haa reviewed subject Environmental lapact Raport (EIR) which addresses the proposed Carlsbad Boulevard Bluff Stabilisation Project at Carlsbad state Baach in the City of Carlsbad, about 30 ailes north of San Diego. TtJ* project involves the development of approximately 4,500 linear feet of ihoraline protection between Oak'Avenue on the north add the entrance to Agua Redionda Lagoon on the south. The project are* i* bounded by Caxlsbed Boulevard and Ocean street on the east and the Pacific Ocean on the west. The project is proposed for the primary purpoe* of preventing the underlaining of Carlsbad Boulevard, a significant coastal accent route through the City. We would lUte to offer the following e Our Department agrees that a shore protection project is needed at Carlsbad to protect Carlsbad Boulevard and supports the project. However, b**ch nourishment IB not an econonically viable altametive for a unilateral undertaking by the City of Carlsbad. • The alternatives discussed in the BIR are adequate to allow the Cityco sel*ct * structure that can be properly designed and constructed to last SO years. The following concerns are. covered somewhat in Table 4-1 of the report, but would have cure impact If discussed in more depth separately on the pages Indicated. • >aq«s i_-_10_* 3-191 Fabrlfor* - Because it i« built on a stseper slope and is inpervioua. fabrifom has less wave energy absorption than rock riprapt therefore, it would have sore reflected wave energy, more toe scour and more run-up. In this location, a fabrifora wall would need to be built higher than the rock rabble rsvetnent to prevent overtopping and it could be lus- ceptible to structural cracking and unravelling due to settlement of the foundation. • ?ages 2-10 6 3-38i Concrete Hall with Rock fill - This typ« of wall 1« smoother and just as steep u Fabrlfora so wave reflection, toe scour and run-up would be even acre severe. It Ls less flexible and more sus- ceptible to foundation settlements' State of California. Department of Boating and Waterways Oo Commenti Department agrees that shore protection Is needed. ---- Beach nourishment not economically viable for City. Response* Comment does not address the adequacy of the Draft EIR, no response b necessary. 2t) Commenti Alternatives discussed tn the Draft EIR are adequate to allow the City to select a suitable structure. _Bgsponaei Comment is noted, no response is necessary. 2c Commenti Several comments are offered regarding the potential Impacts of the fabrlform, concrete waD with rock fill, reinforced earth wall, and reinforced concrete vertical seawall alternatives. It Is recommended that the information provided in Table 4-1 (Bluff Stabilization Project Impact Matrix) be discussed In more depth on pages 2-10 and 2-11 (Project Charac- teristics) and pages 3-38 and 3-40 (Land Use/Coastal Act Compatibility Impacts). Response! The com menu regarding potential Impacts of the various struc- tural alternatives are noted. Relative to rock revetment, fabrlform would likely cause more reflected wave energy, more toe scour and more run-up. A fabrlform wan would have to be built higher to prevent overtopping and It could be susceptible to structural cracking and unravelling due to settle- ment. The concrete wall with rock fill could have similar or more severe Impacts as noted above for fabrication. The structural alternatives lacking toe-stone would likely have additional wave reflection and run-up. In addi- tion to Table 4-1, the most appropriate section In the Draft EIR to discuss the Impacts of wave reflection, toe scour, run-up and foundation settle- ment would have been Section m-A (Oeology/Geotechnlcal Considerations) rather than In the Project Characteristics or Land Use Sections. -2-MAY '1 5 1985 2d 2e 2f . • Paga» 2-10f 2-11 t 1-40t Rainforcad Earth Mall and Reinforced Concrete Vertical Seawall - Without to* stone chese walla would also have additional wave reflection and run-up. e Page 3-43i Conditions change too ouch to guarantee 25* of dry sandy beach at all tines (not there nov). Character of bluffs as they axist is not totally natural. Bluffs are marred by pedestrian traffic and storm drain • erosion gullies. Project nay restore upper bluffs to nore natural condition and reduce future pedestrian erosion. Eliminating to* stone to r«duc* beach encroachment could be a fals* economy, without eo« stone, to* scour at vertical or near vertical walls could erode all the material the City was going to preserve for lateral access by eliminating the to* ston*. * Table j-11^ Reinforced Earth Hall is not susceptible to groundwater seepage) it dxaina readily through joints. If you hav* any questions, plaasa feel fre* to contact George Armstrong, Supervisor, Beach Erosion Branch, at (916) 443-8348. Thai* you for the opportunity to review this document. *ILLIAM H. tVEftS Director cc: George Armstrong 2d Comment i Conditions change too much to guarantee IS feet of dry sandy beach at aU times. Rgsponset Tht statement In the Draft EIR (pg. 3-42) regarding the provi- sion of 25 feet of vertical access U a reiteration of a City of Carlsbad LCP policy/regulation for shoreline dorclopment. Thla cannot be guaranteed, as It 1> noted that In certain stretches of the beach, that condition does not now exist. This Is eon*Mer«<! to be a goal of the bluff stabilization project. 26 Cornmenti The character of the existing bluffs Is not now totally natural. Response! Comment is acknowledged. The Draft EIR concurs In several sections that the bluffs have been Impacted by pedestrian traffic, storm drains and gullies created by their malfunction, as well as other man-made IntrusTbns. The statement In the Draft EIR <pg. 3-42) Is that the general character of the bluffs should be retained. Cut and fill should be mini- mized. Materials should be blended to match natural earthtone colors and textures. Revegetatlon should include native species. £.\ Commenti Eliminating toe stone to reduce beach encroachment could be a false economy. Response; This Is a distinct possibility. Beach scour must be accounted for • during the selected project's design phase for each stretch of beach. fTATf 0'CALITO«HIA OfOBOI OIUKJUtJIAM. O, : STATE LANDS COMMISSION LtO T. htoCAKTHY, Ltouttnv* Omvmw JCMI H KUW, £**e«v of AMDC* ixteunvi OMtei IMI-lMlBlfMtl*m»M, OIlHrnto Ml 14 CLATftt T. DCOftlCX • uwtK* OtfMr May 17, 1985 File Ref: SD 85-04-19 Ht. Michael Howes City of Carlsbad 1200 Elm Avenue Carlsbad, California 9200B Dear Mr. Howesi f Subjact: Caclsbad Boulevard Bluff stabilization Project; Draft Environmental Impact Report - state - Clearinghouse Number S4091201 The State Lands Commission has received a copy of the DC aft Environmental Impact Report for the Carlsbad Boulevard Bluff stabilization project located in the City of Carlsbad, San Diego County. This ia to advise that the Pacific Ocean at this location is ungranted sovereign land under the jurisdiction of the state Lands Commission, Should the method of bank protection used extend waterward of the Ordinary High Water Mark, a permit from this agency will be required. At such tine as a project alternative has been selected, please notify this office so that we can determine if State land is involved in the project. If you have any questions, please contact Debbie Townsend at (916) 322-1219. Very truly yours. State of California, Stile Lands Commission Comment! Any method of bluff protection which extends waterward of the Ordinary High Water Mark will require a permit from the State Lands Commission. Response i Comment b noted. 17431 LESLIE H. GRIMES, Deputy Chief Division of Land Management and Conservation • SUU of Crffomta Momorandum Da* i Gordon F. Snow, Ph.D.r* ' Project Coordinator Resources Agency Department «* PsHis and Rectvation . Th« RMOUTCW Agency of MAY 9, 2 1985 S. Brlner 4a Carlsbad Boulevard Seawall/Bluff Stabilization Project Draft Environmental Impact Report SCH * 84091201 The Department of Parks and Recreation has reviewed the subject document. The proposed construction of a seawall would be located on Carlsbad State Beach, property owned by the Department of Parks and Recreation. We responded to the Notice of Preparation by Tetters dated September 21, and October 16, 1984. The concerns we expressed In those letters were for the project's effects on the esthetic?, natural features, and recreational usage of the State Beach. In addition, we requested that the Draft EIR explore alternatives to a permanent structure on the bluff and beach. It does not appear that this report adequately addresses the questions we raised, and we do not agree with Us analysis and findings. 'Jhlle the report acknowledges the roles of pedestrian traffic, animal burrowing. Inappropriate vegetation -- and most Important, storm runoff and the Inadequate drainage system -- In erosion of the bluff, It understates the necessity of resolving these problems before proposing permanent shoreline protective devices such as the seawall alternatives. The report states that "The current proposed bluff stablUzatlon'proJect will serve as the foundation of the program ...(p- 20-5)". Instead of "the foundation", this project to construct a rock or concrete wall should be considered as a last resort after other less environmentally degrading means have been implemented. The document purports to analyze five alternative methods of bluff protection for this project, as well as the no project alternative (p. 2-5). This Is misleading because the "five alternatives" are all essentially varieties of a permanent rock or concrete structure — a seawall. The analysis, therefore, Is limited to the two extremes of "no project" or seawall. Other alternatives, Including non-structural means, are Inadequately discussed and dismissed In Section V. We believe that the project proponents should expedite their existing "... program to capture all runoff over the bluffs by Installing a storm drain system along Carlsbad Boulevard (p. 2-11)'. This document states that construction has already begun, and that the City of Carlsbad Intends eventually to remove all outfalls now depositing water over the face of the bluff. This action will accomplish much 1n preventing further erosion and bluff retreat (p. 3-18). The storm drain project should be completed before further consideration Is given to construction of 4,000 feet of permanent stone or concrete structure. State olCallfornla, Department of Parka and Recreation. a Commenti The Department of Parks and Recreation offers several general comment! regarding the alternative methods of bluff protection tt Carls- bad State Beach. The Department Is of the opinion that the City should resolve existing storm water runnoff, pedestrian, and animal burrowing problems, and Implement a revegetation program, prior to considering a permanent shoreline protection device. The Department suggests that the proposed project should b« • l**t resort rather than the foundation of a program to halt bluff retreat. Rftsponsei The City of Carlsbad has concluded, based on several engineer- Ing studies (Woodward-Clyde Consultants, 1984) and Leigh ton and Associ- ates, 1964) that the moat significant erosion of the bluffs occurs by wave action during high tide* and storms. This Is supported by several state- ments In the Parks and Recreation Department* General Plan; that the cobble beach Is prone to excessive erosion, that Carlsbad Boulevard Is threatened by seacllff retreat due to direct wave attack at the base of the cliffs, and that bluff erosion Is attributable to several factors, Including pedestrian traffic, sand depletion, seacliff retreat due to direct wave attack, and storm runoff {California Department of Parks and Recreation, 1983). During severs) storm episode* (most recently In 1983), very rapid coastal erosion coincided with spring tide conditions and a high swell, coupled with strong winds. Portions of Carlsbad Boulevard required exten- sive repair and slope rebuilding was required. Therefore, protection of the toe of the bluff by a structural device has been Investigated as the pro- posed project tn the Draft BIR. The potential consequences of Implementing one or several structural alter native* have been presented. Other alternatives, Including the No Project alternative and non-structural means, have been considered but were found to be unable to meet the Immediate project objective of pro- tecting Carlsbad Boulevard from severe storm damage. In addition, how- ever, the City Is preceding with other remedies, such as capturing all storm water now running over the bluff In an areawlde storm drain system now under construction. Additionally, the City Is willing to participate in a beach replenishment program. It would take many years for significant replenishment to occur following the design and approval of a comprehen- sive program. The City Is now considering an immediate solution to an existing problem. Implementation of the proposed project would not preclude future con- struction of a long-term beach replenishment solution. Also, the City will work with the Department of Parks and Recreation to eliminate pedestrian traffic over the bluff and to reregeUte th« exposed dope*. These meas- ures will accompany any selected protection device. 4b 4c 4d 4e Sordofl F. Snow, Ph.D. •agt 2 In addition, tht City of Carlsbad and this Department should coordinate efforts to promote bluff stabilization through revegetatlon, sand replenishment, and localized rehabilitation. Destructive pedestrian trafficand animal burrowing should be eliminated. Measures to remedy these problems are available and far preferable to the environmentally damaging, visually Intrusive alternatives described In this draft EIR. Our cornnenti to specific statements 1n the OEIR are Indicated below, by page number: 2-4 "It Is anticipated that the public parking area, and possibly the paved access road below Tamarack Avenue, will require a more substantial means of shore protection than Is currently In place,...' This Department Is committed to providing public access and appropriate facilities while maintaining natural processes. We will site new facilities with a consideration for the hazards of bluff Instability. 2-5 'The current proposed bluff stabilization project will serve as the foundation of the program and final defense against wave attack," See our corments In the second paragraph. "...the EIR...analyzes five protection device alternatives In detail and provides a discussion of the consequences of the no project alternative." See our comments 1n the third paragraph. The EIRdoes not adequately analyze alternatives other than the structuralseawall type. The EIR should Include thorough analysis of storm drain rerouting, sand replenishment, revegetatlon, and spot rehabilitation. 2-8 "At prt*«nt. It 1$ estimated that the average rate of erosion atCarlsbad State Beach 1s 1 to l.S feet per year (Woodward and Clyde, 1984}.' Compare this statement to p. 3-10: "Lelghton 1> Associates (19M) estimate that the rate of bluff erosion and retreat In the project irea since the 1920s has averaged about three Inches per year." The difference In figures Is significant; what 1s the finding of this analysis regarding the rate of bluff erosion? 2-fl "Under the Ho Project alternative, existing encroachments on Carlsbad State Beach bluffs and beach would remain, leading to a discontinuous pattern of shoreline protection and recreational use/visual quality disruption." What are the "existing encroachments"? There Is no structural device now, so what Is meant by "discontinuous pattern of shoreline protection..."? Any existing non-structural stabilization devices could be removed when the stormdrain problem and the other contributors to bluff erosion are eliminated. 4b Comment! In reference to • statement on page 2-4 of the Draft EIR regarding protection of existing facilities, the Department has indicated that public access and new facilities will be sited In consideration of natural processes and hazards. Response! TftU policy of th« Department of Parks and Recreation Is noted, 4C Comment! In reference to a statement on page 2-5 of th« Draft EIR, the Department has Indicated that the proposed structural bluff protection project should not b* the "foundation" of the City's program. Other alter- natlres should bo thoroughly analyzed. Response! Please refer to respons* 4a. 4d Commenti m reference to statement! on pages 2-8 and 3-10 of the Draft BtR regarding the rate of bluff erosion at Carlsbad State Beach, the Department questions the disparity In the figures. Response; The statement on page 2-8 that the present rate of erosion has been eliminated at 1 to l.S f««t per year Is based on a study of recent bluff erosion at Carlsbad. Severe storm events have caused several feet to erod* m only * few hours In some cases. Lelghton and Associates studied bluff retreat in the project area for a longer time span. Their estimate on pages 3-10 and 3-11 of the Draft EIR, la that the rate has been about 3 Inches per year since tht 1930s. 46 Commenti The Department questions the statement on page 2-8 of the Draft EIR regarding existing encroachments on the Carlsbad State Beach bluffs and beach. Responaei The existing encroachments referred to on page 2-8 of the Draft EIR are further described on pages 3-43 and 3-44. Encroachment include filling and slope^ repair at Acacia, Redwood and Walnut Avenues, large boulders on the beach at Walnut Avenue, and large boulders on the beach at Cherry Avenue to protect the stairway. Other man-made struc- ,, hires, including the drainage pipes, will be removed when the storm drain system along Carlsbad Boulevard Is completed. Gordon F. Snow, Ph.D. Page 3 4h 4i Z-9 '...access to tht beach would remain limited...parking lot... undermined and In a deteriorated condition,...no ramps provided for handicapped persons...Jeopardize safety of public " All of these statements are refuted In the Department's General Plan for Carlsbad State Beach, which establishes policies of public accessibility to the State Beach. These are fin commitments by the Department ofParks and Recreation; they will be Implemented, 2-11 "The City has begun a program to capture all runoff over the bluffs by Installing t storm drain system along Carlsbad Boulevard.... Construction has recently commenced....Eventually all outfalls now depositing water over tht face of the bluff will be removed....project will be completed over a several year period and will be part of «ny selected bluff protective measure." We endorse this effort to eliminate a major cause of bluff Instability and urge the project's completion at an early date. No further action should be taken on a structural device until the new storm drain Is completed. "The proposed project will Include the development of several beach' access stairways* a ramp for handfcapped persons, tnd the retention of the existing parking areafat the south end of the study area." These facilities are Included In the Department's program for public use of the State Beach. Any proposed development must be coordinated with this Department and consistent with the approved general plan. 2-12 "The California Parks and Recreation Department does not have discretionary authority for the project, but will have to Issue an easement or lease for construction," In fact, this Department joes have discretionary authority over properties within the State ParTT" System. A request for easement, lease, or use permit would be considered on Us merits at the time the request Is made. 3-12 "Kuhn and Shepard (1984) attribute localized bluff erosion and retreat to storm drains that were originally Installed to divert storm runoff away fron the bluff. No erosion due to storm drains has been documented, however." This draft EIR omits the rest of the Kuhn and Shepard report, which goes on to say: "...In 1978, 1980, and again In 1983, nany of these drains collapsed, and escaping water severely eroded the bluff face {Kuhn & Shepard 1984:65)". Compare also with a statement later In the same paragraph of the draft EIR: "Two of these (nine drainage pipes) are capped, and the other seven have been so heavily undermined that their open ends do not carry to th« beach, but discharge directly onto the bluff face." Documentary and photographic evidence clearly shows that the 4f Comment! In reference to several statements on page 2-9 of the Draft EIR, the Department Indicates that Its General Plan for Carlsbad State Beach provides for the Implementation of measures to Improve access to the beach. Response i The Draft EIR, In discussing the No Project alternative, has Indicated that existing conditions would remain or deteriorate If nothing Is done to protect the bluffs. It Is acknowledged that the Department of Parks and Recreation has established policies which will, if Implemented, Improve public access to Carlsbad State Beach. 4h 4i Commenti In, reference to the description of the City's on-going storm drain system Improvement program along Carlsbad Boulevard, the Depart- ment suggested that no further action be taken on a structural device until the new storm drain system la complete. Also, all Improvements along the bluffs must be coordinated with the Department and be consistent with their peaeral Plan for Carlsbad State Beach. Response! The City of Carlsbad Is Investigating immediate solutions for the protection of Carlsbad Boulevard. If the City waited until storm drain system improvements along Carlsbad Boulevard were completed before studying bluff protection alternatives, then the actual Implementation of a selected project would be further postponed. This b an unreasonable request wh«n Immediate solutions are necessary. In the response to the second part of the comment, the City understands that an portions of the development must be coordinated with the Department and must be consis- tent with th* approved General Plan, Cojnmgnti The Department does In fact have discretionary authority over the proposed project, which conflicts with a statement on page 2-12 of the Draft EIR. Response! Comment is noted. Commenti Several comments are offered regarding page 3-12 of the Draft EIR. Pint, the Department repeats that significant erosion of the bluffs occurs due to drain pip* failure and storm water runoff. Next, It Is recom- mended that the Department and City coordinate efforts to eliminate ped- estrian traffic across the bhiff face. Also, the stabilization capability of Arundo dona* Is Questioned. Responset The Draft EIR concurs that storm water runoff due to drain pipe failure contributes to bluff erosion. It Is still contended though that wave action during major storms and high tides Is the primary factor caus- ing erosion of the bluffs. (Also, refer to Response 4a). The City wlL Gordon f. Sow, Ph.D. Page 4 4i 4k 41 4m drain pipes have slgnifIcantly undermined the bluff and that the water outfall continues to erode 1t. This cause of bluff erosion has been going on for years, unrelated to severe storms, high tides, •nd direct wave attack. . "Heavy pedestrian traffic appears to be an additional factor In the bluff erosion. ...Localized areas are also affected by animal burrowing." The City of Carlsbad and this Department should coordinate efforts to eliminate these problems. Barricades to foot traffic down the bluff and revegetatlon of impacted areas can help to stabilize the bluffs. "Vegetation along the bluff consists of scattered patches of Iceplant (which) appears to be a contributing factor in the shallow soil slips occurring on the bluff. The tubular root structure of the Arundo donax. on the other hand, contributes to the strength of the poorly-consolidated terrace deposits." Rather than a type of bamboo, A. donax Is a giant reed (see also pp. 3-44 through 3-46). Although the Tee plant does appear to contribute to mat-like soil failures, we question the stabilization properties attributed to , A. donax, since It grows prirrfarlly on flat or very gentle slopes. 3-17 "The maximum probable earthquake on that fault would produce a peak horizontal ground acceleration of about 0.15 g to 0.20 g at the project site." The California Division of Mines and Geology generally recommends structures be designed to withstand an earthquake magnitude of 6.0 with repeatable high ground acceleration of 0.33 g throughout California. 3-19 "Construction of any of the project alternatives will have a minor adverse effect on the supply of sand to the coastal transport system...the proposed project would eliminate this sediment source." Any net loss of sand is. unacceptable because it contributes to the larger cumulative loss. The sediment source of the eroding bluffs is not Insignificant to the State Beach. 3-24 "These wet zones are expected to t>e short-term due to the combination of cliff erosion, high tides, and storm events." In our observation, the wet zones exist year round, as a consequence of Inland irrigation, landscape watering, and other domestic contributors to the seepage situation. The wet zones generally occur at the contact between the Pleistocene terrace deposits (Llndavista formation) and the Tertiary bedrock (Santiago formation). 3-25 "It 1» assumid that the bluffs would be completely altered as partof tht bluff stabilization project." This consequence 1s completely unacceptable to this Department. coordinate measures to eliminate pedestrian traffic over the bluffs as part of thalr overall protection plan. The Draft EIR states that Arundo donax Is ^wmboo-Ulce, not a type of bamboo. On page 3-45 of the Draft EIR, A. donax li Identified as a giant reed. Regarding Its soil stabilization qual- ities, In the opinion of the Draft EIR authors, the giant reed, or any plant with a tubular root structure, aids In the retention of soil, as does the canopy of leaves which further reduces erosion. 4j Comment! The California Division of Mines and Geology recommends that structures be designed to withstand an earthquake magnitude of 6.0 with ground acceleration of 0.33 g throughout California. Reggcnaei The Draft EIR states that the probable peak ground acceler- ation would be about 0.15 g to 0.20 g at the project site. The Draft EIR state* on page 3-21 that the selected project should be constructed accord- ing to selamle design criteria of the Uniform Building Code and state-of- the-art methods outlined by the California Structural Engineers Associa- tion. Project design will adhere to all recommended seismic design crit- eria, Including the referenced California Mines and Geology guidelines. 4k Comrnentt The Draft EIR states that the loss of sand to the coastal transport system due to the proposed project would be an Insignificant effect. The Department does not agree. Responsei It Is acknowledged that the loss of sand to the coastal transport system contributes to a larger regional cumulative loss of sand. Although the Ion would only be a minor Increment In the overall sand supply net- work, this would contribute to a larger, overall cumulative loss of sand In the region. Page 3-S4 of th« Draft EIR states that "the cumulative effects of the proposed project, considered In conjunction with other similar pro- jects and potential future projects along the San Diego County coastline could po«a significant effecti In reducing a source of beach sand." 41 Commenti The Department questions the statement on page 3-24 of the Draft SIR, that the wet zones along the bluffs are expected to be short- term. Response! It to acknowledged that these wet cones exist year-round at the contact point between the Pleistocene terrace deposits and the Tertiary bedrock. The references to "short-term" means that Individual species within these wet zones are likely to bt eliminated by coastal processes, rather than to develop Into mature plants, as would occur in a stable envir- onment. The vegetation within these wet zones Is cycllcle, often removed •* by erosion and/or storm events, only to reappear in another location. 4m Comment! The Department states that the complete alteration" of the" bluffs as a result of the proposed project Is completely unacceptable. 4n 4o 4p 4q 4r 4s Gordon F. Snow, Ph.D. Page ! 3-30 7)i* references to statements In the aporoved General Plan for to C«rlsbad State Beach (November 4, 1983) do not Include the 3-33 Departerent'i current position on development In our coastal units.The current Coastal Erosion Policy, approved on October 24, 1984 was prepared subsequent to the storms of 1983, which caused substantial damage to many of our coastal units, Including Carlsbad State Beach. The policy states, 1n part: "Structural protection and reprotectlon of developments shall be allowed only when the cost of protection Is commensurate with the value (physical and Intrinsic) of the development to be protected, and when _1t_ can be shown the protection will not negatively affect the beach or' the near-shore environment." 3-36 "The proposed bluff protection appears to conform to the statements. policies, and plans contained In the General Plan for Carlsbad State Seach." See our comments on the previous Item regarding the current policy. 3-46 '...the visual Impact of the proposed bluff stabilization would be of low significance." On the contrary, the bluff Is a major visual elanent to beach users, nafty of whom have commented on the unsightly appearance Of the protruding storm drain pipes. Beach users' Interests also extend to the geological and botanical features of the bluff. Bluff stabilization measures should preserve these nature! features and remove those elements (e.g., drain pipes, non-native vegetation, and unnatural devices) that detract from the natural appearance. 3-49 "Revegetatlon of the bluffs should consider the following list of native species or native cultlvars. " He endorse revegetatlon of the bluffs and recommend that this 11st be restricted to Include only local natives. This Department's Resource Protection Division will provide a species list. 3-53 "It Is anticipated that t»e 4,500-foot stretch of beach will need to be closed to the public during the approximate 6-month construction phase. . I'.The south parking lot would be used for storage of construction equipment and materials." These activities would requ1re~perm1ss1on from this Department. 