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HomeMy WebLinkAbout3537; Vista/Carlsbad Interceptor Sewer; North Agua Hedionda Interceptor West Segment; 2004-10-25Environm North Agua Hedionda Interceptor Western Segment Sewer Maintenance, Access Road & Shoreline Protection Project OCTOBER 2004 PREPARED FOR: City of Carlsbad 1635 Faraday Avenue Carlsbad, CA 92008 PREPARED BY: Dudek & Associates, Inc. 605 Third Street Encinitas, CA 92024 PRErACE TO THE EINAL ENVIRONMENTAL IMPACT REPORT The Final Environmental Impacts Report (FEIR) for the North Agua Hedionda hiterceptor Sewer Maintenance, Access Road, and Shoreline Protection Project is comprised of the following: Comments and Responses to the Draft EIR The text of the Draft EIR (Note: The text of the Draft EIR and Technical Appendices have not been modified). DUDEK & ASSOCIATES, INC. 2798-03 February 2004 PTD/CUDHOI l^ffrru far Conplcx Fmitcts 1 I 1 I I COMMENTS f t I ff I f I t » I i RESPONSES E I LETTER A NATIVE M1£RICAPI HERITAGE CXytmS^Cm •j: t Ciiyna. UMA. mon si* M»s« 3, 7tX34 Dew Ms Blaa^Pi; San Oia^a, CA 321M raasi'm n IM pna^ area The Coammxt mifm AO wdMnsntttrta pr^tWMc* if» s^njie irdivklL^. C«o iJm>S. awl tWc Roaourcwi CoWSSMT.W mium* lf» IH(M«» M 6» tWlo*«« m IN st^ra of »f alt (tflvtfonliefM dscum^tK If you have an; quHUcm, ^iltKKO o^ntit^ mn »S Ca*a<Saaimt/J RESPONSE A-1 Comment noted. The City has incorporated notification of the appropriate Native American organization prior to potential disturbance fi^om construction into the Mitigation, Monitoring, and Reporting Program. Notification will consist of a pre-excavation agreement with the San Luis Rey Band of Mission Indians which formalizes procedures for the treatment of Native American human remains, burial, ceremonial or cultural sites that may be uncovered during any ground disturbance activities. DUDEK & ASSOCIATHES, INC. 2798-03 Prafuitoiul Tiomj for Confla Pnijictj f > r f t f I 4 i f I f COMMENTS f I I > f \ f ' i t r f f f 1 t fv ff 1 r » t I RESPONSES I i LETTER A (Cont.) NATIVE MisRiCiUPi com»,jrrs 10"- - , CA 93040 (519)443-6612.13 La JtM Qmi of r.t»iten l^x^s CA 92K)I fS19) US-<m5 (760 ?423?7W2 (raij 742-170( Fax San Psetrwitf Bauxl Of fcBsaicw iftdbni |76(y| 748-3876 Fax S^ejas Band of M«Eton Indians r'O Bex Alp«w . CA 91903 ISiai 445-3510 ISig) 445-5^7 Fax P.O. i3<»i 50 (760) 7<2.I4I1 Fax Pfluma & Yiitna Chilsli^lC:, Covers. Ch^Mison P.0, Box 359 74Z4«a t^J 7*2-3^22 Pax htoA Mfloawis. CNa^rson •jy P.O. 8BW 1477 tuissro TMWdrisi . CA 92593 (509) 676-2768 imjisss-mapm & ASSOCIATES, INC. 2798-03 pTBlaMianai Tttmt fur Compla Pmffcu I r 1 9^ m t § % m M COMMENTS t»ti«ttt RESPONSES t » I I t i LETTER A (Cent) N«T(V6 AKERlCAf* CONl iTS Ban 0)090 l^untv March i. 2004 Flfncon Band of ha«M>;> lilrfbrw Cultore Cc^mittae P.O.Box 648 Vallsy Camer , CA 82082 {TSO} 749-1051 f76m 748^501 U^srsye i CA 92040 mi) 4A3-6^S2 (B19j4«Me8) FAX im Band M^iim in^ian* Henry CooHiuais, Ci^wai f%<«(MR»t i-'.tterTOlK . CA 92028 Cupttno i?ei)) ;^B-e722 - Horn *^ !7f50) 307-3615 - CoB SAn Luis fia/ ^nd <fl Mission Indians RUESBS Bprw. CapijUn Psuma AVwma ViUerio Urarai. TAaJ Atimiwairasix P,0. Box 3B9 LuiEM^o PaumaVa«ey > CA 9?f)6i C7ii(n 742"128a irm) 7-12-S422 fast Pawtra S Vuima P.O. Box 368 Pauemvmy -CA 92061 (7SG} 732^22 Fa* Paums aiiWiiMi P.O. I^x 36» PjBimaV^ , CA 0206! {7em r42-a«a Uikana \7m) 757-3749 - Fax DUDEK & ASSOCIATES, INC. 2798-03 ProfiiHoiuI nam for Csmtilu Projicti TABLE or CONTENTS A, Section Page No. EXECUTIVE SUMMARY E-1 1.0 INTRODUCTION 1-1 1.1 Purpose of the Environmental Impact Report 1-1 1.2 EIR Focus and Scoping of Issues 1 -1 1.3 Content and Format of the EIR 1-2 1.4 EIR Review Process 1-3 1.5 Decisions to be Made and Permits Required 1 -4 m 2.0 PROJECT DESCRIPTION 2-1 2.1 Project Background 2-1 2.2 Introduction and Purpose of the Project 2-4 2.3 Project Objectives 2-6 2.4 Description of the Project 2-8 2.5 Project Construction 2-19 2.6 Staging Areas and Access 2-19 2.7 Summary of Project Design Measures 2-20 3.0 ENVIRONMENTAL ANALYSIS 3-1 1^ 3.1 3.2 Aesthetics 3-1 3.1.1 3.1.2 3.1.3 3.1.4 3.1.5 3.1.6 Methodology 3-1 Existing Conditions 3-3 3.1.2.1 Local Setting 3-3 3.1.2.2 Existing Visual Character 3-3 3.1.2.3 Local Visual Resource Policies 3-5 Criteria for Determining Significance 3-9 Potential Impacts 3-9 3.1.4.1 Potential Impacts to Visual Character 3-9 3.1.4.2 Consistency with Local Visual Resource Policies 3-12 Mitigation Measures 3-15 Significance of Impact after Mitigation and Rationale 3-15 DUDEK & ASSOCIATES, INC. Biology 3-16 3.2.1 Methodology 3-16 3.2.2 Existing Conditions 3-16 3.2.2.1 Vegetation Communities 3-16 3.2.2.2 Jurisdictional Waters 3-27 3.2.2.3 Zoology-Wildlife Diversity 3-28 3.2.2.4 Sensitive Biological Resources 3-29 3.2.2.5 Sensitive Habitats 3-44 2798-03 February 2004 ToC-i PnrfeaiitBtd Teems far Ompiac Proitca TABLE or CONTENTS Section Page No. HP* IM 3.2.2.6 Wildlife Corridors and Habitat Linkages 3-44 3.2.2.7 Regional Resource Planning 3-45 3.2.3 Criteria for Determining Significance 3-46 3.2.4 Potential Impacts 3-47 3.2.4.1 Direct Impacts 3-48 3.2.4.2 Indirect Impacts 3-51 3.2.4.3 Wildlife Corridors and Habitat Linkages 3-52 3.2.5 Required Mitigation Measures 3-52 3.2.5.1 Direct Impacts 3-52 3.2.5.2 Indirect Impacts 3-56 3.2.6 Significance of Impact After Mitigation and Rationale 3-58 3.3 Cultural and Paleontological Resources 3-59 3.3.1 Methodology 3-59 3.3.2 Existing Conditions 3-59 3.3.2.1 Environmental Setting 3-59 3.3.2.2 Cultural Background 3-60 3.3.2.3 Recorded Sites 3-61 3.3.2.4 Paleontological Sites 3-61 3.3.3 Criteria for Determining Significance 3-61 3.3.4 Potential Impacts 3-62 3.3.4.1 Cultural Resources 3-62 3.3.4.2 Paleontological Resources 3-63 3.3.5 Required Mitigation Measures 3-63 3.3.5.1 Culmral Resources 3-63 3.3.5.2 Paleontological Resources 3-64 3.3.6 Significance of Impact After Mitigation and Rationale 3-64 3.4 Geology and Soils 3-65 3.4.1 Methodology 3-65 3.4.2 Existing Conditions 3-65 3.4.2.1 Soils 3-65 3.4.2.2 Groundwater 3-66 3.4.2.3 Faulting and Seismicity 3-67 3.4.3 Criteria for Significance 3-69 3.4.4 Potential Impacts 3-70 3.4.4.1 Soils 3-70 3.4.4.2 Groundwater 3-72 3.4.4.3 Geologic Hazards 3-73 DUDEK & ASSOCIATES, INC. February 2004 Prufariimil Tcinu forComplei PTO)«:II 2798-03 ToC-ir TABLE or CONTENTS mi Section Page No. 3.4.5 Required Mitigation Measures 3-73 - 3.4.5.1 Soils 3-73 «i 3.4.5.2 Groundwater 3-74 3.4.5.3 Geologic Hazards 3-74 3.4.6 Significance of Impact After Mitigation and Rationale 3-75 ^ 3.5 Hydrology and Water Quality 3-76 - 3.5.1 Methodology 3-76 M 3.5.2 Existing Conditions 3-76 3.5.2.1 Hydrology 3-76 ** 3.5.2.2 Floodplains 3-76 3.5.2.3 Surface Water 3-77 p, 3.5.2.4 Groundwater 3-77 ^ 3.5.2.5 Water Quality 3-77 3.5.2.6 Applicable Plans and Policies 3-79 ^ 3.5.3 Criteria for Determining Significance 3-80 ^ 3.5.4 Potential Impacts 3-81 ^ 3.5.4.1 Hydrology 3-81 3.5.4.2 Floodplains 3-8i ^ 3.5.4.3 Surface Water 3-82 - 3.5.4.4 Groundwater 3-82 «. 3.5.4.5 Water Quality 3-82 3.5.5 Required Mitigation Measures 3-83 3.5.6 Significance of Impact After Mitigation and Rationale 3-85 ^ 4.0 ALTERNATIVES 4-1 ^ 4.1 Purpose 4-1 4.2 Background 4-1 4.2.1 Design Concepts for Shoreline Protection and Access Road 4-2 4.2.1.1 Shoreline Protection Methods 4-2 4.2.1.2 Elevated Access Road Design 4-3 4.3 Analysis of Project Alternatives 4-3 4.3.1 No Project Alternative 4-3 4.3.2 Sand Replenishment Alternative 4-4 m 4.3.2.1 Aesthetics 4-4 4.3.2.2 Biology 4-4 ^' 4.3.2.3 Cultural 4-6 ^ 4.3.2.4 Geology/Soils 4-6 0, 4.3.2.5 Hydrology and Water Quality 4-6 4.3.3 Segmented Access Road Alternative 4-6 2798-03 m DUDEK & ASSOCIATES, INC. February 2004 ToC-iii PiT'fffr'"""' Ininu fm Ctmpla Prvftctt TABLE Of CONTENTS Section Page No. 4.3.3.1 Aesthetics 4-7 4.3.3.2 Biology 4-7 4.3.3.3 Cultural 4-7 4.3.3.4 Geology/Soils 4-9 4.3.3.5 Hydrology and Water Quality 4-9 4.3.4 Pump Station/Forcemain Altemative 4-9 4.3.4.1 Aesthetics 4-11 4.3.4.2 Biology 4-11 4.3.4.3 Cultural 4-11 4.3.4.4 Geology/Soils 4-11 4.3.4.5 Hydrology and Water Quality 4-12 5.0 GROWTH INDUCEMENT 5-1 6.0 CUMULATIVE IMPACTS 6-1 6.1 Purpose 6-1 6.2 Cumulative Forecasting Methodology 6-1 6.3 List of Related Projects 6-2 6.4 Impacts to Environmental Factors 6-5 6.4.1 Aesthetics 6-5 6.4.2 Biological Resources 6-5 6.4.3 Cultural Resources 6-6 6.4.4 Geology and Soils 6-6 6.4.5 Hydrology and Water Quality 6-7 7.0 EFFECTS FOUND NOT TO BE SIGNIFICANT 7-1 7.1 Purpose 7-1 7.2 Introduction 7-1 7.3 Agricultural Resources 7-1 7.4 Air Quality 7-1 7.5 Hazards and Hazardous Materials 7-2 7.6 Land Use and Planning 7-2 7.7 Mineral Resources 7-2 7.8 Noise 7-2 7.9 Population and Housing 7-3 7.10 Public Services 7-3 7.11 Recreation 7-3 7.12 Transportation/Traffic 7-3 7.13 Utilities and Service Systems 7-4 DUDEK & ASSOCIATES, INC. 2798-03 February 2004 ToC-iv TABLE or CONTENTS Section Page No. 8.0 REFERENCES 8-1 9.0 LIST OF PREPARERS 9-1 LIST OF FIGURES 2.1-1 Regional Map 2-2 2.1-2 Vicinity Map 2-3 2.1- 3 Photograph of Exposed Manhole No. 18 2-5 2.2- 1 Project Components 2-7 2.4-1 A Detailed Project Components - Western Portion 2-9 2.4-IB Detailed Project Components - Central Portion 2-10 2.4-lC Detailed Project Components - Eastern Portion 2-11 2.4-2 Access Road & Shoreline Protection Wall Section 2-13 2.4-3 Typical Proposed Shoreline Protection Wall 2-14 2.4-4 Agua Hedionda LCP Pedestrian Access Plan 2-18 3.1-1 Visual Simulation Key Map 3-2 3.1-2 Visual Simulation 1 3-4 3.1-3 Visual Simulation 2 3-6 3.1-4 Vista Points 3-8 3.1- 5 Photograph of Typical Crib Wall 3-10 3.2- lA Biological Resources Index Map 3-17 3.2-lB Biological Resources Legend 3-18 3.2-lC Biological Resources Map 3-19 3.2-lD Biological Resources Map 3-20 3.2-lE Biological Resources Map 3-21 3.2-2A Mitigation Site Map 3-54 3.2- 2B Mitigation Site Biological Resources Legend 3-55 3.4- 1 Seismic Fault Map 3-68 3.5- 1 100 Year Floodplain 3-77 4.3- 1 Access Road with Sand Replenishment Altemative 4-5 4.3-2 Segmented Access Road with Shoreline Protection Wall 4-8 4.3-3 Pump Station/Forcemain Altemative 4-10 6.3-1 Related Projects 6-3 IDUDEK & ASSOCIATES, INC. 2798-03 February 2004 ToC-v PrBfaskntal Team fat Cow^xx Ppojicu TABLE or CONTENTS '1 LIST OF TABLES Pag® No, 2.7-1 Summary of Project Design Features 2-21 3.2-1 Acreages of Habitat Types/Land Covers Occurring *" within Project Study Area 3-22 3.2-2 Sensitive Plant Species Detected or Potentially Occurring ^ On the Project Site ^'^^ 3.2-3 Sensitive Wildlife Species Detected or Potentially Occurring in Project Area -^'^^ 3.2-4 Impacts to Vegetation Communities and Land Cover Types within Project Study Area 3-49 ^ 3.4-i Seismic Parameters for Active Faults 3-69 6.1-1 List of Related Projects ^'"^ APPENDICES (under separate cover) Appendix A Notice of Preparation and Response Letters «• Appendix B Biological Resources Technical Report prepared by Dudek, February 2004 m — Appendix C Cultural Resources Survey and Test Program ^ prepared by Gailegos & Associates, December 2003 Appendix D Preliminary Geotechnical Investigations Preferred Wall Altemative ^ prepared by Terra Costa, July 2003 m Appendix E Wave Uprush Study Prepared by Terra Costa, July 2003 MM DUDEK & ASSOCIATES, me. 2798-03 February 2004 ToC-vi EXECUTIVE SLMNARY S-l INTRODUCTION/BACKGROUND The City of Carlsbad (City) proposes to implement the North Agua Hedionda Interceptor (NAHI) Sewer Project. This Draft Program Environmental Impact Report (EIR) addresses the potential environmental consequences of the project. The City is responsible for the respective maintenance, operations, and management of sewer collection system within the city limits. The purpose for implementing the proposed project is to restore an access road and provide shoreline stabilization to avert further undermining and/or erosion, and to allow future routine sewer maintenance, cleaning, rehabilitation and emergency repairs of the NAHI, and to develop a portion of a regional trail consistent with the City General Plan and Agua Hedionda Local Coastal Program (LCP). Due to the multiple objectives of the project, the project includes six components. The City will be the Lead Agency in preparing this EIR in accordance with the Cahfomia Environmental Quahty Act of 1970 (CEQA) statutes (Cal. Pub. Res. Code, §§ 21000 et seq., as amended) and implementing State CEQA Guidelines (Cal Code Regs., Title 14, §§ 15000 et seq., 1998). S-2 PURPOSE AND SCOPE OF REPORT The purpose of this EIR is to assess and disclose potential impacts to the physical environment associated with constmction and operation of the proposed project. This document provides project-level information for consideration by decision-makers and the general pubHc. This EIR focuses on the five issue areas: Aesthetics; Biological Resources; Cultural and Paleantologic Resources; Geology and Soils; and Hydrology and Water Quality. Other issue areas, including Land Use, Public Services and Air Quality, are not evaluated in detail in Section 3.0 of this EIR and are addressed as required by CEQA in Section 7.0 (Effects Not Found to be Significant). Section 1.0 provides an introduction to the document. Section 2.0 describes the project in detail, including the project's objectives and characteristics. Section 3.0 provides the existing environmental setting, discussion of potential impacts and their significance, and proposed mitigation measures to avoid or reduce identified significant impacts. The mitigation measures will be incorporated into a Mifigation Monitoring and Reporting Program (MMRP) to be adopted by the City as conditions of approval for the project. Section 4.0 provides an analysis of 2798-03 DUDEK & ASSOCIATES, INC. February 2004 ES-1 IWculiMal Trami for ComplciProiKl! Executive Summary alternatives to the proposed project. Other considerations required by CEQA are discussed in Section 5.0 (Growth Inducement), Section 6.0 (Cumulafive Impacts), and Section 7.0 (Effects Found Not to Be Significant). Section 5.0 provides the references used in the preparafion of this document and Section 9.0 identifies the list of preparers. S-3 ENVIRONMENTAL PROCEDURES UNDER THE CALIFORNIA ENVIRONMENTAL QUALITY ACT This EIR has been prepared by the City in accordance with the requirements of CEQA and the State CEQA Guidelines, as amended. An EIR is an informational document that is designed to inform decision-makers, other responsible or interested agencies, and the general public of the potential environmental effects of a proposed project; to examine and implement methods of eliminating or reducing any potentially adverse impacts; and to consider alternatives to the project as proposed. While CEQA requires that major consideration be given to avoiding environmental damage, the lead agency(ies) must balance adverse environmental effects against other public objectives, including economic and social goals, in determining whether and in what manner a project should be approved. To identify key issues and concerns relevant to the scope of the EIR, the City encouraged participation in the environmental review process from public agencies, special interest groups, and the general public. A major component of this process is public scoping. Scoping is a process designed to determine the breadth of issues to be addressed in the EIR. The aspects of the public scoping discussed in this secfion include the Nofice of Preparation (NOP) and areas of controversy identified as a result of public scoping. Notice of Preparation The State CEQA Guidelines include requirements for an early and open process to determine the scope of issues that should be addressed prior to implementafion of a proposed action (State CEQA Guidelines, §§ 15082 and 15083). The City inifiated the scoping process on May 12, 2003 through issuance of an NOP that included distribufion to the State Clearinghouse (SCH) at the California Office of Planning and Research, resource agencies, and local property owners. The SCH monitors compliance of state agencies in providing timely responses and assigned state idenfificafion number (SCH # 2003051076) to this EIR. The NOP is included in Appendix A. The NOP provided notification to all federal, state, and local agencies involved with funding or approval of the project, and to other interested organizations and members of the public, that an EIR will be prepared for this project. The NOP was intended to encourage interagency communication concerning the proposed action and provide sufficient background informafion 2798-03 February 2004 ^^"2 Pn^eutDnat Tciunj /or Comftrx ProjicU Executive Summary about the proposed action so that agencies, organizations, and individuals could respond with specific comments and questions on the scope and content of the EIR. The City held a 45-day public review period to solich comments on the NOP, beginning on May 12 and ending on June 26, 2003. Appendix A contains the four comment letters received in response to the NOP. S-4 AREAS OF KNOWN CONTROVERSY Commentors on the NOP expressed concerns about potential impacts to aesthetics, biological, archaeological, and hydrology/water quality resources. These concerns have been identified as areas of known controversy. S-5 PROJECT OBJECTIVES The City of Carlsbad is responsible for providing adequate and efficient wastewater conveyance for its service area. To that end, the City has identified the following objectives for the project: Protect the sewer pipeline from future failure, collapse, or leakage resulting from shoreline erosion; • Establish access to conduct regular maintenance; • Provide reliable sewer service to existing and planned development; Avoid impacts to biological resources to the maximum extent practicable during construction and future maintenance and operation activities; • Preserve lagoon aesthetics; and • Develop a trail consistent with the Agua Hedionda LCP and City General Plan. S-6 PROJECT LOCATION NAHI is a 24-inch diameter vitrified clay pipe gravity sewer, constructed by the City in 1965, along the north shore of Agua Hedionda Lagoon (Figures 2.1-1 and 2.1-2). Agua Hedionda Lagoon is a tidal, saltwater lagoon owned by San Diego Gas & Electric (SDG&E). The NAHI sewer pipeline mns west from the intersection of El Camino Real and Cannon Road, across Agua Hedionda Creek, along the north shore of Agua Hedionda Lagoon to an existing pump station (Foxes Lift Station) immediately east of Interstate 5 (1-5). The pump station conveys wastewater in a pipeline under 1-5 and the NAHI sewer flows westeriy an additional 2,000 feet, approximately, to its termination into a larger interceptor paralleling the railroad right-of-way. The western segment of the NAHI sewer pipeline, as defined for this project, includes the portion extending from manhole number 25, located at Cove Drive, westward to the Foxes lift station and the pipeline segment is approximately 3,800 linear feet in length. 2798-03 TOD1,JK k ASSOCIATES, INC. February 2004 ^^"^ nt Trmns fur Csml^ fVntfrti Executive Summary S-7 PROJECT CHARACTERISTICS The proposed project consists of six components: (1) re-establishment of the sewer maintenance access road; (2) construction of a shoreline protection wall, (3) sewer pipeline improvements; (4) rehabilitation of existing manholes; (5) future maintenance and operation activities for the sewer pipeline facilities; (6) development of a trail. Each component was developed with consideration of project objectives including minimization of impacts to sensitive resources within the existing environment. S-8 AFFECTED ENVIRONMENT The environmental setting for the proposed NAHI project is within a localized area surrounding Agua Hedionda Lagoon. Analysis of biological and hydro logical/water quality resources which extended to the Agua Hedionda watershed within the City of Carlsbad, visual resources from Interstate 5 and public roads adjacent to the north shore of the lagoon, and geology/soils and cultural were analyzed in the area surrounding the lagoon. The environmental setting for each issue area is discussed in more detail in Section 3.(9 of this document. S-9 ENVIRONMENTAL IMPACTS AND CUMULATIVE IMPACTS The analysis of each environmental issue area in Section 3.0 includes a description of the existing conditions within the project study area; the criteria for determining significance; an evaluation of how the specific resources would be affected by implementation of the proposed project; mitigation measures to reduce significant impacts; and residual impacts after mitigation. The study area lies within the City of Carisbad. Refer to figure 2.1-2 for a vicinity map. The evaluation in Section 3.0 is organized generally by the category of environmental affect anticipated by a certain project component. Summary of Impacts and Mitigation Table S-l present potential environmental impacts and mitigation, as applicable, for all components of the proposed project. DUDEK & ASSOCIATES, INC. 2798-03 February 2004 ES-4 Proiasitmul TKBIU for Compla: Pioficli Executive Summary TABLE S-l SUMMARY OF IMPACTS AND MITIGATION IMPACTS NOT FOUND TO BE IMPACTS FOUND TO BE RESOURCE SIGNIFICANT SIGNIFICANT MITIGATION MEASURES Aesthetics • Short-term Construction • Crib walls • Seeding crib walls with • Extension of Hoover native plant species • Access roac! • Shoreline protection wall • Maintenance & operation activities • Consistency with General Plan & LCP • Biology • Permanent loss of non-sensitive • Permanent loss of wetlands • Creation of wetlands vegetation types • Permanent loss of CSS within Agua Hedionda • Temporary loss of non-sensitive • Temporary loss of wetlands lagoon at a 4:1 vegetation types • Temporary loss of CSS replacement ratio • Direct impacts of maintenance Si • Permanent & temporary loss • Creation of at least 1:1 operations of hafiitat and impact of ratio ot CSS within Agua • Direct impacts to sensitive plants individual CAGN Hedionda lagoon and either • Direct loss of habitat & impact of • Short-term indirect impacts creation or preservation of individual salt marsh skipper on adjacent sensitive CSS for at an additional • Impacts to habitat vegetation & wildlife 1:1 ratio (total 2:1 linkage/wildlife corridor • Long-term indirect impacts on replacement ratio). • Short- and long-term indirect adjacent sensitive vegetation • Revegfitation of temporary impacts on sensitive plant S wildlife impact areas. species • CSS creation and/or preservation, revegelation of temporary impacts, avoidance of vegetation clearing during the breeding season • Implementation of BMPs, SWPPP, temporary fencing, avoidance of CAGN breeding season construction or reduction of noise to below 6D dBA at CAGI\I nest locations, biological monitor, monthly reporting • City maintenance training program, trail monitoring and management, planting of crib walls, compliance with JURMP • Cultural & • Direct impacts to CA-SDl-13701 • Potential impacts to Native • Implementation of pre- Paleontologic • Maintenance and operations American cultural sites excavation agreement activities • Potential impacts to buried between City and the San paleontological resources Luis Rey Band ot Mission & ASSOCIATES. INC. February 2004 2798-03 ES-5 Executive Summary TABLE S-l (Continued) IMPACTS NOT FOUND TO BE ' .