3-54 -The bluffs, as a source of sand, are Insignificant, however, when compared to the rivers and streams 1n the area." On the contrary, riven and streams In the area have been controlled and confined to the extent that the bluffs are a major sand supplier for this specific location. Any loss of sand from this remaining source— the bluffs--1s significant. How would a seawall structure affect the sand levels Imnedlately adjacent? 4n 4O 4p Become; Complete alteration of the bluffs Is likewise entirely unaccept- able to the City of Carlsbad. The statement on page 3-25 of the. Draft KIR means that, for the purpose of discussion, It was assumed that the bluff* would be entirely altered. This makes a discussion of Impacts to biological resources possible without specific development plans which show areas to b« disturbed. Comment i The Department* current Coastal Erosion Policy, approved October 24, 1984, was not stated in the Draft EIR, The policy states that "structural protection and reprotection of developments shall be allowed only when the cost of protection Is commensurate with the value (physical and intrlnlc) of the development to b« protected, and when ft can be shown the protection will not negatively affect the beach or the near-shore envir- onment." Responsei The bluff protection project selected by the City of Carlsbad must conform to the Department of Parks and Recreation General Plan policies. This to acknowledged. Telephone conversations with Department staff, as well aj the transmlttal of the General Plan to the Draft EIR authors', o'M not provide Information regarding th« recently adopted Coastal Erosion Policy. That la why the policy was not discussed In the text of the Draft EIR. Commenti The proposed bluff protection project must conform to the statements, policies, and plans contained In the Department's General Plan for Carlsbad State Beach. Response; The City of Carbbad acknowledges that the selected bluff pro- tection project must conform to the Department's General Plan. Commenti The visual impact of the proposed project would be significant because the bluff Is a major visual element to beach users. Response! The Draft EIR cites on page 3-31 several statements extracted from the Departments General Plan regarding existing conditions at Carls- bad State Beach. The General Plan states that sweeping panoramas of the ocean can be seen from the cliff tops and that the view from the beach tends to be focused on the breaking waves and along the surf line. The Draft EIR concurs and states that, since the bluffs are not the primary focal point, and because the proposed project Includes removal of drain pipes and non-native vegetation, and will include the use of natural mate- rials, the aesthetic effect would not be significantly adverse. Commenti The Department's comments that the list of plant species to be used In revegetatlnff the bluffs should be restricted to local natives. Response; The list of species contained on page 3-49 of the Draft EIR contains only natives or native cultlvars. All species listed are considered to to appropriate for revegetattea of thej. bluffs by the author* of the Draft HR. The City will work with the Department* Resource Protection Divi- sion In developing a revegetatlon plan. 4r Commenti The Department states that any beach closure* or the use of the south parking lot for material storage would require their permission. Responset Comment is noted. 4s . Commenti The Deportment Questions a statement on page 3-44 of the Drift SIR that the bluffs are an insignificant source of sand in the area. The second part of the comment questions the affect of a seawall on adja- cent sand level*. Responsei According -to Letghton and Associates (1984), the yearly net transport of sediment southerly within the Oceanslde littoral cell is approximately 425,100 euble yards. The two main rivers acting as eontri- . bating sources in the sand budget are the San Luis Key and the Santa Margarita Riven. For this particular stretch of bluffs considered Indepen- dently, the source of sand Is not a significant portion of the littoral cell's transport. Leigh ton & Associates (1914) estimated the rate of bluff erosion to be 3 inches per year slnoe the 1920s. This would yield 5400 cubic yards of sediment per year to the Oeeanslde littoral cell, about 1% of the cell's y*arty transport. As stated tn the Draft EIR and In response to comment 4K, there are cumulative impacts which must be considered, however. to regards to the effects of a seawall on adjacent sand levels, the Draft BR states in several places, that the loss of sand due to beach scour could be significant for structural alternatives which lack toe stone. The rock revetrent alternative would mlnlmlee beach scour. An estimation of the •and losa adjacent to a selected protection device cannot be calculated without a specific structural design. The City of Carlsbad will account for this potentially slgnfleiant effect during the design of the selected project. (Jordan F. Snow, Ph.D. Pip S 4*1 "The only Impact which cannot be mitigated to a level of Insignificance...is the temporary loss of a portion of the beach as 4* a recreation area during construction," He disagree that the loss ^l -of beach Is temporary, only "during construction.' This document ignores the question—posed In our response to the NOP--of permanent loss of that portion of the beach that will be covered by a permanent solid structure. What 1s the size of the area that will be covered by the structure? 4-3 Table 4-1, Bluff Stabilization Project Impact Matrix, should have t» «ore columns that give a clear comparison of the relative effectiveness and useful life of the proposed methods of bluff stabilization. Our contact for this project Is Jones M. Doyle, Supervisor, Environmental Review Section, *.0. Box 2390, Sacramento, CA 95811, telephone (916) 324-6421. 4t 4u A-17SZR cc: Southern Region San Diego Coast District Comment! The Department states that the loss of the portkm of the beach covered by a permanent solid structure should be considered to be a signifi- cant effect which cannot b« mitigated. The size of the area to be occupied by a protection device Is questioned. Response! it Is acknowledged that th« selection of several of the alterna- tives described In UM Draft EIR could caus« a permanent loss ot a portion of the beach (or exposed rock ledge). The rock revetment and alternatives with toe stone would occupy the greatest area unless significant excava- tions are mad« Into the toe of the bluff to avoid such beach encroachment. In* area which could b« covered by several of the protection devices could range between 15 to 30 feet In the absence of bluff excavation. w '*Commenti The Draft SIR'S bluff stabilization matrix (Table 4-1) should Include columns regarding effectiveness and useful life of the selected alternatives. Response! As stated on page 2-8 of the Draft EIR, certain design assump- tions had to be made in order to compare the selected alternatives. It has been assumed that, among other things, each structure would be designed to provide an equivalent level of protection and have a 50-year design life. It would have been repetitive to Include this information In Table 4-1. IUM Of OUVOMU—0»T<1 Of TM OOvUNOt DfUtHUIAN. OFFICC Or PUNNING AND RESEARCH l« RNtM tlMft lACtAMfMIO, C* «»H Hay 28, 1985 Hike Howes The City of Carlsbad 1200 Elm Avenue Carlsbad, CA. 92008 Subject:Carlsbad Boulevard Seawall/ Boulevard and Stabilization Project SCH I 84091201 Dear Mr, Howes: The State Clearinghouse submitted the above named draft Environmental Impact Report (EIR) to selected state agencies for review. The review period Is closed and the conments of the Individual agency (les) Is (are) enclosed. Also, on the enclosed Notice of Completion, the Clearinghouse has checked which agencies have cconented. Please review the Notice of Completion to ensure that your cocnnent package li complete. If the package la not In ordar, pleaaa notify the Stato'Clearinghouse Iranedlately. Your eight diijlt State Clearinghouse nunfcer should be used so that we may reply promptly. Pleoaa note that recent legislation requires, that a responsible agency or other public agency shall only make substantive corrments on a project which ar» within the area of the agency's expertise or which relate to activities which thtt agency rajst carry out or approve. (AB 2583. Ch. 1511, Stats. 1984.) These conments are forwarded for your use In preparing your final EIR. If you need more Information or clarification, Me suggest you contact the ccrnKntlng agency at your earliest convenience. Pleaae contact Glenn Stober at 916/1^5-0613 If you have any questions regarding the environmental review process. Sincerely, John B. Chanian Chief Deputy Director Office of Planning and Research oc: Resources Agency Cnoloaurea XATM5 RECEIVED UNO USERAWING OmcE 5 , State of California. Office of Planning and Research (OPR) Comment! OPR notes that the Draft EIR for the proposed Carlsbad Boule- vard Bluff Stabilization Project ha* been circulated to selected state agen- clesVorrevlew and Jhat the review period Is closed. Response! The City acknowledges that the review period Is closed. Res- ponses to all comments are contained in this Final BIR, Including responses to the Surfrider Foundation and the California Coastal Commission's let- ters which were received by the City after close of the review period. 6a 6b 6c 6d SurfriderFoundation May 31, 1905 Michael Howes City of Carlsbad 1200 Elm Avenue CarisDad, CA 92006 RE:CM >anti eo Dr«n EIR. SCH M091201 CM-lsbarf Boulevard Bluff Slat I Halloo Project Dear Mr. Howes, Please Include these comments In the public record for the Draft EIR. Our concerns Include potential for Increased wave reflection, beach encroachment, aesthetics, access, and public use of the beach. Increased wave reflection could severely disrupt ocean wave recreation during medium to high tides when the beach width Is minimal. This factor deserves careful consideration in evaluation of structural alternatives. Discussion of structural alternatives (Text and Table 4-1) should provide more detail with respect to beach encroachment. What is the difference In feet between 'minimal', 'moderate', and 'significant' encroachment 7 Discussion of the drainage system and rainfall runoff (page 2-11, paragraph 2), and discussion of access (page 2-11, paragraphs 3 and 4) should be moved to other sections of the report which address these concerns. Discussion of impacts to public vtews (page 3-45. 46 and 47) does not adequately address views from along the beach. This perspective would be the most significantly altered point of view, and the environmental impact report should focus on minimizing this Impact. ijurfrider Foundationi ~ C,j Comment; Increased wave reflection could severely disrupt ocean wave recreation during medium to high tides when the beach width Is minimal. Response; This comment is noted as an Important factor to be considered in the selection and design of a structural bluff protection device. Wave reflection would be greatest for the reinforced concrete seawall or con- crete wall with rock fill, especially If toe stone Is not provided to absorb wave energy. DD . Comment; More detail is needed with respect to beach encroachment. Define the terms minimal, moderate and significant encroachment used In Table 4-1 of the Draft EIR. _ .. Response; The precise extant of beach encroachment cannot be deter- mined at this time. Along certain stretches of the bluff, the selected protection device wttl be designed to encroach upon the exposed rock ledge, while In another location the device may be placed against reeom- pacted soil following excavation, thereby causing no encroachment beyond existing conditions. The terms used in Table +-1 giv« • relative comparison of the alternative protection devices' likely beach encroachment using an assumption that very little bluff excavation will occur. Rock revetment would cause signi- ficant beach encroachment when compared with the other selected alter- natives where encroachment could range up to 30 feet. Moderate encroachment would result from Implementation of a protection device with to* atone which would be about 10 feat. Minimal encroachment rela- tive to the other alternative means about 10-15 feet of beach encroach- ment would probably occur. OC Commenti Several discussions in the Draft EIR should be moved to other sections of the report. Responsei The discussions of the current drainage system improvements and proposed access Improvement! are appropriate where they are In the Project Description section of the Draft EIR. Drainage system and beach access Improvements are to be Integral parts of the City's bluff protection program. 32 North Mentex Streei P.O. Boi e05B2 Pasadena. California 91106 (213)681-3162 Comment; Discussion of Impacts to public views does not adequately address views along the beach. Responsei As discussed in the Draft EIR on pages 3-45, 46 and 47, three primary viewing perspectives are available in the project area. Carlsbad Qf Michael Howes nay 31, 1985 Page 2 Discussion of a submerged offshore breakwater alternative (pages 5- 1 and'5-2) provides an accurate assessment of adverse consequences, '•*• elimination of safe ocean wave recreation In conflict with Coastal Act Policy. We commend the city of Carlsbad for recognition of this fact and not entertaining this most destructive alternative ever proposed for recreational beaches on the Pacific Coast. Beach Replenishment should be considered as a necessary adjunct to any structural solution proposed. We encourage the city of Carlsbad to participate In a major, long-term regional sand replenishment program for our beaches. We would prefer that developments along our coastline were more flexible to allow natural processes to take their course. With regards to flexibility (page 2-5, bottom), we would tike to see more discussion on the possibility of combining alternatives along Carlsbad State Beach, with the objective of minimizing adverse environmental Impacts. Thank you for the opportunity to comment on the Carlsbad Boulevard Blarr Stabilization Project. Please provide us with notice of public workshops or hearings that will follow. Sincerely, Tom Pratte Executive V.P Boulevard provides beach access to many travelers along the coast. The primary view here Is of the Pacific Ocean, therefore the proposed project will not affect that public view. Next, the bluff-top park west of Carlsbad Boulevard offers views to pedestrians and other park users. From here the primary view Is the Pacific Ocean and surf line. Benches and picnic tables In the park are set back from the bluff so views down the face of the bluff are limited. Therefore, again the proposed project would not affect public views. The third primary vlewshed Is available to beach users and surfers. Here the primary focus tends to be the surfllne and ocean. This to substan- tiated by statements In the California Department of Parks and Recrea- tion1* General Plan for Carlsbad State Beach (also refer to Response 4p). Many man-made intrusions existing along the bluff will be removed In con- Junction with the proposed project. Mitigation measures such u the use of natural materials and earthtone colors are available for use In project de- sign. Therefore, the conclusion has been made that the Impact to public views will not be significantly advene. OG Commenti The Surfrlder Foundation coneura that submerged offshore • breakwaters would adversely affect ocean wave recreation. Respotvsei No response to necessary. Of Commenti Beach replenishment should be considered as a necessary adjunct to an? structural alternative. The City should participate In a long-term regional sand replenishment program. Responsei The City of Carlsbad concurs that beach replenishment Is an Important need along San Diego County beaches, and Is prepared to partici- pate tat such A long-term regional program. vQ Commenti The Draft KIR should provide more discussion on the possibility of combining protection alternatives along the bluffi at Carlabad State Beach. Response i As stated on page 3-5 of the Draft EIR, the City may select one of the alternative protection devices or a combination of alternatives, however, final determination will not be made prior to the project's design phase. It Is likely that one method of protection will be used In an area, such as rock revetment, where beach encroachment b not a major factor or where sand scour la an Important consideration. In other areas, no protection may be appropriate or deep foundation excavations and • con- crete vertlcal_seawaU may be the beat alternative. It U pointed out, on_ page 3-20 of the Draft BIR, that discontinuities in the form of gaps or changes from one structure to another along the bluff can produce signifi- •» cant erosional complexities which must be examined closely during project design. All of these factors will be accounted for during the design of the bluff stabilization project. 7a 7b C*Wom«. .George D«iAmt|un. Cow«» OUornu CoMd Commnuon $AN MCO COAST DISTRICT b I $4 Mhuon Gorg* Ro*d. Sort* 220 S-ftDwgo. CA 92120 June t, Hike MOM*City of Carlsba* 1200 Ilm*A»e Carlsbad, Ce. «JOOS Subject: CoMwnt* regarding ito Carlsbad Blvd. Huff Stabilization Project Dear Mr. How**, Thank you for th* opportunity to comment on the draft Environmental Impact for the Carlsbad Boulevard Bluff Itablllzatlon frojact In Carlsbad. As mentioned In the Comlsslon staff! response to the notlc* of Intent to prepare a draft (IB, the project does ralae » number of concerns at to It'a consistency with policies of botk the Coattal Aft end the appUeablt Local Coaital Protraa, Th«ae concern* relate primarily to the project's l«paeta on public aecaaa and the proposed attention of natural landforna In a popular and heavily used public recreation area, At the tlM of ctaff's responae to the notice of Intent to prepare an til. It ma suggested thai the III for the project contain an analysis of • number of alternatives t* ameliorate the eroelon probUns which, exist In the ere*. It was further noted that the report should contain e number of design alternatives for any permanent shoreline devices propoaad. At this time staff feela that while • nuaber of alternatives hay* been addressed in the draft III. they are restricted tei (1) a no 'reject alternative and (2) an analysis of various permanent erosion control structures, each itretching the full *,SOO-feet of the project are*. Thus, alternatives to structural approachea have bee* not be«* fully addressed. While there Is evidence to the affect that sow* erosion exists along the bluffs adjacent Carlsbad Boulevard, It la staff's opinion that reetodles «*y exist for deallot with the eroalon probleo other than the alteration of roughly 4,300-feet of cosital bluffa and the construction of • continuous concrete/rock shoreline erosion structure along this entire lencUt of coastline. Staff would reeosnand that the final BIB for the proposed project address a number of alternatives to the construction of a'shorelln* protective device end reconstruction of the bluffs along Carlibad Boulevard. These might Ineludet a conprehensIv* drainage system which would diminish outflow over the bluff facet revegetatlon of the bluff face for atabllltatlon; or construction of shoreline; protective .devices In those areas where absolutely necessary to prevent undentlnlnt of Carlsbad Boulevard. 7a State of California Coastal Commission Comment: The Draft EIR should address alternatives other than the No Project alternative and various permanent erosion control structures, Responset A discussion of additional alternatives Is provided In Section V of th« Draft EIR. Also, please refer to Response 4a of this Plnal EIR. 7b Cprnmenti The Final EIR should address a number of alternatives to the construction of a shoreline protective device and reconstruction of the bhiffs along Carlsbad Boulevard. Response! Please refer to Responses Sa, 2b, 4a, 4g, Sf and fig for a discus- sion of project alternatives. HUM Hike How**Date Kay 31. 1«S Pag* 1 ~~/C 7d 7e 7f furthar, tout of the coiments contained in the draft EIR rait* concerns •* to their accuracy and implication! regarding th» Impacts associated withconstruction of an erosion control device In tha araa. For instance It ia Indicated In Section 9-19 that, while any of tha proposed structuralapproaches would eliminate tha sediment source of eroded bluff*, that th* effect on sand supply would ba minor. In that only on* of tha upland streamsand rivers In the ration which had *arv*d •• *and supply source* hai been laft In it* natural state, eoa*tal bluff* ramaln a* ona of tha vary f*w *ourcai of aand In lh* b«ach replenishment system. On pag* 3-*7 it 1* it* ted that "...alnca tha bluff I* not tha primary focal point ... tha vl*ual impact [of grading and reconstructing tha bluff faca) would b* of lav significance," Whila th* araa doaa contain Intermittent man-nade encroachments, tha bluffs are primarily In thalr natural *tat* and fora an Integral part of tha tha.interest and baauty of tha araa. It ma for thi* raa*on, that staff had indicated that any project propoiad should keep alteration of tha natural landform* of tha site to an abaoluta mlnlaum. It it Indicated on page 2-6 tfiat if tha no project I* pursued, that th* bluff*in th* area. will certainly erode to th* point that Carlsbad Boulevard will b* undenhlned . Again, if measure* war* taken to ameliorate th* presentconditions of th* *lte such as elimination of tha outflow over th* bluffs and rev*t*tatloA of th* are* to Incraa** slop* •lability, th* assumed undermining of Carlsbad Boulevard may not occur. Staff would again raeoimand that tha a true tun I approaches discussed b* delayed until other remedies are studiedand If appropriate, pursued. In regard l*> th* most appropriate of th* structural approaches suggested, it is staff's •pinion that If • structural approach proves necessary, areinforced concrete, vertical seawall, without toes tone, would provide •ffectlv* erosion protection whtl* addressing th* c0rt«*ra* of maintaining tha maximum amount of lateral public access and alnlmUlng th* alteration of th* natural topography of the area. Th* nrtlcal wall. If properly designed, Mould also poa* th* least amount of visual Impact in a highly scenic area. Her*, consideration of the coloring and texturing of the materials used would be assantlal. tn regard to access, vertical access from Carlsbad Boulevard to tha beach below must also b* considered. Th* draft tlR raconmends that th* existing access points b* retained and iraprftved and that additional points of vertical sccets may b* provided (2-11.) Staff would recommend that a number of addition access points b* provided to repUce existing Informal foot paths which may contribute to erosion of the bluffs. Location and spacing of these eccas* points would be an important consideration and should b* anal/sad. 7C Commenti The comment refers to the bluffs contribution of sand to the regional littoral system as discussed on page 3-19 of the Draft EIR. Response; This issue has been previously discussed in Response 4s of this Final EIR. 7e 7f 7u Commentt Ttie Draft EIR states on page 3-47 that the bluffs are not a primary focal point and that the project's visual Impact would be of low significance. Responsei This Issue has been previously discussed in Responses 4p and 6d of the Final KIR. Comment! The undermining of Carlsbad Boulevard may not occur if the No Project alternative Is pursued as discussed on page 2-8 of the Draft EIR- Reaponset This issue has been previously discussed in Responses 2a, 4a, 4c, 4<J and 4g of this Final EIR. Commentt Tha most appropriate structural bluff protection method add- ressed In th* Draft EIR Is the reinforced concrete vertical seawall without toe stone. Response! Comment It acknowledged. Commenti Coastal Commission staff recommends that, in addition to the retention and improvement of existing vertical access points, the project should provide a number of access points to replace the numerous ex b ting informal foot paths to the beach. Resppnsei Th* City Intends to work with both the California Department of. Parks and Recreation and Coastal Commission to design a bluff protec- tion project which provides adequate vertical beach access- The project will oertalnty go beyond the retention and Improvement of existing stair- ways. RUM Date Hike How** Her 31. 1985 3 An additional concern i* raised by * statement contained on page 3-46 of the dreft til relating to project inplraentatlon for any of the ahorellne protective Structures proposed. On page 3-46 tha report itatai: "It Li anticipated that tha 4,500-foot stretch of beach will need to be doted during the approximate t-month construction phase." Should construction of a shoreline protective device be pursued there Is little doubt that the construction phases of tuch a project will include some impact on pub Lie access to tha beech. Closure of the antlre stretch of beach for a full t-nonthe however represents an unnecessary impact on access in a heavily uaed recreation area. Stsff would recommend that the final KIR for the project Include an analysis of construction methods which would minimize Impact* to public access during the construction phase while allowing progress of the project to the maximum extent feasible. Again, we appreciate the opportunity to coordinate with the City on this important project: and, we apologise for tha tardiness of these comments. Should you have any questions regarding this matter please do not hesitate to call me at our San Diego office. fv Sincerely, Adam Blrnbaun Coastal Planner (0037U 7h Com'menti Regarding the possible closure of the 4500-foot stretch of beach during project construction, it Is suggested that the Final EIR add- ress construction method* which would minimize conflict) with public acc«sS. Staff U of th* opinion that beach closure is an unnecessary impact to • heavily u«ed recreation area. Responsei The Draft EIR states, on page 4-2, that the loss of a portion of the beach as a recreation area will be a temporary, adverse effect of the proposed project which cannot be mitigated to a level of Insignificance. It' Is recommended, on page 3-51 of the Draft EIR, that the project construc- tion period be limited to spring and fan months to avoid the season of highest recreational me. Construction in the winter is not feasible due to the probable occurrence of severe storms. Other measures to be consid- ered by the City Include constructing the bluff stabilization structure In segment! and restricting the work area to the toe of the bluff to the extent possible so that the surfllne area could remain open for public use. Regardless of the method chosen, however, a significant portion of the beach will not be available during construction of the selected stabilization project. TABLE OF CONTENTS Section Title I. INTRODUCTION 1-1 H. PROJECT DESCRIPTION 2-1 A. Project Location 2-1 B. Project Objectives 2-1 C. Project Characteristics 2-5 D. Discretionary Actions/Uses of EIR 2-12 m. ENVIRONMENTAL ANALYSIS 3-1 A. Geology/Geotechnical Considerations 3-1 B. Biological Resources 3-23 C. Land Use/Coastal Act Compatibility 3-26 D. Visual Aesthetics 3-43 E. Short-Term Construction-Related Effects 3-49 1. Traffic Circulation 3-49 2. Noise 3-51 3. Air Quality 3-52 4. Recreation 3-53 F. Growth Inducement 3-54 G. Cumulative Effects 3-54 IV. SUMMARY OF ENVIRONMENTAL CONSEQUENCES 4-1 A. Effects Found Not To Be Significant 4-1 " B. Significant Environmental Effects 4-1 ' C. Significant Effects Which Cannot Be Mitigated 4-1 D. Mitigation Measures Proposed to Minimize Effects 4-2 Section V. VI. vn. TABLE OF CONTENTS (Continued) Title ADDITIONAL PROJECT ALTERNATIVES A. Relocation of Carlsbad Boulevard and Utilities B. Groins and/or Offshore Breakwaters C. Other Bluff Protection Methods REFERENCES CITED/CONTACTS CERTIFICATION OF ACCURACY AND QUALIFICATIONS Page 5-1 5-1 5-1 5-2 6-1 7-1 LIST OF FIGURES Number Title 2-1 Regional Location of Project Site 2-2 Project Site Location as Depicted on the San Luis Rey USGS 7.5' Topographical Quadrangle 2-3 Selected Feasible Project Alternatives Schematic Diagrams 3-1 Geotechnical Map 3-2 Geologic Bluff Profiles A-Ar and B-B' 3-3 Geologic Bluff Profiles C-CT and D-Dr 3-4 Geologic Bluff Profiles E-ET and F-F' Page 2-2 2-3 2-6 3-3 3-4 3-5 3-6 LIST OF TABLES Number Title 4-1 Bluff Stabilization Project Impact Summary Page 4-5 n TABLE OF CONTENTS (Continued) APPENDICES Letter . Title Page A Initial Study A-l B Notice of Preparation (NOP) and NOP Responses B-l C General Coastal Processes C-l D Glossary of Terms D-l in I. INTRODUCTION This Environmental Impact Report (EIR) addresses the proposed Bluff Stabili- zation Project at Carlsbad State Beach in the City of Carlsbad, CA. The project involves the development of approximately 4500 linear feet of shore- line protection between Oak Avenue on the north and the entrance to Agua Hedionda Lagoon on the south. The project area is bounded by Carlsbad Boule- vard and Ocean Street on the east and the Pacific Ocean on the west. Discre- tionary actions required for the project include approval by the City of Carls- bad and the issuance of a Coastal Development Permit by the California Coastal Commission. An EIR is an informational document which is intended to inform public deci- sion-makers, other responsible or interested agencies, and the general public of the environmental effects of a proposed project. The environmental review process has been established to enable public agencies to evaluate a project in terms of its environmental consequences, to examine and implement methods of eliminating or reducing any adverse impacts, and to consider alternatives to the project as proposed. While CEQA requires that major consideration be given to avoiding environmental damage, the responsible public agencies remain obligated to balance possible adverse effects against other public objectives, including economic and social goals, in determining whether and in what manner a project should be approved. Accordingly, this EIR has been prepared in compliance with the California. Environmental Quality Act and State CEQA Guidelines, and with the City of Carlsbad's Environmental Quality Regulations. The EIR is focused on issues determined to be potentially significant based on an Initial Study prepared by the City of Carlsbad (Appendix A). In addition, scoping meetings were held with public agencies (November 2, 1984) and the general public (November 15, 1984) to further define the Bluff Stabilization Project and the focus of the environmental document. 1-1 H. PROJECT DESCRIPTION A. PROJECT LOCATION The proposed Bluff Stabilization Project will be located in Carlsbad about 30 miles north of San Diego in Southern California (Figure 2-1). Carlsbad is a rapidly growing city with a population of 39,000. It is bordered on the north by the City of Oceanside and by the Cities of Vista and San Marcos to the east. The area's projected population for 1995 is 93,325. Carlsbad has a well bal- anced combination of industrial, commercial and residential development, including a large regional shopping center, an auto-retail center with several dealerships, a large industrial park and a regional airport. The city contains three lagoons, extensive agricultural areas and large tracts of undeveloped land. About 25 percent of the land area is presently developed. For the purposes of this EIR analysis, the project site is defined to be the area bounded by the Pacific Ocean on the west, Carlsbad Boulevard and Ocean Street on the east, the entrance to Agua Hedionda Lagoon on the south and Oak Avenue on the north (Figure 2-2). A 20 to 40 foot high bluff is located between the beach and Carlsbad Boule- vard, the primary coastal access route in the area. The stretch of coastline to be affected by the Bluff Stabilization Project lies within Carlsbad State Beach which also extends north and south of the project site. B. PROJECT OBJECTIVES The Carlsbad Boulevard Bluff Stabilization Project is proposed for the primary purpose of preventing the undermining of Carlsbad Boulevard, a significant coastal access route through the City. The western edge of Carlsbad Boule- vard, between Cherry Avenue and Pine Avenue, is generally located within several feet of the top of the coastal bluffs. Several stretches of this portion of the bluff have recently required fairly extensive slope repair in order to prevent the roadway from becoming undermined. In the event of severe storm conditions and accompanying high waves, it is apparent that the existing 2-1 1 5.0 10 IMPERIAL BEACH £ %. MILES C? / „.„,.,..-ii-' Regional Location of Project Site FIGURE a-^i WESTEC Services, Inc.2-2 Project Site Location as Depicted on the San Luis Rey USGS 7.5' Topographical Quadrangle FIGURE 2-2 WESTEC Services, Inc.2-3 roadway and utilities along this stretch of the roadway are in danger of being lost. The toe of the bluff along this stretch of Carlsbad Boulevard is com- pletely exposed to winter storm waves when the narrow beach is eroded. Pro- gressive undercutting of the bluff by waves and slope sloughing will continue and increase in magnitude. The coastal bluff, which forms a buffer zone between the beach and Carlsbad Boulevard, would eventually erode away, util- ity lines would be lost and erosion would progress towards the residential prop- erties to the east. If this bluff retreat is allowed to continue, heavy losses to public property may result along with loss of utility services to a large area and loss of vehicular access to a considerable length of beach. North-south through traffic would also be completely disrupted causing distress to many businesses located along Carlsbad Boulevard. The western edge of Ocean Street at the north end of the project between Pine Avenue and Oak Avenue is also relatively close to the top of the bluff and may be subject to undermining due to erosion. It is also anticipated that the public parking area, and possibly the paved access road below Tamarack Avenue, will require a more substantial means of shore protection than is currently in place or these facilities could also be lost. With this primary purpose in mind, the protection of Carlsbad Boulevard, the City is studying a variety of shoreline protection devices which must meet several objectives along with providing the needed bluff stabilization. These objectives include keeping the protection device's beach encroachment to a minimum. This would apply to the construction phase as well as to the struc- ture itself, but would primarily apply to the end product. The City intends to select a low cost alternative with an anticipated low level of maintenance. The selected shoreline protection device must not be aesthetically objection- able and mitigation measures should be included in the project design to reduce construction-related impacts. The City of Carlsbad will continue to examine additional methods to protect the beach and to provide more recreational area. Beach replenishment pro- grams, sand bypass, artificial seaweed and other devices will be considered along with their subsequent environmental effects. Prior to proceeding with additional beach stabilization or enhancement programs, it would be necessary 2-4 to fulfill CEQA requirements. The current proposed bluff stabilization project will serve as the foundation of the program and final defense against wave attack. C. PROJECT CHARACTERISTICS This Draft EIR is intended to be used by the public, City and State staff in reviewing the environmental consequences of selecting a shoreline protection method for the stretch of bluff between Oak Avenue and Agua Hedionda Lagoon. With this in mind, the EIR does not focus its attention on one selected project, rather it analyzes five protection device alternatives in detail and provides a discussion of the consequences of the no project alterna- tive. The six alternatives selected for a more detailed analysis are as follows (Figure 2-3): • No Project • Rock revetment • Fabriform and/or concrete-filled bags • Concrete wall with rock fill • Reinforced earth wall with toe stone • Reinforced concrete vertical seawall with and without toe stone These alternatives were selected based on: a Feasibility Study, Carlsbad Bou- levard Shore Protection, Carlsbad State Beach, prepared for the City of Carlsbad (Woodward-Clyde Consultants, November 1984); the Geotechnical Environmental Impact Assessment for the Proposed Shoreline Protection Proj- ect, Oak Avenue to Agua Hedionda Lagoon, City of Carlsbad, San Diego County, California (Leighton and Associates, December 1984); and discussions with City staff following the preparation of these reports. It is important to note that the City may select one of the above methods of bluff protection for the entire project area or a combination of alternatives could be built. In some areas no protection may be provided, or a modification of one of the alternatives described herein could be implemented. The exact design of the structure will not be determined until final engineering studies 2-5 A. Rock Revetment WESTERLY EDGE f CARLSBAD BOULEVARD .GENERALIZED NATURAL SI.OPE 3 TO 4 - TON ARMOR STONE END OF FILTER FABRIC LAPPED BACK BEACH LEVEL VARIES B. Fabriform and/or Concrete Filled Bags 2 20 WESTERLY EDGE r CARLSBAD BOULEVARD GENERALIZED NATURAL SLOPE FABRIFORM AND/OR CONCRETE FILLED BAGS EL. 2Z 0.5 SANTIAGO FORMATION CONSTRUCTION EXCAVATION BEACHLEVELVARIES —BEACH SANO C. Concrete Wall with Rock Fill WESTERLY EDGE CARLSBAD BOULEVARD GENERALIZED NATURAL SLOPE REFERENCE: WCC report dated Nov. 1984. (Carlsbad Blvd. Shore Protection. Carlsbad State Beachl NOTE: Concrete wall section vvnh rockfill is superimposed by L&A. Inc. COMPACTED BACKFILL CONCRETE WALL WITH ROCKFILL EL. 23r TEMPORARY TIMBER SUPPORT BEACHLEVELVARIES . BEACH SAND GRAPHIC SCALE IFH REFERENCE: WCC report datad NOv 1984, (Carlsbad Blvd. Shora Prelection, Carlsbad State Beach) NOTE1 FaDnform section issuaenrnpoiea by l&A.lnc, Selected Feasible Project Alternative Schematic Diagrams FIGURE 3-3 WESTEC Services, Inc. 2-6 S 20- D. Reinforced Earth Wall with Toe Stone WESTERLY EDGE .CARLSBAD BOULEVARD GENERALIZED NATURAL SLOPE RECOMPACTED SLOPE REINFORCEDSTRIPS CONCRETE WAVE DEFLECTOR _EL. 22' , PRECAST CONCRETE WALL FACING -_ EL. 14' SANTIAGO FORMATION COMPACTED EARTH BACKFILL' WITH SELECT MATERIAL 3-TON STONE TOE PROTECTION • BEACH LEVEL VARIES CUT OFF \ -"--^_ BEACH SAND WALL FOOTING CONSTRUCTION*^ > _,EXCAVATION ' ? -GRAVEL DRAIN E. Reinforced Concrete Vertical Seawati with Toe Stone WESTERLY EDGE CARLSBAD BOULEVARD GENERALIZED NATURAL SLOPE COMPACTED BACKFILL f REINFORCED CONCRETE VERTICALf WALL WITH TOE STONE 3-TON STONE TOE PROTECTION . BEACH LEVEL VARIES GRAVEL DRAIN REFERENCE WCC report dared Nov. 1964. (CarlsQad Blvd. Shore Projection. Carlibad Stats Beacnl NOTE: Concrete wall section is juDenmoojed bv L&A. Inc. F. Reinforced Concrete Vertical Seawall without Toe Stone WESTERLY EDGE , CARLSBAD BOULEVARD GENERALIZED NATURAL SLOPE COMPACTED BACKFILL _EL. 22- REINFORCED CONCRETEVERTICAL WALL BEACH LEVEL VARIES _ BEACH SAND GRAPHIC SCALE (Fml REFERENCE: WCC report dated Nov. 193d, (Carlsbad Blvd. Shore Proieciion. Carlsbad State Beach]MOTE L Concrete mall section n lupe'imnosed bv L&A. Inc.r Selected Feasible Project Alternative Schematic Diagrams FIGURE 2 *««-3 WESTEC Services, Inc.2-7 are complete. Design assumptions used for comparative purposes in this EIR are that the selected bluff protection device would: 1) be constructed at a slope of approximately 1 1/2:1; 2) utilize deep foundations rather than toe store where feasible; 3) be designed to provide an equivalent level of protec- tion; 4) have a 50-year design life; and 5) require minimal excavations into the bluff. No Project Under the No Project alternative, there would be no beachfront plan for shore- line protection. The bluffs would be' increasingly impacted by direct wave attack, which would continue to cause erosion, loss of beach, slope failures, and the likely failure of nearby man-made structures, including Carlsbad Bou- levard. Carlsbad Boulevard would ultimately be lost or would have to ,be relocated, eliminating a designated scenic highway in Carlsbad's General Plan Scenic Highway Element. The utility lines located in the Carlsbad Boulevard right-of-way (including sewer, water, gas, telephone, electric) would also be lost. In the past a life has been lost at Carlsbad State Beach during a signifi- cant erosion event. The potential for another loss of life will continue. At present, it is estimated that the average rate of erosion at Carlsbad State Beach is 1 to 1.5 feet per year (Woodward and Clyde, 1984). In the event of severe storm conditions and accompanying high waves, it is apparent that Carlsbad Boulevard and utilities under the Boulevard are in danger of being undermined. Progressive undercutting of the bluffs by waves and slopes sloughing will continue and increase in magnitude until the coastal bluff has been eroded away and the roadway has started to collapse. If the bluff dam- age is allowed to continue, heavy loss to public property would result, as well as loss of utility services to a large area, and loss of vehicular access to a considerable length of beach. North-south traffic along the major arterial of Carlsbad Boulevard would also be disrupted, causing hardship to private busi- nesses located along the east side of the Boulevard. Under the No Project alternative, existing encroachments on Carlsbad State Beach bluffs and beach would remain, leading to a discontinuous pattern of shoreline protection and recreational use/visual quality disruption. The 2-8 emergency bluff stabilization measures performed by the City of Carlsbad in 1983, with riprap encroachment on the sandy beach (at Walnut Avenue and Cherry Avenue), will remain. These existing beach encroachments are incon- sistent with Coastal Act policies concerning preservation of the beaches for recreational use and enhancement of visual quality. In addition, access to the beach would remain limited. The paved parking lot at the south end of the beach would remain undermined and in a deteriorated condition, limiting parking availability to the public. Stairway access would remain limited to Cherry Avenue and Tamarack Avenue, with no ramps pro- vided for handicapped persons. Existing access stairways could be expected to deteriorate rapidly, as they have in the past during severe storms. This would present hazardous beach access conditions and would potentially jeopardize the safety of the public. The beach will ultimately be more difficult for $he public to reach because of this decreased and unstable access. With the future elimination of Carlsbad Boulevard under the No Project alternative, access to the beach from the bluff top will be extremely limited. Rock Revetment The Woodward-Clyde Consultants (1984) report analyses a rock revetment type of seawall (Figure 2-3A) with a curved alignment as the basic type of shore protection along the base of the bluff. Their report suggests that in certain locations a reinforced earth wall or sloped crib wall (both with toe stone) or no treatment at all might be appropriate. A typical design would place the top of the revetment at a maximum elevation of +22 feet (NGVD*), the toe at eleva- tion +3 feet and the slope at a 2 to 1 (horizontal to vertical) inclination. The armor toe would consist of 4 ton stone. The revetment would generally follow the toe of the bluff at approximate elevation +6 feet and would be located about 100 to 150 feet west of the western edge of Carlsbad Boulevard. In areas where the bedrock is higher than +6 feet, the top of the revetment could be lowered. *NGVD (National Geodetic Vertical Datum). Level formerly referred to as Mean Sea Level Datum of 1929. Mean Sea Level is the average height of the surface of the sea for all stages of the tide over a 19-year period. 2-9 Fabriform and/or Concrete-Filled Bags The Leighton and Associates (1984) report studies fabriform and/or concrete- filled bags (Figure 2-3B) as one of several feasible methods of shoreline pro- tection which meets the City's project objectives. The top of the structure would extend to approximately the same elevation as the rock revetment, +22 feet minimum, but would conform more closely to the existing vertical sea cliffs at an inclination of either 0.5 to 1 or 1 to 1 (horizontal to vertical). Either a deep foundation or toe stone would be required to stabilize the struc- ture. Concrete Wall with Rock Fill The Leighton and Associates (1984) report also addresses a concrete wall with rock fill (Figure 2-3C) as a suitable method of shoreline protection which meets the City's project objectives. The height of the structure would be the same as the previous two alternatives and it would be constructed at a 0.5 to 1 (horizontal to vertical) inclination. The wall is constructed behind a tempo- rary wooden support structure which is removed following completion of the wall. Reinforced Earth Wall with Toe Stone Shoreline protection involving a reinforced earth wall with toe stone (Fig- ure 2-3D) would provide an acceptable method of meeting the City's objec- tives for this project. The height of the structure would be similar to the previous alternatives, however, considerably more earthwork would likely be required and beach encroachment would be relatively high. The cost of con- struction will be higher than the previously discussed alternatives due pri- marily to the extensive earthwork requirements and the earthwork could initi- ate surface instabilities or slope failures during construction. 2-10 Reinforced Concrete Vertical Seawall With and Without Toe Stone The reinforced concrete seawalls (Figure 2-3E and F) will provide an effective means of protecting Carlsbad Boulevard from deterioration due to bluff insta- bility. The top of the seawall would extend to at least elevation +22 feet and limited earthwork would be required. Without toe stone, the vertical seawall causes only limited beach encroachment relative to the other alternatives being considered, however, the lack of toe stone may pose reflective wave energy problems such as beach sand scour. The addition of toe stone will cause considerable beach encroachment with its offsetting benefit of reduced reflective wave scouring of beach sands. It is also important to note that the City has begun a program to capture all runoff over the bluffs by installing a storm drain system along Carlsbad Boule- vard. Construction has recently commenced at the south end of the project area. From north to south, pipe sizes ranging from 24 inches to 48 inches will carry water south to Agua Hedionda Lagoon. Eventually all outfalls now depositing water over the face of the bluff will be removed. This project will be completed over a several year period and will be part of any selected bluff protective measure. The cost of the drainage system is estimated to be about $700,000. Regardless of the method of shoreline protection selected for implementation by the City, the proposed project will include the development of several beach access stairways, a ramp for handicapped persons and the retention of the existing parking area at the south end of the study area. The existing public access stairways located at Tamarack and Cherry Avenues will be rebuilt. Emergency vehicle access will continue to be provided along Ocean Street near Pine Avenue and from the public parking area at the south. Lat- eral access along the bluff may also be provided. Access to the foot of the bluff during construction will be gained from the parking area at the south end of the beach and this area may also be used to store construction equipment and materials. All shoreline protection methods will entail a rather lengthy construction period (3-6 months) and the selected 2-11 structure would likely be built in sections. The extent of grading for the alternatives would vary. D. DISCRETIONARY ACTIONS/USES OF EIR The proposed Carlsbad Boulevard Bluff Stabilization Project will require a discretionary approval by the City of Carlsbad and the California Coastal Commission must grant a Coastal Development Permit for the project. The U.S, Army Corps of Engineers may require a Section 10 Permit, depending upon whether excavation extends below mean high tide. It does not appear that an agreement with the California Department of Fish and Game will be required. The California Parks and Recreation Department does not have discretionary authority for the project but will have to issue an easement or lease for construction. The California Department of Boating and Waterways r is a potential project funding agency and therefore must consider the proposed project during its budget-making sessions. This EIR is an informational document to be used by the public, the City of Carlsbad, and all affected regulatory and responsible agencies in evaluating the environmental impacts associated with the proposed project. The City is obligated to balance the environmental effects of the project with other public objectives, including economic and social factors, in determining whether the project should be approved. 2-12 HI. ENVIRONMENTAL ANALYSIS This section of the EIR includes the impact analysis of five methods of bluff stabilization for Carlsbad State Beach. Each topic in this section includes the following subsections: Existing Conditions - describes the environmental set- ting for each issue; Impacts - an assessment of the effects related to the project; and Mitigation Measures - discussion of measures which would avoid or reduce any adverse impacts identified. A. GEOLOGY/GEOTECHNICAL CONSIDERATIONS The following discussion of geologic factors and their potential affect on the alternative shoreline protection measures is based on a detailed geotechnical study of the proposed project by Leighton and Associates (L&A, 1984). This study included geologic field reconnaissance and project area geologic map- ping, analysis of sequential stereoscopic aerial photographs, and review of per- tinent published and unpublished geotechnical data for the area, including the Carlsbad Boulevard shore protection feasibility study prepared by Woodward- Clyde Consultants (1984) for the City of Carlsbad. Existing Conditions 1. Landform/Topography The proposed project area is composed of a beach and coastal bluff extending approximately 4500 feet between Oak Avenue and the entrance to Agua Hedionda Lagoon in the City of Carlsbad (see Fig- ure 2-2, Topographic Map). Carlsbad Boulevard, situated along the bluff top, is set back from the bluff face at distances varying from 1 foot in the northern portion of the project area to 54 feet in the southern. This set-back distance generally increases from north to south. Height of the coastal bluff ranges from a low of about 10 feet just north of Pine Avenue to approximately 30 to 40 feet in the central and 3-1 southern portion of the project area. The bluff face varies in slope from about 1:1 to 2:1 (horizontal to vertical slope ratio). In localized areas both steeper and flatter slopes are found. The beach along the base of the bluff varies in width generally in accord with the season. During the summer, when long period waves often deposit sand onshore, the sand beach is typically 100 to 150 feet wide. In the winter months, wave action and higher tides remove sand from the beach and deposit it offshore. The typical beach width dup- ing the winter varies from about 25 feet between Oak Avenue and Redwood Avenue to approximately 60 feet south of Redwood Avenue. 2. Geology and Soils r • Stratigraphy /Lithology Geotechnical features in the proposed shoreline protection proj- ect area are illustrated on Figure 3-1, and geologic profiles through the beach and bluff are provided in Figures 3-2, 3-3 and 3-4. As shown, several geologic units and fill soils underlie or mantle the site. The general characteristics of these units, from oldest to youngest, are described below. Santiago Formation (Map Symbol Ts) - The Eocene-age Santiago Formation consists of hard, gray, clayey to silty sandstone found along the foot of the bluff at elevations of less than about 10 feet above mean sea level (MSL). At several places this rock unit is being eroded into a wave-cut platform that is up to 8 feet in width and approximately 1 to 3 feet above the beach. The Santiago Formation has been observed beneath the sand and cobble beach deposits at a depth of up to approxi- mately 12 feet (Kuhn and Shepard, 1984). Terrace Deposits (Map Symbol Qt) - Terrace deposits comprise the major geologic unit underlying the coastal bluff. The unit was apparently deposited on a wave cut bench formed by the transgressive and regressive episodes of sea level change that occurred during the middle to late Pleistocene Epoch. Terrace deposits consist of friable, reddish brown to brown silty, fine- to medium-grained, sparsely fossiliferous, marine sandstones; silty and clayey sandstones; and stratified layers of cobbles and 3-2 v,®» V^5L0be<SP*-« OfaS ': A^Vi LEGEND Af Artificial Fill QbS Beach SonJ Deposits QbC Beach Cobble Deposits JV.;.'•'.'. J QmW Mass-wasting Deposits Qt Pleistocene Terrace Oepoiits 'S Sonliogo Formation ^•' Approximate location of geologic conloct, gutried where ,1 uncertain, dot'eO where buned •^aytP Riprop ( *' • 8' in diomelerl T Ground wo ler seepoge © Hornofilol bedding Area ot heavy rilling/erosion Area covered bv iceplant vegelation Area covered by bom boo and ohreatophyie type vegetation Appfonmate location btuft profile IFiguf« 3-3,3-3,3-4) © Contour Interval: 5 Feet SOURCE: Leighton and Associates (1984) FIGURE 3-1 Geotechnical Map A 60- o> 20- 0 - B 60- 40-co "5> 0) uj 20- 0 J Parking Area Ocean Street Qbs Qt —? K-Carlsbad Blvd.- Ot Qbc 0 20 A1 -60 -20 -0 B -60 -40 -20 rO 40 SOURCE: Leighton and Associates,1984 Verticol and Horizontal Scale Geologic Bluff Profiles A - A' and B - B' FIGURE 3-2 Ini- 60- •= 40- LJ K Corlsbod Blvd.- Exposed Bedrock Ledge D 60-1 - 40- co <u LJ 20- c1 -60 -40 -20 •o -60 -40 K Corlsbad Blvd. -20 SOURCE: Leighton and Associates, 1984 0 20 40 Vertical and Horizontal Scale Geologic Bluff Profiles C - C' and D-D1 FIGURE 3-3 YNT E 60- 40- co B 20 UJ oH Sidewalk. Fence- Exposed Bedrock Ledge Qbc Qbc Corlsbod Blvd. Qt Ts 60- Of UJ 0- Porking Lot Rood Londscoped • Area-Carlsbad Blvd.- f 0 -40 -20 -0 -40 h20 -0 20 40 SOURCE: Leighton and Associates, 1984 Veriicol and Horizontal Scale Geologic Bluff Profiles E - E' and F - F' FIGURE 3-4 WESTEC Services, Inc. pebbles. The unit's maximum thickness is about 100 feet near Agua Hedionda Lagoon (Wilson, 1972). A weak iron oxide cementation in the upper few feet of this unit forms a more resistant shoulder to the bluff in several places. Mass-Wasting Deposits (Map Symbol Q mw) - Mass wasting deposits occur along the coastal bluff on slopes of the Pleisto- cene terrace unit. Failure of the Pleistocene unit is relatively common and can be observed and mapped along the entire sec- tion of this study area. Mass wasting deposits are usually unsorted mixtures of locally-derived materials. These mate- rials were deposited by processes which include, but are not limited to, slumping, mudflows, sandflows, and debris flows. The thickness of these deposits is highly variable, ranging from a few inches up to several feet. Deposits formed by mass wast- ing accumulate at the beach and tend to be eroded and dis- persed by wave action and littoral drift. Beach Deposits (Map Symbol Qbs-sand; Qbc-cobble) - Beach deposits occur seaward of the coastal bluff, and consist of loose, light gray silty sand, gravel and cobble with shell debris. Beach deposits are temporary sediment accumulations that are in active transit along the shoreline. Deposition (and erosion) of this unit is generally confined to the area between low and high tides. The beach extends from the low water line landward toward the bluff, where there is a notable change in sediment type, physiographic form and/or the line of permanent vegeta- tion. Artificial Fill (Map Symbol Af) - Artificial fill occurs where man has modified the topography by the addition of soil, sedi- ments, rock, vegetative debris, garbage, and other materials. Fill has been mapped on Figure 3-1 only where its thickness is greater than approximately 2 to 3 feet. Geologic Structure Geologic strata in the project area lie flat or are very gently inclined. No significant warping or folding was observed or is expected to exist in the area. Bedding attitudes in the Santiago Formation are generally less than 10°. Bedding within the Pleistocene terrace deposits is nearly horizontal, with some local cross-bedding. The contact between the terrace deposits and Santiago Formation is irregular, but generally slopes to the west at a low angle. 3-7 The terrace deposits are generally not fractured OP jointed. The Santiago Formation, however, is highly jointed and frac- tured and has many northeast-trending fractures and small faults. In the study area, such features as surge channels and sea caves, commonly formed by wave action, are not well developed. Faulting and Seismicity No active, potentially active, or other significant faults were observed or are known to exist at the site. Numerous small faults with minor displacements have been found in the Eocene Santiago Formation. However, these faults were not observed to extend upward into the overlying Pleistocene deposits. , The major seismic hazard affecting the project area would be groundshaking caused by an earthquake on one of the regional active faults. The Elsinore fault zone, located about 25 to 30 miles to the northeast, and the Coronado Banks fault zone, located 18 to 20 miles to the southwest, are considered to be seismically active. These faults are the most significant with respect to intensity of shaking at the site. Other known active faults capable of causing significant ground motion in the area are the San Jacinto fault, about 55 to 60 miles to the northeast, the San Andreas fault, about 70 to 80 miles to the northeast, the Newport-Inglewood fault zone, about 30 miles to the north- west, and the San Clemente fault, about 50 miles to the south- west of the site. A significant potentially-active fault in the project area is the offshore extension of the Rose Canyon fault, located about 5 miles west of the site. However, seismic events are much less likely to occur on potentially active faults. 