- IMPACTS FOUND TO BE RESOURCE SIGNIFICANT SIGNIFICANT MITIGATION MEASURES Indians to allow monitoring • Monitoring of construction fay a [[ualified paleontologist • Geology & Soils • Long-term soil erosion hazards • Placement of walls on • Grading to be observed by • Lcng-term interruption of erosion unstable soils geotechnical engineer, as a sediment transport system • Excavation of unstable soils soils to be excavated to on lagoon shoreline and trenching within unstable competent or formational • Slope instability due to soils soils and benched and groundwater • Stockpiling of loose soil compacted to a minimum • Landslide hazard • Long-term sedimentation into 90%, all trenching shall lagoon via storm runoff comply with GSHA and • Erosion and sedimentation CALOSHA requirements. from temporarily disturbed excavated areas shall be areas shored, sloped back, or • Groundwater or surface stabilized with trench water seepage during shields construction • Dewatering systems shall • Liquefaction resulting in be used during excavation ground settlement of trenches, sheet pile cut- off wall or cofferdams shall also he used during high tides « Liquefiable soils around sewer pipeline to be displaced and compacted/cemented • See conditions under hydrology and water quality • Hydrology & Water • Alteration of existing drainage • Introduction of sediments to • Stockpile soils and Duality patterns lagoon during construction materials to cause minimal • Impediment or redirection of 100-• Degradation of groundwater interference with onsite year flow guality during dewatering drainage patterns. • Impacts on beneficial uses of • Long-term sedimentation from • Use of drainage control Agua Hedionda lagoon runoff devices along toes of • Depletion of groundwater from • Erosion and sedimentation slopes dewatering activities from temporarily disturbed • Dse of silt curtain or other • Groundwater recharge areas device around construction • Alteration of existing sediment • Potential hazardous materials areas transport system on lagoon spill within staging areas • Dewatering to be shoreline conducted in accordance with RWOCB standards & ASSOCIATES, INC. 2798-03 February 2004 ES-6 ol Trami for Compiri Proji. Executive Summary TABLE S-1 (Continued) RESOURCE IMPACTS NOT FOUND TD BE SIGNIFICANT IMPACTS FOUND TO SIGNIFICANT MITIGATION MEASURES City to obtain a NPDES General Storm Water permit City to prepare and implement SWPPP City to comply with JURMP including proper engineering of drainage control devices Installation of silt fences along toe of temporarily disturbed slopes All staging to occur on existing access roads or designated staging areas, ail equipment frequently checked for leaks. All project related spills of hazardous materials shall be reported to appropriate entities LIST OF ACRONYMS BMP - Best Management Practices CAGN - California gnatcetcher CALOSHA - California Occupational Safety and Health Administration CSS - Coastal Sage Scrub JURMP - Jurisdictional Urban Runoff Management Plan LCP - Local Coastal Program NPDES - National Pollution Discharge Elimination System OSHA - Occupational Safety and Health Administration RWQCB- Regional Water Quality Control Board SWPPP - Storm Water Pollution Prevention Program S-10 OTHER CONSIDERATIONS REQUIRED BY CEQA Significant Environmental Effects Which Cannot be Avoided if the Proposed Project is Implemented The RIT< evaluated the proposed project with respect to Aesthetics; Biological Resources; Cultural Resources; Geology and Soils; Hydrology and Water Quality. As described in Section 3.0, potentially significant impacts would occur for each of these issue areas. As discussed in Section 3.0, mitigation measures would reduce impacts for all of these CEQA issue areas. With mitigation, the residual impact is less (han signillcant for all issue areas. & ASSOCIATES', "SL 2798-03 February 2004 ES-7 Pruf, r Irams fr.rComJilr, Ptpjcclj, Executive Summary Significant Irreversible Environmental Changes Which Would be Caused by the Proposed Project Should it be Implemented The proposed project, once constructed, would be considered permanent. The project would support existing and planned growth within the City service areas. Where impacts are significant as defined by CEQA and the City, this EIR includes a process to identify and mitigate such impacts. Having said this, impacts such as changes in the visual appearance of a setting or hillside due to re-establishment of the access road, for example, would be considered an irreversible change. Construction of all project components would be carried out according to all applicable engineering standards to reduce, as much as possible, accidents related to offsite runoff during or post-construction. It should be noted that accidents from both human and naturally caused situations can compromise the integrity of best management practice mitigation measures. For example, a severe storm of unprecedented level could impact the area; precautions included in the project to prevent damage from occurring as a resuh of this type of severe event may be compromised. Depending on the type of disaster and the resources impacted, significant irreversible environmental commitments of resources may occur. However, there will likely be mitigation programs, which can partially mitigate for large, unforeseen disasters. Following engineering standards set out in the project description is the best defense against an unforeseen event and therefore an unforeseen commitment of resources. Construction of sewer facilities involves the relatively permanent consumption of building materials such as pipeline components, surfacing for the road, and energy for digging and earthmoving tasks. These resources, although at some extent in the long-term may be recycled, are considered to be permanently consumed. This type of commitment of resources is neither unusual nor unexpected given the nature of the facilities and is generally understood to be the tradeoff for benefits the system provides to the community. Growth Inducing Impact of the Proposed Project Induced growth is that which exceeds the planned growth and results from new developments that would not have taken place in absence of the project. Growth inducement impacts can result in accelerated economic or population growth, or the construction of new housing, that either directly or indirectly resulted from building a project. Section 15126.2(d) of the CEQA Guidelines requires that EIRs discuss whether a proposed project could: DUDEK & ASSOCIATES, INC. 2798-03 February 2004 ES-8 PrnftinonJ Trami for Coinblei ProHrts Executive Summary ""...foster economic or population growth, or the construction of additional housing, either directly or indirectly, in the surrounding environment. Included in this are projects which would remove obstacles to population growth (a major expansion of a waste water treatment plant might, for example, allow for more construction in service areas). Increases in the population may tax existing community service facilities, requiring construction of new facilities that could cause significant environmental effects. Also (the environmental analysis must) discuss the characteristics of some projects which may encourage and facilitate other activities that could significantly affect the environment, either individually or cumulatively. It must not be assumed that growth in any area is necessarily beneficial, detrimental, or of little significance to the environment."" The proposed project is not considered to be growth inducing for several reasons including that the capacity of the NAHI sewer within the project is not proposed to be increased. Additional, no features of the proposed project would provide wastewater collection service in a manner that would make lands available for development that are not currently available. Effects Not Found to be Significant The CEQA Guidelines (§§ 15128) require that the environmental document include a brief discussion of various environmental issues that were determined not to be significant. This EIR addressed all probable or foreseeable possible effects of the proposed project. Based on the Initial Study and NOP, effects were not found to be significant for the following issue areas: Agricultural Resources, Air Quality, Hazards and Hazardous Materials, Land Use and Plarming, Mineral Resources, Noise, Population and Housing, Public Services, Recreation, Transportation/Traffic, and Utilities and Service Systems. Based on the public scoping process for this, these issue areas were not considered to be areas of controversy and therefore were not addressed in Section 3.0 of the EIR. An evaluation of these issue areas is provided in Section 7.0. S-n ALTERNATIVES Four alternatives to the proposed project are described in Section 4.0 of the EIR and summarized below. Each of the alternatives was evaluated based on the project objectives and reduction or elimination of significant adverse effects on the environment compared with the proposed project. Various design concepts for the shoreline protection and access road components of the project were considered in the course of project design. These designs differ from the proposed project in terms of construction methodology, structural integrity, and size of overall development footprint; however, none were found to reduce or eliminate any significant adverse effects of the proposed project. These design alternatives are discussed in Section 4.2. The 2798-03 & ASSOCIATES, INC. February 2004 ES-9 Pnftaicmii Tatmi firr CtrmfAa Pinjicti Executive Summary alternatives fully evaluated in Section 4.3 include the no project alternative, sand replenishment alternative, segmented access road alternative, and pump station/forcemain alternative. Each of these alternatives is described below. No Project Alternative The No Project Alternative would consist of continued use of the existing NAHI. No direct impacts to aesthetics, biological resources, cultural resources, geology/soils and water quality would occur. City public works staff would attempt to conduct maintenance to the manholes that are accessible; however, due to the inability to reach various portions of the sewer alignment with maintenance vehicles and equipment, a number of manholes would not be maintained. The NAHI sewer would continue to be subject to wave action and shoreline erosion, as shoreline protection would not occur with this altemative. The No Project Altemative would not fulfill any of the project objectives as described in Section 2.3. Sand Replenishment Alternative This altemative involves the re-establishment of an access road identical to the proposed project. The entire sewer alignment and associated manholes would be accessible for ongoing maintenance and operation activities. The access road and sewer would be protected from shoreline erosion through placement of sand on the lagoon side of the road. A 2:1 slope would be created and ongoing sand replenishment activity would be required as the placed sand gradually erodes into the lagoon. The City considered sand replenishment as a means of shoreline protection in order to avoid the visual impacts that are typically associated with permanent stmctures, like a sea wall. However, maintenance efforts would be greater with the sand replenishment alternative, as the sand would need to be continually replenished. In addhion, greater wetlands impacts would be incurred due to the placement of sand in areas currently supporting wetlands habitats. Segmented Access Road Alternative Under this alternative, the City would construct a total of four perpendicular spur roads from Adams Street to conduct maintenance on the manholes and sewer pipeline. Each spur road would be a 12-foot wide paved road with a turnaround area at each terminus. Temporary impacts resulting from cut/fill slopes would occur but cannot be identified without detail engineering design. The City considered this type of access road design in order to reduce the lineal feet of road required to maintain the NAHI and to shift the road away from the lagoon shoreline. This altemative would provide City maintenance crews with direct access to 15 of 20 existing/new manholes, which would allow cleaning of the entire sewer alignment. The five manholes, which would not be directly accessible, would require one-time temporary access for mm 2798-03 & ASSOCIATES, INC. February 2004 ES-10 P^riinrtiJ Ihomi lor CinnllJtl PraltcU Executive Summary rehabilitation but would not be further maintained. The City would also need to construct a cast- in-drilled-hole (CIDH) pier wail similar to the one identified for the proposed project, as a means of shoreline protection. This alternative would result in increased impacts to aesthetic, sensitive upland biological resources, and water quality, but decrease impacts to sensitive wetlands biological resources. Pump Station/Forcemain Alternative The NAHI is a gravity sewer pipeline and is located at a lower elevation than its surrounding service area. It would be possible to avoid conveying sewage through the portion of NAHI within the project study area by pumping and conveying sewage flows through an altemative route. A pump station, forcemain, and numerous individual residential pumps would be required and these facilities could be constructed in roadways or other developed or disturbed areas. The locations for both the pump station and forcemain tie-in are based on existing land uses and the absence of sensitive biological resources. For purposes of this analysis, it was presumed that a pump station would be located at Cove Drive and the forcemain tie-in would occur at Hoover Street near manhole number 10. Other pump station and forcemain tie-in locations may be available, yet all locations would result in a similar set of environmental impacts and therefore only one scenario is analyzed. A portion of the existing gravity sewer would be retained and require ongoing maintenance; however, this portion would be small and the majority of the gravity sewer alignment, including all portions subject to severe shoreline erosion, would be abandoned. Abandonment would require repair of existing corroded manholes and sealing of the sewer pipeline. These activities would require one-time temporary access of the various manholes on the gravity sewer alignment. This alternative would generally avoid impacts to sensitive biological and cultural resources; however, other impacts associated with this alternative that were not previously identified for the proposed project may occur, including air quality, hazardous waste, land use, and noise. Long- term air quality impacts are anticipated due to the greater consumption of energy required to pump sewage and for the burning of diesel fuel to power emergency generators during a power loss. The transport and storage of chemicals and other hazardous materials, which pose a risk to human health, would occur under this altemative. Additional acquisition of rights-of-way solely for the pump station facility would be required and land uses adjacent to the pump station may be affected. Greater noise impacts would also be anticipated with this altemative as a result of the operation of the pumps. While none of these impacts would be considered significant and unmitigable, they do represent an overall increase in environmental impacts when compared to the proposed project. 2798-03 & ASSOCIATES, INC. | February 2004 ES-11 Prnf^iniMjiTTrami forCDAbJa Froitcts SECTION 1.0 INTRODUCTION 1.1 PURPOSE OF THE ENVIRONMENTAL IMPACT REPORT This Environmental Impact Report (EIR) has been prepared to evaluate the potential environmental effects of the City of Carisbad's (City) proposed North Agua Hedionda Interceptor Project. This EIR was prepared in accordance with the criteria, standards, and procedures of the California Environmental Quality Act (CEQA) of 1970 and the State CEQA guidelines. Studies conducted for this EIR have been carried out in accordance with the criteria, standards, and procedures of the CEQA (Public Resources Code Sections 21000 et seq.) and the State CEQA Guidelines (California Administration Code Sections 15000 et seq.). This EIR is intended to inform decision-makers, other responsible or interested agencies, and the general public of the potential environmental effects of the proposed project. The EIR will enable governmental agencies and the public to evaluate the proposed project in terms of its environmental consequences, to examine and implement methods of eliminating or reducing any adverse impacts, and to consider project altematives. In arriving at a decision whether to proceed with the proposed project or an altemative to the project, the City will consider the potential environmental impacts and altematives discussed in the EIR, as well as engineering, operation, cost, and public input issues. 1.2 EIR FOCUS AND SCOPING OF ISSUES Based on an Initial Study, prepared in accordance with CEQA Guidelines, the City of Carlsbad determined that an EIR is required to more fully investigate project effects to aesthetics, biological resources, cultural resources, geology and soils, hydrology and water quality. To further identify key issues and concems relevant to the scope of the EIR, the City contacted affected agencies, organizations and persons who may have an interest in this project. Subsequently, a Notice of Preparation (NOP) was circulated on May 12, 2003 and a pubhc scoping meeting was held on May 22, 2003. The NOP, which included an initial study/environmental checklist, and distribution list and responses to the NOP are found in Appendix A of this EIR. The areas of concem identified through the NOP process are analyzed in the appropriate sections of the EIR. 2798-03 February 2004 1-t 1,0 introdudion 1.3 CONTENT AND FORMAT OF THE EIR This EIR follows the most recent guidelines and amendments to CEQA and includes the following: Executive Summary. The Executive Summary provides a summary of the proposed project, anticipated project impacts and proposed mitigation measures. Section 1.0 Introduction. This section provides an Introduction and procedural overview of the EIR. Section 2.0 Project Description. This secfion provides a detailed description of the North Agua Hedionda Interceptor Sewer Project evaluated in this EIR. The Project Description also includes project purpose, objectives, locafion, characteristics, construction, operation and maintenance. Section 3.0 Environmental Analysis. The Environmental Analysis section examines project effects to aesthetics, biological resources, cultural resources, geology/soils, and hydrology/water quality. The environmental analysis provided in Section 3.0 of this EIR follows a step-by-step format where each environmental issue is addressed separately. For each issue, there is a discussion of methodology, existing conditions, criteria for determining significance, impacts analysis, mitigation measures, and summary of significant impacts. A Mitigation and Monitoring Reporting Plan (MMRP) will be compiled after public review to disclose and operationalize the project's mhigafion measures. The impact analysis section begins with identified significance threshold(s) based on the CEQA Guidelines and are used to judge whether an impact is significant or not. The following terminology is used to denote the significance of environmental impacts of the proposed project: Sign/ficont Impact - A substantial, or potentially substantial, adverse change in any of the physical conditions within the area affected by the project; less Thon Significant Impact - The proposed project may represent an adverse change in physical conditions in the area affected by the project, however, either: the effect is neither substantial nor potentially substantial; or the incorporation of mitigation measures, changes to the proposed project design, or methods of operation would cleariy reduce the effects to level less than significant; & ASSOCIATES, INC. 2798-03 February 2004 ^'^ 1.0 Introduction No Impact - The proposed project, or the existing physical conditions within the area affected by the project, would not be negatively affected by the project's implementation. Section 4 0 Alternatives. This section provides an analysis of alternatives to the Proposed Project including a Sand Replenishment Alternative, Segmented Access Road AltemJtive, Pump Station and Forcemain Altemative and the No Project Alternative. Section 5.0 Grovrth Inducement. This section provides a discussion regarding the potential of the proposed project to induce growth. Section 6 0 Cumulative Impacts This section provides a discussion regarding cumulative impacts resulting from the combined effect of past, present and reasonably foreseeable future projects that are located in proximity to the proposed project. Section 7 0 Effects Found Not to be Significant. This section addresses any potential enviromnentai effects that were determined not to be significant during the imUal project scoping and, therefore, were not discussed in detail in the EIR. APPENDICES. Appendices to this EIR include: Appendix A Appendix B Appendix C Appendix D: Appendix E: Notice of Preparation Biological Resources Technical Report Cultural Resources - Background Study for the North Agua Hedionda Interceptor Sewer Maintenance Access Road Project Preliminary Geotechnical Investigation Prefeired Wall Altemative North Agua Hedionda Interceptor Access Road & Shoreline Protection Wave Study North Agua Hedionda Interceptor Access Road & Shoreline Protection 1.4 EIR REVIEW PROCESS The City has filed a Notice of Completion (NOC) of the Draft EIR with the Governor's Office of ^L?g and Research. Concurrently, a notice of availability of the Draft PEIR has been published wtth distribution of this document. A 45-day public revrew penod has been established for the Draft EIR. When reviewing the EIR, affected public agencies and the interested public should focus on the sufficiency of the document in identifying and analyzing the possible .nr.pacts on the envnomnent and ways in wh.ch the significant effects of the project are proposed to be avoided or mitigated. 2798-03 1.0 Introduction Following the close of the public comment period, responses to comments on the Draft EIR will be prepared and, together with the Draft EIR, will constitute the Fmal EIR. A Mitigation Monitoring 'and Reporting Program and CEQA Findings of Facts ^t—t of OverrM^^^^^ Considerations, if required, will also be prepared m conjunction with the Final EIR. Those documents will be considered by the City Planning Commission in their deliberations regarding the proposed project. Written comments on the EIR should be sent to the following address. Comments should address the accuracy and sufficiency of the EIR. City of Carlsbad 1635 Faraday Avenue Carlsbad, CA 92008 Attn: Elaine Blackburn 1.5 DECISIONS TO BE MADE AND PERMITS REQUIRED The City of Carlsbad is the Lead Agency for the preparation of the EIR. The Carlsbad Ci y Plamiing Commission will consider the Fmal EIR at a public meeting and determine whether to Z7fy fhe document as being complete and in compliance with CEQA. THe City Planning Commission must consider the EIR prior to taking actions related to the project. n the Commission's review of the project, environmental considerations, economic and social factors will be weighed to determine the most appropriate course of action, which may include: (1) Approve the proposed project as described below; (2) Approve an alternative with specific constraints and mitigation measures; or (3) Deny the project. In addition to City of Carlsbad approval, this EIR is intended to be used by responsible and trustee agencies that may have review authority over the project. The City of Carlsbad will obtain all permits as required by law. The followmg federal, state and local permits or approvals are expected to be required for the North Agua Hedionda Interceptor project. California Coastal Commission - Issuance of a Coastal Development Permit; 2798-03 OTMS 1& ASSOCIATES, INC. February 2004 Introduction California Department of Fish and Game - Review in accordance with the state End^gered Species Act and issuance of a Section 1603 Streambed Alteration Agreement pursuant to Section 1603 of the California Fish and Game Code; City of Carlsbad - Issuance of a Special Use Permit for construction within the 100-year flood zone; Regional Water Quality Control Board - Issuance of a Water Quality Certification pursuant to Section 401 of the fedenil Clean Water Act, General Construction Activity Stormwater Permit, National Pollution Discharge Elimination System Permit; United States Army Corps of Engineers - Issuance of an Individual Permit pursuant to Section 404 of the federal Clean Water Act; and United States Fish and Wildlife Service - Consuhation under Section 7of the federal LtiXcies Act and issuance of a Biological Opinion or issuance of take authorization under Section 10a of the Endangered Species Act. 2798-03 ^DEK ^DEK February 2004 ^ASSOCIATES, INC. February 2004 m SECTION 2.0 PROJECT DESCRIPTION 2.1 PROJECT BACKGROUND The City of Carlsbad provides water, wastewater collection and recycled water to approximately 85 percent of its jurisdiction. As part of its wastewater collection services, the City of Carlsbad maintains approximately 145 miles of collection pipelines, 40 miles of sewer laterals, 16 pump stations and associated access roads. Currently, all of the wastewater from the City's conveyance facilities flows into the Encina Wastewater Treatment Facility located west of Interstate 5 south of Palomar Airport Road. A Sewer Master Plan Update has been prepared for the City to evaluate the wastewater collection needs for the planning period between 2002 and build-out of the City's service area as anticipated by the City of Carlsbad General Plan. The Sewer Master Plan Update identifies deficiencies in the existing system and recommends improvements to be implemented as part of the City's Capital Improvement Program (CIP). Based on the evaluation of the existing wastewater conveyance facilities, it was determined that the North Agua Hedionda Interceptor (NAHI) required maintenance and other remedial actions. NAHI is a 24-inch diameter vitrified clay pipe gravity sewer, constructed by the City in 1965, along the north shore of Agua Hedionda Lagoon (Figures 2.1-1 and 2.1-2). Agua Hedionda Lagoon is a tidal, saltwater lagoon owned by San Diego Gas & Electric (SDG&E). The NAHI sewer pipeline runs west from the intersection of EI Camino Real and Cannon Road, across Agua Hedionda Creek, along the north shore of Agua Hedionda Lagoon to an existing pump station (Foxes Lift Station) immediately east of Interstate 5 (1-5). The pump station conveys wastewater in a pipeline under 1-5 and the NAHI sewer flows westerly an additional 2,000 feet, approximately, to its termination into a larger interceptor paralleling the railroad right-of-way. The western segment of the NAHI sewer pipeline, as defined for this project, includes the portion extending fi"om manhole number 25, located at Cove Drive, westward to the Foxes Lift Station and the pipeline segment is approximately 3,800 linear feet in length. Although the 38-year old sewer pipeline is considered to be in good condition, the original unpaved sewer maintenance access road has deteriorated substantially due to wave, water and wind-driven erosion. The original construction of the western segment of the NAHI sewer included an unpaved access road extending from Hoover Street to the current location of Jose's Boat Launch, near Cove Drive, and rip-rap along the shoreline to protect the access road. Routine maintenance and inspection of the sewer pipeline and associated manholes are no longer possible due to the DUDEK & ASSOCIATES, INC. 2798-03 February 2004 2-1 Orange County San Diego Mexico r = 8 Miles Tifuana IM Hi North Agua Hedionda Sewer Western Segment EIR Regional Map FIGURE 2.1-1 BASE MAP SOURCE: USGS 7.5 Minute Series, San Luis Rey Quadrangle r =2000' Ml North Agua Hedionda Sewer Western Segment EIR Vicinity IVlap FIGURE 2.1-2 2.0 Project Description disappearance of portions of the original access road and rip-rap shoreline reinforcement. As seen on Figure 2.1-3, manholes are currently exposed to tidal fluctuations. Under an emergency condition {such as breach or blockage of the sewer), access to these portions of the sewer alignment would be substantially impaired. Access to several manholes has also been further precluded by the construction of a private volleyball court and driveway on top of the sewer alignment near Cove Drive. Other documents addressing NAHI include an inspection report prepared in October 2001, North Agua Hedionda Sewer Manhole Inspection (DUDEK 2001). This report identified a number of deteriorating manholes along the NAHI alignment, which require rehabilitation. All of the manholes inspected in the westem portion of the NAHI were considered to be in poor condition with deteriorated interior concrete walls, exposed aggregate, and/or filtration of groundwater and sediment. The pipeline has been found generally to be in good condition; however, limited accessibility to manholes has prevented the cleaning and inspection of portions of the pipeline. The original maintenance road has also served as an informal trail for use by the public to access the lagoon. Erosion of portions of the maintenance access road and overgrowth by vegetation have limited the use of the road as a walking trail. In 1982, the City of Carlsbad formally designated a trail to occur along the northern shoreline of Agua Hedionda Lagoon in its Land Use Plan for the Agua Hedionda Local Coastal Program (LCP) and its General Plan. As described in the LCP, the lagoon provides public recreational opportunities, including walking, hiking, wildlife viewing, boating and waterskiing (Carlsbad 1982). Policies contained in the LCP, which address shoreline access, state that both a bicycle and a pedestrian trail shall be developed along the northem shoreline of the lagoon. A small 700-foot segment of public trail, extending west from the terminus of Cove Drive, currently exists parallel with the sewer alignment, closer to the lagoon. The City's General Plan also identifies recreational opportunities at the lagoon and has designated Agua Hedionda as a Special Resource Area. These areas are defined as local amenities with unique passive and/or active recreational qualities. In general these Special Resource Areas are recreational sites characterized by the existence of a special or unusual feature, natural or manmade, i.e., a water body, earth formation, historical amenity, ecological reserve, etc. Consequently, these Special Resource Areas have a visitor attraction or drawing power to users locally and beyond (Carlsbad 1994). 