3-8 3. Coastal Processes Proper development of any coastal property requires an understanding of the coastal processes operating both at that site and for some dis- tance up and down the coast. Background information, illustrations and a general discussion of relevant coastal processes are contained in Appendix C of this EIR. In addition, Appendix D contains a glossary defining the shoreline and coastal process terms used in this report. Existing coastal conditions in the vicinity of the Carlsbad Boulevard shoreline protection project are described below. • Beach Deposits As described earlier, beach deposits are composed primarilyrof fine- to coarse-grained sand and cobble. There is a general increase in the abundance of cobble in the northern section of the project area. South Carlsbad has the longest cobble beach in southern California (Kuhn <5c Shepard, 1984). As noted by Emery in 1960, the cobbles of Carlsbad State Beach appear to be the product of local cliff erosion. In 1984, however, many cobbles appear to be much larger than as described by Emery, and may be those dredged from the Oceanside small-boat har- bor as early as 1963 and transported to the site by ocean cur- rents. As observed during the winter storms of 1978, 1980, and 1983, cobbles can be a destructive element contributing to the undermining of beach roads and damaging structures. Pres- ently, the abundant cobbles in the project area form a low berm of varying width along the inland edge of the beach. Ongoing erosion and retreat of the coastal bluff, as described below, contributes to the sediment supply of the beach. Assum- ing that the average rate of bluff retreat ranges from 1 inch to 1 foot per year, the annual contribution of sand is conserva- tively estimated to be on the order of 1800 to 18,000 cubic yards per year. This calculation is based on the total exposed 3-9 surface of the bluff face which includes irregularities such as gullies and overhangs. Transgression and Regression of Beach Sands The sandy beaches that usually front seacliffs and bluffs along the San Diego County coastline have, in the recent past, pro- vided some buffer against wave attack. This past winter, heavy storm and surf conditions along with strong currents have removed much of the beach sand, and thereby removed the buf- fer between the ocean and seacliff. Predictions for return of the protective sandy beaches are not encouraging; there are indications that overall sand loss in the littoral cell will result in less sand returned to the beach. As a result, it is believed that the coastal bluffs will be increasingly impacted by direct wave attack. The natural process of sand depletion and accu- mulation is poorly known; therefore, the magnitude of this pro- cess on sea cliff and coastal bluff stability is unpredictable. Slope Stability The upper 30 to 40 feet of coastal bluff in the project area is composed of sandy, friable Pleistocene terrace deposits which do not have the hardness of the underlying sandstone, and which are not capable of standing in steep slopes for any length of time. These sand deposits are more rapidly eroded by water and wind action, and when the underlying sandstone support is removed, they are highly prone to slope failure. The terrace sands, in their oversteepened condition, are also more prone to the vibrational effects of earthquake shaking. Bluff Erosion and Retreat Leighton & Associates (1984) estimate that the rate of bluff erosion and retreat in the project area since the 1920s has 3-10 averaged about 3 inches per year. During several episodic rapid retreat events, erosion in some localized areas has been as much as several feet. The retreat rates are referred to as "average" since the number of feet of retreat is simply divided by the number of years over which the retreat occurred. These "average" rates do not fully reflect those severe storm occur- rences when several feet of coastal or shoreline property may be lost in a single day or in a few hours. As a case in point, Kuhn and Shepard (1984) observed that in early 1983, 15 to 20 feet of cliff retreat occurred during one storm event. Although this occurred south of the project area, a similar event could occur at Carlsbad State Beach. This coincided with very high spring tides, 10 to 12 feet swells, and extremely strong winds. Within the project area, two bath houses were undermined and submerged, the lower foundation of a main stairway was lost, and the parking lot south of Tamarack Ave- nue was undermined. Portions of Carlsbad Boulevard, both adjacent to Carlsbad State Beach and the Encino Power Plant, were severly damaged and, in places, collapsed. Total damage was estimated at $625,000 (California Coastal Commission, Preliminary Report on January 1983 Storms, February 14, 1983). Erosion and subsequent retreat of the coastal bluffs is con- trolled by several factors, including the degree of faulting, jointing, fracturing and consolidation of sediments; steepness of slope; ground water and surface water conditions; vegetation; and intensity of pedestrian and animal traffic. Wave action, precipitation and wind are also important factors. In the project area, wave action is directed primarily at sand- stones of the Santiago Formation which underlie the lower sev- eral feet of coastal bluff. The upper bluffs, underlain by the much more loosely consolidated terrace deposits, are not sub- ject to direct wave attack except during intense storms. 3-11 However, as wave action continually undermines the Santiago Formation, this sandstone is unable to support the overlying terrace sediments. Kuhn and Shepard (1984) attribute localized bluff erosion and retreat to storm drains that were originally installed to divert storm runoff away from the bluff. No erosion due to storm drains has been documented, however. Currently, there are nine drainage pipes between Agua Hedionda Lagoon and Oak Avenue. The diameter of the pipes varies from 3 to 18 inches. Two of these (3-inch diameter) are capped, and the other seven have been so heavily undermined that their open ends do not carry to the beach, but discharge directly onto the bluff face. This situation will be remedied by the ongoing City project,,to install a stormwater collection system along Carlsbad Boule- vard. All drainage pipes will eventually be removed. Heavy pedestrian traffic appears to be an additional factor in the bluff erosion. Several footpaths dissect the bluff face, the most heavily used being directly across from Walnut Avenue. Many of the other paths follow the drainage pipes where heavy undermining, rilling, and subsequent removal of vegetation have already produced natural access to the beach. In other areas, where jute netting has been laid on the slope to retard surface water erosion, pedestrians have utilized the smooth, gradual slope and created footpaths directly down the bluff face. Localized areas are also affected by animal burrowing. Vegetation along the coastal bluff consists of scattered patches of iceplant and native grasses, with locally dense stands of Arundo donax (a bamboo-like plant). Due to the iceplant's shal- low root structure and the abundance of water weight in its leaves, this plant appears to be a contributing factor in the shallow soil slips occurring on the bluff. The tubular root struc- ture of the A. donax, on the other hand, contributes to the 3-12 strength of the poorly-consolidated terrace deposits. In addi- tion, the abundance of its leaves provides a canopy for the underlying soil thereby reducing the effects of subaerial ero- sion. Several slope repair measures have been initiated in an attempt to reduce the effects of mass wasting and heavy wave attack on the bluffs. Fairly extensive slope repair was required in 1983 west of Acacia, Walnut, and Sycamore Avenues. Slope repair measures consisted of grading a 20 to 60-foot wide section at the top of the bluff and placing a fill slope down to the level of the beach. Jute netting was laid on the face of the fill to retard surface water erosion, and riprap was used to protect the toe of the slope. Vandalism has decreased the effectiveness, of the jute netting. 4. Hydrology • Surface Water As described earlier, a significant surface water factor in the project area is rainfall runoff discharged through storm drains onto the face of the coastal bluff. Direct runoff over the edge of the bluff also contributes to existing erosion problems. Groundwater A perched groundwater table was observed as seeps at several locations on the coastal bluff along the contact between the Pleistocene terrace deposits and the Santiago Formation. Groundwater seeps in the bluff were also mapped within the terrace deposits (see Figure 3-1). Leighton & Associates (1984) indicate the source of ground- water in the area is primarily surface water introduced locally 3-13 as rainfall and irrigation. These waters percolate through the permeable terrace sands, then travel laterally upon contact with the relatively impermeable Santiago Formation until reaching the bluff. A line of vegetation commonly grows at the seepage points along the bluff face. The irrigation of land- scaped areas affects the coastline by raising the water table during dry periods and adding to the weight of the soil. In addition, elevated pore water pressures, due to the presence of groundwater, increase the potential for landslides. Impacts The principal objective of the proposed project is to provide an effective means of stopping or retarding the coastal bluff erosion and retreat that^ is presently threatening Carlsbad Boulevard. Several alternative methods of bluff protection have been identified, as described in Section II of this report. Implementation of any of these alternatives will require careful geotechnical planning and design to assure that: 1) the stated project objective is metj 2) existing geologic hazards, both of local and regional significance, do not adversely affect project construction and operation; and 3) adjacent or nearby coastal properties are not adversely affected. In the following paragraphs these factors are addressed relative to each of the alternatives under consid- eration. 1. Geotechnical Advantages/Disadvantages of Bluff Protection Methods The five bluff protection devices would provide protection to the coastal bluff along Carlsbad Boulevard. Each, however, has certain unique design, construction and maintenance characteristics that should be considered in selecting the optimal system. The following discussion of the geotechnical and coastal engineering advantages and disadvantages of the proposed alternatives is based on a technical analysis of the project prepared by Leighton and Associates (1984). 3-14 Rock Revetment This alternative represents the most effective of the proposed systems in providing protection for Carlsbad Boulevard. It can be more quickly constructed than systems requiring structural forming, and can be built to conform to the toe of the existing bluff. Rock revetment provides excellent wave-energy absorp- tion, allowing less reflective wave energy. In addition, it is not significantly subject to structural weakening due to foundation settlement. Rock revetment systems have relatively low main- tenance requirements, although over time the rocks tend to become dislodged and require replacement. Fabriform and/or Concrete-Filled Bags Relative to rock revetment, this alternative may provide a somewhat less expensive but reasonably effective means of pro- tecting Carlsbad Boulevard. It is simpler to construct than the other alternatives and can be designed to conform to much of the existing bluff face. The wave-energy absorption qualities of fabriform are good, although these systems are usually con- fined to areas not subject to direct wave attack. This alterna- tive has low maintenance requirements and is not as prone as rock revetment to the accumulation of trash and debris. Concrete Wall With Rock Fill The protection of Carlsbad Boulevard provided by this alterna- tive would be nearly as effective as rock revetment, although probably at a slightly higher cost. Like the previous two alter- natives, it can be built to conform to the existing bluff. The construction may involve some difficulties such as in placement of the rock fill. A concrete wall with rock fill would be expected to require low maintenance. 3-15 • Reinforced Earth Wall With Toe Stone This system would be designed to provide an acceptable barrier to bluff erosion and retreat. There could be construction prob- lems because of the need to cut extensively into the existing bluff. This system is generally built for protection against low energy waves, and not where it would be subjected to direct wave attack. The reinforced earth wall alternative would have low to medium maintenance requirements. • Reinforced Concrete Vertical Wall (With or Without Toe Stone) This alternative would be effective in protecting Carlsbad Bou- levard, although it may pose problems resulting from relatively low energy absorption characteristics and subsequent high reflective wave energies. It is the most costly of the proposed alternatives. Construction difficulties could be realized, pri- marily due to variables in tidal and beach conditions. In addi- tion, special consideration would be necessary to avoid poten- tial damage due to foundation settlement. Maintenance requirements are low to moderate relative to the other alterna- tives. 2. Geologic Hazards As described in this section, there are several geologic factors that could adversely affect the proposed project. In addition, the project could affect adjacent shoreline properties if special engineering is not performed at the north and south ends of the selected protective device. Many of these potential impacts are common to all five alter- natives, while others are specific to just one or two of the proposed shoreline protection systems. These impacts are described further below. 3-16 Seismicity The seismicity impact of greatest potential concern at the proj- ect site is groundshaking due to earthquakes on active faults in the region. The nearest major active fault is the Coronado Banks fault, located 18 to 20 miles to the southwest. The maxi- mum probable earthquake on that fault would produce a peak horizontal ground acceleration of about 0.15 g to 0.20 g at the project site. The most likely consequence of such groundshaking would be surficial failures in locally oversteepened portions of the bluff face. In addition, shallow soil failures and failure of unstable blocks of bedrock could occur. Soil liquefaction may be possi- ble where coastal protection structures are not founded on competent Santiago Formation sandstones. Soils Unconsolidated to poorly consolidated beach sands, artificial fills and mass-wasting deposits along the bluff toe may provide inadequate bearing capacity to the proposed coastal protection systems. The more rigid of the proposed alternatives (such as a fabriform seawall; a reinforced concrete vertical wall and, to a lesser degree, a concrete wall with rock fill) would be most susceptible to subgrade or backfill movements if foundation preparation is not adequate. Rock revetment or a reinforced earth wall could be much less subject to structural weakening due to settlement. Slope Stability Strong wave action, uncontrolled storm runoff, and the pres- ence of incompetent terrace soils are among the factors adversely affecting stability of the coastal bluff. Construction 3-17 of the proposed coastal protection system, combined with the provision of adequate storm drainage facilities, will result in a significant improvement in slope stability. However, construc- tion of the reinforced earth wall alternative, which would require an extensive cut into parts of the bluff, may initiate surface instabilities OP slope failures during grading. Bluff Erosion Implementation of the proposed project including storm drain improvements will significantly limit bluff erosion due to wave action. However, there are seven storm drains in the project area that discharge directly onto the bluff face. Rainfall run- off directly over the bluff edge also contributes to existing ero- sion problems. Such erosion will continue until adequate storm drain improvements are provided. Coastal Protection Design Criteria Woodward-Clyde Consultants (WCC, 1984), in their feasibility study for the proposed project, selected a set of engineering criteria for preliminary design purposes. These criteria are: a. Tidal Range MLLW *NGVD datum datum (feet) (feet) Highest estimated water level +7.79 +4.91 Mean higher high water +5.61 +2.73 Mean high water +4.89 +2.01 Mean sea level (NGVD datum) +2.88 +0.00 Mean lower low water +0.00 -2.88 Lowest estimated water level -2.18 -5.06 *NGVD - National Geodetic Vertical Datum (formerly called Sea Level Datum of 1929). b. Estimated storm surge and wave set-up: 2.1 feet 3-18 c. Highest estimated still water level (SWL): +9.9 feet (MLLW datum) d. Deep water wave period: 16 seconds e. Elevation at toe of revetment: +3 feet (MLLW datum) f. Assumed worst condition: sand scoured down to toe of revement so water depth (ds) = 6,9 feet g. Average inshore slope: 1 to 25 (m=0.04) h. Maximum wave height of wave breaking on revetment: Hb = 8.6 feet i. Stability coefficient for two layers of armor stone: Specific gravity of armor stone: S = 2.64 Sand Supply Construction of any of the project alternatives will have .a minor adverse effect on the supply of sand to the coastal trans- port system. By design, the proposed project would eliminate this sediment source. Relative to the amount of sediment con- tributed annually to the Oceanside littoral cell, the expected loss of sand is considered insignificant. Longshore Currents The proposed project will not effect longshore currents and related sediment transport processes. Impacts would only occur if the selected coastal protection structure extends seaward into the ocean. Even an impact associated with a bluff protec- tion device extending into the ocean would be minor, as opposed to the significant adverse effects associated with offshore coastal protection structures as groins or breakwaters. 3-19 • Sediment Accumulation/Erosion Given the preliminary nature of project design and the complex coastal processes presently affecting the area, prediction of the precise location and significance of any project-related changes is very difficult. However, it can be expected that the greatest changes would be noted at the ends of the proposed shoreline protection structure, and at or near any interim location where there are discontinuities. Such discontinuities may take the form of gaps in the structure or changes from one type of pro- tective device to another. It is at these points that any changes in the energy regime would be concentrated. • Flooding There is a minor potential for erosion due to flooding at the southerly end of the project due to flood-level flows through Agua Hedionda Lagoon. This potential should be reviewed dur- ing final project design. • Groundwater Seepage The presence of groundwater, as evidenced by seepage at sev- eral places along the bluff, adversely effects slope stability. In addition, seeps behind those project alternatives that form rigid, impermeable walls could be structurally impacted by high hydrostatic pressures due to the buildup of groundwater. The rock revetment alternative would be not susceptible to this impact and other protection devices would incorporate drains into their design. This should not pose a significant effect. Mitigation Measures Design considerations recommended to mitigate adverse geology-related impacts are described below. These measures would eliminate potentially 3-20 significant adverse impacts associated with construction of any alternative bluff protection device. 1. Seismicity • Project construction should adhere to the seismic design crite- ria of the Uniform Building Code and state-of-the-art methods outlined by the California Structural Engineers Association. • Stability of the coastal bluff under seismic loading should be analyzed to determine appropriate setbacks for Carlsbad Boule- vard and its utility lines, or if necessary, to define special foun- dation provisions. r • Final geotechnical investigations should address soil liquefac- tion potential where foundations might be within a few feet of the groundwater table and not founded on the Santiago Forma- tion. 2. Soils The location of any adverse soil conditions that might impact structural foundations should be identified by a geotechnical engineer during detailed study of the project area prior to final project design. Where unusually deep soils of low bearing capacity are encoun- tered, this condition should be accommodated by design of spe- cial foundation support systems. Where inadequate shallow foundation soils are encountered, this condition should be mitigated by deepening of foundations until satisfactory bearing materials are reached. 3-21 3. Slope Stability An engineering analysis of the gross stability of the coastal bluff should be a part of final project design. Significant cuts into the bluff are not proposed, however, should deep cuts be necessary fop project construction, carefully- phased grading may be necessary to avoid the creation of tem- porarily oversteepened and unstable slopes. 4. Bluff Erosion A system for diverting storm runoff away from the bluff and directly onto the beach should now be constructed. This should be considered during project design. Native vegetation should be used to landscape all exposed sur- faces on the upper bluff to reduce the velocity of storm runoff and to stabilize soils. Large-leaf ice plant should not be used in bluff landscaping. Any landscaping should be accomplished without terracing or large excavation of the bluff face. Further, a regular mainte- nance schedule should be established, which includes measures to avoid over-irrigation. A permanent irrigation system should not be installed. Pedestrian traffic on the bluff face should be eliminated, and erosion-protected beach access routes established. 5. Erosion Patterns Preference should be given in final project design to avoiding the creation of significant gaps or other discontinuities in the shoreline protection structure. 3-22 Special consideration should be made in the design of the north and south terminations of the shoreline protection structure to avoid creating significant and possibly damaging changes in coastal wave dynamics OP current patterns. 6. Flooding Should a significant flooding potential be found to exist, the southern end of the bluff protection structure should be designed to avoid any related erosion. 7. Groundwater • Subdrains should be provided behind any impermeable portipns of the bluff protection structure. Such drains would carry groundwater around OP through the structure and avoid the buildup of adverse hydrostatic pressures. B. BIOLOGICAL RESOURCES Existing Conditions The bluffs between Carlsbad Boulevard and the beach were presumably cov- ered by southern coastal sage scrub in the past (Thome, 1976). The bluffs in the project area have been heavily disturbed but pockets of native vegetation do remain. Native species present within the project area include coastal isocoma (Haplopappus venetus ssp. furfuraceus), mission dudleya (Dudleya edulis), coast buckwheat (Eriogonum parvifolium), coast cholla (Opuntia ppoli- fera), and California box-thorn (Lycium californicum). Much of the bluff area has been altered by recent erosion control efforts and continuing foot traffic. Some of these disturbed areas are denuded while others are covered by introduced nonnative species. Sea fig or large-leaved ice-plant (Carpobrotus sp.) is relatively common on portions of the bluff as is giant reed (Arundo donax), and saltgrass (Distichlis spicata). The presence of 3-23 high numbers of sea-lavender (Limonium sp.) and stock (Matthiola incana) may be indicative of past revegetation efforts on the bluffs. A variety of common nonnative weedy species are also scattered along the bluffs and horticultural species are present in a bluff-top park at the southern end of the study area. Seepage and drainage along the base of the bluff has created wet zones which are occupied by a variety of mesic-adapted plants. These include watercress (Rorippa sp.), cat-tail (Typha angustifolia), New Zealand-spinach (Tetragonia tetragonioides), spearscale (Atriplex patula ssp. hastata), nightshade (Solanum douglasii), sea-blite (Sueada californica), tamarisk (Tamarix sp.), dock (Rumex sp.), and alkali bulrush (Scirpus robustus). These wet zones are brackish in character and are scattered along the base of the bluff but are nowhere espe- cially well-developed. They are small, disjunctive and constrained from fur- ther development by the limits of the bluff and the adjacent beach. Mos$ if not all of thse wet zones are expected to be short-term due to the combination of cliff erosion, high tides and storm events. Wildlife use of the bluffs in the project area is expected to be low due to the disturbed character of the habitats and the extensive human use (including dogs) of the area. The California ground squirrel was observed on the bluffs but did not appear to be as common as one might expect. Other species expected would be urban-adapted birds, side-blotched and western fence liz- ards, as well as Pacific treefrogs in the seepage areas. No rare or endangered plant or animal species as officially listed by the U.S. Fish and Wildlife Service (USFWS, 1983ab) and the California Department of Fish and Game (CDFG, 1980; 1984) were observed or expected onsite. A couple of plant species listed by the California Native Plant Society (Smith and York, 1984) have been recorded along the ocean bluffs south of Batiquitos Lagoon and could potentially be found onsite. These are western dichondra (Dichondra occidentalis) and NuttalTs lotus (Lotus nuttallianus). NuttalTs lotus is considered rare in California but common elsewhere (Baja California) and western dichondra is on the CNPS "watch list". Nuttall's lotus could be found in the upper beach environment adjacent to the bluffs, although human use of the beach probably prevents its establishment. Western dichondra is an 3-24 herbaceous perennial which could potentially be found under and about the low native shrubs on the bluffs. No regionally declining reptiles (McGurty, 1980) amphibians (San Diego Herpe- tological Society, 1980), OP birds (Remsen, 1978; Everett, 1979) are expected onsite. Impacts It is assumed that the bluffs would be completely altered as part of the bluff stabilization project. Given the lack of sensitive plant and animal species, small extent of native cover, and the existing level of disturbance of the area, the loss of the remaining terrestrial habitats is not considered a significant biological impact. The small wetlands at the base of the bluff do not con§ti- tute a significant wildlife habitat. While the mesic zones onsite are no doubt wetlands under the definitions included in the Statewide Interpretive Guidelines for Wetlands and Other Envi- ronmentally Sensitive Habitat Areas (adopted February 4, 1981, California Coastal Commission), they are not considered a cumulatively significant habi- tat which must be mitigated if the project is carried out. The Wetlands Guide- lines allow for restoration projects if the wetlands are small, extremely iso- lated and incapable of being restored. The proposed project would appear to fall under this exemption category. The Coastal Act, in Section 30235, allows for projects such as that proposed (see discussion under Land Use/Coastal Act Compatibility). Mitigation Measures Given the lack of significant biological effects, no specific mitigation mea- sures are necessary. Revegetation of portions of the bluff are discussed under sections dealing with erosion control and aesthetics. 3-25 C. LAND USE/COASTAL ACT COMPATIBILITY Existing Conditions City of Carlsbad Carlsbad State Beach is designated as open space on the Land Use Plan of the City of Carlsbad's General Plan (1983). Surrounding land use includes high density residential on the east side of Carlsbad Boulevard, extending north to Walnut Avenue. Land use north of Walnut Avenue consists of travel services and commercial. The shoreline north of Oak Avenue, and west of Ocean Street, adjacent to the project site's northern boundary, is designated for high density residential development, r In the Open Space and Conservation Element of the General Plan, Carlsbad State Beach is identified as a "Prime Open Space and Conservation Area" (City of Carlsbad, 1973). These areas in the City of Carlsbad are recognized as "valuable, unique or representative examples of natural, ecologic, scenic or cultural resources, and geologic hazard areas." .The Open Space and Conserva- tion Element of the General Plan recommends that special regulations be uti- lized to assure that the intent of the Plan is carried out when development is proposed that may have an affect on the prime open space areas. Open Space and Conservation Element goals are listed below: • To coordinate open space uses with other land uses for mutual enhance- ment and creation of a "human" urban environment, which includes development and expansion of recreational land, conservation of natural and man-made amenities, and preservation of options with regard to agricultural land. • To preserve optimum sustainable environmental quality levels with respect to air, water, sound levels, and plant and animal life. • To prevent incompatible development of areas that should be preserved or regulated for scenic, historic, conservation or public health and safety purposes. 