2.2 INTRODUCTION AND PURPOSE OF THE PROJECT The westem portion of the NAHI provides wastewater conveyance for existing residential homes and commercial land uses located north and northwest of the lagoon. The sewer pipeline is operating at capacity and no increase in capacity is anticipated as part of this project. 2798-03 & ASSOCIATES, INC. February 2004 2-i t^rofeuional Teatns for Conjfiex Proiccli Exposed Manhole No. 18 at Agua Hedionda Lagoon North Agua Hedionda Sewer Western Segment EIR Photograph of Exposed IVIanhole No. 18 FIGURE 2.1-3 m 2.0 Project Description The purpose of this project .s to restore the access road and provide shoreline stabihzation to avert further undermintng and/or erosion, and to allow future routine sewer maintenance, cleaning rehabilitation and emergency repairs of the NAHI and to develop a portion of a regional trail consistent with the City General Plan and Agua Hedionda LCP. In order to provide and maintain access to the western segment of the NAHI sewer, the City proposes to re-establish 2,400 feet of access road from manhole number 8 to manhole number 19, construct a shoreline protection wall along 1,800 feet of the access road where erosion is most severe, and relocate approximately 300 feet of sewer pipeline that is inaccessible due to current land uses (Figure 2 2-1) Also as recommended m the 2001 inspection report, the City proposes to rehabilitate a number of manholes to avoid future failure, collapse and leakage of wastewater. Implementation of the proposed project would also serve the purpose of providing a trail as Identified m the Agua Hedionda LCP and City General Plan, along the northem shore of the lagoon The re-estabhshment of the access road would allow for continuous access along the shoreline of the lagoon for pedestrians and mountain bikers. The trail would generally follow the sewer easement from the cul-de-sac at Hoover Drive to manhole number 19 and include amenities such as interpretative signage, trash cans and pet waste disposal facilities. 2.3 PROJECT OBJECTIVES The City of Carlsbad is responsible for providing adequate and efficient wastewater conveyance for Its service area. To that end, the City has identified the following objectives for the project: Protect the sewer pipeline fi-om fUhire failure, collapse, or leakage resulting from shoreline erosion; Establish access to conduct regular maintenance; Provide reliable sewer service to existing and planned development- Avoid impacts to biological resources to the maximum extent practicable during construction and future maintenance and operation activities; • Preserve lagoon aesthetics; and Develop a trail consistent with the Agua Hedionda LCP and City General Plan. |& ASSOCIATES. INC. 2798-03 February 2004 2-6 L L L Sewer System A/ New Sewer Access Road //<>// Existing Paved Access Road /V Existing Public Trail A/ Shoreline Protection Wall Non-Improved Sewer Access Road BASE PHOTO SOURCE: AERIAL ACCESS LLC, JAN/MAR 2002 200 Scale in Feet North Agua Hedionda Sewer Western Segment EIR Project Components FIGURE 2.2-1 2.0 Project Description 2.4 DESCRIPTION OF THE PROJECT The proposed project consists of six components: (1) re-establishment of the sewer maintenance access road; (2) construction of a shoreline protection wall, (3) sewer pipeline improvements; (4) rehabilitation of existing manholes; (5) future maintenance and operation activities for the sewer pipeline facilities; (6) development of a portion of the regional trail system. Each of these components is further described below. Sewer Maintenance Access Road The proposed alignment for the sewer maintenance access road is the result of discussions with City staff and review of the existing biological conditions of the project site. The proposed access road alignment follows the centerline of the NAHI and also utilizes existing roads, where possible. The westem segment of the NAHI sewer pipeline is approximately 3,800 feet in length, of which 2,400 feet requires re-establishment of an access road. From manhole number 8 west toward Foxes Lift Station, an existing sewer access road will be used to access the sewer pipeline and associated manholes. The proposed access road alignment follows the centerline of the NAHI and extends from manhole number 8 east to new manhole number 1 (Figure 2.2-1). The access road would be generally 12 feet wide, the minimum width necessary for City maintenance vehicles, and constructed of decomposed granite with the exception of an approximately 150-foot section east of manhole number 19, where the alignment is currently paved (Jose's Boat Launch). From new manhole number 1 to manhole number 21, the maintenance access road diverges from the centerline of the sewer pipeline. This portion of the access road would be shifted approximately 70 feet south toward the lagoon to provide contiguous access between manholes {Figure 2.2-1). This portion of the access road would utilize the existing compacted sandy base and would not be constructed of decomposed granite. Crib walls are proposed in two areas to avoid large cut slopes and minimize impacts to coastal sage scrub (CSS). The location and the dimensions of the crib walls are illustrated on Figures 2.4-1 A through C. The westerly wall would be approximately 270 feet in length and will be a maximum of seven feet in height. The easterly crib wall will be approximately 292 feet in length and would be a maximum of 5 feet in height. DUDEK 2798-03 & ASSOCIATES, INC. February 2004 2-8 Pro/ewional Teams for Complex Projects North Agua Hedionda Sewer Western Segment EIR Project Components • Western Portion FIGURE 2.4-1 A I r I I I I i: I I D C I I I c AGUA HEDIONDA LAGOON DETAIL 1 ^ ^""^''^ / '^^^ PROPOSED 15* WIDE EXISTING SEWER / ^> TEMPORARY CONSTRUCTION EASEMENT /' \ ^^^Y PROPOSED 20' WIDE ^„^r.^o^r> /-- V ^SEWER EASEMENT PROPOSED ----~A-T_T ~_T_T ~ ~^^/ ~\ 12' WIDE \ D.G. -^r' ^ \ / EXISTING 15' WIDE ACCESS \ \ / SEWER EASEMENT ROAD / 7^ ' PROPOSED . ~ v;; CIDH WALL— \ '^^^Ov PROPOSED 5' WIDE \-—" ^--/^ TEMPORARY CONSTRUCTION EASEMENT SOURCE: DUDEK S ASSOCIATES, SEPT 2003 SHORELINE (+5.0 MSL) BASED ON 1965 AS-BUILTS OF 24" SEWER SHORELINE (+5.0 MSL) BASED ON 1998 SURVEY BY PHOTOGEODETIC CORP. EXISTING MANHOLE & SEWERLINE 80 Scale in Feet North Agua Hedionda Sewer Western Segment EIR Detailed Project Components - Central Portion FIGURE 2.4-1 B \ PROTECTION WALL PLAN SOURCE: DUDEK & ASSOCIATES, SEPT 2003 SHORELINE (+5.0 MSL) BASED ON 1965 AS-BUILTS OF 24" SEWER SHORELINE (+5.0 MSL) BASED ON 1998 SURVEY BY PHOTOGEODETIC CORP. EXISTING MANHOLE 8c SEWERLINE Scale in Feet North Agua Hedionda Sewer Western Segment EIR Detailed Project Components - Eastern Portion FIGURE 2.4-1 C 2.0 Project Description p" ... • The access road would have a 2% side slope towards the lagoon for positive drainage. A swale would be constructed at the junction of the shoreline protection wall and access road to transport •* surface water flow away from the road surface towards catch basins located at low point along the m road {Figure 2.4-2). The swale would be approximately 18 inches wide and be composed of ^ concrete colored to match the shoreline protection wall. A minimum of four culverts and three catch basins will be installed at low points along the alignment to collect and discharge runoff. The catch " basins will be approximately three feet by three feet in size. m ^ In addition to the 2,400 feet of decomposed granite access road, a 230-foot long paved approach road from Hoover Street is proposed. A gate would be constructed to preclude off-road vehicle use on the access road; however, pedestrians would be able to enter and hike along the road for recreation and to access scenic views of Agua Hedionda Lagoon. m Shoreline Protection Wall The proposed shoreline protection wall is designed to incorporate the surrounding visual — characteristics of Agua Hedionda Lagoon. The wall will include a sculpted face colored to simulate a natural bluff adjacent to the lagoon edge. The shoreline protection wall would extend approximately 1,800 feet from manhole numbers 10 to 19. Generally, the top of the shoreline protection wail would be approximately 0.5 to 1.0 foot above the manholes and access road. The height of the manholes in relation to the shoreline varies and therefore, the height of the wall, in ^ relation to the shoreline, would vary from no exposed wall to approximately six feet of exposed ^ sculpted wall (Figures 2.4-1 A through C). The shoreline protection wall is proposed at a constant offset from the centerline of the existing W sewer alignment and would be constructed with a drilled pier foundation (also referred to as a cast-in-drilled-hole [CIDH] pier wall or auger cast pile wall). The drilled pier foundation consists of 24-inch diameter, structurally-reinforced piers spaced on 6- to 8-foot centers, with the clear space between drilled piers in-filled with structural concrete {Figure 2.4-3). The foundation would extend m to the stable subsurface bedrock (approximately 5 to 30 feet below existing grade elevation). The face would extend approximately two feet above mean high tide elevation and an additional two feet below the existing grade elevation. Cable railing anchored into the shoreline protection wall is proposed where the height of the wall would exceed 30 inches from the shoreline. The cable railing would be constructed in compliance with Caltrans standards (3.5-foot tall, three-cable wire type). IM imii [& ASSOCIATES, INC. Profeui«uil Icomifor CoMpIci PrDfub 2798-03 February 2004 2-12 (-PROPOSED 2:1 SLOPE (MAX) CALTRANS CABLE RAIL (WHERE REQUIRED) 12' rl2'* MIN. AGGREGATE ROAD SECTION SWALE. COLOR ^- TO MATCH WALL FILL (WHERE REQUIRED) 2' ALLUVIUM/COLLUVIUM 1 A MEAN HWL (5.5) 4" MIN. CARVED/HAND- SCULPTURED FACE TRANSIENT BEACH SANDS PROPOSED DRILLED PIER WALL TOTAL LENGTH OF DRILLED PIER APPROX. 30' TYPICAL PROPOSED DRILLED PIER WALL - SECTION NOT TO SCALE SOURCE: TERRACOSTA CWiSULUNG GROUP Im North Agua Hedionda Sewer Western Segment EIR Access Road & Shoreline Protection Wall Section FIGURE 2.4-2 BUNDLED BARS TYP.. (V) I 6" TO 8' O.C. (TYP.) 24" DIA. (TYP.) NO. 5 O _ DRILL AND EPOXY INTO PIER NO. 5 © 12" EA. FACE 6" DIA. PVC SLEEVE NO. 5 © 8 EA. FACE NO. 5 © 12 DRILL AND EPOXY INTO PIER (TYP.) I'-C 4" MIN. CARVED/HANe'-SCULPTURED FACE Typical Proposed Shoreline Protection Wall - Plan View SCALE: r=5' SOURCE: TERRACOSTA CONSULTING GROUP North Agua Hedionda Sewer Western Segment EIR Typical Proposed Shoreline Protection Wall FIGURE 2.4-3 2.0 Project Description Sewer Pipeline Improvements Two portions of the sewer pipeline alignment potentially require relocation to allow permanent access without disrupting existing land uses. Manhole number 20 and approximately 70 feet of sewer pipeline are currently located within a private volleyball court, which was constructed on top of the existing sewer easement. Manhole number 20 would be abandoned and as a replacement, a new manhole (new manhole number 1, see Figure 2.4-IC) would be constructed outside of the private volleyball court. Realignment of the 70 feet of sewer and abandonment of manhole number 20 would allow regular maintenance without disruption of the existing land use. Between manhole numbers 22 and 24, two manholes and approximately 240 feet of sewer are within a private driveway, which has been constructed over the existing sewer easement. The City will construct a new sewer pipeline and two manholes (new manholes numbers 2 and 3) in this stretch to allow continued access from Cove Drive along the alignment. The City might also abandon two manholes and the existing sewer segment if it is determined in the design phase that lateral connections could be made to the new alignment Other improvements to NAHI include construction of two residential lateral connections that would provide sewer service to two residential lots planned for development west of manhole number 19 {Figure 2.4-lQ. Currently no connections are available within these existing lots. The lateral connections would be constructed entirely within the existing sewer easement ROW and tie into manhole number 19. All sewer line improvements will be implemented at the same time as the access road and shoreline protection wall construction. Rehabilitation of Manholes As recommended in the North Agua Hedionda Sewer Manhole Inspection Report (Dudek 2001^, a number of manholes would be rehabilitated by lining and structural concrete patching of deteriorating concrete. Conventional slip-lining techniques or in-situ epoxy grouting would be conducted to repair minor cracks in the sewer pipeline without excavation. These procedures would take approximately 30 days to complete and would be conducted after construction of the access road and shoreline protection wall. This repair work would extend the service life, of the existing sewer pipeline and help prevent future failure, collapse and leakage of wastewater from occurring. iDUDEK |& ASSOCIATES, INC. 2798-03 February 2004 2-15 2.0 Project Description Future Maintenance and Operation Activities The City of Carlsbad Public Works would perform routine maintenance on the sewer pipeline and associated manholes depicted on Figures 2.4-1 A through C. Manhole number 20, and potentially manholes 23 and 23A, would be abandoned as part of the proposed project and no future maintenance will be performed for these manholes. Routine maintenance by the City would require the use of a vacuum/water jet pump vehicle to clean accumulated debris from the sewer pipeline and manholes. The City currently uses a Vactor truck with a gross vehicle weight of 36,000 lbs. for this purpose. Other routine maintenance would include inspection of the access road, shoreline protection wall, cable railing and drainage swale. These tasks would also be performed by City of Carlsbad Public Works personnel on a quarterly (at maximum) or bi-annual basis and would consist of the following: Maintenance and Operation Activities Minor grading, including the addition of decomposed granite to renew the road grade to match existing manholes; Inspection of manholes and manhole covers; Removal of any graffiti conducted in accordance with the City's anti-graffiti program; Repair/replacement of cable railing; Removal of debris/trash from the swale; Manual weed removal along the access road; Cleaning of culverts and catch basins to remove debris and sediment; and Vacuum/jet cleaning of sewer pipeline with vactor truck. Due to the proximity of sensitive biological resources to the sewer alignment, the City has committed to maintaining and operating the NAHI in a manner that would avoid or minimize impacts during future activities. Guidelines for conducting maintenance and operation activities include the following: Maintenance and Operation Guidelines Maintenance would be scheduled outside the breeding season (March 1 through August 15) to avoid noise impacts to breeding wildlife occurring near project site. However, visual inspections of the manholes and seven pipeline may occur on a monthly basis throughout the year. DUDEK &ASSOaATES,INC. 2798-03 February 2004 2-16 2.0 Project Description Storage of any equipment or parking of any vehicles would be located within the City's sewer easement. Maintenance vehicles and equipment would not idle for more than 15 minutes when not in service. Any spills of hazardous materials would be reported to appropriate entities, including but not limited to the City, USFWS, CDFG, RWQCB. Such spills would be cleaned up immediately and contaminated soils removed offsite. Loose soils, debris, and trash would not be stockpiled along adjacent upland areas or within drainages or waterways. • Removal of exotic plant species would be removed from the site to the extent feasible. Weed removal would be performed manually. If herbicides are necessary, they would be applied by a licensed agent. Development of a Portion of the Regional Trail System The Agua Hedionda LCP and City General Plan identify a trail along the northem shore of Agua Hedionda, as shown on Figure 2.4-4, and re-establishment of the maintenance access road would implement a portion of this trail system. The maintenance access road, as proposed, is consistent with the design requirements of the trail described in the LCP. The 12-foot wide maintenance access road meets the minimum width for trails and access to the trail will be provided at Hoover Street. Trail amenities would include signage describing trail rules and regulations, trashcans and pet waste disposal facilities. All trail amenities would be located at cither end of the newly designated trail segment: at the end of the cul-de-sac at Hoover Street and near manhole number 19 {Figure 2.1-2). Typically, City trails would be designed to be compliant with the Americans with Disabilities Act (ADA), wherever possible (Carisbad 1999). The City's Trails Program contains guidelines for developing facilities that are readily accessible and usable by individuals with disabilities. Compliance with ADA may require amenities such as park benches, pop-out areas, and trail grades of less than five percent slope. In order to minimize significant impacts to known sensitive habitat and species located adjacent to the trail, the City has determined that constructing an ADA compliant trail is not practicable along the northem shore of the lagoon since the footprint of an ADA trail would be larger than what is currently proposed. The City has committed to providing the trail amenities mentioned above and would pursue outside funding for assistance in maintaining the trail. Trail easement designations are proposed where the City is acquiring a new sewer easement as part of this project. In general, the trail easement would be coincident with the access road where a shoreline protection wall is proposed from approximately manhole numbers 10 to 19 (Figure 2.4-4). Future trail easements would have to be acquired through conditions of approval for friture & ASSOCIATES, INC. 2798-03 February 2004 2-17 PnifeHwnaJ Ttams for Cont^fx Projccd 1 ti 11 fi »i Ml «i fi fi r 1 fi fi fi ti »i i« »• •« I I EXHIBIT J PEDESTRIAN ACCESS PLAN . MUOf i»H SOURCE: CITY OF CARLSBAD, LOCAL COASTAL PROGRAM, MAY 1982 North Agua Hedionda Sewer Western Segment EIR Agua Hedionda LCP Pedestrian Access Plan FIGURE 2.4-4 m m 2.0 Project Description development along the approximately 250-foot long section of shoreline east of the end of the shoreline protection wall, since no development is currently proposed. This fiiture trail easement would connect to the existing trail extending west from the end of Cove Drive {Figure 2.2-1). 2.5 PROJECT CONSTRUCTION Project consfruction is expected to last up to 180 days and would be conducted between August 16 and February 28 in order to avoid impacts to sensitive bird species. Under normal circumstances, work activities would not be conducted within the coastal zone during the rainy season; however, due to the seasonal restrictions associated with the sensitive bird species near the project corridor, this may not be possible. In the event that work would be conducted during the rainy season. Best Management Practices (BMPs) would be employed in accordance with the requirements of the Regional Water Quality Control Board (RWQCB) to ensure that soil erosion does not occur during construction. During construction, some grading of topsoil would occur landward of the access road in order to create 2:1 slopes designed to prevent erosion post-construction. Upon completion of the proposed project, the shoreline protection wall would strengthen the shoreline, reducing further erosion of the banks of the lagoon. Re-establishment of the maintenance access road, construction of the shoreline protection wall and relocation of pipeline may involve the use of the following equipment: cranes, excavators, front end loaders, delivery (dump) trucks, soil compactors, pumps for dewatering, desilting tanks and/or graders. The City would first remove existing vegetation along the project corridor, then excavate along the shoreline to install the shoreline protection wall. After backfilling behind the shoreline protection wall, the City would grade the roadbed, compact the soils and install the road surface aggregate. Sewer improvements, including relocation, construction of sewer laterals and new manhole installation, in the vicinity of the eastern project terminus would be accomplished via open trenching. To implement the proposed project, the City would need to acquire new utility access easements along portions of the sewer alignment where they currently do not exist. The City would notify all property owners, prior to commencement of work of the upcoming work schedule and to request that any vegetation or structures installed by the property owner within the City's easement be removed. 2.6 STAGING AREAS AND ACCESS A total of three staging areas is proposed as part of the project. They are approximately 50 feet by 50 feet in size and occur in developed or disturbed areas. The westernmost staging area is located IDUDEK & ASSOCIATES, INC. 2798-03 February 2004 2-19 TSofetiunaf Tmnu far Cvnipla Pri^nli 2.0 Project Description south of the Hoover Street terminus near manhole number 10. The other two staging areas are located north of manhole number 14 and manhole number 19 {Figure 2.4-lA through C). A temporary construction easement would be required to construct the proposed project. An additional 10 feet beyond the permanent impact area on the landward side and an additional 5 feet on the lagoon side is proposed for the temporary construction easement. Access to the project area from the west can be gained from Harrison and Hoover Streets. Access to the eastern portion of the project area can be gained from Cove Drive. 2.7 SUMMARY OF PROJECT DESIGN MEASURES A summary of the project design measures which have been incorporated into project to reduce potential environmental impacts is provided in Table 2.7-1. The table also provides the responsible entity and time period for compliance with the design feature. msm & ASSOCIATES, INC 2798-03 February 2004 2-20 2.0 Project Description TABLE 2.7-1 SUMMARY OF PROJECT DESIGN FEATURES llSTAF-MONITOR % CQMPUANCE ^ t DAXE OF kOMPLiANCE ^est/ist/cs AES-1: The sea wall will be sculpted and colored to simulate a natural bluff City Public Works and Planning Departments, Construction Contractor During construction \BiQlogicaJ Resources I BIO-1: Installation of two crib walls to reduce potential impact of large cut slopes. City Public Works and Planning Departments, Construction Contractor During construction BIO-2: The access road shall include a 2% side slope towards the lagoon. Where the seawall is proposed adjacent to the road, an 18-inch wide concrete drainage swale, colored to match the wall, shall be constructed lo direct runoff to catch basins. City Public Works and Planning Departments, Construction Contractor During construction ' B!0-3: A gate will be installed at the cul-de-sac at Hoover Street and will be maintained to prevent off-road vehicle use. City Public Works and Planning Departments, Construction Contractor During construction and following construction BiO-4: Conventional slip-lining techniques or in-situ epoxy grouting shall be used to repair/rehabilitate manholes without sewer pipeline excavation. City Public Works and Planning Departments, Construction Contractor During rehabilitation Cultural Resources ' CULT-1: Monitor shall he present during construction • A project archaeologist shall be retained and will attend pre-construction meetings with the construction manager and grading contractor. At this meeting, the project archaeologist will identify all areas to be monitored and be advised of the construction schedule, • The project archaeologist or hisi'her qualified monitor shall be present full-time during the grading or excavation of native soils and document the observations on a routine basis. City Public Works and Planning Departments, Project Archeologist During construction nil DEK & ASSOCIATES, INC. February 2004 o/cjjiond Tcjn-j /cr CompJu Pro if 2-21 2.0 Project Description TABLE 2.7-1 (Continued) JES GN" FEATURES STAFF MON.TGR ^;cdMPLiANCE - '-f DATEOF. 1 CQMPUANCE • In the event of a discovery, the archaeologist or archaeological monitor shall divert, direct, or temporarily halt ground-disturbing activities in the area of discovery to allow for preliminary evaluation of potentially significant archeological resources. • For significant resources, a research design and data recovery program shall be prepared by the project archaeologist and shall be carried out to mitigate impacts prior to resumption of ground disturbing activities in the area of discovery. • If human remains are encountered, the archaeologist shall act in accordance with the California Public Resources Code and the Slate Health and Safety Code. Established procedures are to be followed if the remains are determined to be Native American. • All recovered archaeological material collected is to be cleaned, catalogued and permanently curated at an appropriate institution. All artifacts and all faunal material shall be analyzed. A final report is to be produced within a specified time of project completion. • All sites shall be recorded at the South Coastal Information Center at San Diego State University. 