3-26 • To preserve and create an open space system of aesthetic value that will maintain community identity, achieve a sense of natural spacious- ness, and provide visual relief in the cityscape. • To preserve an adequate amount and variety of open space for outdoor recreation which shall include, but not be limited to, parks, beaches, areas for organized sports, connecting corridors with trails, water rec- reation areas (beaches, lagoons, lakes) unique conservation areas for nature study, and semi-developed areas for camping. • To protect select wildlife through the preservation of feeding, nesting, and breeding areas. • To conserve and encourage the use of all forms of vegetation neede4 to (a) prevent erosion, siltation and flooding, (b) protect air and water resources, and (c) protect and enhance visual resources. Specific Open Space and Conservation Element policies which apply to the proposed project are listed below: • Landformsi To protect the unique variety of landforms distinctive of the City's topography and to ensure that the development process con- siders and strives to preserve these landforms rather than to create an unnatural, uniform landscape. • Outdoor Recreation: To conserve, develop, and utilize areas particu- larly suited for outdoor recreation by preserving areas of unique scenic, historical and cultural value and developing areas especially suited for active park and recreational purposes. • Preservation of Natural Resources: To preserve natural resources by: protecting fish, wildlife, and vegetation habitats; retaining the natural character of waterways, shoreline features, hillsides, and scenic areas; safeguarding areas for scientific and educational research; respecting the limitations of our air and water resources to absorb pollution; 3-27 encouraging legislation that will assist logically in preserving these resources. The Open Space and Conservation Element also states that "No use, develop- ment or alteration of land identified on the map titled "Prime Open Space and Conservation Areas" should be allowed unless there is compliance with the objectives and guidelines of the Open Space and Conservation Resource Man- agement Plan" (City of Carlsbad, 1973). California Coastal Act The proposed bluff stabilization project is also located within the boundaries of the Coastal Zone established by the California Coastal Commission. Devel- opment must comply with the policies of the California Coastal Act of 19?6. The Act contains several policies relating to shoreline protective devices in terms of the physical effects of the devices and the rights of the general public. The City of Carlsbad has not yet adopted a Local Coastal Program for the area of the City in which the seawall will be built, therefore a Coastal Development Permit must be granted by the Coastal Commission for the proj- ect. Coastal Act policies applicable to the proposed seawall project involving pub- lic access, construction, visual resources and natural resource protection, are outlined below: • Section 30211: Development shall not interfere with the public's right of access to the sea... • Section 30221: Oceanfront land suitable for recreational use shall be protected for recreational use and-development... • Section 30235: Revetments, breakwaters, groins, harbor channels, sea- walls, cliff retaining walls, and other such construction that alters nat- ural shoreline processes shall be permitted when required to serve coastal-dependent uses or to protect existing structures or public 3-28 beaches in danger from erosion and when designed to eliminate OP miti- gate adverse impacts on local shoreline sand supply. • Section 30240b: Development in areas adjacent to environmentally sen- sitive habitat areas and parks and recreation areas shall be sited and designed to prevent impacts which would significantly degrade such areas... • Section 30251: The scenic and visual qualities of coastal areas shall be considered and protected as a resource of public importance. Per- mitted development shall be sited and designed to protect views to and along the ocean and scenic coastal areas, to minimize the alteration of natural land forms, to be visually compatible with the character of surrounding areas, and, where feasible, to restore and enhance visual quality in visually degraded areas. • Section 30253: New development shall: 1) Minimize risks to life and property in areas of high geologic, flood and fire hazard. 2) Assure stability and structural integrity, and neither create nor contribute significantly to erosion, geologic instability, or destruction of the site or surrounding area or in any way require the construction of protective devices that would substantially alter natural landforms along bluffs and cliffs. Even though the Local Coastal (LCP) Program for the City of Carlsbad has not been adopted by the City, it was certified by the Coastal Commission on June 18, 1981. The LCP designates a Coastal Shoreline Development Overlay Zone which includes the coastline area of the City of Carlsbad, including the beaches, bluffs and adjacent land, or those areas located between the ocean and the first public road parallel to the ocean. 3-29 The regulations for development along the coastline under the Coastal Shore- line Development Overlay Zone are very similar to the Coastal Act policies listed above, in that they are intended to maintain the shoreline as a unique recreational and scenic resource, and to promote public safety and access. In addition to those policies stated in the Coastal Act, the LCP identifies the' following regulations for shoreline development: • As a condition of approval, permitted shoreline structures (seawalls) may be required to replenish the beach with imported sand. • Provisions for the maintenance of any permitted seawalls shall be included as a condition of project approval. • Seawalls and other shoreline protective devices shall be conditioned^to provide the public with the right of access to a minimum of 25 feet of dry sandy beach at all times of the year. • Seawalls shall also be conditioned to provide the public with lateral access to the sandy beach. • Insofar as is feasible, natural topography and scenic features of the site will be retained and incorporated into the proposed development. • Any grading or earth moving operations in connection with the proposed development will be executed so as to blend with the existing terrain both on and adjacent to the site. California Department of Parks and Recreation General Plan Resolution 78-83 adopted by the State Park and Recreation Commission on November 4, 1983, established a General Plan for the San Diego Coastal State Park System, including Carlsbad State Beach. The General Plan contains sev- eral statements and policies which would affect the proposed bluff stabiliza- tion project (California Department of Parks and Recreation, 1983). 3-30 The Resource Element describes the existing conditions at Carlsbad State Beach and contains policies for its development and protection. Statements and policies which would affect the proposed project are summarized below: • Sweeping panoramas of the ocean can be seen from the cliff tops. • The view from the beach is less dramatic and the focus tends to be on the breaking waves and along the surf line. • In the planning of improvements to be undertaken within state recrea- tion units, consideration shall be given to compatibility of design with the surrounding scenic and environmental characteristics. • The function of the California Department of Parks and Recreation, at Carlsbad State Beach shall be to preserve and protect public opportuni- ties for ocean beach-oriented recreation in a high-quality environment. A natural setting for recreational activities shall be preserved. • Insofar as possible, the entire area of sandy littorals will be available for recreational use and visual enjoyment. • Only in areas where structures or areas of public use are threatened, should the State resort to funding or approving remedial measures. When necessary, projects should restore natural processes, retain shore- line characteristics, and provide recreational benefits. • The planning and improvement of parks and beaches should be done in a way consistent with protection against potential erosion of the affected segment of the coastline. • Development of a new storm drain system to carry runoff parallel to the coastline rather than directly down cliff faces shall be considered. • Fencing or similar measures shall be considered to discourage foot traffic down the cliff faces. Elevated stairways should be provided. 3-31 Interpretive programs shall describe the permanent destructive effects of climbing on bluffs. The Land Use and Facilities Element of the General Plan provides information on current land uses and recommends new facilities and uses. The project area described in this EIR is called out as Area 2 in the State's General Plan. Statements and policies extracted from this Element of the General Plan are listed below: • This area is experiencing severe sand depletion. The remaining cobble beach is prone to excessive erosion. • Two beach restrooms and a stairway have been destroyed by surf. r • The Tamarack Avenue parking lot is being eroded by surf. • Carlsbad Boulevard is threatened by seacliff retreat due to direct wave attack at the base of the cliffs. • Bluff erosion is excessive due to pedestrian traffic, sand depletion on the beach, seacliff retreat from direct wave attack, and storm runoff. • Several facility recommendations are made: Determine feasibility of installing +4000 lineal feet of beach protection device. A longard tube is suggested as a possible protection device. Replenish beach sand with imported sand. Revegetate bluff areas with native vegetation. Install interpretive panels. 3-32 • The threat to Carlsbad Boulevard is obvious creating a potential prob- lem for the City of Carlsbad. • There is no change in the longstanding policy of the Resources Agency that only in those situations were structures OP areas of public use are threatened should the State resort the funding OP approving remedial projects. Where remedial measures are deemed necessary, projects should restore natural processes, retain shoreline characteristics, and provide recreational benefits to the extent possible. • Area 2 is considered to be the greatest area of concern because of the potential loss of Carlsbad Boulevard. The Environmental Impact Element of the General Plan analyses the poten^al impacts of the policies and plans contained in the State's document. A sum- mary of relevant findings is provided below: • Installation of the beach protection device and sand replenishment of Area 2 will have a significant positive effect on the recreational resources of the state beach. • As part of the proposed project, a new storm drain system will be developed to minimize erosion. Bluffs will be revegetated with native vegetation to retard erosion. • Under the no project alternative, damage caused by the surf would con- tinue. Impacts City of Carlsbad Overall, the proposed bluff stablization methods may be both consistent and inconsistent with several of the Open Space and Conservation Element policies of the City of Carlsbad General Plan. Generally, concerning landforms, the 3-33 project is consistent with the City's mandate to protect the unique variety of landforms distinctive of the City's topography, in that the bluffs would be preserved. However, the provision of a seawall could also create an unnatural landscape by the placement of a man-made revetment or wall at the base of the natural, though disturbed, bluffs. Regarding outdoor recreation, the proposed methods of stablization would pre- serve Carlsbad Boulevard, which offers a unique scenic experience to motor- ists along the project area and provides access to coastal recreational areas. At the same time, the project could potentially encroach upon the sandy beach or cause sand scour, as described under the Coastal Act impacts. In this EIR "beach encroachment" means the permanent placement of a bluff stabilization device between the water's edge and the base of the coastal cliffs on any area available for recreational use. This would include the sandy beach and exposed rock ledge. The degree of beach encroachment will depend upon the method of bluff protection selected as the preferred project. Relatively speaking, rock revetment will cause somewhat more beach encroachment when com- pared with the other feasible alternatives. Regarding preservation of natural resources, the project would be consistent with the Open Space and Conservation Element in that the bluff shoreline features would be retained; however, the sandy beach shoreline feature may be decreased somewhat. California Coastal Act Generally, the proposed bluff stabilization and improvements are consistent with Coastal Act Section 30211 in that the development will not interfere with the public's right of access to the sea. In fact, the development is proposed to provide improved access through the restoration of existing accessways and the construction of two new accessways, including a ramp to accommodate handicapped persons. Also, the bluff protection project will enable Carlsbad Boulevard to continue to function as a primary coastal access route of regional significance. 3-34 The stabilization methods analyzed may be inconsistent with the intent of Coastal Act Section 30221 in that land suitable for recreational use may not be entirely protected for recreational use. The pock revetment or seawalls with toe stone may extend onto the sandy beach in several areas and will likely cover the exposed Santiago Formation ledge which is currently used by beach- goers (Woodward-Clyde, 1984). The proposed bluff stabilization project appears to be consistent with Coastal Act Section 30235, which permits such construction only when required to serve coastal dependent uses or to protect existing structures or public beaches from erosion. The primary purpose of the bluff stabilization project is to protect the bluff which supports a roadway (Carlsbad Boulevard) and its underlying utilities. If the roadway is defined as an "existing structure", then the project is consistent with this Coastal Act section. Also, if the bluffs are considered a part of the public beach, then the bluff stabilization project could be considered consistent with Coastal Act Section 30235, in that the bluffs are being preserved. The seawall stabilization project may be in partial conflict with Coastal Act Section 30240(b) in that the development could potentially degrade the beach recreation area. For several alternatives, the completed project would extend onto the sandy beach area and would cover the exposed rock ledge. Sensitive design measures, as recommended in the Visual Aesthetics section, could increase visual compatibility of the development with the natural bluffs. The seawall stabilization project would be consistent with Coastal Act Section 30251 in that the development is designed to protect views to and along the ocean through the protection of the bluffs supporting Carlsbad Boulevard, a designated City of Carlsbad Scenic Highway. Preservation of the bluff's nat- ural landform and assurance of visual compatibility with the character of the surrounding area can be achieved through sensitive project design and mitiga- tion measures delineated in the Visual Aesthetics section, such as use of natu- ral materials in construction, revegetation of slopes, and limitation of place- ment of the rock revetment or toe stone. 3-35 The bluff stabilization project would be consistent with Coastal Act Section 30253 in that the development would minimize risks to life and property in an area of high geologic hazard. With the improvement and construction of new accessways to the beach from Carlsbad Boulevard, the use of hazardous foot trails over the bluffs would be decreased or eliminated. Existing accessways already deteriorating from wave action and bluff erosion are proposed to be improved for public safety. The new development would not substantially alter natural landforms along the bluffs, as the bluffs have already been sub- ject to significant man-made intrusions; and sensitive project design measures would assure compatibility with the natural bluff landform. The bluff stabilization project may be in conflict with Coastal Act Section 30253(2) in that some bluff stabilization methods may contribute to erosion. The seawalls without toe stone protection would protect the bluffs, but rpay actually increase beach erosion, exacerbating winter wave destruction (refer to Section III-A of this report for a more detailed discussion of beach erosion and geotechnical considerations). Department of Parks and Recreation General Plan The proposed bluff protection project appears to conform to the statements, policies and plans contained in the General Plan for Carlsbad State Beach. In terms of aesthetics, it is agreed that views are not directed at the bluffs but rather towards the ocean and surfline. Improvements at the base of the bluff would not significantly deteriorate the viewshed. The selected alternative should minimize beach encroachment in order to comply with the General Plan policies concerning maximizing the use of the beach area. The General Plan recommends protecting Carlsbad Boulevard and concurs that it is now threat- ened. The City's ongoing storm drain system improvements along Carlsbad Boulevard are directly in compliance with the General Plan. The proposed project will discourage vertical pedestrian traffic in accordance with State policy and revegetation with native plants is proposed. The General Plan concurs that the effects of a beach protection program will be positive and that the no project alternative would continue the existing condition of surf damaged bluffs. 3-36 Land use impacts concerning each method of bluff stabilization are detailed below. • Rock Revetment The rock revetment method of bluff stabilization consists of the place- ment of 3 to 4-ton armor stone on a base of 1/2-ton stone, quarry waste, and filter fabric at the base of the bluff (Figure 2-3). The rock revetment method of stabilization could be considered incon- sistent with Open Space and Conservation Element policies of the City of Carlsbad General Plan, in that it would not serve to retain the nat- ural character of the shoreline feature and would create an unnatural, uniform landscape. The construction of a rock revetment, utilizing 3- r to 4-ton armor stone, could encroach onto the sandy beach in certain areas unless considerable bluff excavation is performed. In any event encroachment onto the rock ledge will occur which may be in conflict with City and State General Plans and their policies to conserve, develop and utilize areas particularly suited for outdoor recreation. Concerning Coastal Act and State General Plan policies, the wall may be inconsistent with Section 30221 in that beach would not be fully protected for recreational use with the encroachment of the armor stone. The rock revetment would substantially alter the natural bluff landform and visual quality of the shoreline, and may thus be considered inconsistent with Sections 302405, 30251 and 30253. The rock revetment is considered the most effective system for pro- tection of Carlsbad Boulevard because of its ability to provide good wave energy absorption and its structural soundness. Thus the bluff stabilization project would ensure preservation of the distinctive bluff formation. 3-37 Fabriform and/or Concrete-Filled Bags This method of bluff stabilization involves the stacking of fabriform OP concrete-filled bags from the base of the bluffs upward and in confer- mance to the vertical sea bluff. The wall could involve the use of some compacted backfill. The wall is supported by a deep concrete founda- tion (Figure 2-3). With sensitive design features, including matching the color of the bags to the native bluff sandstone, this method of stabilization would be considered consistent with Open Space and Conservation Element poli- cies of the City of Carlsbad General Plan and the State General Plan, in terms of landform. The use of textures and colors to match the exist- ing bluffs would also serve to preserve the bluff landform rather tljan create an unnatural, uniform landscape. As the wall would provide good wave energy absorption and would withstand direct wave attack, it would also ensure preservation of the bluffs. Concerning Coastal Act policies, this stabilization method would be consistent with Coastal land use policies. The wall would not extend onto the sandy beach area and thus would be consistent with Section 30221 in the protection of beach land for recreational use. If sensitive design measures are instituted, using natural materials in seawall con- struction, the wall would not substantially alter the natural landform or visual quality of the shoreline and would thus be consistent with Coastal Act Sections 30240b, 30251 and 30253. Because of its slanted, stepped construction, this bluff stabilization method would not contribute sig- nificantly to beach sand erosion as with a vertical seawall, and is thus in conformance with Section 30253 of the Coastal Act. Concrete Wall with Rock Fill This stabilization procedure consists of a thick concrete and rock fill wall placed against the face of the sandstone bluff. The wall would be composed of concrete mixed with large rock material (Figure 2-3). 3-38 The concrete wall with rock fill method of stabilization would be con- sidered largely consistent with Open Space and Conservation Element policies of the City of Carlsbad General Plan and the State General Plan. The wall would conform to the existing vertical sea cliff land- form although the use of large rocks mixed with concrete would create an unnatural, uniform landscape. The concrete could be colored and textured to match the native sandstone, however, the large rocks would also be visible and would not present a natural appearance. The thick wall could also potentially encroach onto the rock ledge or sandy beach, although this is not likely. Regarding Coastal Act policies, the concrete and rock fill wall con- struction would potentially be inconsistent with Section 30221 if it extended onto the beach sand. However, the wall would not involve, as much encroachment on beach sand as a rock revetment or a wall with toe stone, if encroachment occurred. Also, because the wall may alter the natural bluff landform and visual quality of the shoreline, it would be potentially inconsistent with Sections 30240b, 30251 and 30253. Reinforced Earth Wall with Toe Stone This method of stabilization consists of removing and then recompact- ing the earth at the base of the bluff. Metal or plastic reinforcing strips, connected to pre-cast concrete panels, are inserted into the fill. A wave deflector is typically placed at the top of the pre-cast panels to prevent damage by wave action. Toe stone protection at the base of the concrete seawall consists of 3-ton stone (Figure 2-3). With specific design measures, the reinforced earth wall method of stabilization would be considered consistent with Open Space and Con- servation Element policies of the City of Carlsbad General Plan and the State General Plan, in terms of landform. The stabilization project would ensure preservation of the distinctive bluff formation, provided the wall is constructed to withstand direct wave attack. The use of concrete and compacted earth backfill of a texture and color to match the existing bluff would also serve to preserve the bluff landform rather 3-39 than create an unnatural, uniform landscape. However, the use of toe stone at the base of the seawall would not serve to retain the natural character of the shoreline feature, and could create an inconsistency with the Open Space and Conservation Element and State General Plan policies regarding preservation of natural resources. With toe stone, the wall would also potentially encroach onto the sandy beach and exposed rock ledge and could thus be in conflict with the City and State General Plans and their policies to conserve, develop, and utilize areas particularly suited for outdoor recreation. Concerning Coastal Act policies, the reinforced earth wall with toe stone would be both consistent and inconsistent with land use policies. The wall would be inconsistent with Section 30221 in that beach land would not necessarily be protected for recreational use with the encroachment of the toe stone on the sand and rock ledge. If sensitive design measures are instituted, using natural materials in seawall con- struction, the wall would not substantially alter the natural landform OP visual quality of the shoreline and would thus be consistent with Coastal Act Sections 30240b, 30251, and 30253. Reinforced Concrete Vertical Seawall The reinforced concrete vertical seawall method of stabilization con- sists of a vertical concrete wall with its footing buried at the base of the bluff. The wall is backed by a minimal amount of compacted back- fill and can also be constructed with a 3-ton stone toe protection in front of the wall (Figure 2-3). With sensitive design measures, the concrete wall method of stabiliza- tion (without toe stone) would be considered consistent with Open Space and Conservation Element policies of the City of Carlsbad General Plan, in terms of landform. The stabilization project would ensure preservation of the distinctive bluff formation and the use of colored and textured concrete to match the existing sandstone bluff would pre- serve the bluff landform. With toe stone, the reinforced concrete vertical seawall could be expected to encroach onto the sandy beach and rock ledge and could thus be in confict with City and State General Plans and their policies to conserve, develop and utilize areas particularly suited for outdoor recreation. Regarding Coastal Act policies, if the reinforced concrete vertical sea- wall is constructed with toe stone, it would potentially be inconsistent with Section 30221 in that beach land would not be protected for recre- ational use solely, with the encoachment of the wall onto the sand and rock ledge. If sensitive design measures are instituted, using natural materials in seawall construction, the wall would not substantially alter the natural landform or visual quality of the shoreline and would thus be consistent with Coastal Act Sections 30240b, 30251 and 30253. If the reinforced concrete vertical seawall is constructed without toe stone, the method of bluff stabilization would present a vertical, imper- meable surface to direct wave attack, directing the water downward to the base of the wall. This action could cause scouring at the base of the wall, and thus contribute to beach sand erosion. The increase in beach sand erosion would potentially be in conflict with Coastal Act Section 30253, which states that the seawall should neither create nor contribute significantly to erosion. Mitigation Measures There are several measures which have not been included in the project speci- fications, but that are recommended to be incorporated into the project design to reduce potential land use impacts. Potential impacts identified with the five bluff stabilization methods include public access, loss of the natural char- acter of the bluff landform, beach encroachment, and sand erosion. Mitigation measures recommmended for these impacts include the following: • The proposed project will provide vertical access including several stairways and a ramp for handicapped persons. As indicated in the 3-41 LOP, seawalls should be conditioned to provide the public with the right of access to a minimum of 25 feet of dry sandy beach at all times of the year. Since existing foot trails will be eliminated, proper vertical access will be provided. In addition, lateral access should be provided through the creation of a walkway along the top of the bluff or along the top of the proposed seawall or revetment. It is important that special design features be included to ensure public safety such as a fence OP landscape buffer between the walkway and bluff face. • Retain the natural character of the bluffs. Minimize cut and fill wherever possible. If implemented, the vertical concrete or concrete- filled bag seawalls should be constructed of materials which blend with adjacent bluff faces, through the use of matching colors and textures. The use of earth-toned, sandstone textured concrete would reduce the level of significance of the impact to the natural bluff landform. Revegetation of manufactured slopes after construction will present a more natural slope appearance. Revegetation should incorporate native plant species or native cultivars as listed in the Visual Aesthetics sec- tion. Although these measures will reduce the level of impact to the existing natural landform, the impact can only be completely mitigated by a No Project alternative. • Reduce the amount of _ beach encroachment. Bluff stabilization methods which include the use of toe stone or rock revetment may encroach onto beach sand and the exposed rock ledge. To reduce recre- ational use impacts, an effort should be made to build deep foundations rather than provide toe stone. This may require excavation into the bluff, however, an action which could create further bluff instability. The consequences of bluff excavation must be determined prior to final design as described in Section ni-A of this report. The fabriform/con- crete bag, concrete wall with rock fill or seawall without toe stone would have less beach encroachment than rock revetment, and there- fore the selection of one of these alternatives would mitigate this potential impact. 