1 i Other Project Design Features OTHER-1: Cable railing shall be constructed where the height of the sea wall exceeds 30 inches above the shoreline. Cable railing shall be constructed in compliance with Caltran's standards (3.5-fool tall, three-cable wire type), City Public Works and Planning Departments, Construction Contractor During construction OTHER-2: Implementation of Maintenance and Operation Guidelines: • Maintenance shall be scheduled outside the breeding season (March 1 through August 15) to avoid noise impacts to breeding wildlife occurring near project site. However, visual inspections of the manholes and the pipeline may occur on a monthly basis throughout the year. • Storage of any equipment or parking ot any vehicles shall be located within the City's sewer easement. • Maintenance vehicles and equipment shall not idle for more than 15 minutes when not in service. • Any spills of hazardous materials shall be reported to appropriate entities, including but not limited to the City, USFWS, CDFG, RWQCB. Such spills shall be cleaned up immediately and contaminated soils removed offsite. City Public Works and Planning Departments, Following construction DUDEK Si ASSOCIATES, INC. February 2004 2-22 2.0 Project Description TABLE 2.7-1 (Continued) V JES'GN-E;TURES -V! -'STAFi MONITOR COMPLIANCE ' COMPLIANCE • loose soils, debris, and trash shall not be stockpiled along adjacent upland areas or within drainages or waterways, • Exotic plant species shall be removed from the site to the extent feasible. • Weed removal shall he performed manually. If herbicides are necessary, they shall be applied by a licensed agent. OTHER-3: Trail signage, describing trail rules and regulations, trashcans and pet waste disposal facilities shall be installed at both ends of the designated trail segment (/>., the cul-de-sac at Hoover Street and near manhole 19), City Public Works and Planning Departments, Following construction •&ASSOCIATES, INC. February 2004 2-23 P™/fiiloTiai Tfcmi tor Comfilti Prii|t;li SECTION 3.0 ENVIRONMENTAL ANALYSIS This section contains the impact analyses for resources that were identified as having potentially significant environmental impacts in the Initial Study prepared for the proposed project. The following resources are addressed in this section; Aesthetics Biology Resources Cultural Resources Geology and Soils Hydrology and Water Quality Each resource discussion includes a description of the methodology, environmental setting, ^ criteria for detennining significance, potential impacts, required mitigation measures, and significance of impact after mitigation and rationale. 3.1 AESTHETICS This section focuses on the components of the project, which may produce visual impacts or ^ affect visual character upon implementation. A brief description of visual resources is given ^ followed by the visual impact analysis. " 3.1.1 Methodology mm Ml The proposed project was analyzed for visual quality and aesthetic impacts through a ^ combination of field visits, review of existing land uses, review of apphcable land use plans, and examination of computerized visual simulations. Existing visual characteristics were described • from a regional setting and several site-specific viewpoints that were visible from a public • vantage point such as a roadway, pubUc look-out or recreational trail. The specific viewpoints ^ selected for the visual simulations include northbound 1-5 and on the shoreline of Agua Hedionda near manhole number 10 {Figure 3.1-1). These viewpoints were selected for the lack of obstructing features {i.e., vegetation, topography) present at the viewpoint and because they represent the most prominent public views of the project area. Viewpoints fi-om private residences are not included in this analysis as the City has no view protection ordinance. Only public views identified in the Agua Hedionda LCP are protected. DUDEK & ASSOCIATES, INC 2798-03 February 2004 3-1 PnfciMTKi Tttwit for Complex Pn^ccU m m m SCALE: r=800 1 ) CAMERA LOCATIONS FOR 30 SIMULATIONS North Agua Hedionda Sewer Western Segment EIR Visual Simulation Key Map FIGURE 3.1-1 3.0 Environmental Analysis 3.1,2 Existing Conditions 3.1.2.1 Local Setting Agua Hedionda Lagoon is one of three coastal lagoons within the City of Carlsbad and is located in the west-central portion of the City. The lagoon comprises approximately 230 acres of water surface and extends 1.7 miles inland from the coast. At its widest point, the lagoon is 0.5 mile wide. Agua Hedionda Creek enters the lagoon at its easternmost point. The general visual setting of the lagoon is characterized by open areas along the northern shoreline with residential development occurring on the bluffs above the lagoon to the north. Active agricultural fields occupy a portion of the slopes along the southern shoreline. Several electrical transmission lines and towers are also present along the southern banks of the lagoon. Distant views of commercial land uses to the east are visible from the lagoon. Interstate 5 and the Atchison, Topeka, & Santa Fe (AT&SF) Railroad cross over the lagoon near its western end. Vegetation cover along the lagoon includes a mixture of coastal sage scrub on the slopes and wetlands habitat types, including intertidal rocky beach, mudflats and sah marsh. In addition, developed areas associated with residences and boat launches are present, as well as patches of ornamentally landscaped areas. Elevation ranges from 0 feet to 10 feet above mean sea level. 3.1.2.2 Existing Visual Character The view of the project site, which extends along the northem shore of Agua Hedionda from Foxes Lift Station to Cove Drive, is available to motorists traveling on northbound 1-5 and consists primarily of coastal bluffs dominated by native vegetation. At the foot of the bluffs, views of sandy beach areas along the shoreline, intertidal rocky areas, mudflats and salt marsh habitats are visible. Residential development occurs on tiie level terrain above the coastal bluffs. Hoover Street, which terminates in a cul-de-sac, is also visible from this public vantage point. Existing views of the project from northbound 1-5 are shown on Figure 3.1-2. Views of the project site from along the northem shore of Agua Hedionda consist of development generally occurring at the eastem and western portions of the project site and native vegetation on the bluffs. Development that is visible along the shorefine includes a boat rental area located south of Harrison Street and a paved access road that extends from manhole number 8A to the boat rental area. Private residences occur along Hoover Street, Adams Street and Cove Drive. A private marina associated witii the residences along Cove Drive is located at the eastem end of the project site. An existing public trail, accessible from Cove Drive, extends from manhole number 23 west to Jose's Boat Launch {Figure 2.2-1). There are no other public trails or recreational facilities along Agua Hedionda; however, a private volleyball court and informal walking trail, extending from the terminus of Hoover Street to the shore, are present 2798-03 XJ KJ M-f I\ 3-3 & ASSOCIATES, INC. February 2004 3-3 Pniftuioiull Tconu /" Cmfirx Projecli m m 3.0 Environmental Analysis several man-made stmctures along the shoreline. Mitigation to reduce significant impacts to the visual character is required. With implementation of the proposed project, views of the project site from public vantage points would include the shoreline protection wall. The shoreline protection wall would appear as a sea wall with a sculpted face colored and textured to match adjacent coastal bluffs. The shoreline protection wall would vary in height to match the grade of tiie manholes and access road; therefore, the wall may extend up to six feet tall in some areas and it may be absent in areas where manholes are at the same elevation as the shoreline protection wall. The view of a shoreline protection wall with a sculpted wall face would not adversely affect the aesthetics of the lagoon because the design of the wall includes a color and textured finish that mimics the adjacent coastal bluffs. Constmction of the shoreline protection wall would not have a substantial adverse effect on a scenic vista nor would it substantially degrade the existing visual character of the project site. No permanent lighting is proposed as part of the project, which would create a new source of substantial light or glare. Therefore, no significant visual impacts associated with constmction of the shoreline protection wall are anticipated Future maintenance and operation activities would involve City public works staff accessing the project site with maintenance vehicles and equipment up to four times a year. Maintenance and operation activities would occur during the day; therefore no lighting will be required and no permanent lighting is proposed as part of the project. Views of the work crews and equipment are not considered an impact to the aesthetics of the lagoon because the visits are short in duration and no permanent storage of equipment or lighting would occur. 3.1.4.2 Consistency with Local Visual Resource Policies A discussion of the project's consistency with the City's General Plan Open Space and Conservation Element and Agua Hedionda LCP is provided below. Open Space and Conservation Element of General Plan • Assure that where feasible from an environmental standpoint, developments near or adjacent to bodies of water provide open space that has public access to and views of the water. Project Consistency: The proposed project includes development of a portion of a public regional trail, as identified in the City's General Plan and Agua Hedionda LCP. A trail easement would be recorded for the portion of the trail paralleling the shoreline protection wall Public access would be provided at Hoover Street and at Cove Drive. The proposed project would provide pedestrians/hikers additional opportunities, that were DUDBi: & ASSOCIATES, INC. 2798-03 February 2004 3-12 Pw/iuiomil Tiemi fur DrniptEtPiojecU m^ 3.0 Environmental Analysis not previously available, to view Agua Hedionda Lagoon. No feature of the proposed project would obstruct views of the lagoon. art m Require that grading be accomplished in a manner that will maintain the appearance of natural hillsides and other landforms wherever possible. Project Consistency: The appearance of natural hillsides would be maintained by restricting manufactured slopes to a 2:1 ratio and revegetating temporarily disturbed areas with a hydroseed application containing plant species known to occur in the project area. The elevation of the access road would generally follow existing topography to reduce the amount of landform alterations necessary to support a roadway. Two crib walls would be installed to minimize the amount of grading necessary (and minimize impacts to CSS) to match existing contours of the slopes.. Conserve and encourage the use of appropriate forms of vegetation and sensitive grading techniques needed to (a) prevent erosion, siltation and flooding, (b) protect air and water resources, and (c) protect and enhance visual resources. Project Consistency: The project would prevent erosion, sihation and flooding and protect water resources through prompt revegetation of temporarily disturbed areas, and by minimizing mnoff into the lagoon through the installation of silt fencing along the toe of slopes. The project would protect air resources by not allowing maintenance vehicles and equipment to idle for more than 15 minutes when not in service, as described in Section 2.0, Maintenance and Operation Guidelines. The project would protect and enhance visual resources by sculpting and coloring the face of the shoreline protection wall to mimic adjacent coastal bluffs. In addition, revegetation of temporarily disturbed areas will include native plant species similar to ones currently established along the coastal bluffs. Preserve natural resources by protecting fish, wildlife, and vegetation habitats; and retaining the natural character of waterways, shoreline features, hillsides, and scenic areas and viewpoints. Project Consistency: The project preserves natural resources by avoiding constmction during the breeding season of sensitive birds and designating staging areas and access routes in developed and disturbed areas. Where avoidance of impacts to natural resources are not possible, mitigation is provided, as described in Section 3.2.5, Required Mitigation Measures for Biological Resources. The natural character of waterways, shoreline features, hillsides and scenic areas and viewpoints would be retained through design features such as the sculpted wall face of the shoreline protection wall, planting of DUDEK 2798-03 & ASSOCIATES, INC.] February 2004 3-13 PtafaAmi limn) fat Caap\tx PnjrrU 3.0 Environmental Analysis the crib walls, and dedication of a trail easement along a portion of the shoreline to preserve scenic points. Agua Hedionda LCP • Special vista points and viewing areas shall be preserved, and made available to the public, as indicated on Figure 3.1-4. Project Consistency: Special vista points and viewing areas will not be affected by the proposed project. Public access to these vista points and areas would continue to be available with implementation of the proposed project. • Where a significant elevation difference (e.g., 35 feet) exists between the shoreline and the first parallel public road, as in the case of Hedionda Point and Snug Harbor, no portion of a structure in the intervening area shall be permitted to exceed the elevation of the roadway. Project Consistency: No component of the proposed project would exceed the elevation of Adams Street, the first parallel public road from the shoreline. • Where no significant elevation difference exists between the shoreline and the first parallel public road, permitted development in the intervening area shall provide a view corridor, of a width equivalent to at least one-third of the road frontage of the parcel, which shall be kept free of all structures and free of landscaping which at maturity would rise above a reasonable viewline from vehicles passing on the public road. Project Consistency: The City does not own the entire area between the shoreline and first parallel public road, and therefore would not be able to provide the entire view corridor. For the portion of the shoreline for which the City does have an easement, the City would ensure that landscaping would not obstmct view corridors for passing vehicles. The project does not propose any stmctures that would rise above a reasonable viewline from vehicles passing on the public road. • On all property adjoining the shoreline, permitted development shall be designed to "step down " in height, to avoid casting shadows on the shoreline areas and to produce a perceived transition from open space areas to developed areas. Project Consistency: No component of the project would cast substantial shadows on the shoreline as the access road and shoreline protection wall would generally follow existing topography. The wall at its highest point would be seven feet tall and the ODUDEK & ASSOCIATES, INC. 2798-03 February 2004 3-14 Pro/Hlioiial T»aiiu Im Cpmpta PnjjKU 3-0 Environmental Analysis shoreline protection wall would be 5.5 tall. The structures would not create a substantial shadow on the shoreline. • Any development proposed to be located on or near a significant landform (e.g., Hedionda Point) shall be designed so as to minimize disturbances of natural landforms, and shall be developed in a manner that assures its compatibility and harmony with the natural landform through use of such architectural techniques as terraced or pole foundations and variation of roof lines to complement the topography. Project Consistency: Disturbance of natural landforms would be minimized through use of crib walls to reduce the amoimt of grading necessary and minimize impacts to CSS and through design of the shoreline protection wall that is consistent in texture and color with the adjacent coastal bluffs. The proposed project is consistent with policies addressing preservation of visual quality as described in the Open Space and Conservation Element of the City of Carlsbad General Plan and the Agua Hedionda Land Use Plan. No significant conflicts with policies relating to visual quality would occur as a result of the proposed project. 3.1.5 Mitigation Measures Mitigation for visual impacts resulting from the constmction of the crib walls would include seeding the open areas of the crib walls with native plant species. The planting of the crib wall would be described in the Coastal Sage Scmb Mitigation and Monitoring Plan, which would, at a minimum, include a discussion of site preparation, planting, irrigation (if necessary), and a five- year maintenance and monitoring plan. The plan would identify a plant palette consisting of native plant species and would outline a maintenance schedule that prevented the invasion of non-native exotic species. 3.1.6 Significance of Impact after Mitigation and Rationale Impacts to the visual character of Agua Hedionda Lagoon resulting from the constmction of the crib walls can be reduced to less than significant with implementation of the mitigation measure described in Section 3.1.5. It is anticipated that views of the crib walls would diminish as native plants that are seeded into the crib wall establish and obscure views of the walls. The crib walls would blend in with the bluffs as the plants grow and mature to reduce the wall's visibility. No significant adverse impacts would remain after mitigation. DUDEK & ASSOCIATES, INC. 2798-03 February 2004 3-15 Proftslicrid Ttanu for drntla ProttcU 3.0 Environmental Analysis 3.2 BIOLOGY The project study area encompasses the northern shoreline of Agua Hedionda Lagoon and adjacent upland areas. The evaluation of potential impacts of implementation of the proposed project components on those biological resources occurring within the project study area has been made utilizing existing resource databases and knowledge of design requirements and constmction methods. The following discussion includes a description of the methodology of analysis, the resuhs, and conclusions in terms of potential impacts, analysis of significance, and proposed mitigation. 3.2.1 Methodology The following analysis is based on the Biological Resources Technical Report for the North Agua Hedionda Western Segment Sewer Maintenance, Access Road and Shoreline Protection Project, prepared Febmary 2004 by Dudek and Associates, Inc., which is included as Appendix B to this EIR. The biological resources are characterized based on literature reviews, database compilation and field reconnaissance. Surveys included general botanical and wildlife surveys, wetlands delineation, rare plant survey, habitat assessment for several rare plants and the federally-listed endangered Pacific pocket mouse {Perognathus longimembris pacificus) and focused surveys for the federally-listed threatened coastal Califomia gnatcatcher {Polioptila californica californica) and non-listed but considered locally sensitive salt marsh (wandering) skipper (Panoquina errans). The study area for the proposed project is based on the existing alignment of NAHI. The project study area encompasses a 200-foot-wide corridor generally centered on the NAHI alignment. 3.2.2 Existing Conditions 3.2.2.1 Vegetation Communities Based on species composition and general physiognomy, eight native plant communities or habitat types were identified onsite: open water, intertidal mudflat, intertidal rocky shore, southern coastal salt marsh, disturbed southern coastal salt marsh, disturbed southern willow scmb, coastal sage scmb, and disturbed coastal sage scmb. In addition, five altered or non- native habitat types are present: annual (non-native) grassland, eucalyptus woodland, mderal habitat, ornamental plantings, and disturbed habitat. Finally, a category for developed land is included. These habitat types or land covers are described below and Figures 3.2-lA through E 2798-03 DWDEK & ASSOCIATES, INC. February2004 3-16 ProfeoioiiBl Tcami for CarnpUi PiOftcU r 1 r ^ r ^ r i rn^n m wrt rm r% r% r i m ^ m % r i w^i t i i i SEE FIGURE 3.2-1 B FOR BIOLOGICAL RESOURCES LEGEND North Agua Hedionda Sewer Western Segment EIR Biological Resources Index Map FIGURE 3.2-lA VEGETATION TYPES/LANDCOVERS: Annual Grassland AGL DH CSM CSS DEV Coastal Salt Marsh Coastal Sage Scrub Developed Land EUC IM IRB Disturbed Habitat Eucalyptus Woodland Intertidal Mudflat Intertidal Rocky Beach NOTE: A lower case'd' in front of a vegetation type designator indicates that it is disturbed. An upper case 'J' following a vegetation type designator indicates that it is Jurisdictional. / •. 1 :7 Waters of the U. S. (Number indicates width of unvegetated channel.) o Data Station Limits of Permanent Impact Limits of Temporary Impact SENSITIVE ANIMAL SPECIES: CAGN California gnatcatcher (Dudek, 2001) SMS Salt marsh skipper (Dudek, 2003) BASE PHOTO SOURCE: CITY OF CARLSBAD SEWER SYSTEM SOURCE: CITY OF CARLSBAD GIS DEPT. (ADJUSTED TO TOPOGRAPHIC FEATURES) ORN OW ROD SWS Ornamental Open Water Ruderal Southern Willow Scrub \ Study Area Impact Area Sewer System CAGN General Area of Calling/Movement SENSITIVE PLANT SPECIES: Ac Adolphia californica Ja Juncus acutus ssp. leopoldii liOTE: Number indicates individual plant counts at that location. North Agua Hedionda Sewer Western Segment EIR Biological Resources Legend FIGURE 3.2-1B North Agua Hedionda Sewer Western Segment EIR Biological Resources Map FIGURE 3.2-1C UJ g SEE FIGURE 3.2-1 B FOR BIOLOGICAL RESOURCES LEGEND North Agua Hedionda Sewer Western Segment EIR Biological Resources Map FIGURE 3.2-1D SEE FIGURE 3.2-1 B FOR BIOLOGICAL RESOURCES LEGEND 0 160 SCALE IN FEET North Agua Hedionda Sewer Western Segment EIR Biological Resources Map FIGURE 3.2-1E 3.0 Environmentai Analysis illustmtes Iheir spatial distributions. Table 3.2-1 presents the acreages for each habitat type or land cover oceorring within the project study area. TABLE 3.2-1 ACREAGES OF HABITAT TYPES/LAND COVERS OCCURRING WITHIN PROJECT STUDY AREA Habitat Type/Land Cover Acreage Open Water 0.91 Intertidal Mudflat 3.34 Intertidal Rocky Beach 0.25 Southern Coastal Salt Marsh 0.36 Disturbed Southern Coastal Salt Marsh 0.06 Disturbed Southern Willow Scrub 0.11 Coastal Sage Scrub 8.00 Disturbed Coastal Sage Scrub 1.05 Annual (non-native) Grassland 0.08 Eucalyptus Woodland 0.38 Ruderal 3.49 Ornamental 0.72 Disturbed Habitat 1.59 Developed Land 8.20 lOFAl 23.1 R Open Water This habitat type refers to the lagoon area beyond the sh{)re, which permanently contains water and does not contain emergent vegetation. This land cover type onsite is present along the southwestern and southern borders of the project site. This habitat is regulated under Sections 401 and 404 of the Clean Water Act and Section 1600 of the Msh and Game Code as a wetland, is of limited occurrence in southern California, and therefore is considered sensitive. & ASSOCIATES, INC. 2798-03 February 2004 3-22 3^ Environmentai Analysis Intertidal Mudflat Intertidal mudflat areas include all of the sandy shore located within the normal tide How between highest tide (4.91 ft msl) and mean low tide (-2.K8 ft nisi). This area contains little vegetation aside from algae, but it is used for foraging by some shorebirds. This habitat occupies the majority of (he intertidal zone within the project corridor. Although this area contains mostly sand, it is not considered a sandy beach because it is regularly inundated and does not have the loose soil composition typical of a sandy beach community. This habitat is regulated under Section 404 of the Clean Water Act and Section 1600 of the Fish and Game Code as a wetland, is of limited occurrence in southern California, and therefore is considered senshive. Intertidal Rocky Beach The rocky intertidal areas in the project area consist of exposed bedrock and rip-rap probably remnant from the shoreline protection associated with construction of the sewer line and access road in 1965. All rocky intertidal habitat within the project corridor is unvegetated. Two rocky intertidal areas were identitled; one is located near the middle of the project (approximately 200 ft in length) and another smaller area (approximately 50 ft in length) is located near the eastern terminus of the project, 'fhis habitat is regulated under Sections 401 and 404 of the Clean Water Act and Section 1600 of the Tish and Game Code as a wetland, is of limited occurrence in southern California, and therefore is considered sensitive. Southern Coastal Salt Marsh Southern coastal salt marsh occurs in bays, lagoons and estuaries receiving marine tidal influence (Holland 1986). Vegetation, contaimng salt-tolerant hydrophytes, is typically highly productive, forming moderate to dense cover up to one meter (m) tall. Most species are active in the summer and dormant in the winter. Vegetative composition varies with tidal influence and period of inundation with the greatest diversity of species oecumng with least tidal influence. Typical species include alkali weed {Cressa iruxillensis), salt grass, salty Susan {Jaumea carnosa), salt- eedar {Monanlhochloe Hltoralis), picklewced {Salicornia spp.), California cordgrass {Spartina foliosa) and California sca-blite {Suaeda californica). Onsite, southern coastal salt marsh occurs below ten feet in elevation, adjacent lo the sandy or rocky shoreline. Typical species found were salt grass, common piekleweed, salty Susan, spiny rush and saltbush {Airiplex spp.). Coastal salt marsh patches are present in a variety of sizes and arc concentrated in the western region of the project site. Four large patches of salt marsh are located along the shoreline near Hoover Street and near the middle of the project adjacent to the & ASSOCIATES, INC. 2798-03 February 2004 3-23 Pro/«"(ina[ Trtjmj for Complex FVttfPcli 3,0 Environmental Analysts rocky shore. For the remainder of the project site southern coastal salt marsh is interspersed with ruderal and coastal sage scrub habitats. According to the California C'oastal Conservancy, coastal saU marsh hal^tat has been reduced by 80% statewide. This incremental loss of wetland habitat has placed coastal salt marsh and other w^ctland habitat under sensitive status. Furthermore coastal salt marsh is a regulated habitat under Sections 401 and 404 of the Clean Water Act and under Section 1600 of the California Fish and Game Code as wetland habitat. Disturbed Southern Coastal Salt Marsh Three areas of disturbed southern coastal salt marsh are mapped in the eastern portion of the project corridor. These patches support salt grass and other indicator species but also several non-native species including Bermuda grass {Cynodon dactylon) and several escaped exotics from adjacent landscaping. Although disturbed, this community provides similar function as a non-disturbed salt marsh and is regulated under the Clean Water Act and Fish and Game Code as wetland habitat. Therefore, this community is considered sensitive. Disturbed Southern Willow Scrub Holland (1986) describes southern willow scrub as a dense, broad-leafed, winter-deciduous riparian thicket dominated by several species of willow (Salix spp.), with scattered emergent Fremont's cottonwood {Populus fremontii) and western sycamore (Platanus racemosa). 