3-42 • The use of a seawall stabilization method that presents a permeable surface, such as rock revetment, will reduce the impact of sand erosion by minimizing the amount of scour that could occur at the base of the seawall. The use of toe stone also decreases the occurrence of scour- ing. D. VISUAL AESTHETICS Existing Conditions The coastal bluffs along Carlsbad State Beach range between 30 to 40 feet in elevation above the sandy beach surface. Physiographic features of the proj- ect site include, from west to east, beach sand fronting the Pacific Ocean; the Santiago Formation at the base of the bluffs which is either exposed, covered by a cobble berm or covered by a thin layer of sand; and the bluffs composed of Pleistocene Terrace Deposits. Seepage and drainage along the base of the bluff has created some wet zones which are temporary due to the combination of cliff erosion, high tides and storm events. The bluff faces are cut extensively by erosional gullies and deep ravines, the upper portion of many of which have been partially filled with material dumped from the top of the bluffs. Extensive filling and slope repair has occurred at Acacia, Redwood and Walnut Avenues, in which fill material extends completely down the bluff slope. At Walnut Avenue, the fill is rein- forced and protected from wave action at the beach level with large boulders placed on the Santiago Formation. At Cherry Avenue, a public access stair- way extends down the bluff slope to the beach. At the beach level, large imported boulders to break the wave action and protect the stairway extend onto the sandy beach. Other man-made intrusions onto the bluff face and beach include a paved access to a lifeguard station pad at Pine Avenue off of Ocean Street at the north end of the beach. The narrow roadway which extends down to the beach across the bluff face has a locked gate at Ocean Street. The lifeguard station pad at the bottom of the road and bluff is composed of sand protected by large 3-43 boulders extending onto the sandy beach. The bluffs directly below Ocean Street, just north of the paved access road, are vegetated with large stands of non-native bamboo. Iceplant and an occasional stand of bamboo comprises vegetation on the bluffs further south. Public beach access concrete-and-wood stairways, which extend from Carlsbad Boulevard at the top of the bluffs down to the beach level, are located at Cherry Avenue, and at Tamarack Avenue near a public restroom facility. At the bottom of the Cherry Avenue stairway, on the sandy beach, are concrete foundations where a public restroom once stood (destroyed by winter storms of 1983). At the south end of the beach, a paved public access road extends from the bluff top at Tamarack Avenue down to a paved, boulder-reinforced parking 4ot at beach level. The undermined, deteriorating parking area includes approxi- mately 2 acres and is located north of two parallel rock jetties which extend seaward about 200 feet from the mouth of Agua Hedionda Lagoon. Drainage pipes are located along the bluffs at several locations, and carry storm water and surface runoff from surrounding neighborhoods. The large drainage pipes have eroded out of the bluffs in most cases and present an adverse man-made intrusion to the natural sandstone bluff face. The City of Carlsbad has begun to replace this nap-hazard drainage system with an area- wide system along Carlsbad Boulevard that would empty into Agua Hedionda Lagoon. At the east boundary of the project site, Carlsbad Boulevard extends generally parallel to and along the bluff top above Carlsbad State Beach. At the north end of the beach, Ocean Street and a paved parking lot extend along the bluff top from Oak Avenue south to Pine Avenue, as Carlsbad Boulevard turns inland. The Boulevard is set back from the bluff edge at distances ranging from 2 feet to 50 feet. Between Pine Avenue and Cherry Avenue to the south, the Boulevard is located at the edge of the bluffs, separated by a guard rail. From Cherry Avenue south to Tamarack Avenue, a bluff-top day use area has been established between the Boulevard and the edge of the bluffs. The day 3-44 use area includes landscaping, grassy areas, benches, picnic tables, a meander- ing concrete walkway, a wooden fence rail at the edge of the bluffs, a rest- room, and parallel parking along the Boulevard. The day use area offers an opportunity for the public to view Carlsbad State Beach and the Pacific Ocean. Three types of views of Carlsbad State Beach are available to visitors in the project vicinity: • Views available to travellers in vehicles along Ocean Street and Carls- bad Boulevard at the bluff top are limited to the Pacific Ocean and wave interaction offshore. This is because of the steepness of the bluffs, the proximity of the roadways to the bluff edge, and the lack of parking spaces between Pine Avenue and Cherry Avenue. Stands^of giant reed (Arundo donax) along Ocean Street limit the view to the ocean and the sandy beach from parked vehicles along the street. There is no distant, full-length view of Carlsbad State Beach available to travellers on Carlsbad Boulevard or Highway 101 as with other beaches to the south along 101. In the project vicinity, residences and commercial establishments are located only on the east side of Carls- bad Boulevard or Ocean Street and have a view only of the ocean because of the setback from the bluffs. • Views from the west side of Carlsbad Boulevard between Cherry Ave- nue and Tamarack Avenue at the bluff top are available to pedestrians because of the roadside park. Parallel parking is available to travellers on Carlsbad Boulevard in this area. The primary view from this point is of the Pacific Ocean and shoreline wave interaction with the sandy beach. The cliffs below the park are not of primary focus because of their steepness in some places and because of erosional disturbance. Since the benches and picnic tables in the park are set back from the bluff edge and separated from it by a wooden rail fence, views are oriented toward a more distant wave interaction and ocean view. 3-45 • Views to surfers and beach users at the base of the bluffs are primarily of the ocean and wave interaction, the length of the beach, and of the eroding bluffs. The bluffs are not considered of primary visual impor- tance in this setting, however, because of man-made intrusions includ- ing fill material, extensive bluff repairs and some stone revetments protecting the south parking lot, the Pine Avenue lifeguard station, the Walnut Avenue repair fill and the Cherry Avenue public access stair- way. Drainage pipes and their associated erosional gullies, man-made accessways, and the non-native vegetative cover of bamboo stands and iceplant also deter the view of the natural character of the bluffs. The most desirable view is of the sandy beach, wave interaction and the ocean. No urban development is located on the west side of Carlsbad Boulevard or Ocean Street so there is no view of structures at the top of the bluffs to those using the beach below. Objects in sight at the top of the bluffs from below include guard rails, streetlights, trash cans along Carlsbad Boulevard, and the wooden rail fence lining the park area between Cherry Avenue and Tamarack Avenue. At the north and south ends of the beach, the bluffs are lower in elevation, and structures on the east side of Carlsbad Boulevard or Ocean Street can be seen by beach users at this point. City of Carlsbad General Plan Scenic Highways Element The City of Carlsbad's Scenic Highways Element, adopted in February 1975, designates local routes that are eligible for further study within the context of the City's Scenic Highways Program. The ultimate objective of the Program is the protection and enhancement of prime scenic and historical areas in the City. The Scenic Highways Element, which designates Carlsbad Boulevard as an eligible route for further study, is closely interrelated with the objectives of the Open Space and Conservation Elements, in that the program of scenic routes will "help initiate some of the goals and policies contained in those Elements" such as "recreational uses, scenic and historical preservation, visual relief, protection of community identity, and the utilization of proper design criteria to preserve the unique and special resources in the City." 3-46 Impacts. Several types of shoreline protection methods are available for the bluffs at Carlsbad State Beach. All five of the proposed bluff stabilization construction methods analyzed would alter the natural character of the bluffs, but not to an extent that would be visually disruptive from above, provided sensitive design measures.are instituted. There would be no visual impact to the travellers in vehicles on Carlsbad Boulevard, as there is no view of the bluff base from the bluff-top roadway. The project itself may be considered a beneficial impact to the view from designated scenic Carlsbad Boulevard, as the seawall would ultimately preserve Carlsbad Boulevard from erosional damage. The impact to pedestrian views from the top of the bluffs would be minimal at the park area between Cherry Avenue and Tamarack Avenue. The seawall to the north would be visible, but the ocean and wave interaction in this park like area is the primary view. Visual impacts are of a low significance. Use of design measures as indicated in mitigation measures would assure mitigation and reduction of potential visual impacts. The view to surfers and beach users would be altered by the placement of any of the five stabilization improvements along the base of the bluffs. The degree of visual impact with each stabilization procedure varies according to the ability to use natural materials or sensitive design measures. However, since the bluffs are not the primary focal point, and since the existing access stairways, parking lot, fill slopes, non-native vegetation, extending drainage pipes, and occasional existing rock revetments do not have a natural appear- ance, the visual impact of the proposed bluff stabilization would be of low significance. Mitigation Measures There are several measures which have not been included in the project speci- fications, but that are recommended to be incorporated into the project design to reduce potential visual impacts. However, the visual impact of placement of a man-made seawall adjacent to natural bluffs is only completely mitigable by the No Project alternative. 3-47 • Ensure that the rock revetment or toe stone causes minimal encroach- ment onto the Santiago Formation and not onto the sandy beach, to preserve shoreline view and beach length view. • Compacted backfill slopes on the reinforced earth concrete seawall design should use material of a color and texture to match the existing bluff slopes. • Vertical concrete or concrete-filled bag seawalls should be built of materials which visually blend with adjacent bluff faces. The use of earth-toned, sandstone textured concrete would reduce the impact to a level of insignificance. • Provision of lateral overlooks accessible to the public from Carlsbad Boulevard, and located below the street level, could be instituted through the creation of a walkway along the top of the proposed sea- wall. In those areas where significant erosion has occurred on the bluffs, such as at Walnut Avenue, Maple Avenue, Acacia Avenue and Cherry Avenue, the reclamation of land and provision of overlooks through the construction of a seawall would provide an improved visual appearance where public access is now limited. The bluff-top public park along Carlsbad Boulevard at present only extends from Cherry Avenue to Tamarack Avenue. The provision of overlooks would provide visual access to the beach along Carlsbad Boulevard between Cherry Avenue and Pine Avenue, and would be consistent with the policies of the Local Coastal Program. • The upper shoreward portions of the rock revetment seawall could be filled with soil and planted with fast growing ground cover tolerant of coastal conditions (see list below). This mitigation would lessen the harsh appearance of the revetment and integrate the protective device into the natural bluffs. • Reseeding the graded fill surfaces of the bluffs after construction of seawalls will present a more natural slope appearance, thus decreasing 3-48 the visual impact of the man-made backfill adjacent to the natural bluffs. Revegetation of the bluffs should consider the following list of native species or native cultivars. These species are adapted for coastal habitat uses, provide erosion control,, are drought-tolerant and require low maintenance: Galvezia speciosa Eriogonum species fasciculatum giganteum parvefolium ssp. paynei Iva hayesiana Lavatera assurgentiflora Coreopsis maritime Coreopsis gigantea Encelia californica Erigeron glaucus Ceanothus gloriosus Baccharis pilalaris Limonium californicum var. mexicanum Lynothamnus floribundus Ribes viburnifolium Island Bush Snapdragon Buckwheat 'Dana Point' (prostrate) St. Catherine's Lace Buenaventura Buckwheat (dense mat) Poverty Weed Tree Mallow Sea Dahlia Giant Coreopsis California Encelia Beach Aster 'Point Reyes' Ceanothus Coyote Bush 'Twin Peaks' 'Pigeon Point' Coastal Statice Catalina Ironwood Catalina Perfume Re-orient storm drain system along Carlsbad Boulevard and then remove existing obstrusive drainage pipes along the entire bluff face within the project area. E.SHORT-TERM CONSTRUCTION-RELATED EFFECTS 1.Traffic Circulation At the present time, Carlsbad Boulevard is the major traffic artery and accessway to Carlsbad State Beach. The Boulevard, which follows 3-49 the bluff top parallel to the shoreline, has an average daily traffic count of about 18,700 vehicles (City of Carlsbad," July 1984). The City of Carlsbad places Carlsbad Boulevard at a future average daily traf- fic count of 22,100 to 24,100 vehicles between Elm Avenue and Tama- rack Avenue. The Boulevard presently serves as a 4-lane major arte- rial in the City of Carlsbad, and is designed to handle traffic volumes in excess of 20,000 vehicles per day (City of Carlsbad, 1975). Parallel parking is available along the west side of Carlsbad Boulevard between Cherry Avenue and Tamarack Avenue at the bluff-top public park. A 2-acre parking lot on the beach level at Tamarack Avenue is also available to motorists. Implementation of the bluff stabilization project will require the use of heavy trucks to transport various construction materials such, as armor stone, earth, steel reinforcements, readi-mix concrete, paving material and miscellaneous materials. Each of the stabilization methods will require a different number of truck trips per day, how- ever, none of the construction methods will increase traffic by more than 400 ADT and thereby create a significant impact to Carlsbad Boulevard, which is designed to handle daily traffic volumes in excess of 20,000 vehicles per day. Most of the bluff stabilization construction will take place from the beach level of the bluffs, rather than from bluff-top Carlsbad Boule- vard. It is estimated that only 15 percent of seawall construction would take place from above. No temporary roads will be constructed on the beach; however, construction trucks will be traversing the beach on the existing compacted sand. It is intended that the south parking lot would be used for storage of construction equipment and armor stone, thus the lot would be closed to public use. If the use of this lot is not possible, the equipment and material storage area would likely be located at the north end of the project site along Ocean Street. 3-50 The trucks and other construction equipment would not have a signifi- cant impact on traffic flow capacity of the residential streets adja- cent to Carlsbad Boulevard during the approximate 6-month construc- tion period. However, use of the south parking lot would be temporar- ily lost and the truck traffic could create a local traffic annoyance on weekdays during daytime hours. The use of the beach will be discour- aged during the construction period, so there will be little need for parking at that time; thus no short-term parking impacts are expected. The short-term traffic annoyance impacts caused by construction vehicles can be minimized by the measures listed below but cannot be eliminated except by a No Project alternative. The following mea- sures would serve to reduce potential noise impacts as well. • No detouring of traffic will be allowed. At least two lanes- of traffic on Carlsbad Boulevard must be maintained, one in each direction. Southbound to eastbound left-turn lanes on Carlsbad Boulevard should be maintained to serve the high-density resi- dential and commercial uses, and should be at least 10 feet in width. • Muffle heavy equipment to State and local standards. • Limit the bluff stabilization construction period to spring and fall months, when use of the beach and associated Carlsbad Boulevard is less than during the summer, and severe winter storms and high tides can be avoided. • Store construction equipment and materials in the south parking lot. The use of an alternative site would worsen construction- related adverse effects. 2. Noise The major sources of noise in the project area are passenger vehicles travelling along Carlsbad Boulevard at speeds of 35 to 40 mph, and the sound of surf along the shoreline below the bluffs. 3-51 Implementation of the Carlsbad State Beach bluff stabilization project would bring heavy trucks to the project area during the proposed 6-month construction period (Table 3-1). The truck traffic and associ- ated noise impacts would be limited to Carlsbad Boulevard. The aver- age increase of daily truck trips would not significantly increase noise levels along Carlsbad Boulevard, which has an average daily traffic volume of 18,700. The ambient noise levels along Carlsbad Boulevard can be expected to increase for the time period that the street is being used for access to the project site. The project related truck traffic would not create a significant noise impact unless it was to occur at night, following the decrease of regular through traffic. In any event, the adverse effect would be temporary. The impact of construction noise at the base of the bluffs related to the bulldozer, placement of riprap, and construction of reinforced earth walls, would not adversely effect the high-density residential areas east of Carls- bad Boulevard due to their elevated position above the construction zone. No homes are located at the top of the bluffs west of Carlsbad Boulevard, therefore construction related noise is considered to be insignificant. The Noise Element of the Carlsbad General Plan states that it is the City's policy to "make sure that noise generated by construction" be reduced to the lowest possible level (City of Carlsbad, 1975). The measures recommended under the Traffic Section would aid in reduc- ing construction noise levels. It is also the City's policy to "include maximum noise level requirements in specifications for . . . construc- tion contracts" (City of Carlsbad, 1975). Since the construction- related impacts will be short-term and are not expected to signifi- cantly impact surrounding land uses, no further mitigation measures are necessary. 3. Air Quality Pollution caused by vehicle emissions associated with the Carlsbad State Beach bluff stabilization project construction process would be 3-52 short term. The majority of vehicle use would be for transport of materials. The impact to air quality is considered insignificant because of the short term nature of the source, and because the amount of pollution generated would be a minor incremental addition to the existing ambient air quality. Dust and particulate matter would also be generated as a result of the construction process, creating a potential short term impact to the local area. During the construction process, water spraying along the access route could be required to keep dust emissions down as spraying reduces the amount of dust emitted by approximately 50 percent. Even though localized particulate levels would be elevated during the construction period, the project would not cause a measurable impact on local air quality. , 4. Recreation The beach season in Carlsbad is generally considered to be year around. Maximum use is in the summer months on weekends and holi- days. Minimum use is in the winter months on weekdays. Based on City of Carlsbad data, the average daily use for the 4500 feet of beach is 2640 persons, which gives an annual use of approximately 963,600 persons. It is anticipated that the 4500-foot stretch of beach will need to be closed to the public during the approximate 6-month construction phase. A majority of the construction will be carried out from the beach level. Use of the beach will include construction vehicle move- ment, equipment hauling, and the possible building of a temporary sand berm to protect construction equipment. The south parking lot would be used for storage of construction equipment and materials. This temporary beach encroachment, as a result of project construc- tion would result in a short-term impact to recreation. The level of impact could be decreased by limiting construction to non-summer 3-53 months during the weekday periods; however, the short-term impact to recreation can be mitigated to a level of insignificance only by selec- tion of the No Project alternative. F. GROWTH INDUCEMENT The proposed project is not expected to directly or indirectly foster growth in the Carlsbad State Beach area. Growth inducement typically occurs when an impediment to development is removed, as is the case when public utilities OP an access road are extended into a previously undeveloped area. That circum- stance does not apply to this project which would preserve the bluffs of a beach bounded by the ocean, high density residential, and travel services com- mercial development. There is no land on the west side of Carlsbad Boulevard which could be developed as a result of bluff preservation. Therefore, rno growth inducement impacts are expected with this project. G. CUMULATIVE EFFECTS Geology/Geotechnical Considerations The cumulative effects of the proposed project, considered in conjunction with other similar projects and potential future projects along the San Diego County coastline, could pose significant effects in reducing a source of beach sand and causing the scour of existing beach sand. The bluffs, as a source of sand, are insignificant, however, when compared to the rivers and streams in the area. Other man-made devices, such as dams, have greatly reduced the flow of sand from rivers and streams and pose a much more serious threat to the source of sand for area beaches. Beach scour may be a significant cumula- tive effect if seawalls are not designed to mitigate this potential impact. Biological Resources No significant cumulative effects to biological resources have been identified. 3-54 Land Use Construction of the proposed seawall will not change existing land use in the project area, and Carlsbad State Beach will remain as open space with improved access. Visual Aesthetics The project would ultimately have a beneficial cumulative impact on visual resources in the Carlsbad State Beach area. Preservation of the bluffs through stabilization at the base' will preserve Carlsbad Boulevard as a scenic roadway, and will enable continued views of the ocean and shoreline, not only to travel- lers on the Boulevard, but to pedestrians using the park at the top of the bluffs between Cherry Avenue and Tamarack Avenue. Traffic Circulation, Noise, and Air Quality Traffic Circulation, Noise, and Air Quality impacts will be short-term, tempo- rary effects related to the construction phase of the proposed project. Subse- quent to project completion, however, traffic, noise and air quality conditions will remain the same as existing conditions. Thus no cumulative impacts are associated with the project under these three issues. 3-55 IV. SUMMARY OF ENVIRONMENTAL CONSEQUENCES Impacts concerning each of the five alternative bluff stablization methods are summarized on a matrix in Table 4-1 appearing at the end of this section. A. EFFECTS FOUND NOT TO BE SIGNIFICANT As a focused environmental impact report, this study has been limited to only those issues identified by the City of Carlsbad to be potentially significant. This determination was made on the basis of an Initial Study prepared for the project based on information supplied by the applicant and other data available to the City. Documentation of this determination is included in Appendix A of this report. Effects found not to be significant include: public service availa- bility, cultural resources, light and glare, natural resources, population, hous- ing, energy, human health, and utilities. B. SIGNIFICANT ENVIRONMENTAL EFFECTS Potentially significant effects that could result from the use of the various bluff stabilization methods include the following: • Bluff destabilization duping construction, beach encroachment which could interfere with public recreational use; sand erosion as a result of scour at the seawall base; loss of the natural character of the sandstone bluff landform as a result of placement of the seawall; public access concerns; beach encroachment could interfere with shoreline view and beach length view; loss of beach use during construction period; and traffic delays. C. SIGNIFICANT EFFECTS WHICH CANNOT BE MITIGATED Mitigation measures have been recommended in this Draft EIR or incorporated into the project concept which would either eliminate or lessen to a level of insignificance all significant or potentially significant impacts described in the preceding section of this report. The only impact which cannot be mitigated 4-1 to a level of insignificance, either by incorporating mitigation measures, or by selecting a project alternative which creates a lesser impact, is the temporary loss of a portion of the beach as a recreation area during construction. D. MITIGATION MEASURES PROPOSED TO MINIMIZE EFFECTS The following mitigation measures have been proposed to minimize the signifi-/• cant or potentially significant environmental effects of the proposed project. Geology/Geotechnical Considerations • Explore methods of beach replenishment. • Adhere to Uniform Building Code seismic design criteria. • Perform analysis of coastal bluff under seismic loading. • Final geotechnical investigation should address soil liquefaction. • Locate adverse soil conditions prior to final project design. • Design special foundations where necessary. • Perform engineering analysis of gross stability of coastal bluff. • Minimize excavations into bluff. • Divert storm runoff away from bluff. • Landscape with native vegetation. • Reduce pedestrian traffic on the bluff face. • Minimize discontinuities in shoreline protective device. • Special design at north and south terminations. • Provide subdrains behind impermeable portions of structure. Biological Resources • No mitigation measures necessary. Land Use/Coastal Act Compatibility • Provide vertical and lateral public access. • Retain natural character of bluffs. • Match construction material color and texture. 4-2 • Revegetate slopes with native species. • Minimize beach encroachment. • Minimize beach scour. Visual Aesthetics • Minimize beach encroachment. • Match backfill and construction materials with existing bluff slopes. • Provide lateral overlooks and access ways. • Landscape with native plants. Short-Term Construction-Related Effects • Limit the construction period to spring and fall months to avpid extreme tides and winter storms. • Provide noise attenuation on all equipment. • Provide dust control in construction area. • Use the existing parking lot at the south end of the project area for storage of construction vehicles and materials. The following matrix (Table 4-1) provides a comparison of the previously dis- cussed project alternatives, plus the no project alternative. Many effects of these alternatives are the same for all development alternatives, therefore no comparison is provided. This would include: biological resources - no signifi- cant impacts; short-term traffic circulation and parking - loss of use of south parking area and traffic disruption along Carlsbad Boulevard; short-term noise - no significant impacts; short-term air quality - no significant impacts, generation of particulate matter is minimal; and short-term recreation - loss of beach use during construction. The no project alternative would avoid the above-described short-term effects. 4-3 Proposed Method of Bluff Stabilization No Project Geology/Ceo technical Considerations Continued bluff erosion, eventual loss of Carlsbad Boulevard and utilities. Re In live Construction Cosl Mo immediate impact. Eventual high costs associmea with maintaining or rebuilding Curls- bad Boulevard and .'or replacing utililv lines. Relative Level of Maintenance Continual and in- creasing City main- tenance costs. Rock Revetment Potential Surficial failures or soil liquefaction as a result of ground shaking. Medium-low. Fabriform/Conereie Filled Bags Concrete Wall With Rock Fill Reinforced Earth Wall With Toe Stone Reinforced Concrete Vertical Seawall With Toe Stone Reinforced Concrete Vertical Seawall With- out Toe Stone Potential surficial failures or soil liquefaction as a result of groundshaking. Susceptible to grade or backfill movements. Susceptible to groundwater seepage buildup. Potential surficial failures or soil liquefaction as a result of groundshaking. Susceptible to subgrade or back- fill movements. Susceptible to groundwater seepage buildup. Potential surficial failures or soil liquefaction as a result of groundshaking. May initiate surface instabilities or slope failures during grading. Susceptible to groundwater seepage buildup. Potential surficial failures or soil liquefaction as a result of groundshaking. Susceptible to subgrade or back- fill movements. Susceptible to groundwater seepage buildup. Potential surficial failures or soil liquefaction as a result of groundshaking. Susceptible to subgrade or back- fill movements. Susceptible to groundwater seepage buildup. Low.Low. Medium-low.Low. High-medium.