'fhe closed canopy of this riparian community typically inhibits the development of a diverse undcrstory. Onsite, disturbed southern willow scrub occurs between Foxes Lift Station and the manufactured slope of T-5 within a drainage ditch. The area supports a canopy of mature arroyo willow (Salix lasiolepis) with an undcrstory dominated by exotic invasive species such as castor-bean (Ricinis communis), black-eyed susan fl^hunbergia alata), and fan palm (Washingtonia robusta). Despite the disturbance of invasive species, this community onsite retains wetlands functions and values and is regulated during the Clean Water Act and Fish and Game Code as wetlands habitat. Therefore, this community is considered sensitive. & ASSOCIATES. INC. 2798-03 February 2004 3-24 3.0 Environmental Analysis Coastal Sage Scrub Coastal sage scrub is a native plant community composed of a variety ol" soft, low, aromatic slirubs, characteristically dominated by drought-deciduous species such as California sagebrush {Artemisia californica), flat-top buckwheat (Eriogonum fascicufatiun), and sages {Salvia spp.), with scattered evergreen shrubs, including Icmonadeberry {Rhus integrfolia), laurel sumac (Malosma laurina) and toyon {Heleromeles arbulifolia). It typically develops on south-facing slopes and other xeric situations. Coastal sage scrub is the most common upland habitat along the project corridor. C:oastal sage scrub habitat extends landward ftoin the southern coastal salt marsh and ruderal habitat. This habitat type is dominated by California sagebrush, black sage, California encelia {Encelia californica), flat-top buckwheat, coyote brush {Baccharis piluiaris), lemonadeberry and laurel sumac, but also includes pampas grass (Cortaderia selloana) and priekly-pear {Opuntia littoralis). Coastal sage scrub is recognized as a sensitive plant community by local, state, and federal resource agencies. It supports a rich diversity of sensitive plants and animals, and it is e.stimated that it has been reduced by 75-80% of its historical coverage throughout southern California. It is the focus of the current State of Caliibrnia Natural Communities Conservation Program (NCCP). Disturbed Coastal Sage Scrub Five areas of disturbed coastal sage scrub were mapped in the project corridor. These patches contained Icmonadeberry, laurel sumac, black sage {Salvia mellifera). and other indicator species, but they also contained several non-native species including pampas, hottentot-flg {Carpobrotus edulis), curly dock (Rumex crispus), horehound {Marrubium vulgare), and slender wild oat {Avena barbata). Disturbed coastal sage scrub onsite supports 20 to 50% cover by coastal sage scrub indicator species. Although disturbed, this habitat type provides similar function as the non-disturbed variety and therefore is considered sensitive. Annual (non-native) Grassland Where native plant communities have been subject to repeated or severe disturbance, the habitat frequently reverts to annual or non-native grassland. These areas usually are dominated by annual grasses, such as bromes {Bromus spp.) and wild oats {Avena spp.), and other disturbance- 2798-03 & ASSOCIATES, INC. February 2004 3-25 3,0 Environmental Analysis tolerant species such as filarees {Erodium spp,), telegraph weed {IJeterotheca grandiflora). and doveweed (Eremocarpus seligenis). Onsite- annual (non-native) grassland is present in one patch in approximately the middle of the project site, adjacent to a developed area. This area is dominated by ripgut grass {Bromus diandrus). slender oat {Avena barhala), and Bermuda grass. Other introduced, weedy species such as black mustard {Brassica nigra), sw^eet fennel {Focniculum vulgarc), and bristly ox- tongue {Picris echioides) are also present in this habitat type onsite. Annual grassland is typically only considered sensitive when it occurs in large blocks of open habitat where it may provide significant function for raptor foraging and rodent habitat. The occurrence of annual grassland within the project corridor is not considered sensitive. Eucalyptus Woodland Although not recognized as a native plant community by Holland (1986), eucalyptus woodland is a distinct vegetation type that is fairly widespread in southern California. It typically consists of monotypic stands of introduced. Australian eucalyptus trees [Eucalyptus spp.). The understory is either depauperate or lacking owing to shade and the possible allelopathic (toxic) properties of the eucalyptus leaf litter. Although eucalyptus woodlands are of limited value to most native plants and animals, they frequently provide nesting and perching sites for some local raptors. •fwo stands of eucalyptus are present in the eastern section of the study area. Eucalyptus woodland is not considered a sensitive habitat although some raptor species may use it tor nesting. Ruderal Ruderal habitats are dominated by non-native forb species but may also contain some non-native grasses. Ruderal habitat onsite is dominated by hottentot-fig, but also includes cockle-bur {Xanthium slrumarium), Bemiuda grass, telegraph weed and castor-bean. The largest extent of ruderal habitat was mapped in the area extending from Hoover Street to the shore, ddie remainder of the ruderal habitat occurs in two smaller patches in the westem region of the project site and in one small patch along Cove Street in the eastern region. Ruderal habitat is not considered sensitive. & ASSOCIATES, INC. 2798-03 February 2004 -^"^^ 3,0 Environmental Analysis Ornamental/Developed Lands Ornamental land cover consists of landscaped areas associated with private development, 'fhe ornamental vegetation includes Bermuda grass and a variety of woody and herbaceous landscape plants. Developed land cover refers to areas which currently support structures. Developed areas include: the boat launeh/rcslaurant, several pilings, a volleyball court (part of the private residence) and a parking garage and sidew^alk adjacent to an apartment complex. Ornamental/developed land is not considered sensitive; however, in four areas in the eastern portion of the study corridor, these land use types occur below Hve feet above msl and area therefore considered regulated habitat under Sections 401 and 404 of the Clean Water Act and Section 1600 of the Fish and Game Code. These areas below Ave feet above msl are considered sensitive. Disturbed Habitat •fhese areas generally are the result of severe or repeated mechanical perturbation but appear to be capable of recovering to a native vegetation community. Within the project corridor, this vegetation type includes areas that appear to experience a high level of vehicular and pedestrian traffic. This habitat type is only sparsely vegetated by a mixture of coastal sage scrub species (less than 20%), nomnative grass and forbs. Disturbed habitat was found mainly in the eastern region of the project and surrounding the boat launch, with a small patch mapped near the center of the project. Disturbed habitat is not considered sensitive. Floral Diversity A total of 130 species of vascular plants: 76 native (58 percent) and 54 non-native (42 percent), was recorded from the site (Appendix A of Biological Resources 'fechnical Report). The recorded flora of the site is limited as a consequence of the limited number and extent of native plant communities, and the fact that surveys were conducted in winter and fall. 3.2.2.2 Jurisdictional Waters In addition to the regulated wetland habitat types described above, two unvegetated ephemeral steam channels occur in the project study corridor. These areas are defined by a bed and bank, support a ordinary high water level between one and three feet wide, but do not support wetland vegetation. Rather, they support vegetation consistent with surrounding uplands. As stream channels, these area arc considered non-wetland waters regulated by Sections 401 and 404 of the Clean Water Act and Section 1600 of the Fish and Game Code and are therefore considered sensitive resources. 2798-03 & ASSOCIATES, INC. February 2004 3-27 P™|riiiDi\a( Ttami /or Cumplti Projcfli 3,0 Environmental Analysis 3.2.2.3 Zoology-Wildlife Diversity Birds d'hirty-seven bird species were observed during the cumulative survey visits {Appendix B). The diversity of birds is limited due to the small amount of habitat and relatively low habitat quality. The coastal sage scrub and ornamental plantings onsite provide habitat for a variety of birds, including house finch {Carpodacus mexicanus), Anna's hummingbird {Calypte anna), California towhee {Pipilo crissalis), bushtit {Psaluiparus minimus), American crow {Corvus hrachyrhynchos) and the federally-listed threatened coastal California gnatcatcher. The coastal salt marsh and intertidal areas provide habitat for a number of birds, including great blue heron {Ardea herodias), California killdeer {Charadrius vociferus), willet {Catoptrophorus semipalmalus) and American coot {Fidica amcricana). All species were observed within the project corridor with the exceptit>n of a brown pelican {Pelecamis occidenlalis californicus), state- and federally-listed as endangered- and Caspian and Forster\s terns (Sterna ca.spia and S. foresti) which were observed south of the project corridt)r on open water. Reptiles and Amphibians One reptile species was observed onsite: side-blotched lizard (Ula stanshuriana). However, reptiles common in the area and likely to occur onsite include western fence lizard (Sceloporus occidentalis). gopher snake (Filuophis melanoleucus), red-diamond rattlesnake {Croiahis ruber). eoachwbip {Masticophis flagellum) and common kingsnake (Lampropellis gciulus). No amphibian species were observed during the survey; however, one or more of the following species may occur onsite: garden slender salamander {Balrachoseps attenuatus). western toad {Bufo boreas) and Pacific treeftog {Ilyla regilla). Habitat quality for reptiles and amphibians is low and the diversity of these species is expected to be low because of the small amount of habitat available and the likely ncgafive effects of the adjacent urban development. Mammals Mammal species, or their sign, observed onsite during the survey include brush rabbit {Sylvilagus bachmani), Botta's pocket gopher {Thomomys bottae), California pocket inouse {Chaetodipus californicus). striped skunk {Mephitis mephitis) and domestic dog {Canis familiaris). Mammals not observed onsite but likely to be present include California ground squirrel {Spermophilus heecheyi), Califomia mouse {Peromyscus californicus), deer mouse 2798-03 & ASSOCIATES, INC. February 2004 3-28 ProfiisiDnijI Ttit.ni fo> Cumplci Priijttli 3.0 Environmental Analysis {Peromyscus manicidatus), Dulzura California pocket mouse {Chaetodipus californicus femoraiis), cactus mouse (Peromyscus eremicus), woodrat {Neotoma sp.), Virginia opossum {Didelphis virginiana) and coyote (Canis latrans). Invertebrates A number of intertidal species were observed during the survey visit which was scheduled during a springtime low tide in order to maximize detection of invertebrates. The species observed include those that occur within mudflat habitats and those that occur within the rocky intertidal zone. The mudflat species included the mud-flat crab (Hemigrapsus oregonensis), and scattered dead individuals of clams and scallops that had washed onto the mudflat areas. Burrows of clams were visible but individuals were not dug up in order to idenUfy them. It is likely there are many other mudflat dwelling organisms including a variety of worms and other soft bodied invertebrates. Within the limited areas of rocky intertidal habitat, clusters of blue mussels {Myiilus cduiis) and barnacles {Balanus glandula) were observed with scattered individuals of various limpet and snail species. A complete list of the invertebrates observed during the visits is included in Appendix B. Fight species of butterfly were recorded during surveys including cabbage butterfly (Pieris rapae), west coast lady (Vanessa annahella), pygmy blue (Brephidium exile), fiery skipper (Hylephila phyleus), salt marsh skipper, and buckeye {Junonia coenia). The moderate plant species richness onsite is undoubtedly accompanied by a fairly diverse number of phytophagous (plant4eeding) insect species. In parficular, a variety of species of Lepidoptera (butterflies and moths) and a comparable number of Coleoptera (beetles), Hymenoptera (bees, ants and wasps), and Diptera (flics) are expected to be present within the local area. 3.2.2.4 Sensitive Biological Resources The following resources are discussed in this section: (1) plant and animal species present in the project vicinity that are given special recognifion by federal, state, or local eonservafion agencies and organizations owing to declining, limited, or threatened populations, that ai'e the results, m most cases, of habitat reduction; and (2) habitat areas that are unique, are of relatively limited distribufion, or are of parficular value to wildlife. Sources used ibr determination of sensifive biological resources are as follows: wildlife - U.S. Fish and Wildlife Service (USFWS 2001), California Department of Fish and Game (CDFG 2002), Remsen (1978), Everett (1979), McGurty (1980), and Murphy (1990); plants - USFWS (2001), CDFG (2002), and Skinner and Pavlik (2001); and habitats - Holland (1986). & ASSOCIATES, INC [•n-fciLOtuif Ttnnu /or Com pin Prnjjci 2798-03 February 2004 3-29 3.0 Environmental Analysis Sensitive Plant Species One sensitive plant species was detected within the project corridor: southwestern spiny rush. The site does not support habitat for the other listed plant species. Table 3.2-2 lists the listed species that occur within the region and the reason for their absence from the site. Table 3.2-2 also lists other sensitive plant species known for the region and the potenfial for their occurrence within the project area. TABLE 3.2-2 SENSITIVE PLANT SPECIES DETECTED OR POTENTIALLY OCCURRING ON THE PROJECT SITE Scientific Name Common Nnme Status FGderallState/ Other CNPS List, R-E-D Primary AssDciati.ms liff Form/Blooming Period Potential to Occur Abronia maritime Red sand-verbena None/None 4, 1-2-2 Coastal dunes/perennial herb/February- November Low/ potential, no suitable habitat/ soils onsite. Acanthomintha ilicifolia San Diego thornmint FT/SE IB, 2-3-2 Chaparral, coastal sage scrub, valley and foothill grassland, vernal pools, claysf annual herb/April-June Low potential, no suitable habitat/ soils onsite. Aclmatherum diegoense San Diego County needlegrass None/None 4, 1-2-1 Chaparral, coastal sage scrub/perennial herb/May-June Low potential, would have been observed. Adolphia californica California adolphia rJone/None 2, 1-31 Chaparral, coastal sags scrub, valley and foothill grassland, clays/shrub/December- April Moderate potential, would have been observed. Agave sfiawii Shaw's agave FSC/None 2, 3-3-1 Coastal bluff scrub, coastal sage scrub/ shfublMay-July Low potential, would have been observed. Ambrosia cbenopodiifolia San Diego bur-sage None/None 2, 3-3-1 Coastal sage scrub/shrub/April-June Low potential, would have been observed. Ambrosia pumifa San Diego ambrosia PFE/None IB, 3-3-2 Chaparral, coastal sage scrub, valley and foothill grassland, vernal pools, clays/ perennial herb/June- September Low potential, would have been observed. Aphanisma blitoides Aphanisma FSC/None IB, 2-2-2 Coastal bluff scrub, coastal sage scrub, sandy soils/annual Low potential, no suitable habitat/ soils onsite. & ASSOCIATES, INC. February 2004 3-30 Piii/fuionul Teums Joi Cimplci Profn. 3.0 Environmental Analysis TABLE 3.2-2 SENSITIVE PLANT SPECIES DETECTED OR POTENTIALLY OCCURRING ON THE PROJECT SITE Scientific Name Common Namn Status Federal/State/ Other CNPS List, RED Primary Habitat Associations/Life Form/Blooming Periorf Status Onsite or Potential to Occur herb/April-May Arctostapbyfos g/a/fdu/osassp. Crassifolia Del Marmanzanita FE/None IB, 3-3-2 Southern maritime chaparral, sandy mesas and bluffs/ shrub/December-April Low potential, no suitable habitat/soils onsite, would have been observed. Artemisia palmeri San Diego sagewoU None/None 4, 1-2-1 Chaparral, coastal sage scrub, riparian forest and scrub, sandy soils/ shrub/July-September Low potential, would have been observed. Astragalus toner •^m. titi Coastal dunes milk-vetch FE/SE IB, 3-3-3 Coastal bluff scrub, coastal dunes/annual herb/March-May Low potential, no suitable habitat/ soils onsite. Auiplex coulteri Coulter's saltbush None/None IB, 2-2-2 Coastal bluff scrub, coastal dunes, coastal sage scrub, valley and foothill grassland, alkaline or clay soils/ perennial herb/March- October Low potential, no suitable habitat/ soils onsite. Airiplex pacifica South Coast saltscale FSC/None IB, 3-2-2 Coastal bluff scrub, coastal sage scrub, playas/annual herb/ March-October Moderate potential, would have been observed. A triplex serrenana u a r. davidsonii Davidson's saltscale None/None IB, 3-2-2 Coastal bluff scrub, coastal sage scrub, alkaline soils/annual berb/April-October Low potential, no suitable habitat/soils onsite. Baccharis vanessae Encinitas baccharis FT/SE IB, 2-3-3 Chaparral on sandstone/shrub/ August-November Low potential, no suitable habitat/ soils onsite. Brodiaea filifolia Thread-leaved brodiaea FT/SE IB, 3-3-3 Coastal sage scrub, cismontane woodland, valley and foothill grassland, vernal pools, ciays/perennial herb/March-June Low potential, no suitable habitat/ soils onsite. Brodiaea orcuttii Drcutt's brodiaea FSC/None IB, 1-3-2 Closed-cone conifer forest, chaparral, cismontane woodland, meadows and seeps. Low potential, no suitable habitat/ soils onsite. & ASSOCIATES, INC. 2798-03 February 2004 3-31 VjcjcisiananramijoT CM\p\ri Proic. 3.0 Environmental Analysis TABLE 3.2-2 SENSITIVE PLANT SPECIES DETECTED OR POTENTIALLY OCCURRING ON THE PROJECT SITE Scientific Name Common Name Status Federal/State/ Other CNPS List, RED Primary Habitat Associations/Lifj Form/Bloomiiig Period Status Onsite or Potential to Occur' valley and foothill grassland, vernal pools, clays/perennial herb/May-July Calindrinia mar it im a Seaside calindrinia None/None 4, 1-2-1 Coastal bluff scrub, valley and foothill grassland, sandy soils/ annual herb/Marcb-May Low potential, no suitable habitat/ soils onsite. Camissonia lewisii Lewis's evening primrose None/None 3, ?-?-2 Coastal bluff scrub, cismontane woodland, coastal dunes, coastal sage scrub, valley and foothill grassland, sandy or clay soils/ annual herb/March- June Low potential, no suitable habitat/ soils onsite. Caulantbus simulans Payson's jewelflower FSC/None 4, 1-2-3 Chaparral, coastal sage scrub, sandy and granitic soils/annual herb/March-June Low potential, no suitable habitat/soils onsite. Ceanothus verrucosus wart-stemmed ceanothus FSC/None 2, 2-2-1 Chaparral/shrub/ January-April Low potential, no suitable habitat/ soils onsite. Centromadia IHemizoniaJ parryi spp. australis Southern tarplant FSC/None IB, 3-3-2 Valley and foothill grasslands (vernally mesic), estuary margins, vernal pools/annual herb/ June-November Moderate potential, would have been observed. Chorizantfie orcuttiana Orcutt's spineflower FE/SE IB, 3-3-3 Chaparral, closed-cone conifer forest, coastal sage scrub/annual herb/March-April Low potential, no suitable habitat/ soils onsite. Cborizanthe polygonoides\z\. longispina Long-spined spineflower FSC/None IB, 2-2-2 Chaparral, coastal sage scrub, meadows and seeps, valley and foothill grassland, often clay/annual herb/ April-July Low potential, would have been observed. Comarostapfiyfis diversifolia ssp. diversifolia Summer holly None/None IB, 2-2-2 Chaparral/shrub/April- June Low potential, no suitable habitat/ soils onsite. & ASSOCIATES, INC. 2798-03 February 2004 3-32 3.0 Environmental Analysis TABLE 3.2-2 SENSITIVE PLANT SPECIES DETECTED OR POTENTIALLY OCCURRING ON THE PROJECT SITE St'itus tlnsitc ur I l'olentg|,tqJccyy Scientific Name Common Name Status Federal/State/ Other CNPS List, R-E-D Primary H<ibitat AssDciations-'Lifo Form/Bloom'..a: St'itus tlnsitc ur I l'olentg|,tqJccyy Small lluwiTod mnrniny glory 4, 1 2 7 Coastril sagp scrub, valley and foothill grassland, clay, serpentinite seeps/ annual herb/March- June . 3te potential; would have been observed. Cordylanthus maritimus s^p. maritimus Salt matsh bird's-beak FE/SE IB, 2-2-2 Coastal dunes, coastal saltwater marshes and swamps/annual herb/ May-October Low potential, no suitable habitat/ soils onsite. Cordylanthus orcuttianus Orcutt's bird's-beak FSC/None 2, 3-3-1 Coastal sage scrub/annual fierb/ March-July Low potential. Coreopsis maritima Sea dahlia None/None 2, 2-2-1 Coastal bluff scrub, coastal sage scrub/ perennial herb/March- May Low potential, would have been observed. Corethrogyne filaginifolia'itiX. in can a San Diego sand aster None/None IB, 3-3-2 Coastal sage scrub/perennial herb/ June-August Low potential would have been observed. Corethrogyne fi!aginifotia\?i\. linifolia Del Mar Mesa sand aster FSC/None IB, 3-3-3 Chaparral, coastal sage scrub/perennial herb/July-September Moderate potential, would have been observed. Dichondra occidenlalis Western dichondra None/None 4, 1-2-1 Chaparral, cismontane woodland, coastal sage scrub, valley and foothill grassland/ perennial heib/March- May Moderate potential, would have been observed. Dudleya attenuata ssp. orcuUii Orcutt's dudleya FSC/None 2, 3-3-1 Coastal bluff scrub, chaparral, coastal sage scrub/perennial herb/ May-July Low potential, no suitable habitat/ soils onsite. Dudleya blocbmamae spp. blochmaniae Blochman's dudleya FSC/None IB, 2-3-2 Coastal bluff scrub, coastal sage scrub, valley and foothill grassland, rocky, often clay or serpentinite soil/perennial herb/ April-June Low potential, no suitable habitat/ soils onsite. & ASSOCIATES, INC. February 2004 J for Compff j; P»op>rtT 2798-03 3-33 3.0 Environmental Analysis TABLE 3.2-2 SENSITIVE PLANT SPECIES DETECTED OR POTENTIALLY OCCURRING ON THE PROJECT SITE Scientific Name Common Name Status Federal/State/ Other CNPS List, RED Primary Habitat Associations/Life Form/Blooming Period Status OnsitQ or Potential to Occur. U'JCleyJ b!CV:fc.!3 Short leaved dmiliiyn 1 SCSI lli 3 3 3 Ciinp-'irr.il, '..oastal saijc scrub, Torrey sandstone/perennial herb/April Low [lotfntial, no suitable habitat/ soils onsite. Dudleya multicaulis Many-stemmed dudleya FSC/None IB, 1-2-3 Chaparral, coastal sage scrub, valley and foothill grassland, often clays/perennial herb/May-July Low potential, no suitable habitat/ soils onsite. Dudleya variegata Variegated dudleya FSC/None IB, 2-2-2 Chaparral, cismontane woodland, coastal sage scrub, valley and foothill grassland, vernal pools/perennial herb/May-June Moderate potential; would have been observed. Dudleya viscida Sticky dudleya FSC/None IB, 2-2-3 Coastal bluff scrub, chaparral, coastal sage scrub,rocky areas/ perennial herb/May- June Low potential. Ericameria palmeri ^^p. palmeri Palmer's goldenbush FSC/None 2,3-2-1 Coasts! sage scrub/shrub/ September-November Low potential, would have been observed. Erysimum ammophilum Coast wallflower FSC/Wone IB, 2-2-3 Coastal dunes/perennial herb/February-June Low potential, no suitable habitat/soils onsite. Euphorbia misera Cliff spurge None/None 2, 2-2-1 Coastal bluff scrub, coastal sage scrub, rocky areas/shrub/ January-August Low potential, would have been observed. Eerocactus viridescens San Diego barrel cactus FSC/None 2, 1-3-1 Chaparral, coastal sage scrub, valley and foothill grassland, vernal pools/shrub/ May-June Moderate potential, would have been observed. Erankenia palmeri Palmer's frankenia None/None 2,3-3-1 Coastal dunes, saltwater marsh and swamps, playas/ perennial herb/May- Moderate potential, would have been observed. & ASSOCIATES, INC. 2798-03 February 2004 3-34 Pni/tj!inT.al Ttom. ComplEiPio/frti 3.0 Environmental Analysis & ASSOCIATES, INC. Jjo/ev.iuna^ Trim! /in Cofnplii I'mir.-li TABLE 3.2-2 SENSITIVE PLANT SPECIES DETECTED OR POTENTIALLY OCCURRING ON THE PROJECT SITE Scientific Name Common Name Status Federal/State/ Other CNPS List, R-E-0 Primary Habitat Associations/Life Form/Blooming Period Status Onsite or. Potential to Occur July Harpagonella palmeri Palmer's grapplinghook None/None 4, 1-2-1 Chaparral, coastal sage scrub, valley and foothill grassland, clays/annual herb/ March-April Moderate potential; would have been observed. Hazardia orcuttii Orcutt's hazardia FSC/None IB, 3-3-2 Chaparral, coastal sage scrub/shrub/ August- October Low potential, would have been observed. Holocarpha virgatas^p. elongata Graceful tarplant FSC/None 4, 1-2-3 Coastal sage scrub, cismontane woodland, chaparral (?), valley and foothill grassland/ annual herb/August- November Low potential, would have been observed. Hordeum Intercedons Vernal barley None/None 3, ?-2-2 Valley and foothill grassland (saline flats and depressions), vernal pools/annual herb/March-June Moderate potential; would have been observed.. Isocoma menzlesih^r. decumbens Decumbent goldenbush None/None IB, 2-2-2 Coastal sage scrub (sandy, often disturbed areasl/shrub/April- November Low potential, would have been observed. Iva hayesiana San Diego marsh elder FSC/None 2, 2-2-1 Playas, riparian, floodplain-upland ecoTone/perennial herb/April-September Moderate potential, would have been observed. Juncus acutus ^pp. leopoldii Southwestern spiny rush None/None 4, 1-2-3 Coastal dunes, meadows and seeps (alkaline), saltwater marsh/perennial herb/ May-June Approximately 35 individuals located in two areas, east of Hoover Street. Lepidium virginicum var. robins onii Robinson's pepper-grass None/None IB, 3-2-2 Chaparral, coastal sage scrub/annual herb/January-July Low potential. Lotus nuttalllanus Nuttall's lotus FSC/None IB, 3-3-2 Coastal dunes, coastal sage scrub/annual herb/March-June Low potential. Machaerantbera juncea Rush-like bristleweed None/None 4, M l Chaparral, coastal sage scrub/perennial Low potential, would have been February 2004 3-35 3.0 Environmental Analysis TABLE 3.2-2 SENSITIVE PLANT SPECIES DETECTED OR POTENTIALLY OCCURRING ON THE PROJECT SITE Scientific Name Common Name Status Federal/State/ Other CNPS list. R-E-D Primary Hab Associations.! if u FormlBlooming Period Status On: Potential to'Occur! herb/June-October observed. Mlcroseris douglasil var. platycarpha Smail-flowered microseris None/None 4, 1-2-2 Cismontane woodland, coastal sage scrub, valley and foothill grassland, clays/annual herb/March-May Low potential. Muilfa cfevefandii San Diego goldenstar FSC/None IB, 2-3-2 Chaparral, coastal sage scrub, valley and foothill grassland, vernal pools/perennial herb/May Low potential. Nemacaulis denudata var. gracilis Slender woolly-beads None/None 2, 2-2-1 Coastal dunes, desert dunes, Sonoran Desert scrub/annual herb/March-May Low potential, no suitable habitat/ soils onsite. Orobranche parishii ssp. brachyloba Short-lobed broom-rape None/None 4, 1-2-2 Coastal bluff scrub, coastal dunes, coastal sage scrub, sandy soils/perennial herb/May-August Low potential, no suitable habitat/ soils onsite. Pbacelia stellaris Brand's phacelia None/None IB, 3-3-2 Coastal dunes, coastal sage scrub/annual herb/March-June Low potential, no suitable habitat/soils onsite. Pinus torreyanaspp. torreyana Totrey pine FSC/None IB, 3-2-3 Closed-cone conifer forest, chaparral, sandstone/tree/NA Low potential, would have been observed. Quercus dumosa Nultall's scrub oak FSC/f\ione IB, 2-3-2 Chaparral, coastal sage scrub, sandy and clay loam soils/shrub/ February-March Low potential, would have been observed. Senecio aphanactls Rayless ragwort None/None 2,3-2-1 Cismontane woodland, coastal sage scrub, alkaline soils/annual herb/January-April Low potential, no suitable habitat/ soils onsite. Vlgulera lacinlata San Diego County viguiera None/None 4, 1-2-1 Chaparral, coastal sage scrub/shriib/ February- June Low potential, would have been observed. & ASSOCIATES, INC. nal Ttctml /nr Complu Projc 2798-03 February 2004 3-36 3,0 Environmentai Analysis TABLE 3.2-2 (Continued) Legend Bold species and common name indicates Carlsbad Draft HMP Covered Species FE: Federally-listed as endangered FSC: Federal species of concern FT: Federally-listed as threatened PFE: Proposed for federal listing as endangered SCE: State candidate for listing as endangered SE: State-listed as endangered SR: State rare CNPS Lists lA: Presumed Extinct in California IB: Rare or Endangered in California and Elsewhere 2: Rare or Endangered in California, More Common Elsewhere 3: Need More Information 4: Plants of Limited Distribution H-E-D code R (Rarity) . . . , 1- Rare, but found in sufficient numbers and distributed widely enough that the potential for extinction or extirpation is low at this time. 2- Occurrence confined to several populations or lo one extended population. 3- Occurrence limited to one or a few highly restricted populations, or present in such small numbers that it is seldom reported. E [Endangerment) 1- Not endangered 2- Endangered in a portion of its range 3- Endangered throughout its range D (Distribution) 1- More or less widespread outside of California 2- Rare outside California 3- Endemic to California Sensitive Wildlife Species One federally-listed threatened wildlife species was detected within the project corridor: two pairs ol'the California gnatcatcher. The California gnatcatcher is a Draft flMP covered species. One non-listed wildlife species considered locally sensitive, the salt marsh skipper, was observed within the project corridor. Focused surveys resulted in observation of 16 individuals in seven locations throughout the project alignment, fhe salt marsh skipper is a Drdi\ HMP covered species, 'fhe general Agua Hedionda Lagoon environment does support habitat for the other sensitive wildliTe species as discussed in Talyle 3.2-3. This table identiHes the listed species that occur within the region and the reason for their absence from the site. Table 3.2-3 also lists other sensitive wildlife species known for the region and the potential for their occurrence within the project area. 2798-03 & ASSOCIATES, INC. February 2004 ^'^'^ Pjofdiionul Team! lor CDmplti Piojccti 3.0 Environmentai Analysis TABLE 3.2-3 SENSITIVE WILDLIFE SPECIES DETECTED OR POTENTIALLY OCCURRING IN PROJECT AREA SCfENTfFlCNAME COMMON NAME STATUS FEDERAL/ STATE PRIMARY HABITAT ASSOCIATIONS STATUS uriSiiL on rUTENIIAL 10 OCCUR AMPHIBIANS Liisatinn e^diuitn Hauhcri 1 ;iine \)k-U\M salamander IS, ONI •'CSC [lak '.voi'dl'jnd, i;hapairal, coastal sage scrub, coastal dunes, conifer forest No potential: '-ot observed; no suitable habitat in project area. Scaphiopus hammondi Western spadefoot toad None/CSC, P Most common in grasslands, coastal sage scrub near rain pools or vernal pools; riparian habitats Low potential; not observed; no suitable habitat in project area. REPTILES Anniella pulcbra pulcbra Silvery legless lizard PS, CNF/CSC Loose soils (sand, loam, humus) in coastal dune, coastal sage scrub, woodlands, and riparian habitats Moderate potential; not observed; although marginally suitable habitat is present, current disturbance and nearby development may preclude their presence; the reguired humus soils are not present. Arizona elegans occidenialis Coastal (California) glossy snake None/None Grassland, chaparral, coastal sage scrub, woodlands in sandy and rocky substrates Low potential; not observed; more common in desert habitats and requires rocky outcrops. Char in a [Lichanura] trivlrgata rosea fusca Coastal rosy boa FS, CNF/None Rocky chaparral, coastal sage scrub, oak woodlands, desert and semi-desert scrub Low potential; not observed; although suitable habitat is present, current disturbance and nearby development may preclude their presence and rocky habitat feature is not present. Cnemidophorus tigris multlscutatus Coastal western whiptail None/None Coastal sage scrub, chaparral Moderate potential; not observed; although suitable habitat is present, current disturbance and nearby development may preclude their presence Cnemidophorus hyperythrus beldingi Orange throated whiptail None/CSC, P Coastal sage scrub, chaparral, grassland, juniper and oak woodland Moderate potential; not observed; although suitable habitat is present, current disturbance and nearby development may & ASSOCIATES, INC. 2798-03 February 2004 3-38 3.0 Environmentai Anaiysis TABLE 3.2-3 SENSITIVE WILDLIFE SPECIES DETECTED OR POTENTIALLY OCCURRING IN PROJECT AREA SClENTfFICNAME COMMON NAME STATOS FEDLRAU STATE PRIMARY HABITAT ASSOCIATIONS STA7US ONSITl. I'OUNIIAI rOOCLUIt preclude their presence Crotalus ruber ruber Northern red- diamond rattlesnake None/CSC Variety of shrub habitats where there is heavy brush, large rocks, or boulders Low potential; not observed; although suitable habitat is present, current disturbance and nearby development may preclude their presence and rocky habitat is not present. Phrynosoma coronatum blainvillei San Diego horned lizard FS, CNF/CSC, P Coastal sage scrub, annual grassland, chaparral, oak and riparian woodland, coniferous forest Low potential; not observed; although suitable habitat is present, current disturbance and nearby development may preclude their presence BIRDS Accipiter coaperii Cooper's hawk PIF, SBNF/CSC Riparian and oak woodlands, montane canyons. Low potential; not observed; no suitable habitat in project area. Agelaius tricolor Tricolored blackbird PIF, MNBMC/CSC Nests near fresh water, emergent wetland with cattails or tules; forages in grasslands, woodland, agriculture Low potential; not observed; no suitable habitat in project area. Aimophita ruficeps canescens So. Cal. rufous- crowned sparrow None/CSC Grass-covered hillsides, coastal sage scrub, chaparral with boulders and outcrops High potential; not observed; suitable habitat is present on slopes within the project area. Ammodramus savannarum Grasshopper sparrow PIF, SMCI None Open grassland and prairie, especially native grassland with a mix of grasses and forbs Low potential; not observed; little suitable habitat in project area. Aquila chrysaetos Golden eagle PIF, SBNF/ CSC, P Open country, especially hilly and mountainous regions; grassland, coastal sage scrub, chaparral, oak savannas, open coniferous forest Low potential; not observed; little suitable habitat in project area and adjacent development may preclude occurrence. Asia flammeus Short-eared owl PIF, MNBMC/ CSC Grassland, prairies, dunes, meadows, irrigated lands, saline and freshwater emergent wetlands Low potential; not observed; no suitable habitat in project area and adjacent & ASSOCIATES, INC. 2798-03 February 2004 3-39 Piuifs-'ionol Tfomj Cumfil" Projt 3.0 Environmentai Anaiysis TABLE 3.2-3 SENSITIVE WILDLIFE SPECIES DETECTED OR POTENTIALLY OCCURRING IN PROJECT AREA SClENTfFfCNAME COMMON NAME STATUS FEDERAL/ STATE PRIMARY HABITAT ASSOCIATIONS SI A ins ONSIII IIR POTENTIAL TD OCCUR development may preclude occurrence. Botarus lentlginosus American bittern PIF, SMC/ None Emergent habitat of freshwater marsh and vegetation borders of ponds and lakes Low potential; not observed; no suitable habitat in project area. Charadrius afexandrinus nivosus Western snowy plover FT, MNBMC/ CSC (only coastal nesting population is listed) Nesting habitat along coast includes sandy or gravelly beaches; inland nesting habitat is barren or sparsely vegetated ground at alkaline or saline lakes, reservoirs, ponds, riverine sand bars, and sewage, salt-evaporation and agriculture waste-water ponds Moderate potential for foraging; not observed; recorded for the lagoon by CNDOBbut no nesting habitat is within the project area. Circus cyaneus Northern harrier PIF/CSC Open wetlands (nesting), pasture, old fields, dry uplands, grasslands, rangelands, coastal sage scrub Low potential; not observed; little suitable habitat in project area and adjacent development may preclude occurrence. Empidonax traillii extimus Southwestern willow flycatcher FE, PIF, CMF/ SE Riparian woodlands along streams and rivers with mature, dense stands of willows or alders; may nest in thickets dominated by tamarisk Low potential; not observed; no suitable habitat in project area. Eremopbila alpestris actia California horned latk NonelCSC Open habitats, grassland, rangeland, shortgrass prairie, montane meadows, coastal plains, fallow grain fields High potential; not observed; may forage in sparse CSS and ruderal habitat; little suitable nesting habitat within project area. Ealco peregrinus ana turn American Peregrine falcon FE, FS, PIF, CNF, MNBMC/SE, P, CDF Nests on cliffs, buildings, bridges; forages in wetlands, riparian, meadows, croplands, especially where waterfowl are present Low potential; not observed; may occur as a winter visitor to forage in the lagoon; no breeding habitat is available. Haliaeetus leucocephalus Bald eagle FT, PIF, CNF/ SE, P, CDF Seacoasts, rivers, swamps, large lakes; winters at large bodies of water in lowlands and mountains Low potential; not observed; may occur as a winter visitor to forage in the lagoon; no breeding habitat is available. 2798-03 & ASSOCIATES, INC. P^o/niiVlnol Tfnrru (or CumpffT Pl-ojtcl February 2004 3-40 3.0 Environmentai Anaiysis TABLE 3.2-3 SENSITIVE WILDLIFE SPECIES DETECTED OR SCfENTlFfC NAfi^E COMMON NAME STATUS FEDERALI STATE PRIMARY HABITAT. ASSOCIATIONS STATUS ONSITE CR IMIILNIIAI ID OCCUR Icteria vuens Yellow breasted chat PII,SB?0[,' CSC Ocnse, lolatively wide riparian woodlands and thickets of willows, vine tangles and dense brush. low potential; not observed; no suitable habitat in project area. Ixobrychus exills besperis Western least bittern MNBMC/CSC Dense emergent wetland vegetation, sometimes interspersed with woody vegetation and open water Low potential; not observed; no suitable habitat in project area. Lanius ludo vie I an us Loggerhead shrike MNBMC/CSC Open ground including grassland, coastal sage scrub, broken chaparral, agriculture, riparian, open woodland Moderate potential; not observed; no breeding habitat is available, may forage onsite but available area is probably too small to be suitable. Pandion haliaetus Osprey PIF, SBNF/ CSC, CDF Large waters (lakes, reservoirs, rivers) supporting fish; usually near forest habitats, but widely observed along the coast Low potential; not observed; may occur as a winter visitor to forage in the lagoon; no breeding habitat is available. Passerculus sandwicbensis roslratus Large-billed Savannah sparrow None/CSC Saltmarsh, piekleweed Moderate potential; not observed; very little suitable habitat within project area but may be able to use it for foraging. Passerculus sandwicbensis beldingi Belding's Savannah sparrow None/SE Saltmarsh, piekleweed Moderate potential; not observed; very little suitable habitat within project area but may be able to use it for foraging. Petecanus occidentalis californicus California brown pelican FE, MNBMC/ SE, P Open sea, large water bodies, coastal bays and harbors Low potential; observed foraging with lagoon; no nesting or foraging habitat is within the project area. Plegadis cbihi White-faced ibis SMC/CSC Nests in marsh; winter foraging in shallow lacustrine waters, muddy ground of wet meadows, marshes, ponds, lakes, rivers, flooded fields and estuaries Moderate potential; not observed; no nesting habitat available but may forage within mudflat area. & ASSOCIA'ITiS, INC. 2798-03 February 2004 3-41 no! lianu/ui CDmpIci FrciyiiCi 3.0 Environmentai Anaiysis TABLE 3.2-3 SENSITIVE WILDLIFE SPECIES DETECTED OR POTENTIALLY OCCURRING IN PROJECT AREA SCIENTIFIC NAU/IE COMMON NAME STAIUS FEDERAL/ SFAIl PRIMARY HABITAT ASSOCIATIONS SIAIUS ONSITE OR POTENTIAL TO OCCUR, Polioptila californica California gnatcatcher FT, CNF/CSC Coastal sage scrub, coastal sage scrub-chaparral mix, coastal sage scrub-grassland ecolone, riparian in late summer High potential; two pairs observed in CSS habitat onsite. Ballus longirostris tevipes Light-footed clapper rail FE/SE, P Coastal saltmarsh dominated by cordgrass Low potential; not observed; no suitable habitat in project area. Speotyto cunicularia hypugaea Western burrowing owl BLM, MfJBMC/CSC Grassland, lowland scrub, agriculture, coastal dunes and other artificial open areas Moderate potential; not observed; available area is probably too small to be suitable. Sterna elegans Elegant tern MNBMC/CSC Coastal waters, estuaries, large bays and harbors, mudflats Moderate potential; not observed; no nesting habitat available; may forage in lagoon; may rest on mudflat area within project site. Sterna anlillarum browni California least tern FE, MNBMC/ SE, P Coastal waters, estuaries, large bays and harbors, mudflats; nests on sandy beaches Moderate potential; not observed; no nesting habitat available; may forage in lagoon; may rest on mudflat area within project site. Vireo belHi pusillus Least Bell's vireo FE, CNF/SE Nests in southern willow scrub with dense cover within 1-2 meters of the ground; habitat includes willows, cottonwoods, baccharis, wild blackberry or mesguite on desert areas Low potential; not observed; no suitable habitat in project area. Mammals Chaetodipus fallax fallax Northwestern San Diego pocket mouse None/CSC Coastal sage scrub, grassland, sage scrub-grassland ecotones, sparse chaparral; rocky substrates, loams and sandy loams Low potential; not observed but no live trapping was conducted; project area contains some suitable habitat but does not contain required rocky habitat. & ASSOCIATES, INC. 2798-03 February 2004 3-42 ;[ Tf oml /or Compltj ?To\t 3.0 Environmentai Anaiysis TABLE 3.2-3 SENSITIVE WILDLIFE SPECIES DETECTED OR POTENTIALLY OCCURRING IN PROJECT AREA SCIENTIFIC NAME-COMMON NAME SIAIUS FEDERAL/ STAIE PRIMARY HABITAT ASSOCIATIONS SIATUS HNSIlFflR POTENTIAL TO OCCUR Chaetodipus californicus femoraiis Oulzura California pocket mouse None/CSC Coastal sage scrub, chaparral, riparian-scrub ecotone; more mesic areas High potential; not observed but no live trapping was conducted; project area contains suitable habitat and the species is fairly common within the region. Lepus californicus bennettii San Oiego black- tailed jackrabbit None/CSC Arid habitats with open ground; grasslands, coastal sage scrub, agriculture, disturbed areas, rangelands Moderate potential; not observed; although suitable habitat is present, current disturbance and nearby development may preclude their presence Neotoma lepida intermedia San Oiego desert woodrat None/CSC Coastal sage scrub, chaparral, pinyon-juniper woodland with rock outcrops, cactus thickets, dense undergrowth High potential; not observed but no live trapping was conducted; project area contains suitable habitat and the species is fairly common within the region Onychomys torridus ramona Southern grasshopper mouse None/CSC Grassland, sparse coastal sage scrub Low potential, habitat is too dense. Perognathus longimembris pacificus Pacific pocket mouse FE/CSC Grassland, coastal sage scrub with sandy soils; along immediate coast Low potential based on location and soil; not observed and trapping was deemed not warranted; habitat not suitable in size or guality. Taxidea taxus American badger SBNF/R Dry, open treeless areas, grasslands, coastal sage scrub Moderate potential; not observed; although suitable habitat is present, current disturbance and nearby development may preclude their presence INVERTEBRATFS Panoquina errans Saltmarsh skipper None/None Salt marsh from Los Angeles to Baja, Mexico 16 individuals observed in seven locations throughout the project corridor, generally nectaring on wild heliotrope (Heliotropium currassavicumf. & ASSOCIATES, INC. 2798-03 February 2004 3-43 ol Trams ftrr Complu ProjKli 3.0 Environmentai Anaiysis TABLE 3.2-3 SENSITIVE WILDLIFE SPECIES DETECTED OR POTENTIALLY OCCURRING IN PROJECT AREA SCIENTIFIC NAME COMMON NAME SIAIUS FEDERAL/ STATE PRIMARY HABITAT ASSOCIATIONS STATUS ONSITE OR POIINIIALTO UCUUIt Fish Eucyclogobius newberryi Tidewater goby FE/CSC Low-salinity waters in coastal wetlands Low potential; not observed; no suitable habitat in project area. Gasterosteus aculeatus Threespine stickleback None/None Low-salinity waters in coastal wetlands Low potential; not observed; no suitable habitat in project area. Boldface: Draft HMP Covered species. Federal Designations: BLM Bureau of Land Management Sensitive Species CNF Cleveland National Forest Sensitive Species FE Federally-listed Endangered FS Forest Service Region 5 Sensitive Species FT Federally-listed as Threatened TABLE 3.2-3 (Continued) MNBMC PFT PIF SBNF SMC State Designations: CDF CSC P R SE ST Fish and Wildlife Service Migratory Nongame Birds of Management Concern Proposed for listing as Federally Threatened Partners in Flight Watch List San Bernardino National Forest Sensitive Fish and Wildlife Service Region ! Species of Management Concern California Department of Forestry and Fire Protection Sensitive Species California Special Concern Species California Department of Fish and Game Protected and Fully Protected Species California ftare Species State-listed as Endangered State-listed as Threatened 3.2.2.5 Sensitive Habitats Sensitive habitats are tliose that are considered rare within the region, support sensitive plant and/or wildhfe species, or function as corridors for wildhfe movement. Habitat types found onsite that are considered sensitive inchrde coastal sage scrub (including disturbed forms), southern coastal salt marsh {including disturbed forms), disturbed southern willow scrub, open water, mtertida! mudflat, and intertidal rocky heacli. Although not a habitat type, non-wetland waters (ephemeral stream channels) in two locations in the project corridor are considered sensitive. &ASSOCIATI':S, INC. 2798-03 February 2004 3-44 Pru/c. 3-0 Environmentai Anaiysis 3.2.2.6 Wildlife Corridors and Habitat Linkages Wildlife corridors are linear features that connect large patches of natural open space and provide avenues for the immigration and emigration of animals. Wildlife corridors contribute to population viability in several ways: (1) they assure the continual exchange of genes between populations which helps maintam genetic diversity; (2) they provide access to adjacent habitat areas representing additional territory for foraging and matmg; (3) they allow for a greater carrying capacity; and (4) they provide routes for colonization of habitat lands following local population extinctions or habitat recovery from ecological catastrophes (e.g., fires). Habitat linkages are patches of native habitat that function to join two larger patches of habitat. They serve as comiections between habitat patches and help reduce the adverse effects of habitat fragmentation. Although individual animals may not move through a habitat lirtkage, the linkage does represent a potential route for gene flow and long-term dispersal. Habitat linkages may serve as both habitat and avenues of gene flow for small animals such as reptiles and amphibians. Habitat linkages may be represented by continuous patches of habitat or by nearby habitat "islands" that function as "stepping stones" for dispersal. Hue to its location and surrounding residential development, the habitat present within the project site is not connected to any substantia! natural terrestrial habitat. Several small patches of coastal sage scrub occur noithcast of the site but are separated by development. These areas likely limction more as a buffer for waterbirds using the lagoon or intertidal area than as a movement corridor for upland species. I'he intertidal area also is not likely to function as a movement corridor as it is bounded on botfi the east and west ends 3.2.2.7 Regional Resource Planning In terms of compliance with regional resource plamimg documents, the Carlsbad F^raft flMP is the most recently approved document and supercedes previous plans in terms of permitted biological impacts. Other regional resource documents are discussed briefly below. The lagoon lies within Local Facilities Management Zone 1 as addressed in the City's Open Space and Conservation Resource Management Plan (1992). The planning standards for this zone include no net loss of wetlands, preservation of coastal sage scrub, and management of natural habitats adjacent to the lagoon as wetlands buffers. Unavoidable impacts should be mitigated by creation or enhancement of like habitats adjacent to the lagoon or within biological core and linkage areas. Agua Hedionda Lagoon is also regulated by the City's Agua Hedionda Land Use Plan and LCP (1982). The LCP identifies the lagoon as supporting water quality, viewshed, public use. and biological values that require protection. & ASSOCIATES, INC. 2798-03 February 2004 3-45 rm/f!!i<mol Tram! for Ciimpta P,o]CL!i 3-0 Environmentai Anaiysis The proposed project is located within the City of Carlsbad, which has a Draft HMP to guide biological resource plarming, protection and development within the City in conformance with the NCCP. At the time of this report, the Draft HMP has been approved by the City and CCC; however, the USFWS and CDFG have not issued Take Authorization for any covered species and an Implementing Agreement has not been finalized. The Draft HMP identified core and linkage areas throughout the City and focused preserve assembly on these areas. The Agua Hedionda Lagoon lies within Core 4 and has associated linkages east of the lagoon. These core and linkage areas contain important vegetation communities including saltmarsh, freshwater marsh, coastal sage scrub, southern maritime chaparral, and riparian scrub. Important populations of saltmarsh skipper, light-footed clapper rail (Rallus longirostris levipes), westem snowy plover (Charadrius alexandrinus nivosus), California least tern (Sterna antillarum browni), and Belding's Savannah sparrow (Passerculus sandwicbensis beldingi) occur in the estuarine habitats associated with Agua Hedionda Lagoon. This lagoon is also important for the California brown pelican and American peregrine falcon (Ehlco peregrinus anatum). Upland species identified as having important occurrences within this area include wart-stemmed ceanothus (Ceanothus verrucosus). Based on proposed development and biological resources, hard and sol^ line Focus Plarming Areas (FPA) are designated in the Draft HMP. Hard line areas generally require 100% conservation and soft line areas generally require specific conservation standards to be implemented during development review. The proposed project lies mostly within the hardline FPA. The project study corridor contains several habitat types considered sensitive by the Draft HMP: intertidal mudflats, intertidal rocky beach, open water, disturbed southern willow scrub, southern coastal salt marsh and coastal sage scrub. Sensitive species found within the study area, which are covered under the Draft HMP, include California gnatcatcher and salt marsh skipper. Due to the status of the Draft HMP, the impacts to sensitive biological resources may be permitted under two scenarios, referred to here as the "HMP scenario" and the "Endangered Species Act (ESA) scenario." It should be noted that in the discussion of mitigation related to the ESA scenario, impacts, which are significant under CEQA, but would not require permits or mitigation under the ESA, are discussed as well. As a public infrastructure project within the proposed FPA, the Draft HMP allows for impacts to covered habitats and species but also requires mitigation. This mitigation is identical to that which would be recommended under the ESA scenario. Therefore, although the project may be permitted under the HMP or ESA, the mitigation recommendations would not differ. 3.2.3 Criteria for Determining Significance For this analysis, the following are criteria for determining the significance of an impact based 2798-03 & ASSOCIATES, INC. February 2004 3-46 Profi.ji™al T.-BTU for Comp\a Pro/ertI Environmentai Analysis on section 15126.2 Consideration and Discussion of Significant Environmental Impacts, of the CEQA guidelines as well as the Initial Study Checklist (Appendix G of the CEQA guidelines). • Substantial adverse effect, either directly or through habitat modifications, on any species identified as a candidate, sensitive, or special status species in local or regional plans, policies, or regulations, or by the CDFG or USFWS is considered significant. • Substantial adverse effect on riparian habitat or other sensitive natural community identified in local or regional plans, policies, regulations or by the CDFG or USFWS is considered significant. • Substantial adverse effect on federally protected wetlands as defined by Section 404 of the Clean Water Act (including, but not limited to, marsh, vernal pool, coastal, etc.) through direct removal, filling, hydroiogical interruption, or other means, is considered significant. • Substantially interfering with the movement of any native resident or migratory fish or wildlife species or with established native resident or migratory wildlife corridors, or impede the use of native wildlife nursery sites is considered significant. • Conflicting with any local policies or ordinance protecting biological resources, such as a tree preservafion policy or ordinance is considered significant. • Conflicting with the provisions of an adopted Habitat Conservation Plan, Natural Community Conservation Plan or other approved local, regional or slate habitat conservation plan is considered significant. The evaluation of whether or not an impact to a particular biological resource is significant must consider both the resource itself and the role of that resource in a regional context. Substanfial impacts are those that contribute to, or result in, permanent loss of an important resource, such as a population of a rare plant or animal. Impacts may be important locally because they result in an adverse alteration of existing site conditions, but considered not significant because they do not contribute substantially to the permanent loss of that resource regionally. The determination of whether an impact can be mitigated to a level below significant is most dependent on the feasibility and availability of adequate and appropriate mitigation. 