• Medium. High.Medium. High.Medium. V. ADDITIONAL PROJECT ALTERNATIVES This section presents additional project alternatives considered for the Carls- bad Bluff stabilization project. Many alternatives are available, however, some have been dismissed due to their cost or adverse environmental conse- quences. A. RELOCATION OF CARLSBAD BOULEVARD AND UTILITIES This alternative would involve relocating Carlsbad Boulevard and all utilities underneath it further east, or making Garfield Street a major arterial and relocating the utilities along that street. Existing conditions at Carlsbad State Beach, future problems with beach access, and loss of a Carlsbad Scenic High- way would remain the same as under the No Project alternative (pages 2-5, to 2-7). In addition, this alternative would require the City of Carlsbad to obtain own- ership of portions of private land east of Carlsbad Boulevard. Travel services and commercial developments currently located east of Carlsbad Boulevard would be bypassed, resulting in a hardship to local business. Realignment of Garfield Street and surrounding roadways would also be necessary at the south end of the street at Agua Hedionda Lagoon in order to connect up with High- way 101 and the bridge over the lagoon. Complete relocation of Carlsbad Boulevard and its associated utilities, or the expansion of Garfield Street is not considered consistent with the General Plan or economically feasible to the City of Carlsbad or private landowners in the area. B. GROINS AND/OR OFFSHORE BREAKWATERS This alternative would provide an offshore type of breachfront protection. At present, Carlsbad State Beach is within the Oceanside littoral cell which extends from Oceanside south to La Jolla. Longshore currents transport sand southward within the cell, replenishing sand on downshore beachfronts. Under this alternative, the City of Carlsbad could construct a series of groins, or rock walls extending out from the beach to intercept sand being transported 5-1 southward within the littoral cell. This would widen the sandy beach along the Carlsbad State Beach in both summer and winter months. An example of this type of beach replenishment already exists at the south end of the beach, where the Agua Hedionda Lagoon rock jetties extend into the ocean and beach sand is wider in this area, north of the jetty. The wider beach face would often increase protection to the existing bluffs by absorbing wave energy. Adverse consequences, such as sand loss would probably occur south of any rock jetty. The rock walls could also be a disadvantage to recreational users of the beach and ocean, in that expansive water areas for surfing, a popular sport in this area, would be minimized or unsafe. An offshore breakwater would also widen the sandy beach along the Carlsbad State Beach. A submerged rock structure could be constructed offshore, to intercept waves, causing them to break further seaward and preventing dam- age to the existing bluffs. This offshore breakwater, however, would also eliminate safe recreational uses of surfing at the State Park, and would thus be in conflict with Coastal Act policy. C. OTHER BLUFF PROTECTION METHODS Several other bluff protection methods have been analysed including use of the longard tube, beach replenishment, cribwall with toe stone, and H-pile with wood or concrete lagging and toe stone. The longard tube alternative was considered and rejected for several reasons. It has not proven to be an effec- tive, long-term method for protecting beaches and bluffs in the southern Cali- fornia coastal area. Attempts to implement this alternative in Del Mar and Carlsbad have not proved successful. Vandalism and major storm events have rendered the devise inoperable. Beach replenishment was investigated and found to be an overly expensive method to maintain a sand supply on the beach at Carlsbad State Beach. Although technically feasible, such a system would include exhorbitant construction costs, yearly maintenance costs, a budget for temporary pumping facilities and a budget for ongoing research to determine seasonal sand supply. In terms of cost and technical effectiveness of protect- ing bluffs from significant storm events, other alternatives were considered 5-2 and eliminated from further study. The reader is also referred to Woodward- Clyde (1984) and Leighton and Associates (1984), on file with the City of Carlsbad Planning Department, for a further discussion of these alternatives. 5-3 VI. REFERENCES CITED California Department of Fish and Game, 1980, Endangered rare and threat- ened animals of California, The Resources Agency, September 15. California Department of Fish and Game, 1984, Designated endangered OP rare plants, The Resources Agency, July 1. California Department of Parks and Recreation, 1983, San Diego Coastal State Park System General Plan - Carlsbad, July. City of Carlsbad, 1973, General Plan, Open Space and Conservation Elements. City of Carlsbad Planning Department. City of Carlsbad, 1975, General Plan, Scenic Highways 'Element. City of Carlsbad Planning Department. City of Carlsbad, 1975, General Plan, Geologic and Seismic Safety Element. City of Carlsbad Planning Department.r City of Carlsbad, 1975, General Plan, Noise Element. City of Carlsbad Plan- ning Department. City of Carlsbad, 1975, General Plan, Circulation Element. City of Carlsbad Planning Department. City of Carlsbad, 1981, Zoning Ordinances, Local Coastal Program (Mello Bill II Properties), Attachment to Staff Recommendation of June 8. City of Carlsbad, 1983, General Plan, Land Use Element. City of Carlsbad Planning Department. City of Carlsbad, 1984, telephone communication with Marty Bouman, traffic engineer, December 3. City of Carlsbad Engineering Department, 1984, telephone communication with Steve Tisdale, November 21. Emery, K.O., 1960, The Sea off Southern California: A Modern Habitat of Petroleum. New York: Wiley and Sons. Everett, William T., 1979, Threatened declining and sensitive bird species in San Diego County, San Diego Audubpn Society, Sketches, June. Kuhn, G.G., and F.P. Shepard, 1984, Sea Cliffs, Beaches and Coastal Valleys of San Diego County: Some Amazing Histories and Some Horrifying Impli- cations, University of California Press. Leighton and Associates, 1984, Geotechnical Environmental Impact Assess- ment for the Proposed Shoreline Protection Project, Oak Avenue to Agua Hedionda Lagoon, City of Carlsbad, San Diego County, California. Pre- pared for the City of Carlsbad, December. 6-1 McGurty, B., 1980, Survey and status of endangered and threatened species of reptiles natively occurring in San Diego County, prepared for Fish and Wildlife Committee, San Diego County Department of Agriculture. PRC Engineering, Inc., 1984, Environmental Impact Report, Beach and River- front Protective Device, Del Mar, California. Prepared for the City of Del Mar, SCH #84011808, May. Remsen, V., 1978, The species of special concern list: an annotated list of declining or vulnerable birds in California, Western Field Ornithologists, prepared for California Department of Fish and Game, Museum of Verte- brate Zoology, University of California, Berkeley. San Diego Herpetological Society, 1980, Status of the indigenous amphibians of San Diego County, sponsored by Fish and Wildlife Committee, San Diego County Department of Agriculture. Smith, J.P., Jr. and R. York, 1984, Inventory of rare and endangered vascular plants of California, California Native Plant Society, Special Publication No. 1 (3rd Edition). State of California, 1976, California Coastal Act. Division 20. Thorne, R.F., 1976, The vascular plant communities of Californa in Symposium Proceedings-Plant Communities of Southern California, June Latting (editor), California Native Plant Society, Special Publication No. 2. Tisdale, Steve, 1984, Telephone conversation with Terri Jacques. City of Carlsbad Engineering Department, November 21. United States Fish and Wildlife Service, 1983a, Endangered and threatened wildlife and plants: Supplement to review of plant taxa for listing as endangered or threatened species, Federal Register, 48(229):53640- 53670, November 28. United States Fish and Wildlife Service, 1983b, Republication of the lists of endangered and threatened species, Department of Interior, July 27, 25 pp. WESTEC Services, Inc., 1981, Sunset Cliffs, Upper Cliff Stabilization Project, Environmental Impact Report. Prepared for the City of San Diego Envi- ronmental Quality Division. Wilson, K.L., 1972, Geologic Map of the. San Luis Rey Quadrangle, San Diego County, California, unpublished, San Diego State University, Geology Department Senior Report. Woodward-Clyde Consultants, 1984, Feasibility Study, Carlsbad Boulevard Shore Protection, Carlsbad Beach State Park. Prepared for the City of Carlsbad, November. 6-2 CERTIFICATION OF ACCURACY AND QUALIFICATIONS This report was prepared by WESTEC Services, Inc. of San Diego, California. Members of the WESTEC Services' professional staff and consultants contrib- uting to the report are listed below: Ernest R. Artim (Leighton and Associates); M.A. Geology David W. Claycomb; B.S. Botany, M.S. Natural Resources Management Terri E. Jacques; M.A. History Frank A. Kingery; B.S. Geochemistry, M.S. Geology Stephen B. Lacy; M.S. Biology Joseph C. Sener (Leighton and Associates); Ph.D. Geotechnical Engineering Jeanell Lee Trant (Leighton and Associates); B.A. Geology r I hereby affirm that to the best of our knowledge and belief, the statements and information herein contained are in all respects true and correct and that all known information concerning the potentially significant environmental effects of the project has been included and fully evaluated in this EIR. David W. Claycomb| Project Managed. 7-1 APPENDIX A INITIAL STUDY ENVIRONMENTAL IMPACT ASSESSMENT FORM - Part II (To Be Completed By The PLANNING DEPAKttENT) CASE NO. DATE: I. BACKGROUND 1. APPLICANT: CITY OF CARLSBAD 2, ADDRESS'AND PHONE NUMBER OF APPLICANT:_ 1200 Elm Avenue Carlsbad, CA 92QQ8 438-5591 3. - DATE CHECKLIST SUBMITTED: II. ENVIRONMENTAL IMPACTS " ' ' (EXPLANATIONS OF ALL" AFFIRMATIVE ANSWERS ARE TO BE WRITTEN UNDER Section III - DISCUSSION 0? ENVIRONMENTAL EVALUATION) Yes Maybe No 1. Earth Will the proposal have signi- ficant results in: a. Unstable earth conditions or in changes in geologic substructures? y b. Disruptions, displacements, com- paction or overcovering of the soil? x c. Change in topography or ground surface relief features? X d. The destruction, covering or modification of any unique geologic or physical features? x_ e. Any increase in wind or water erosion of soils, either on or off . the site? x f. Changes in deposition or ero- sion of beach sands, or changes in siltation, deposition or erosion which may modify the channel of a river or stream or the bed of the ocean or any bay, inlet or lake? x_ A-i Yes Maybe No 2. Air: Will the proposal have signi- results in: a. Air emissions or deterioration of ambient air quality? b. The creation of objectionable odors? . X c. Alteration of air movement, mositure or temperature, or any change in climate, either locally or regionally? - x 3. Water: Will the proposal have sigi- ficant results in: a. Changes in currents, or the course or direction of water move- ments, in either marine or fresh waters? . X b. Changes in absorption rates, drainage patterns, or the rate and amount of surface water runoff? c. Alterations to the .course or flow of flood waters? : d. Change in the amount of sur- face water in any water body? e. Discharge into surface waters, or in any alteration of surface water quality, including but not. limited to temperature, dissolved oxygen or turbidity? f. Alteration of the direction or rate of flow of ground waters? g. Change in the quantity of ground waters, either through direct additions or withdrawals, ' ' or through interception of an aquifer by cuts or excavations? h. Reduction in the amount of water otherwise available for public water supplies? X A-2 Yes Maybe No 4. Plant Life. Will the proposal have signi- . ficant results in: a. Change in the diversity of species, or numbers of any species of plants (including trees, shrubs, grass, crops, microflora and aquatic plants}? X_ b. Reduction of the numbers of any unique, rare or endangered species of plants? c. Introduction of new species of plants into an area, or in a barrier to the normal replenish- ment of existing species? x d. Reduction in acreage of any . agricultural crop? _ x 5. Animal Life. Will the proposal have signi- ficant results in: a. Changes in the diversity of species, or numbers of any species of animals (birds, land animals including reptiles, fish and shell- fish, benthic organisms, insects or microfauna)? X b. Reduction of the numbers of any unique, rare or endangered species of animals? c. Introduction of new-species of animals into an area, or result in a barrier to the migration or movement of animals? ' X d. Deterioration to existing fish or wildlife habitat? X 6. Noise. Will the proposal signi- ficantly increase existing noise levels? . x 7. Light and (Hare. Will the pro- posal significantly produce new light or glare? 8- I-and Use. Will the proposal have significant results in the alteration of tlie present or planned land use of an area? x A-3 Yes Mavbe No 9. Natural Resources. Will the pro- posal have significant results in: a. Increase in the rate of use of any natural resources? x b. Depletion of any nonrenewable natural resource? * X 10. Risk of Upset. Does the proposal involve a significant risk of an explosion or the release of haz- ardous substances (including, but not limited to, oil, pesticides, chemicals or radiation) in the event of an accident or upset conditions ? 11' Population. Will the proposal significantly alter the- location, - ' distribution, density, or growth rate of the human population of an area? • . X 12- Housing. Will the proposal signi- ficantly affect existing housing, or create a demand for additional housing? 13. Transportation/Circulation. Will the proposal have significant re- sults in: a. Generation of additional vehicular movement? X b. Effects on existing parking facilities, or demand for new parking? c. Impact upon existing, trans- portation systems? d. Alterations to present patterns of circulation or move- ment, of people and/or goods? e. Alterations to watcrborne, rail or air traffic? x f. Increase in traffic hazards to motor vehicles, bicyclists or pedestrians? . -• A-4 Yes Maybe N'o 14. Public Sendees. Kill the pro- posal have a significant effect upon, or have significant results in the need for new or altered governmental services in any of the following areas: a. Fire protection? X_ b. Police protection? X_ c. Schools? X_ d. Parks or other recreational facilities? X e. Maintenance of public facili- ties, including roads? f. Other governmental services? •• 15. Energy. Will the proposal have significant results in: a. Use of substantial amounts of fuel or energy? - • b. Demand upon existing sources of energy, or require the develop- ment of new sources of energy? x_ 16. Utilities. Will the proposal have significant results in the need for new systems, or alterations^ to the following utilities: a. Power or natural gas? X_ b^ Communications systems? '_ X c. Water? . X d. Sewer or septic tanks? e. Storm water drainage? - X_ f. Solid waste and disposal? 17. Human Health. Will the proposal have sitingicant results in the creation of any health hazard or potential health har.ard (excluding1 mental health)? A-5 Yes Maybe No 18. Aesthetics. Will the proposal have - significant results in the obstruc- tion of any scenic vista or view open to the public, or will the pro- posal result in the creation of an aesthetically offensive site open to public view? x_ 19. Recreat:on. IVill the proposal have signiticant results in the impact upon the quality or quantity of existing recreational opportunities? X_ 20• Archeological/Historical. Will the proposal have significant results in the alteration of a significant archeological or historical site, structure, object or building? *21. ANALYZE VIABLE ALTERNATIVES TO THE PROPOSED PROJECT SUCH AS: a) PHASED DEVEJ.OPWi.\T OF THE PROJECT; b) ALTERNATE SITE DESIGNS; c) ALTERNATE SCALE OF DEVELOPMENT; d) ALTERNATE USES FOR THE SITE; e) DEVELOPMENT AT SOME FUTURE TIME RATHER THAN XOW; f)' ALTERNATE SITES FOR THE PROPOSED USE; g)" NO PROJECT ALTERNATIVE. If this project is not implemented there is a strona oossibility that the portion of Carlsbad Boulevard adjacent to this site could be destroyed by future winter storms, A different desian then proposed could have less environmental effects. This possibility will be examined in .the environmental imnact renort being prepared for this project. A-6 Yes Maybe No 22. MANDATORY FINDINGS OF1 SIGNIFICANCE. a) DOES TIE PROJECT HAVE THE POTEN- TIAL TO DEGRADE TIE QUALITY' OF THE ENVIRONMENT, OR CURTAIL THE DIVERSITY IN THE ENVIRONMENT? b) DOES THE PROJECT HAVE THE POTEN- TIAL TO ACHIEVE SHORT-TERM, TO THE DISADVANTAGE OF LONG-TERM, ENVIRONMENTAL GOALS? (A SHORT- TERM IMPACT ON THE ENVIRONMENT IS ONE WHICH OCCURS IN A RE- LATIVELY BRIEF, DEFINITIVE PERIOD OF TOE WHILE LONG-TERM IMPACTS WILL ENDURE WELL INTO THE FUTURE.) c) DOES THE PROJECT HAVE IMPACTS WHICH .ARE INDIVIDUALLY LIMITED, BUT CUMULATIVELY CONSIDERABLE? (A PROJECT MAY IMPACT ON TWO OR MORE SEPARATE RESOURCES WHERE THE IMPACT ON E^CH RE- SOURCE IS RELATtVELY SMALL, BUT WHERE THE EFFECT OF THE TOTAL OF THOSE IMPACTS ON THE ENVIRONMENT IS SIGNIFICANT.) d) DOES THE PROJECT HAVE ENVIRON- MENTAL EFFECTS WHICH WILL CAUSE SUBSTANTIAL .ADVERSE EFFECTS ON HUMAN BEINGS, EITHER DIRECTLY OR INDIRECTLY? X X X III.- DISCUSSION OF ENVIRONMENTAL EVALUTION The Ci.ty is proposing to construct a seawall at the base of the bluffs between Pine Avenue and Tamarack Avenue. Due to the number of environmental issues involved the City is having an environmental impact report prepared.. ' A-7 IV. DETERMINATION. (TO BE COMPLETED BY THE PLANNING DEPARTMENT) On the basis of this initial evaluation: _ I find the proposed project COULD NOT have a significant effect on the environment, and a NEGATIVE DECLARATION will be prepared. _ I find that although the proposed project could have a significant effect on the environment, there will not be a significant effect in this cas*e because the mitigation measures described on an attached sheet have been added to the project. A conditional negative declaration will will be prepared. * I find the "proposed project MAY have a significant effect on the environment, and an ENVIRONMENTAL IMPACT REPORT is required. Date:ft /*? V Signature V. MITIGATING MEASURES (IF .APPLICABLE) A-: APPENDIX B NOTICE OF PREPARATION (NOP) AND NOP RESPONSES DEVELOPMENTAL SERVICES LAND USE PLANNING OFFICE 1200 ELM AVENUE CARLSBAD, CALIFORNIA 92008-1989 (619) 438-5591 Citp of Car Is bat) PUBLIC NOTICE OF PREPARATION PLEASE TAKE NOTICE: The Land Use Planning Office of the City of Carlsbad intends to prepare an Environmental Impact Report for the following project Project Description: Construction of approximately 4000 feet of seawall to provide storm damage protection to the bluff west of Carlsbad Boulevard fron Oak Avenue southerly to the edge of Agua Hedionda Lagoon. Project address/Location: and Agua Hedionda Lagoon. Carlsbad State Beach between Oak Avenue Anticipated significant impacts: Drainage, and Circulation. Geological, Aesthetic, Biological, We need to know your ideas about the effect this project might have on the environment and your suggestions for ways the project could be revised to reduce or avoid any significant environmental damage. Your ideas will help us decide what issues to analyze in the environ- mental review of this project. Your comments on the environmental impact of the proposed project may be submitted in writing to the Land Use Planning Office, 1200 Elm Avenue, Carlsbad, CA 92008, no later than September 19, 1984. DATED: August 29, 1984 CASE NO: EIR 84-2 APPLICANT: City of Carlsbad PUBLISH DATE: September 1, 1984 MICHAEL Land Use Planning Manager ND 3 5/81 B-l STATE OF C All FORM I A-THE RESOURCES AGENCY GEORGE DEUKMEJIAN, Governor DEPARTMENT OF PARKS AND RECREATION P.O. BOX 2390 SACRAMENTO 95811 (916) 445-7067 SEP 2 1 1984.. Mr. Michael Howes City of Carlsbad 1200 Elm Avenue Carlsbad, CA 92008 Dear Mr. Howes: Carlsbad Boulevard Seawall, SCH #34091201 The Department of Parks and Recreation has reviewed the Public Notice of Preparation for the proposed Carlsbad Boulevard seawall (SCH #84091201). The proposed construction would be a major visual and esthetic intrusion on ' land owned and managed by this Department. Carlsbad State Beach was developed, and is operated, for the public enjoyment of scenic, natural, cultural, and recreational resources of the ocean beach. We are firmly committed to the preservation and protection of a high quality, natural setting for beach-oriented recreational activities. We are just as firmly opposed to a visually offensive -- and inevitably ineffective -- seawall structure on the state beach. Mr. James M. Doyle, Supervisor, Environmental Review Section, is this Department's contact person regarding this project; he can be reached by telephone at (916) 324-6421. We received your NOP from the State Clearinghouse on September 12, 1984. This is not sufficient time to review the proposal and comply with your suspense date of September 19, 1984. The law requires 30 days. Sincerely, laurice H. Getty, Chief Resource Protection Division I-1419R SB ,.j B-2 STATE OF CALIFORNIA—THE RESOURCES AGENCY GEORGE DEUKMEJIAN. Governor DEPARTMENT OF FISH AND GAME Marine Resources Region 245 West Broadway, Suite 350 Dng Beach, California 90802 (213) 590-5117 <\K\•>J October 1, 1984 Mr. Michael Howes City of Carlsbad 1200 Elm Avenue Carlsbad, California 92008 Dear Mr. Howes: You propose to prepare an Environmental Impact Report {SCH 84091201) for the construction of approximately 4,000 feet of seawall, to protect the bluff west of Carlsbad Boulevard from Oak Avenue to the edge of Agua Hedionda Lagoon. The document to be prepared should include the following: 1. Provide a description of existing resources which could be impacted as a result of project implementation. This description should include a discussion of existing habitat types such as: a) rocky or sandy intertidal and subtidal habitats and resources, b) terrestrial habitats and resources above the mean higher high water level and c) the amounts of each habitat type and the major resources associated with each. 2. Describe impacts to habitats and resources which would occur through project implementatin. Items such as loss of terrestrial, intertidal and subtidal habitats and resources as well as the modification of one habitat type to another need to be described. A discussion of the positive and negative impacts of habitat gains, losses and modifications as well as measures to mitigate negative impacts or project modifications to offset impacts must also be included. We also recommend that the proposed seawall be designed and constructed so that losses of marine intertidal and subtidal habitats and resources do not occur, or are minimized to the fullest extent practicable. B-3 - 2 - Should you have any questions or need to arrange for a meeting, please contact Mr. Rolf Mall, Environmental Services Supervisor. His phone nubmer is (213) 590-5155. Sincerely/ John L. Baxter Regional Manager Marine Resources Region cc: Office of Planning and Reseach B-4 STATE OF CALIFORNIA—THE RESOURCES AGENCY GEORGE DEUKMEJIAN. Governor DEPARTMENT OF PARKS AND RECREATION P.O. BOX 2390«UMENTO 95811 ) 445-7067 October 16, 1984 Mr. Mike Howes Assistant Planner City of Carlsbad 1200 Elm Avenue Carlsbad, CA 92008-1989 EIR SCH 84091201 NOP Dear Mr. Howes: The project involves the proposed construction of a seawall on Carlsbad State Beach. The following effects should be evaluated: The loss of public beach should quantified. The loss of access should be identified and quantified. The degree of effects on sand movement should be identified. The effects of the No Project alternate should be projected. Mitigation measures should be developed to reduce adverse effects and alternatives, including the relocation of the street, proposed. The EiR should include a project description with sufficent detail to enable reviewers to provide constructive comments. We request that the City provide us with a copy of responses to the NOP, Sincerely, Maurice H. Getty, Chief Resource Protection Division B-5 State of California, George Deukmejian. Governor California Coastal Commission SAN DIEGO COAST DISTRICT 6154 Mission Gorge Road, Suite 220 San Diego, CA 92120 (714)280-6992 rf, *r \. L- October 25, 1984 Michael Holzmiller 1200 Elm Avenue Carlsbad, CA 92008-1989 Dear Mr. Holzmiller: Thank you for the opportunity to comment on the notice of preparation of an Environmental Impact Report for the construction of a seawall adjacent to a portion of Carlsbad Boulevard in Carlsbad. The staff of the Coastal Commission would like at this time to address several issues that we feel are of importance regarding the impacts of such a project. ' Primarily our concerns relate to the necessity of such a project to be designed so as to: retain to the extent feasible the natural landforms that • mark the area; and, to maintain the maximum amount of public access to and along the beach. While the Commission staff is aware of continued erosion problems in the area and the economical constraints of such a large project, there is a concern that any protective device proposed be of such a design and scale so as to minimize the amount of grading or alteration of the natural topography required for project implementation. To this end we would suggest that any EIR on the project contain an analysis of a number of alternative designs that would achieve this goal including reinforced vertical walls, rock walls or combination thereof. One of the concerns regarding the scale of such a protective device would be its potential impact on oublic access to and along this heavily used public beach. The area in question contains a number of foot paths along Carlsbad Boulevard which have been customarily used as vertical access to the beach. In that access is a prime concern addressed in the applicable Local Coastal Program segment(s) any protective device for the area should incorporate a design which would either retain the existing accessways or provide for alternative (vertical) access points at frequent intervals. The scale of such a protective device would also have an impact on lateral access along the beach. Again we would suggest that an EIR on the project discuss possible alternative designs which would minimize encroachment of the protective device on beach areas. B-6 Michael Holzmiller October 25, 1984 Page 2 While addressing the issues of retention of natural topography and maintenance of public access to the maximum extent feasible incorporate our main concerns at this time, we acknowledge that there may be other concerns which have not been addressed at this time. Should you have any questions regarding this matter please do not hesitate to contact me or Adam Birnbaum at our San Diego office. Sincerely, Charles Damm Assistant District Director CD:AB:el B-7 State of California Memorand um The Resources Agency of California To : Mr. Rand/ Pestor State Clearinghouse Office of Planning and Research 1400 Tenth Street Sacramento, California 95814 Date : Movember 9, 1984 Subject: Carlsbad Boulevard Seawall, SCH #84091201 From : Department of Boating and Waterways In response to the Public Notice of Preparation and the environmental scoping meeting for the proposed Carlsbad Boulevard Seawall Project, the Department of Boating and Waterways is forwarding the following comments for your consideration in preparing the Environmental Impact Statement. t The City provides access to the beach through the use of city streets. If a project of protecting the shoreline is not constructed at Carlsbad Boulevard, the City will suffer serious losses (including Carlsbad Boulevard) and access to the beach will be seriously impaired. The proposed project plans to enhance the existing access. Most of the seawall would be constructed on the bedrock at the toe of the bluff. This bedrock is primarily above and landward of the present usable beach. Any encroachment of a seawall structure seaward of the present bluff toe could be considered as merely re-establishment of the pre-existing bluff line to a position it occupied prior to the last 8-10 years of erosion activity. A combined seawall using a reinforced earth wall can undulate horizontally and can have a textured, colored surface to attempt to simulate the natural conditions and reduce the visual impact. The Department expects that the wall will be designed for a useful life of 50 years. A similar wall was completed at Sunset Cliffs in the City of San Diego in 1982. That wall has been accepted aesthetically and withstood the 1982-83 storms with no sign of distress. The value of the eroding bluffs as beach renourishment is probably negli- gible. If 60' of erosion occurred along the .full length of the bluff during the life of the project, it would produce approximately 250,000 cubic yards of material. If 40% of this material was suitable for beach fill Can unusually high percentage), it would produce only 100,000 cubic yards of fill over the 50-year life of project. This could cause about B-8 Mr. Randy Pestor . -2- November 9, 1984 $20 million or more in damages or a minimum of $200 in damages per cubic yard of beach sand. In addition, some of the finer sands and silts would probably be transported into the lagoon to enlarge the shoals. If you have any questions or comments, please contact Ron Jespersen at (916) 322-1809 or me at the number listed below. By BILL S. SATOW Assistant Director GEORGE A. ARMSTRONG, Supervisor Beach Erosion Branch (916) 445-8349 cc: Ron Beckman /Michael Howes Louis Lee B-9 APPENDIX C GENERAL COASTAL PROCESSES APPENDIX C GENERAL COASTAL PROCESSES This appendix provides a generalized discussion of coastal processes pertinent to the proposed Carlsbad Beach State Park bluff stabilization project. In addition, typical shoreline features are illustrated in Figure C-l on the following page. These materials have been excerpted from the Geotechnical Environmental Impact Assessment for the Proposed Shoreline Protection Project, Oak Avenue to Agua Hedionda Lagoon, City of Carlsbad, San Diego County, California, prepared by Leighton and Associates in Decem- ber 1984. Beach Fluctuations The amount of sand on a beach changes continually in response to changes in the properties of the waves incident on the shoreline. During times of low swell {principally during the summer months op between winter storms) the beach may advance slowly seaward, either due to replacement of offshore sand from nearby sand bars or transpor- tation of sand to the site by the prevailing longshore current. During periods of high swell (a combination of storm and/or high tides), the scouring energy of waves incident to the beach removes sand which is then redeposited immediately offshore OP removed and transported downdpift in the longshore currents. A case in point: From September 1982 to February 1983 the area approximately 1 mile south of the San Luis Rey River suffered net erosion, while the area off Carlsbad accreted overall. The accretion of the Carlsbad beach, despite the severe wave conditions duping the 1983 winter, can only be accounted for by southerly migration of Oceanside beach sand (Waldorf et al., 1983). Filling of a beach normally occurs slowly over a period of a few days or weeks, whereas cutting and recession of the beach can actually occur rapidly in a period of a few hours to 1 to 2 days. Because California beaches are subject to a seasonal wave regime, the cumulative effect of cutting and filling results in beaches building from about February to September and receding in the fall and early winter. At times when the protective beach fronting the coastline becomes eroded, the backshope area and coastal bluffs are cut by wave action and become the line of defense against the impinging waves. Their degree of resistance will determine the extent to which the coast will then recede during that particular event. Approximately 3 feet of vertical cut of the berm (see Figure C-l) occurs regularly during a typical winter beach configuration (Flight and Waldorf, 1984). Sudden beach or coastal losses C-l LA JOLLA SUBMARINED- CANYON MILES LONGSHORE TRANSPORT SOURCE: Leighton and Associates, 1984 Littoral (nearshore) Celts in San Diego County FIGURE C-1 C-2 WESTEC Service*, Inc during severe storms or tides may be followed by periods of many years when the coastline fluctuates seasonally but experiences no significant overall permanent changes. Based on historical documents, the 30 years preceding the stormy year of 1978 were free of conditions that would produce either extensive coastal erosion or flooding. For example, during this time period the beach widths in the Oceanside area varied between 40-60 feet, with few sand bars offshore. In 1978, stormy weather and extensive bluff and canyon erosion produced extremely high sediment yields, resulting in a widening of the beaches by at least 40 feet and producing offshore sand bars (Kuhn and Shepard, 1984). Reliability of Sand Supply and Maintenance of Beach (Sand Budget) The sand budget for a given beach is an accounting of the rates of sand supply and loss. If more sand is supplied to the area than is eroded, the coastline will accrete or build seaward. If more sand is lost than is supplied to the system, the result will be coastal recession and a permanently eroding beach. • Sand Sources The most probable sources of sand to the Carlsbad project site are: 1. Rivers The two main rivers acting as contributing sources in the sand bud- get are the San Luis Key and the Santa Margarita. Currently, 24,000 cubic yards of sand per year are deposited by the Santa Margarita River. The San Luis Key River contributes 37,000 cubic yards per year of sand to the beach just south of Oceanside Harbor. This is one of the last remaining natural sources of beach sand for the 45 mile shoreline between Camp Pendleton and La Jolla Shores. The San Dieguito River used to be a major source until dammed to form Lake Hodges in 1918. 