3.2.4 Potential Impacts Direct impacts would result from implementation of the first three components of the proposed project: (1) re-establishment of the sewer maintenance access road, (2) construction of a 2798-03 February 2004 2 47 a\ Ttans fiTT Cumplfx Projectj 3-0 Environmental Anaiysis shoreline protection wall, and (3) relocation of 300 feet of the sewer pipeline. Direct permanent impacts include the footprint of the proposed road, seawall, cribwalls, and areas between the road and walls. Potential direct temporary impacts may occur in three ways: (1) graded slopes and trench for sewer realigrmient; (2) a construction easement corridor surrounding all grading and trenching activity and three designated staging areas; and (3) a section of designated access road which would not have an improved surface but would be subject to long-term vehicular use. The first category of temporary impacts would result in definite short-term mechanical soil disturbance. The second category is a maximum area of potential short-term disturbance, which would likely be limited to stockpiling and construction traffic with limited soil disturbance. The final category of temporary impacts would be a long-term ongoing traffic impact with limited soil disturbance. Each of these direct impacts were quanfified separately by overlaying the footprints on the biological resources map of the site (Figures 3.2-1A through E). Indirect Impacts are very difficult to idenfify and quantify but are presumed to occur. They primarily result from adverse "edge effects": either short-term indirect impacts related to construction or long-term, chronic indirect impacts associated with the location of urban development in proximity to biological resources within natural open space. In particular, long- term indirect impacts associated with this project include the last three project components: (1) rehabilitation of manholes, (2) future maintenance and operation activities, and (3) development of a portion of the regional trail system. During construction of the project, short-term indirect impacts may include dust and noise which could disrupt habitat and species vitality temporarily and construction related soil erosion and runoff Long-term indirect impacts may include intrusions by humans and domestic pets, noise, lighting, invasion by exotic plant and wildlife species, effects of toxic chemicals {e.g., fertilizers, pesticides, herbicides, and other hazardous materials), urban runoff form developed areas, soil erosion, litter, fire, and hydroiogical changes (e.g., groundwater level and quality). 3.2.4.1 Direct Impacts Vegetation Communities and Jurisdictional Waters of the U.S./Wetlonds Construction of the access road/seawall and sewer line improvement components of the project would result in the direct permanent and temporary loss of several vegetation communities, land use types, and non-wetland waters. Potenfial permanent and temporary impacts to vegetation communities and land cover types are presented in Table 3.2-4. & ASSOCIATES, INC. 2798-03 February 2004 3-48 PTDfruiimol Tiomi fur Cimiplci Pro/f cli 3.0 Environmental Analysis Permanent Impacts Significant direct permanent impacts include 0.04 acre of intertidal mudflat, <0.01 acre of interfidal rocky beach, 0.10 acre of southern coastal sah marsh, 0.30 acre of coastal sage scrub, and <0.01 acre of unvegetated ephemeral stream channel. All other vegetation communities and land cover types with direct permanent impacts identified in Table 3.2-4 are not considered significant because the communities themselves are not rare, threatened, or otherwise sensitive. Short-Term Temporary Impacts Significant direct short-term temporary impacts include a maximum of 0.07 acre of intertidal mudflat, 0.01 acre of intertidal rocky beach, 0.10 acre of southern coastal salt marsh, <0.01 acre of disturbed southern coastal sah marsh, 0.74 acre of coastal sage scrub, <0.01 acre of disturbed coastal sage scrub, <0.01 acre of developed land within tidal jurisdicfion, and <0.01 acre of unvegetated ephemeral stream channel. All other vegetation communifies and land cover types with direct permanent impacts identified in Table 3.2-4 a.rQ not considered significant because the communities themselves are not rare, threatened, or otherwise sensitive. TABLE 3.2-4 IMPACTS TO VEGETATION COMMUNITIES AND LAND COVER TYPES WITHIN PROJECT STUDY AREA liiipactod Acreage remporary VngGtatmn (^DinmiinitiflSi' 1 and Covers Permanent Short Term Giadinq/ Trenchinti Short Term nonstriiction Long Term Total Open Water -- Intertidal Mudflat 0.04 0.07 0.02 0.13 Intertidal Rocky Beach <0.01 0.01 -0.01 Southern Coastal Salt Marsh 0.10 <0.01 0.10 --0.20 Disturbed Southern Willow Scrub •-Disturbed Southern Coastal Salt Marsh <0.01 <0.01 <0.01 Coastal Sage Scrub 0.30 0.17 0.57 1.04 Disturbed Coastal Sage Scrub <0.01 <0.01 Annual (Non-native) Grassland Eucalyptus Woodland Ruderal 0.36 0.02 0.49 0.87 Ornamental <0.01 0.12 0.09 0.20 Ornamental (Tidal Jurisdiction) 0.03 0.03 Disturbed Habitat 0.10 <0.01 0.34 0.01 0.46 Developed Land 0.01 0.07 0.19 0.27 & ASSOCIATES, INC. February 2004 2798-03 3-49 Profijiionol Ttum! for L'omjild ProjfcU 3.0 Environmentai Analysis TABLE 3.2-4 IMPACTS TO VEGETATION COMMUNITIES AND LAND COVER TYPES WITHIN PROJECT STUDY AREA Imparted Acreage Temporary Vegetation Communities,' Land Covprs Pnrmanont Short Term Grading/ Trenching Short Temi Construction Long- Term Total ' Developed Land (Tidal Jurisdiction) <0.01 <0.01 <0.01 Unvegetated Stream Channel <D.01 <0.01 <0.01 <0.01 0.01 rDFALS* 0.90 0?6 1.89 0.15 - 3.22 * Unvegetated ephemeral stream channel is an overlay on the vegetation layer and therefore is not included in the total calculations. Numbers may not total precisely due to rounding Long-Term Temporary Impacts Direct long-term temporary impacts occur in a portion of the project where compacted surfaces do not require improvement to allow regular maintenance access. Ongoing maintenance activity is not expected to change the vegetation communities or soil composition in these areas and therefore no significant impact would occur. Sensitive Plant Species Implementation of the proposed project would result in direct impacts to approximately 35 individual spiny rush plants within the project corridor. These impacts are regarded as less than significant because it is a List 4 CNPS species, and the species is fairly common along the shoreline of Agua Hedionda Lagoon. Sensitive Wildlife Species Implementation of the proposed project would result in the permanent and temporary loss of habitat that is occupied by two pairs of the federally-listed threatened coastal Califomia gnatcatcher. Construction activities may potentially impact gnatcatcher individuals. These are considered direct impacts to both pairs. The permanent and temporary loss of salt marsh habitat is considered a direct impact on the salt marsh skipper population onsite. All 16 individuals observed would be potentially impacted by the project. All impacts to native plant communities are considered a direct impact to those sensitive species not detected but with high potential to occur within the project alignment (e.g., San Diego homed lizard [Phrynosoma coronatum blainvillei], orange-throated whiptail [Cnemidophorus hyperythrus], southern Califomia mfous- crowned sparrow [Aimophila ruficeps canescens], and Dulzura Califomia pocket mouse [Chaetodipus californicus femoraiis]). 2798-03 February 2004 3-50 Pmttinanal Tfumi for CompUx PinjEdi 3.0 Environmentai Anaiysis The temporary and permanent loss of a total of up to 1.04 acres of habitat that is potentially occupied by two pairs of California gnatcatcher is considered significant. In addhion, the potential for the project construction to directly impact coastal California gnatcatcher individuals is significant. The temporary and permanent loss of up to 0.20 acre of southern coastal sah marsh potentially occupied by salt marsh skipper is not considered significant. Likewise, potential direct impacts to 16 individual butterflies observed along the alignment are not considered significant. This species is relatively common in coastal marsh enviroimients and the impacts would affect only a small portion of the available suitable habitat in the lagoon (0.20 acre of approximately 100 acres according to regional vegetation mapping). In fact, the major extent of salt marsh habitat in the lagoon occurs east of the project site. Therefore, the loss of habitat and potentially individuals would not have a substantial adverse affect on the species populafion and the species can be expected to persist at sustainable levels in this area. Direct impacts to other potentially occurring sensitive species are not considered significant because these species are relatively common and the overall loss of habitat is low compared to available upland and wetlands habitats in the sun-ounding lagoon environment. Habitat Linkages/Wildlife Corridors Due to its location and surrounding residential development, the habitat present within the project site is not coimected to any substantial natural terrestrial habitat. Several small patches of coastal sage scrub occur northeast of the site but are separated by development. These areas likely function more as a buffer for waterbirds using the lagoon or intertidal area than as a movement corridor for upland species. The intertidal area also is not likely to function as a movement corridor as it is bounded on both the east and west ends by marinas. Therefore, the proposed project would not directly impact the function of the intertidal zone as a linkage or corridor. 3.2.4.2 Indirect Impacts Vegetation Communities and Jurisdictional Waters of the U.S./Wetlands Short-Term Impacts Indirect impacts to vegetation communities primarily would result from adverse "edge effects." During construction of the access road/seawall, sewer line improvements, and manhole rehabilitation, edge effects may include dust which could disrupt plant vitality or construction related soil erosion, pollution, siltation, and runoff which can result in habitat destruction or habitat conversion. These effects may be particularly detrimental to jurisdictional wetlands and coastal sage scmb and therefore are considered significant. 2798-03 & ASSOCIATEs/lNC. February 2004 3-51 3,0 Environmentai Anaiysis Long-Term Impacts Long-term indirect impacts on vegetation communities may result from trail and sewer maintenance activities and include increased trash, introduction of exotic species, dust, and chemical pollution. Trail amenities and gating to prevent off road vehicle activity would reduce some of these effects; however these affects are still considered significant. In addition, alteration of surface hydrology due to the introduction of the access road/seawall into this coastal environment may indirectly affect plant vitality and/or type convert vegetation communities. The long-term alteration of hydrology may include changes in storm water patterns at various locations along the alignment, erosion, and sediment transfer. Although the incorporation of a decomposed granite access road surface reduces potential long-term indirect impacts related to alteration of hydrology, the general conveyance of storm water along the alignment would significantly affect adjacent sensitive vegetation communities. Sensitive Plants Most of the indirect impacts to vegetation communities cited above can also affect sensitive plants. However, sensitive plants identified within adjacent habitat to the access road/seawall are limited in extent and are not considered highly sensitive. Due to the low degree of sensitivity of this species, indirect impacts to sensitive species are not considered significant. Sensitive Wildlife Most of the indirect impacts to vegetation communities and sensitive plants cited above can also affect sensitive wildlife. In addition, short-term noise during construction of the access road/seawall, sewer line improvements, and manhole rehabilitation has the potential to affect wildlife activity including bird breeding behavior. The short-term rise in noise related to construction of the access road/seawall and the manhole rehabilitation has a potentially significant impact on California gnatcatcher breeding activity. Other short-term indirect impacts related to construction such as dust, soil erosion, pollution, siltation, and runoff would also have a significant impact on sensitive wildlife species. Long-term maintenance and trail use is expected to result in increased trash, introduction of exotic species, dust, chemical pollution and noise, fhese indirect affects may impact sensitive wildlife species occupying habitat adjacent to the alignment. Long-term indirect impacts may include increased trash, introduction of exotic species, dust, chemical pollution, and noise. Noise levels would not be of a frequency or intensity to result in significant impacts on sensitive wildlife species including California gnatcatcher. Other indirect impacts would result in significant affects on sensitive wildlife species. 2798-03 February 2004 3-52 3.0 Environmentai Analysis 3.2.4.3 Wildlife Corridors and Habitat Linkages As stated previously, the project area does not act as a habitat linkage or movement corridor for any known species and therefore these features are not indirectly impacted by implementation of the project. 3.2.5 Required Mitigation Measures 3.2.5.1 Direct Impacts Vegetation Communities and Jurisdictional Waters of the U.S./Wetlands Permanent Impacts The loss of 0.04 acre of intertidal mudflat, <0.01 acre of intertidal rocky beach, and 0.10 acre of southern coastal salt marsh, and <0.01 acre of unvegetated ephemeral stream channel shall be mitigated through like-habitat creation, within Agua Hedionda Lagoon, at a ratio of 4:1. The loss of unvegetated ephemeral stream channel can be mitigated by creation of any wetland habitat type. A preliminary location has been identified as suitable for the creation of these habitat types (Figure 3.2-2A and B). Portions of the site have been found to be currently disturbed, supporting little or no vegetation, and suitable for the creation of communities which require mitigation (0.16 acre of intertidal mudfiat, 0.01 acre of intertidal rocky beach, and 0.41 acre of southern coastal marsh). A Conceptual Wetlands Mitigation and Monitoring Plan shall be prepared, approved by the City Plaiming Director, and implemented to further the current effort towards revegetation of appropriate native habitats within the Agua Hedionda Lagoon. At a minimum, the plan shall include discussion of grading, site preparation, planting, irrigation, five-year maintenance and monitoring, and long-term preservation. The loss of 0.30 acre of coastal sage scrub shall be mitigated through the creation of like-habitat within the Agua Hedionda Lagoon area at a ratio of 1:1 and through either habitat preservation at a ratio of 1:1 within the planned Lake Calavera mitigation bank or through the creation of like- habitat within the Agua Hedionda Lagoon area at a ratio of 1:1. The total mitigation for permanent impacts to coastal sage scrub shall consist of 0.60 acre, or a 2:1 mitigation ratio. Areas within Agua Hedionda Lagoon have been identified as significantly disturbed and suitable for coastal sage scrub revegetation/creation. A Coastal Sage Scrub Mitigation and Monitoring Plan shall be prepared, approved by the City Planning Director, and implemented to further the current effort towards revegetation of appropriate native habitats within the Agua Hedionda Lagoon. At a minimum, the plan shall include discussion of grading, site preparation, planting. & ASSOCIATES, INC. 2798-03 February 2004 3-53 3-0 Environmentai Anaiysis irrigation, five-year maintenance and monitoring, and long-term preservation. Short-Term Temporary impacts The potential loss of up to 0.07 acre of intertidal mudflat, 0.01 acre of intertidal rocky beach, 0.10 acre of southern coastal sah marsh, <0.01 acre of disturbed southern coastal sah marsh, 0.74 acre of coastal sage scrub, <0.01 acre of disturbed coastal sage scmb, <0.01 acre of developed land within tidal jurisdicfion, and <0.01 acre of unvegetated ephemeral stream chamiel shall be mitigated through the restoration, in-place, at a 1:1 ratio, of appropriate habitat types immediately following construction. Restoration of trenching and disturbed construction work areas previously supporting these sensitive vegetation communities shall consist of the pre- existing vegetation type. Restoration of habitats within graded areas (i.e., slopes) shall consist of coastal sage scrub. Restoration of wetlands shall be discussed in a Conceptual Wetlands Mitigation and Monitoring Plan which shall, at a minimum, include discussion of impact assessment, recording of pre-construction site conditions, post-construction site preparation, planting, irrigation, five-year maintenance and monitoring, and long-term preservation. Restoration of uplands shall be discussed in a Coastal Sage Scrub Mitigation and Monitoring Plan which shall, at a minimum discuss impact assessment, recording of pre-construction site conditions, post-construction site preparation, planting, irrigation, maintenance, and monhoring. Sensitive Wildlife Species The permanent loss of coastal sage scrub habitat occupied by coastal California gnatcatcher shall be mitigated through deduction of credits at a 1:1 ratio at the Lake Calavera mitigation bank, 'fhis bank supports occupied coastal sage scrub and therefore provides appropriate species mitigation. The temporary loss of habitat for the species shall be mitigated through implementation of the Coastal Sage Scrub Mitigation and Monitoring Plan discussed above. In addition, the potential for direct impacts to coastal California gnatcatcher individuals shall be mitigated by restricting the clearing of coastal sage scrub within the project alignment to outside of the gnatcatcher breeding season (August 16 through February 28). 3.2.5.2 Indirect Impacts Short-Term impacts Indirect short-term impacts including dust, soil erosion, pollution, siltation, and runoff shall be reduced through implementation of typical construction BMPs and implementation of an approved Storm Water Pollution Prevention Plan (SWPPP). Implementation of these practices shall include: 2798-03 & ASSOCIATES, INC. February 2004 3-54 Pniffi-'ional Ttorru (nr Complti ProjetO •.^^H Dedication ^ Property Une SEE FIGURE 3.2-2B FOR LEGEND 200 • Scale in Feet AERIAt BASE MAP SOURCE: AERIAt ACCESS LLC, JAN/MAR 2002 North Agua Hedionda Western Segment EIR Mitigation Site Map FIGURE 3.2-2A VEGETATION TYPES/LANDCOVERS: Brackish Marsh BM DH CCSM CSS DEV Coastal Salt Marsh Coastal Sage Scrub Developed Land FWM IM ORN Disturbed Habitat Freshwater Marsh Intertidal Mudflat Ornamental NOTE: A lower case'd' in front of a vegetation type designator indicates that it is disturbed. / •-t '/ Waters of the a S. (Piumber indicates width of unvegetated channel.) O Data Station ^ y Dedication / i Property Line OW RGD SB Open Water Ruderal Sandy Beach SENSITIVE PLANT SPECIES: AP Atriplex pacifica Ja Juncus acutus ssp. leopoldii NOTE: Number indicates individual plant counts at that location. SENSITIVE ANIMAL SPECIES: CAGN California gnatcatcher North Agua Hedionda Sewer Western Segment EIR Mitigation Site Biological Resources Legend FIGURE 3.2-2B 3-0 Environmental Analysis Placement of stockpiles of soils and materials such that they cause minimal interference with onsite drainage patterns. Hay bale barriers or gravel bags will be placed along the toes of graded slopes to help reduce sedimentation during grading operations. Placement of a silt curtain or other drainage control device around construction areas to protect natural drainage channels from sedimentation. Dewatering conducted in accordance with the standard regulations of the RWQCB. A permit to discharge water from dewatering activities will be required. Use of paved roadways or designated staging areas for all equipment and vehicle refueling and maintenance. Implementation of dust control measures such as watering. temporary fencing of the limits of the temporary construction easement and staging areas with clearly visible orange construction fencing. In order to ensure that these measures are adequately protecting adjacent biological resources, construction activity related to the access road/scawall, sewer line improvements, and manhole rehabilitation would be monitored by a qualified biologist familiar with the sensitive flora and fauna of the area. Biological monitoring shall be of a frequency and duration necessary to reasonably assure that indirect impacts arc minimized. This shall include implementation of a contractor education program, verification of proper construction staking/fencing, full-time monitoring of vegetation removal periodic monitoring of construction activity adjacent to sensitive resource areas, and reporting of contractor compliance and impact minimization measures on a monthly basis. These measures shall ensure that indirect impacts on vegetation communities, including dust, erosion, sedimentation, pollution, siltation, and runoff are reduced to level below significant. Long-Term Impacts On-going indirect impacts related to maintenance and trail activities shall be mitigated through implementation of a training program for City maintenance staff and regular trail monitoring and management. The training program for City maintenance staff shall be conducted by senior Public Works and Planning staff and include discussion of biologically sensitive resource areas, existing permit regulations, seasonal restrictions, and protocols for unauthorized impacts. Trail monitoring and management shall be conducted by the City or designated management entity. The management entity shall retain qualified personnel to monitor and manage trail use such that impacts on adjacent resources are minimized. The name and contact information of the management entity shall be visibly identified on trail signs such that users can contact the appropriate trail managers regarding issues. Trail maintenance is expected to be largely conducted as part of the access road maintenance; however, additional monitoring of adjacent m 1: 2798-03 & ASSOCIATES, INC. February 2004 3-57 Ttumi fi>r Complti Pr-oirili 3-0 Environmental Analysis habitat conditions shall be conducted quarterly. The results of the monitoring effort shall be used to adaptively manage trail usage and, if necessary, to implement use restrictions. These measures shall reduce long-term indirect impacts to a level below significant by reducing unauthorized encroachment into sensitive resource areas by City maintenance staff and public trail users and reducing levels of trash, dust, exotic plant species, and chemical pollution. The potential for introduction of exotic plant species into adjacent native plant communities shall be reduced through planting of both cribs wall proposed as part of the project. The planting shall consist of native coastal sage scrub materials and shall be conducted in accordance with the Coastal Sage Scrub Mitigation and Monitoring Plan. The plan shall include, at a minimum, discussion of planting, irrigation (if necessary), maintenance and monitoring. The successful planting of the crib wall with native plant species will reduce the potential for exotic plant species invasion to a level below significant. Potential long-term indirect impacts related to alternation of hydrology shall be reduced through compliance with the City's Jurisdictional Urban Runoff Management Plan (JURMP). Compliance with the JURMP shall include proper engineering design and construction of drainage control devices to collect and direct surface water runoff to natural drainage features present along the alignment. Culverts designed into the project to collect and channel drainage from areas upstream of the road shall also be properly sized to handle storm water volumes. These measures, as well as existing project design measures such as the decomposed granite access road surface, shall reduce potential long-term indirect impacts to a level below significant. Sensitive Wildlife The permanent loss of coastal sage scrub habitat occupied by coastal California gnatcatcher shall be mitigation through the creation of 0.30 acre of coastal sage scrub within Agua Hedionda Lagoon and either the deduction of 0.30 acre credits at the Lake Calavera mitigation bank or creation of an additional 0.30 acre of coastal sage scrub within Agua Hedionda Lagoon. The temporary loss of habitat for the species shall be mitigation through implementation of the Habitat Restoration Plan discussed above. In addition, the potential for direct impacts to coastal California gnatcatcher individuals shall be mitigated by restricting the clearing of coastal sage scrub within the project alignment to outside of the gnatcatcher breeding season (August 16 through February 28). Short-term and long-term indirect impacts to sensitive wildlife arc similar to potential indirect impacts to sensitive vegetation communities. Thus, measures discussed in Sections 7.L3 and 7.L4 above, also serve to reduce indirect impacts lo sensitive wildlife. In addition, the potential short-term increase in noise related to construction of the access road/seawall, sewer line improvements, and manhole rehabilitation shall be mitigated through avoidance of construction & ASSOCIATES. INC. 2798-03 February 2004 3-58 PrafllsiDnairiom, fa, Camilla Pruif 3.0 Environmental Analysis during the gnatcatcher breeding season OR maintenance of noise levels below 60 dBA Leq at occupied nest locations. The maintenance of appropriate noise levels shall be confirmed through protocol gnatcatcher surveys to determine presence of all gnatcatcher within 500 feet of project construction and noise measurements at nest locations during peak construction activity by a qualified acoustician. 3.2.6 Significance of Impact After Mitigation and Rationale Although impacts to biological resources v/ould occur as a resuh of construction of the proposed project, all impacts would be mitigated to a level below significant. Implementation of the required mitigation measures will ensure that the identified impacts are reduced to a level below significant. 3.3 CULTURAL AND PALEANTOLOGIC RESOURCES The purpose of this section is to identify potential cultural and paleontologic resources that may occur within the project study site and to evaluate the potential impacts of implementation of the proposed project. The following analysis is based on the Cultural Resource Survey and Test Program for the Carlsbad Sewer Line Project Carlsbad. California prepared by Gailegos & Associates in i:)eeember 2003. The cultural report is included as Appendix C to this EIR and documents literature review, analysis of previous studies, as well as onsite testing. 