2. Coastal bluff erosion The concept of average, long-term, coastal bluff retreat is valid over thousands of years. Short-term provincial bluff retreat is episodic and appears to be related to meterological conditions, structural composition, and induration of cliff forming formations. Aerial photographs, old maps, weather reports, ship logs, deterio- ration of dated inscriptions, and records of land ownership have been utilized by geolo- gists to validate this phenomenon. An early cliff erosion study on the property of Scripps Institution of Oceanography in Southern California (Vaughn, 1932) determined a retreat rate of 10 to 20 feet between 1913-1930. Hannan (1975) studied these cliffs by field measurements and compared his results to the 1912 and 1966 topographic maps and concluded that the cliff had retreated 19 to 54 feet between 1912 and 1975. C-3 Consolidated Cretaceous and Eocene rocks from Leucadia to Point Loma were studied by Pinckney and Lee (1973). They determined an erosion rate of less than 6 inches per year. A study by Norris (1968) of the Santa Barbara coastline where the cliffs are composed of rocks of middle to late Miocene and Pliocene age, concluded the cliff retreat rate to be 3 to 10 inches per year. In Isla Vista, a cliff retreat study by Cottonaro (1975) focused on the sea cliffs cut in Miocene rock. He determined the average retreat rate to be 2 to 15 inches per year. 3. Littoral transport Sand along the shoreline is in a constant state of movement. Pre- cise quantities of sediment and their direction of movement can only be estimated. The various techniques utilized by oceanographers still yield conflicting figures in the actual amounts of transported sand and conflicting ideas concerning the localities of disperse- ment of the sand within the longshore transport system. Dr. Douglas Inman from Scripps Institution of Oceanography has calculated that net longshore transport of sediment to the south from San Clemente to La Jolla (see Figure C-2) is approximately 425,100 cubic yards per year. In a northerly direction, from Silver Strand State Beach to Coronado, the longshore transport is at least 2,354,000 cubic yards per year (Nordstrom and Inman, 1973). It has been esti- mated that 444,720 cubic yards per year of sand are diverted to the ocean by way of Scripps and La Jolla submarine canyons. An elongated body of sediment lying close to the shore and extending the full length of the Oceanside littoral cell has been sug- gested. It is separated from the beach by a strip of exposed bedrock. This deposit is obelieved to contain approximately 5.232 x 10 cubic yards of sand (Henry, Barry and Fischer, 1976). 4. Dredging of Oceanside Harbor The dredging process is a major contributing factor in producing suspended sediments in the sand transport system. Approximately 4 million cubic yards of material were dredged to construct the Oceanside small-craft harbor in 1963. The dredge spoil material contained many cobbles derived from floods of the San Luis Ray River. In total, approximately 10 million cubic yards of sediment, including cobbles, have been dredged from Camp Pendleton Basin and Oceanside Harbor between 1942 and 1980 (Kuhn and Shepard, 1984). C-4 Coastal area Coast j /WMJUKJV Bluff -,\ or ^"3 escarpment^! \ Beach or shore Backshore ^ jS*~~?~ Berms _^ ^.^.JULJU-^ ^ Foreshore or Beach Face ^y— " ^^ Nearshore zone (defines area of nearshore currents) Inshore or Shoreface (extends through breaker zone) • Breakers — _ Hiqh water level , *? -i^ Offshore jjrdinary low water level Plunge point Bottom •Surf or Breaker zone Waves peak up but do not break on this bar at high tide Backrush Beach face Outer bar (Inner bar, low tide) Deep bar (Outer bar, low tide) riSOURCE: Leighton and Associates, 1984 Typical Shoreline Features FIGURE C-2 WESTEC Services, Inc. C-5 • Sand.Loss Sand may be lost from the coastal system due to the following reasons: Offshore movement into deeper water where the sand cannot move onshore again. Longshore currents moving sand down current away from the site. Entrapment by submarine canyons where the sand flows to deeper water. Abrasion and breakdown on individual sand grains. Deflation (wind transport) inland away from the beach. The construction of dams. The sandy beaches that usually front coastal bluffs in San Diego County provide some buffer against wave attack; however, with the recent heavy storms and surf conditions, beach sand has been removed and no buffer remains between the ocean and seacliff. Predictions for the return of the protective sand beach are not encourag- ing. There is every indication that the overall loss of sand in the littoral cell will mean that less sand is returned to the beach. As a result, even during the lower winter tides, and during summer high tides, the seacliffs may experience some wave attack. Addi- tionally, for future years with winter storm conditions, there is the possibility of an increase in the number of times the seacliffs will be directly impacted by wave energy. There is no method for predicting this natural occurrence, therefore, the future effects on bluff stability are also unknown. The sandy beaches that were once more common in San Diego County are experiecing a sand depletion related to coastal conditions that influence the source and transport of sand along the coast. Sand beach deposits that have traditionally protected the coastal seacliffs from wave attack are continuing to be depleted from season-to- season, and predictions are that sand losses along the beaches will exceed the input of new sand. It is estimated that approximately 200,000 to 300,000 cubic yards of sand is lost each year in the Southern California transport system. C-6 REFERENCES CITED Cottonaro, W.F., 1975, Seacliff erosion, Isla Vista, California. California Geology, Vol. 28, No. 6, pp. 140-143. Flick, R.E. and B.W. Waldorf, 1984, "Performance Documentation of the Longard Tube of Del Mar, California 1980-1983," Coastal Engineering, 8, pp. 199-217. Henry, Berry and Fisher, 1976, Holocene sediment deposits on the continental shelf of Southern California: Geological Society of America, Abstracts with Program, V.8, No. 3. Hannan, 1975, Sea Cliff Stability West of the Marine Biology Building: Scripps Institute of Oceanography, La Jolla, California. Benton Engineering Project No. 75-9- 18 FG. Kuhn, G.G. and F.P. Shepard, 1984, Sea Cliffs, Beaches and Coastal Valleys of San Diego County: Some Amazing Histories and Some Horrifying Implications, Uni- versity of California Press. r Nordstrom and Inman, 1973, Beach and Cliff Erosion in San Diego County, California, In Arnold Ross and Robert Dowlen (eds.), Studies on the Geology and Geologic Haz- ards of the Greater San Diego Area, California, San Diego Assoc. Geologist's Field Trip Guide Book. Norris, R.M., 1968, Sea Cliff Retreat at Santa Barbara, California, Mineral Information Service (Calif.) V. 21, pp. 87-91. Pinckney, C.J. and L.E. Lee, 1973, Seacliff recession study, southern one-half of San Diego County. In: W.J. Elliott (editor), Engineering Geologic Problem Areas, Southwestern San Diego County, California, San Diego Association of Geologists Guidebook. U.S. Army Coastal Engineering Research Center, 1975, Shore protection manual: U.S. Government Printing Office, Washington, DC 20402, Vols. I, II and in. Vaughan, T.W., 1932, Rate of seacliff recession on the property of the Scripps Institute of Oceanography at La Jolla, California, Science 75:250. Waldorf, B.W., R.E. Flick and D.M. Hicks, 1983, Beach Sand Level Measurements - Oceanside and Carlsbad, California, December 1981 to February 1983 Data Report, SIO Reference No. 83-6. C-7 APPENDIX D GLOSSARY OF TERMS GLOSSARY OF TERMS ACCRETION May be either NATURAL or ARTIFICIAL. Natural accretion is the buildup of land, solely by the action of the forces of nature, on a BEACH by deposition of waterborne or airborne material. Artificial accretion is a similar buildup of land by reason of an act of man, such as the accretion formed by a groin, breakwater, or beach fill deposited by mechanical means. Also AGGRADATION. ALLUVIUM Soil (sand, mud, or similar detrital material) deposited by streams, or the deposits formed. ALONGSHORE r Parallel to and near the shoreline; same as LONGSHORE. ARTIFICIAL NOURISHMENT The process of replenishing a beach with material (usually sand) obtained from another location. AWASH Situated so that the top is intermittently washed by waves or tidal action. Condition of being exposed or just bare at any stage of the tide between high water and chart datum. BACKRU5H The seaward return of the water following the uprush-of the waves. For any given tide stage the point of farthest return seaward of the backrush is known as the LIMIT of BACKRUSH or LIMIT BACKWASH. BACKSHORE That zone of the shore or beach lying between the foreshore and the coastline and acted upon by waves only during severe storms, especially when combined with exceptionally high water. Also BACKBEACH. It comprises the BERM or BERMS. D-l (I) See BACKRUSH. (2) Water or waves thrown back by an obstruction such as ship, breakwater, or cliff. BATHYMETRY The measurement of depths of water in oceans, seas, and lakes? also information derived from such measurements. BEACH The zone of unconsolidated material that extends landward from the low water line to the place where there is a marked change in material or physiographic form, or to the line of permanent vegetation (usually the effective limit of storm waves). The seaward limit of a beach - unless otherwise specified - is the mean low water line. A beach includes FORESHORE AND BACKSHORE. BEACH BERM A nearly horizontal part of the beach or backshore formed by the deposit of material by wave action. Some beaches have no berms, others have one or several. BEACH EROSION The carrying away of beach materials by wave action, tidal current, littoral currents, or wind. BEACH FACE The section of the beach normally exposed to the action of wave uprush. The FORESHORE of a BEACH. (Not synonymous with SHOREFACE). BENCH (I) A level or gently sloping erosion plane inclined seaward. (2) A nearly horizontal area at about the level of maximum high water on the sea side of a dike. BLOWN SANDS See EOL1AN SANDS. BLUFF A high steep bank or cliff. D-2 BREAKWATER A structure protecting a shore area, harbor, anchorage, or basin from waves. BULKHEAD A structure or partition to reta+n or prevent sliding of the land. A secondary purpose is to protect the upland against damage from wave action. CLIFF A high, steep face of rock; a precipice. See also SEA CLIFF. COAST A strip of land of indefinite width (may be several miles) that extends from the shoreline inland to the first major change in terrain features. > COASTAL AREA The land and sea area bordering the shoreline. COASTLINE (I) Technically, the line that forms the boundary between the COAST and the SHORE. (2) Commonly, the line that forms the boundary between the land and the water. CREST OF WAVE (I) the highest part of a wave. (2) That part of the wave above stillwater level. CURRENT A flow of water. CURRENT, COASTAL One of the offshore currents flowing generally parallel to the shoreline in the deeper water beyond and near the surf zone. They are not related genetically to waves and resulting surf, but may be related to tides, winds, or distribution of mass. D-3 CURRENT, EBB The tidal current away from shore or down a tidal stream. Usually associated with the decrease in the height of the tide. CURRENT, LITTORAL Any current in the littoral zone caused primarily by wave action, e.g., longshore current, rip current. See also CURRENT NEARSHORE. CURRENT, LONGSHORE The littoral current in the breaker zone moving essentially parallel to the shore, usually generated by waves breaking at an angle to the shoreline. CURRENT, NEARSHORE A current in the NEARSHORE ZONE. t CURRENT, TIDAL The alternating horizontal movement of water associated with the rise and fall of the tide caused by the astronomical tide-producing forces. Also CURRENT, PERIODIC. See also, CURRENT, FLOOD and CURRENT, EBB. DATUM, PLANE The horizontal plane to which surroundings, ground elevations, or water surface elevations are referred. Also REFERENCE PLANE. The plane is called a TIDAL DATUM when defined by a certain phase of the tide. DEFLATION The removal of loose material from a beach or other land surface by wind action. DOWNCOAST In United States usage, the coastal direction generally trending toward the south. DQWNDRIFT The direction of predominant movement of littoral materials. D-4 DRIFT (Noun) (I) Sometimes used as a short form for LITTORAL DRIFT (2) The speed at which a current runs. (3) Also floating material deposited on a beach (driftwood). (4) A deposit of a continental ice sheet, as a drumlin. DRIFT CURRENT A brood, shallow, slow-moving ocean or lake current. DUNES (I) Ridges or mounds of loose, wind-blown material, usually sand. (2) BED FORMS smaller than bars but larger than ripples that are out of phase with any water-surface gravity waves associates with them. EMBAYMENT An indentation in the shoreline forming an open bay. EOLtAN SANDS (or BLOWN SANDS) - Sediments of sand size or smaller which have been transported by winds. They may be recognized in marine deposits off desert coasts by the greater angularity of the grains compared with waterborne particles. EROSION The wearing away of land by the action of natural- forces. On a beach, the carrying away of beach material by wave action, tidal currents, littoral currents, or by deflation. ESCARPMENT A more or less continuous line of cliffs or steep slopes facing in one general direction which are caused by erosion or faulting. FETCH The area in which SEAS are generated by a wind having a rather constant direction and speed. Sometimes used synonymously with FETCH LENGTH. FLOOD TIDE The period of tide between low water and the succeeding high water; a rising tide. D-5 FOAM LINE The front of a wave as it advances shoreward, after it has broken. FOLLOW ING WIND Generally, same as tailwind; in wave forecasting, wind blowing in the direction of ocean- wave advance. FOREDUNE The front dune immediately behind the backshore. FORESHORE The part of the shore lying between the crest of the seaward berm (or upper limit of wave wash at high tide) and the ordinary low water mark, that is ordinarily traversed by the uprush and backrush of the waves as the tides rise and fall. FREEBOARD The additional height of a structure above design high water level to prevent overflow. Also, at a given time, the vertical distance between the water level and the top of the structure. On a ship, the distance from the waterlines to main deck or gunwale. GROIN (British, GROYNE) - A shore protection structure built (usually perpendicular to the shoreline) to trap littoral drift or retard erosion of the shore. HIGH TIDE, HIGH WATER (HW) The maximum elevation reached by each rising tide. HIGHER HIGH WATER (HHW) The higher of the two high waters of any tidal day. The single high water occurring daily during periods when the tide is diurnal is considered to be a higher high water. HIGHER LOW WATER (HLW) The higher of two low waters of any tidal day. D-6 HIGH WATER LINE In strictness, the intersection of the plane of mean high water with the shore. The shoreline delineated on the nautical charts of the U.S. Coast and Geodetic Survey is an approximation of the high water line. For specific occurrences, the highest elevation of the shore reached during a storm or rising tide, including meteorological effects. LEEWARD The direction toward which the wind is blowing; the direction toward which waves are traveling. LITTORAL DRIFT The sedimentary material moved in the littoral zone under the influence of waves and currents. LITTORAL TRANSPORT The movement of littoral drift in the littoral zone by waves and currents. Includes movement parallel (longshore transport) and perpendicular (on-offshore transport) to the shore. LITTORAL TRANSPORT RATE Rate of transport of sedimentary material parallel to or perpendicular to the shore in the littoral zone. Usually expressed in cubic yards .(meters) per year. Commonly used as synonymous with LONGSHORE TRANSPORT RATE. LITTORAL ZONE In beach terminology, an indefinite zone extending seaward from the shoreline to just beyond the breaker zone. LOAD The quantity of sediment transported by a current. Itjncludes the suspended load of small particles, and the bedload of large particles that move along the bottom. LONGSHORE Parallel to and near the shoreline. D-7 LONGSHORE TRANSPORT RATE Rate of transport of sedimentary material parallel to the shore. Usually expressed in cubic yards (meter) per year. Commonly used as synonymous with LITTORAL TRANS- PORT RATE. LOWER HIGH WATER (LHW) The lower of the two high waters of any tidal day. The single low water occurring daily during periods when the tide is diurnal is considered to be a lower low water. LOW TIDE (LOW WATER, LW) The minimum elevation reached by each falling tide. LOW WATER DATUM An approximation to the plane of mean low water that has been adopted as a standard reference plane. r LOW WATER LINE The intersection of any standard low tide datum plane with the shore. MEAN HIGHER HIGH WATER (MHHW) The average height of the higher high waters over a 19-year period. For shorter periods of observations, corrections are applied to eliminate known variations and reduce the result to the equivalent of a mean 19-year value. MEAN HIGH WATER (MHW) The average height of the high waters over a 19-year period. For shorter periods of observations, corrections are applied to eliminate known variations and reduce the results to the equivalent of a mean 19-year value. All high water heights are included in the average where the type of tide is either semidiurnal or mixed. Only the higher high water heights are included in the average where the type of tide is diumal. So determined, mean high water in the latter case is the same as mean higher high water. MEAN LOWER LOW WATER (MLLW) The average height of the lower low waters over a 19-year period. For shorter periods of observations, corrections are applied to eliminate known variations and reduce the results to the equivalent of a mean 19- year value. Frequently abbreviated to LOWER LOW WATER. D-8 MEAN LOW WATER (MLW) The overage height of the low waters over a 19-year period. For shorter periods of observations, corrections are applied to eliminate known variations and reduce the results to the equivalent of a mean 19-year value. All low water heights are included in the average where the type of tide is either semidiurnal or mixed. Only lower water heights are included in the average where the type of tide is diurnal. So determined, mean low water in the latter case is the same as mean lower low water. MEAN SEA LEVEL The average height of the surface of the sea for all stages of the tide over a 19-year period, usually determined from hourly height readings. Not necessarily equal to MEAN TIDE LEVEL. NEARSHORE (ZONE) In beach terminology an indefinite zone extending seaward from the shoreline well beyond the breaker zone. It defines the area of NEARSHORE CURRENTS. r NGVD (NATIONAL GEODETIC VERTICAL DATUM) Any level formerly referred to as Mean Seal Level Datum of 1929. NOURISHMENT The process of replenishing a beach. It may be brought about naturally, by longshore transport, or artifically by the deposition of dredged materials. OFFSHORE (I) In beach terminology, the comparatively flat zone of variable width, extending from the breaker zone to the seaward edge of the Continental Shelf. (2) A direction seaward from the shore. OFFSHORE WIND A wind blowing seaward from the land in the coastal area. OUTFALL A structure extending into a body of water for the purpose of discharging sewage, storm runoff, or cooling water. D-9 OVERTOPPING Passing of water over the top of a structure as a result of wave runup or surge action. OVERWASH That portion of the uprush that carries over the crest of a berm or of a structure. PERIGEAN TIDE Large semidaily tides that occur monthly when the moon is closest to the earth. PIER A structure, usually of open construction, extending out into the water from the shore, to serve as a landing place, a recreational facility, etc., rather than to afford coastal protection. In the Great Lakes, a term sometimes improperly applied to jetties. r PILE A long, heavy timber or section of concrete or metal to be driven or jetted into the earth or seabed to served as a support or protection. POCKET BEACH A beach, usually small, in a costal reentrant or between two littoral barriers. PROBABLE MAXIMUM WATER LEVEL A hypothetical water level (exclusive of wave runup from normal wind-generated waves) that might result from the most severe combination of hydrometeorological, geoseismic and other geophysical factors that is considered reasonably possible in the region involved, with each of these factors considered as affecting the locality in a maximum manner. PROFILE, BEACH The intersection of the ground surface with a vertical plane; may extend from the top of the dune line to the seaward limit of sand movement. REVETMENT A facing of stone, concrete, etc., built to protect a scarp, embankment, or shore structure against erosion by wove action or currents. D-10 RIDGE, BEACH A nearly continuous mound of beach material that has been shaped up by wave or other action. Ridges may occur singly or as a series of approximately parallel deposits. RIP A body of water made rough by waves meeting an opposing current, particularly a tidal current; often found where tidal currents are converging and sinking. RIPRAP A layer, facing, or protective mound of stones randomly placed to prevent erosion, scour, or sloughing of a structure or embankment; also the stone so used. RUBBLE (I) Loose angular waterworn stones along a beach. (2) Rough, irregular fragments of broken rock. RUBBLE-MOUND STRUCTURE A mound of random-shaped and random-placed stones protected with a cover layer of selected stones or specially shaped concrete armor units (armor units in primary cover layer may be placed in orderly manner or dumped at random). RUNUP The rush of water up a structure or beach on the breaking of a wave. Also UPRUSH. The amount of runup is the vertical height above stillwater level that the rush of water reaches. SCARP, BEACH An almost vertical slope along the beach caused by erosion by wave action. It may vary in height from a few inches to several feet, depending on wave action and the nature and composition of the beach. SCOUR Removal of underwater material by waves and currents, especially at the base or toe of a shore structure. D-ll SEA CLIFF A cliff situated at the seaward edge of the coast. SEAWALL A structure separating land and water-areas, primarily designed to prevent erosion and other damage due to wave action. SEICHE (1) A standing wave oscillation of an enclosed water body that continues, pendulum fashion, after the cessation of the originating force, which may have been either seismic or atmospheric. (2) An oscillation of a fluid body in response to a disturbing force having the same frequency as the natural frequency of the fluid system. Tides are now considered to be seiches induced primarily by the periodic forces caused by the sun and moon. (3) In the Great Lakes area, any sudden rise in the water of a harbor or a lake whether or not ft is oscillatory. Although inaccurate in a strict sense, this usuage is well established in the Great Lakes area. SEISMIC SEA WAVE (TSUNAMI) A long-period wave caused by an underwater seismic disturbance or volcanic eruption. Commonly misnamed "tidal wave." SHORE The narrow strip of land in immediate contact with the sea, including the zone between high and low water lines. A shore of unconsolidated material is usually called a beach. 5HOREFACE The narrow zone seaward from the low tide SHORELINE covered by water over which the beach sands and gravels actively oscillate with changing wave conditions. SHORELINE The intersection of a specific plane of water with the shore or beach (e.g., the highwater shoreline would be the intersection of the plane of mean high water with the shore or beach). The line delineating the shoreline on U.S. Coast and Geodetic Survey nautical charts and surveys approximates the mean high water line* D-12 SHORE The degree of inclination to the horizontal. Usually expressed as a ratio, such as 1:25 or I on 25, indicating I unit vertical rise in 25 units of horizontal distance; or in a decimal fraction (0.04); degress (2° 18'); or percent (4%). STILLWATER LEVEL The elevation that the surface of the water would assume if all wave action were absent. STORM SURGE A rise above normal water level on the open coast due to the action of wind stress on the water surface. Storm surge resulting from a hurricane also includes that rise in level due to atmospheric pressure reduction as well as that due to wind stress. SURF r The wave activity in the area between the shoreline and the Outermost limit of breakers. SURF ZONE The area between the outermost breaker and the limit of wave uprush. SUSPENDED LOAD (I) The material moving in suspension in a fluid, being kept up by the upward components of the turbulent currents or by collodial suspensron. (2) The material collected in Or computed from samples collected with a suspended load sampler. (A suspended load sampler is a sampler which attempts to secure a sample of the water with its sediment load without separating the sediment from the water). Where it is necessary to distinguish between the two meanings given above, the first one maybe called the "true suspended load." SWASH The rush of water up onto the beach face following the breaking of a wave. SWELL Wind-generated waves that have traveled out of their generating area. Swell character- istically exhibits a more regular and longer period, and has flatter crests than waves within their fetch. D-13 TERRACE A horizontal or nearly horizontal naturdl or aftifical- tbpogrdphrc feature interrupting a steeper slope, sometimes occurring in a series^ TIDAL RANGE The difference in height between consecutive-high and low (or higher high and'lower low) waters. TIDAL WAVE (1) the wave motion of the tides. (2) In popular usua§e$ ariy unusually Wgb and destructive water level along a shore. It usually refers to STORM SURGE or TSUNAMI. TIDE The periodic rising and falling of the water that results-from gravitational attraction of the moon and sun and other astronomical bodies'acting Ajpbn the-Yotating;earth. Although the accompanying horizontal movement of the water TesOltihg ;fr6m the same cause is also sometimes called the tide, it is preferable to designdte^the latter as TIDAL-CURRENT, reserving the name TIDE for the vertical movement."- TSUNAMI A long-period wave caused by an underwater "disturbance such as a volcanic eruption of earthquake. Commonly miscalled "tidal wave/1 UPCOAST In United States usage, the coastal direction generally trending toward the north. UPDR1FT The direction opposite that of the predominant rhoveprtertt:of'litt6fai materials. WATERLINE A juncture of land and sea. This line migrates, changing;With the tide or other fluctuation in the water level. Where waves are present on the'beach, this line is also known as the limit of bockrush. (Approximately the intersection of the land with the stillwater level). WAVE HEIGHT The vertical distance between a crest and the preceding trough. D-14-