3.3.1 Methodology Information related to the distribution and nature of potential cultural resources within the project study site were compiled through literature rcvievv', record searches conducted at South Coastal Information Center and San Diego State University, and review of previous studies conducted in the study area. Information related to the distribution of potential paleontologic resources were assembled through literature review and discussions with the San Diego Natural History Museum. The study area for the proposed project is based on the existing alignment of NAHI and encompasses a 200-foot-widc corridor generally centered on the alignment. The permanent impact area includes a 20-foot-wide corridor centered on the alignment. One cultural resource site. CA-SDl-13701, was documented within the study area. This site was tested in the field lo determine site significance. The field testing involved surface site mapping and shovel test pits to determine site size and depth (Gailegos 2003). & ASSOCIATES, INC. 2798-03 February 2004 3-59 P?D/fin'unul Tfa.ni for Camplci Piojfcli 3-0 Environmental Analysis 3.3.2 Existing Conditions 3.3.2.1 Environmental Setting The proposed project is located along the northern shore of Agua Hedionda, a major estuary in northern San Diego County. Coastal bluffs and nearby fresh water resources associated with Agua Hedionda Creek provided suitable habitation sites, as evidenced by the presence of a number of archeological sites in the project vicinity. The proximity of fresh water and food resources also contributed to the desirability of settlement. The project area has been subject to various amounts of disturbance, including the construction of the railroad in the late 1800s, the bridging of the lagoon mouth in 1910, the North Agua Hedionda sewer and access road in 1965,1-5 freeway corridor in 1967, residential development, and commercial recreational uses. SDG&E dredged Agua Hedionda and opened the lagoon mouth to permanent tidal Hushing between 1952 and 1954. 3.3.2.2 Cultural Background Prehistoric occupation of the County of San Diego dates back to 10,000 years ago and generally spans two major cultural traditions: the Early Period/Archaic (from 10,000 to 1,300 years ago) and the Late Period (1,300 years ago to historic contact). The Historic Period dates from the time the Spanish explorers arrived to present day. Early Period/Archaic Some of the earliest Archaic sites are found near coastal lagoons and river valleys of San Diego County, including Agua Hedionda Lagoon. The culture of this time is typified as a hunting and gathering society which exploited coastal and inland resources of plants, animals, shellfish and fish. The northern San Diego County coastal lagoons supported large populations circa 6,000 years ago, as shown by numerous radiocarbon dated sites adjacent to these lagoons (Gailegos 2003). A general absence of archeological sites in northem San Diego County from 3,000 years ago to 1,500 years ago may be the result of siltation in the lagoons and depletion of shellfish and other lagoon resources. Late Period The culture of this period rellects a more intensive and efficient exploitation of local resources. Artifacts and cultural patterns of this period can be found in the numerous Kumeyaay/Diegucno and Luiseno habitation sites and include small projectile points, pottery, establishment of permanent or semi-permanent seasonal village sites, acorn milling sites, the appearance of 2798-03 & ASSOCIATES, INC. February 2004 3-60 ProUiiional Ttams /m- Complex Projfcti 3.0 Environmental Analysis obsidian from Obsidian Butte, and interment by cremation (Gailegos 2003). Historic Period fhe Historic Period is characterized by the settlement of the Spanish, Mexican and American people and consists of the Spanish Period (1769 to 1821), Mexican Period (1821 to 1848) and the American Period (1848 to present day). During the Spanish Period, horses, cattle, agricidtural goods and architectural style were introduced. During the Mexican Period, cattle ranching increased and transportation routes expanded, 'fhis period ended as a result of the Mexican-American War. The American Period began when California became part of the United States as part of the Treaty of Guadalupe Hidalgo. The growth of towns occurred with the availability of free land, the agricultural economy and transportation routes. 3.3.2.3 Recorded Site The literature review and record searches conducted at the South Coast Information Center at San Diego Stale University and materials on file at Gailegos & Associates indicate two studies have been performed in the vicinity of the project study site. The result of the two studies revealed the presence of one cultural resource site, CA-SDI-13701. Site CA-SDI-13701 was initially recorded by Malcolm Rogers (circa 1920) as a habitation site containing shell, charcoal and metates located within 15 acres. The site record was updated by by Strudwick and Gailegos in 1994 as a habitation site consisting of shell, manos, firc-affected rock, and lithic tools. The site is approximately 450 meters by 300 meters in size and is located at the intersection of Adams Avenue and Highland Drive. A portion of CA-SDi-13701 was surveyed as part of another projeclin 1996 and was determined not to be a significant site. The remaining portion of CA-SDI-13701, which occurs within the project study area, was tested for significance in November 2003 by Gailegos & Associates. The results of the testing concluded that the site was not significant as defined by CEQA. The site had poor site integrity and produced a low amount of faunal materials and artifacts sufficient to address research questions (Gailegos 2003). 3.3.2.4 Paleontological Sites Paleontological resources are fossil remains of prehistoric plant and animal life, including bones, shells, leaves and pollen. Fossils are created when such items are buried, and eventually become part of geologic deposits. The geologic composition of an area, therefore, is indicative of the potential for resources lo occur. 2798-03 & ASSOCIATES. INC. February 2004 3-61 I'rofiiiionat Trams for Complrx Prt>/«lj 3-0 Environmental Analysis No known paleontological resources have been identified along the project corridor, although the possibility of encountering unknown paleontological sites docs exist. The project site is underlain by the Santiago Formation, which is considered to be moderately sensitive, in terms of fossil bearing potential (pers. comm., Hugh Wagner, Collections Manager, Department of Paleontology, San Diego Museum of Natural History, April 1999). Moderately sensitive formations may contain both invertebrate and vertebrate fossils. 3.3.3 Criteria for Determining Significance The criteria for determining significance are based on Appendix G of the CEQA Guidelines. A significant cultural resources impact would occur if Ihe proposed project is determined to: • Cause a substantial adverse change in the significance of a historical resource as defined in §15064.5, which includes (1) resources listed in or determined to he eligible by the State Historical Resources Commission, resources for listing in the California Register of Historical Resources; (2) resources included in a local register of historical resources or identifies as significant in an historical resource survey; and (3) any object, building, structure, site, area, place, record or manuscript determined by a Lead Agency to be historically significant; • Cause a substantial adverse change in the significance of an archeological resource pursuant to §15064.5; • Directly or indirectly destroy a unique paleontological resource or site or unique geologic feature; or • Disturb any human remains, including those interred outside of formal cemeteries. 3.3.4 Potential impacts 3.3.4.1 Cultural Resources Grading activities associated with the rc-establishmenl of the access road and construction of the retaining walls would destroy artifacts located within one identified cultural resource site, CA- SDI-13701. Surficial and buried artifacts would be disturbed during vegetation clearing and construction of cut and fill slopes. Also, construction of the shoreline protection structure would impact CA-SDl-13701. As part of the construction of the shoreline protection structure, piers will be installed to a depth of approximately 30 feet. Excavation for the piers may potentially destroy buried artifacts. Because the portion of CA-SDI-13701 within the project study area is not significant, impacts resulting from construction of the proposed project would be less than significant. However, there is a potential to encounter buried cultural resources during construction. Therefore, the following design feature is recommended and will be incorporated into the project. 2798-03 & ASSOCIATES, INC. February 2004 3-52 rruftisiona] Teams for Complcn Projeas 3-0 Environmental Analysis Project Design Feature • A project archaeologist shall be retained and will attend preconstruetion meetings with the construction manager and grading contractor. At this meeting, the project archaeologist will identify all areas to be monitored and be advised of the construction schedule. • The project archaeologist or his/her qualified monitor shall be present full-time during the grading or excavation of native soils and document the observations on a routine basis. • In the event of a discovery, the archaeologist or archaeological monitor shall divert, direct, or temporarily hah ground-disturbing activities in the area of discovery to allow for preliminary evaluation of potentially significant archeological resources. • For significant resources, a research design and data recovery program shall be prepared by the project archaeologist and shall be carried out to mitigate impacts prior to resumption of ground disturbing activities in the area of discovery. • If human remains are encountered, the archaeologist shall act in accordance with the California Public Resources Code and the State Health and Safety Code. Established procedures are to be followed if the remains are delermined to be Native American. • All recovered archaeological material collected is to be cleaned, catalogued and permanently curated at an appropriate institution. All artifacts and all faunal material shall be analyzed. A fmal report is to be produced within a specified time of project completion. • All sites shall be recorded at the South Coastal Information Center at San Diego State University. Project construction would occur in areas formerly inhabited by the Luiseno tribe of Native American Indians. Potential impacts to unrecorded Native American cultural sites or human remains are considered significant and require mitigation. The long term maintenance and operation of the NAHI sewer would involve field visits up to four times a year. No significant impacts as a result of maintenance and operation activities are anticipated because all work would be conducted within the sewer access road or immediately adjacent along the shoreline protection structure. No maintenance work outside of previously disturbed areas would occur. 3.3.4.2 Paleontologic Resources Implementation of the proposed project may potentially disturb unknown buried paleontologic resources. As previously mentioned, construction of the shoreline protection structure requires installation of piers to a depth of approximately 30 feet. Excavation to this depth would reach & ASSOCIATES, INC. 2798-03 February 2004 3-63 Prciff Jjifrtfll Teams fur Complrx Prujfdi 3.0 Environmental Analysis the Santiago Formation, a geologic formation with moderate sensitivity for bearing paleontologic resources. Buried fossils may physically be destroyed during excavation activities. Impacts to buried paleontologic resources are considered significant and require mitigation. The long term maintenance and operation of the NAFII sewer would involve field visits up to four times a year. No significant impacts as a result of maintenance and operation activities are anticipated because all work would be conducted within the sewer access road or immediately adjacent along the shoreline protection structure. No maintenance work outside of previously disturbed areas would occur. 3.3.5 Required Mitigation Measures 3.3.5.1 Cultural Resources The following mitigation measure shall be implemented to reduce potential impacts to unrecorded Native American cultural sites to less than significant: • The City will enter into a pre-excavation agreement with the San Luis Rey Band of Mission Indians. The purpose of the agreement will be to formalize procedures for the treatment of Native American human remains, burial, ceremonial or cultural sites that may be uncovered during any ground disturbance activity. 3.3.5.2 Paleontologic Resources Because the geologic formation underlaying the project site is considered moderately sensitive for paleontologic resources, the following mitigation measures shall be implemented: • Monitoring shall be performed by a qualified paleontologist during all new excavation activities, which are to occur along slopes with gradients steeper than 2:1. In the event that a fossil is revealed during new excavation activities, grading shall be stopped immediately and the qualified paleontologist shall conduct further study to determine the significance of an artifact or site. • The City will enter into a pre-excavation agreement with the San Luis Rey Band of Mission Indians. The purpose of the agreement will be to formalize procedures for the treatment of Native American human remains, burial, ceremonial or cultural sites that may be uncovered during any ground disturbance activity. & ASSOCIATES, INC. 2798-03 February 2004 3-64 rVofrs-iiinai Tfiiini for Camfilrx PiDjfcIs 3.0 Environmental Analysis 3.3.6 Significance of Impact After Mitigation and Rationale Although impacts to cultural resources may occur as a result of construction of the proposed project, all impacts would be mitigated to a level below significant. Implementation of the required mitigation measures will ensure that the identified impacts are reduced to a level below significant. 3.4 GEOLOGY AND SOILS The purpose of this section is to assess the existing geologic site conditions and identify potential design constraints within the project area, fhe following analysis is based on a preliminary geoteclinical investigation and a wave uprush study prepared by TerraCosta Consulting Group, Inc. (TCG) in July 2003. The geotechnical report and wave uprush study are included respectively as Appendices D and E to this EIR. 'fhe extent of the geotechnical investigation include areas between manhole number 10 to mtmhole number 20. 3.4.1 Methodology The evaluation of the geologic site conditions was conducted through a review of available geologic literature and maps, geotechnical data, aerial photographs, site reconnaissance, six exploratory borings, and results of the EQFAULT 3.0 computer search for active earthquake faults. A wave uprush study evaluated the effects of wave action and tidal Auctuations on the shoreline and assessed the potential for future shoreline erosion to degrade the proposed shoreline protection wall and existing sewer facilities. Based on the studies, potential geologic hazards were identified, as well as site constraints that may affect the design and construction of the proposed project. In addition, the affect of the project on existing sediment transport mechanisms within the lagoon shoreline environment was evaluated. 3.4.2 Existing Conditions 3.4.2.1 Soils Formational bedrock materials, including the Santiago Formation, and surf"icial units consisting of artificial fill soils, alluvial and eolluvial soils, and Quaternary Bay Deposits were encountered during field investigations (TCG 2003a). The various soil units are described below in order of increasing age and are depicted in the geotechnical report prepared by TCG. 2798-03 & ASSOCIATES, INC. February 2004 3-65 Prafc^io-al Tramz for Complrx Prujrtli 3.0 Environmental Anaiysis Artificial Fill Soils Fill soils associated with the original construction of the sewer pipeline are present along much of the existing sewer alignment. These soils appear to be locally derived and are relatively shallow. Alluvial and Colluvial Soils Alluvial and colluvial soils are present along the entire project corridor. These soils generally consist of clayey sand and sandy clay, with thin lenses of gravel and cobble. Quaternary Bay Deposits Quaternary Bay deposits are encountered in two areas: north of manhole number lOA and from near manhole numbers 12 to 16. These deposits consist primarily of loose, interbedded, silty sands and silty to sandy clays. Santiago Formation The Santiago Formation underlies the project corridor and consists of very dense, gray-brown, interbedded, well-indurated, silty to clayey sand. Flighly cemented zones may be encountered within this unit. As previously mentioned in Section 2. /, Project Background, Ihe northern shoreline of the lagoon is subject to erosion associated with wind-driven wave action. A wave uprush study, prepared by TCG, indicates that the height of wave runup is influenced by the depth of the lagoon and the fetch, the horizontal distance over which wind travels (TCG 2003b). The lagoon is considered relatively shallow with a consistent depth to the bottom ranging from -4 to -6 feet in elevation. Average wind speeds are six miles per hour (mph) and peak gusts have been recorded at 63 mph. The maximum fetch ranges from 1,200 feet to 1,400 feet with winds originating from the west-southwest to south-southwest, respectively. For wind speeds between 20 to 60 mph, wave runup would reach a maximum elevation of 7 feet MSL. fhis elevation is partially located within portions of the NAf^I sewer easement {Figures 2.4-1A through C). Areas below the 7 feet MSL are subject to wave action and shoreline erosion. Based on comparisons of topographic maps between 1965 and 1998 of the project site {Figures 2.4-1 A through C), overall shoreline retreat is apparent and estimated to occur at a rate of approximately 0.4 feet per year, plus or minus 50 percent (TCG 2003b). Over a 30-year time frame, horizontal shoreline retreat would equal 12 feet and the corresponding vertical loss of shoreline, for a beach with an 8-degree slope, would be 1.7 feet (TCG 2003b). 2798-03 & ASSOCIATES, INC. February 2004 3-66 rrfies%iima\ Teanu/m- CumplttrVo/fcli 3,o Environmental Analysis 3.4.2.2 Groundwater During the site reconnaissance, a number of groundwater seeps or areas with the predominance of phreatic vegetation (plants that grow in saturated conditions) were observed near manhole numbers 11. 16 and 17. The groundwater table is considered to be relatively shallow and fluctuates with the rise and fall of the lagoon tides ('fCG 2003a). 3.4.2.3 Faulting and Seismicity The project is located within seismically active southern California, an area where several faults and fauh zones are considered active by the California Division of Mines and Geology. Alquisl-Priolo earthquake fault zones (A-P zones) have been established for the majority of these faults and fault zones, "fhe purpose of the A-P zones is to prohibit the location of structures on the traces of active faults, thereby mitigating potential damage due to fault surface rupture. The project site is not listed in an Alquist-Priolo special study zone. The two populated areas listed in the Alquist-Priolo special study zone in San Diego County are Point Loma and La Jolla, with several areas in the sparsely populated mountains and deserts in eastern San Diego County. As part ofTCG's evaluation of geologic conditions, a search for known active earthquake faults within a 62-mile radius was conducted using the EQFAULT computer program. The search concluded that a total of 18 major active and potentially active fault zones were identified within the search radius. The nearest know active fault is the Rose Canyon Fault located approximately five miles offshore {Figure 3.4-1). During the site reconnaissance, an umiamed fault segment was noted approximately 0.3 mile north of the project site and extending across the project alignment near manltole number 16. This fault segment is considered small and not currently or potentially active. As previously mentioned, a number of active and potentially active fault zones occur within 62 miles of the project site. T'he seismic sources and their parameters for faults within 40 miles of the project site are shown on Table 3.4-1. A table that includes all the active faults generated by the EQFAUL'f for the search area can be found in the geotechnical report included as Appendix Dto this EIR As indicated in the table above. Rose Canyon Fault is the closest fault to the project site and is located approximately 5.3 miles to the west. This fault could result in an earthquake of moment magnitude 6.9. An earthquake of this magnitude has the possibility of causing damage to 2798-03 & ASSOCIATES, INC. February 2004 3-67 Profcjjiiinal Tiami fm Complti Prufat! Legend M bMd M rw •«) MM, IS>1. CWHIC SCMl t 1' - atoo' . AM n-M IM* . IwMte im. KM* M* - 1 I MOO >,M> IM Vm,k^ C«n>K k O. tin MM lU uva MOM. ROM CanytMi Fault Zon«' Ucmban •( FwA Pacific Ocean SOURCE: CITY OF CARLSBAD, GENERAL PLAN, 1994 North Agua Hedionda Sewer Western Segment EIR Seismic Fault Map FIGURE 3.4-1 3.0 Environmental Anaiysis TABLE 3.4-1 SEISMIC PARAMETERS FOR ACTIVE FAULTS Pot9ntial Causative Fault Distance from Fault to Site (miles) Maximum Earthquake Magnituc Rose Canyon 5.3 6.9 Newport-lnglewood (offshore) 6.1 6.9 Coronado Bank 21.2 7.4 Eisinore-Temecula 24.1 6.8 Elsinore-Julian 24.2 7.1 Elsinore-Glen (vy 34.3 6.8 Palos Verdes 36.5 7.1 struetures, craeks in the ground and may lead to rupture of underground pipes (TCG 2003a). The Rose Canyon Fault is considered a Type B seismic source according to the Uniform Building Code (TCG 2003a; pers. comm., Eckcrt). Geologic Hazards General geologic hazards associated with faulting and seismicity include ground lurching, ground rupture, slope instability, ground shaking, lateral spreading, liquefaction, and landslides. As previously mentioned, no known active faults occur within the project study area. Based on the site conditions and review of available literature, there is a low likelihood for hazardsassoeiated with ground lurching, ground rupture, or slope instabilit}' to occur as a result of a seismic event (TCG 2003a). Hazards associated with seismic-induced ground shaking and lateral spreading (or movement) of soil have a moderate to high likelihood of occurring within the project study area (TCG 2003a). Areas susceptible to liquefaction include areas with loose to medium dense, sandy soils that have become saturated. The existing sewer alignment is underlain by alluvial soils and the groundwater table within the project study site is relatively shallow. Therefore, the likelihood of liquefaction to occur as a result of a seismic event is considered moderate to high (TCG 2003a). Based on review of aerial photographs and the site reeomiaissance performed by TCG, no indication of a potential for a deep-seated landslide was present onsite. However, there is a likelihood for debris flow to occur during extreme rainfall events, as evidenced by previous debris flow occurrence. & ASSOCIATES, INC. 2798-03 February 2004 3-69 Pro/*jjinna! Trams for Complex Troje. 3.0 Environmental Anaiysis 3.4.3 Criteria for Determining Significance The criteria for determining significance are based on Appendix G of the CEQA Guidelines. Significant impacts resulting from existing geologic hazards and/or soil conditions would occur if the proposed project is determined to: • Expose people or structures lo potential substantial adverse effects, including the risk of loss, injury or death involving: Rupture of a known earthquake fault, as delineated on the most recent Alquist-Priolo Earthquake Fault Zoning Map issued by the State Geologist for the area or based on other substantial evidence of a known fault. Refer to Division of Mines and Geology Special Publication 42; - Strong seismic ground shaking; Seismic-related ground failure, including liquefaction; or - Landslides. • Result in substantial soil erosion or the loss of topsoil; • Be located on a geologic unit or soil that is unstable, or that would become unstable as a result of the project, and potentially resuh in on- or off-site landslide, lateral spreading, subsidence, liquefaction, or collapse; • Be located on expansive soils, as defined in Table 18 - 1-B of the Uniform Building Code (1994), creating substantial risks to life or property; or 3.4.4 Potential Impacts Geologic constraints or hazards to construction are those geologic features and events that could affect the design of struetures, create unstable conditions during construction, or cause damage to structures if seismic events were to occur. Other site factors affecting the project design include wave action and tidal fluctuation of the lagoon. Based on the preliminary studies, the geologic constraints that may be encountered, which would be most likely to affect the proposed project design and overall stability of the proposed project, are unconsolidated soils, groundwater seepage, and geologic hazards including, ground shaking, lateral spreading, liquefaction and landslides/debris flow. 2798-03 & ASSOCIATES, INC. February 2004 3-70 rVa(r..;Diia[ Trami for Complti Pro/fcli 3-0 Environmentai Anaiysis 3.4.4.1 Soils The soils encountered during the geotechnical investigation consist of fill soils, alluvium, coUuvium, bay deposits and formational soils. The formational soils are considered to be competent and would not cave or collapse during construction. The formational soils are considered stable and could support structures. The fill soils, alluvium, coUuvium, and bay deposits are comprised of loose to medium dense sands, silty sands, and clayey sands. These soils are unstable when they become saturated during periods of high tide (TCG 2003a). Placement of the shoreline protection wall and crib walls on top of these unstable soils may cause collapse of these structure and injury to people. Therefore, construction of the proposed project on unstable soils would result in a signiflcant impact and mitigation would be required. During excavation, the loose and/or saturated fill, alluvium and coUuvium soils present may cave and jeopardize the integrity of the trench, as well as injure construction workers. Exposure of people or structures to hazards associated with caving or sloughing of unstable soils during trenching is considered a signillcant impact and requires mitigation. During project construction, soil would be excavated to create a trench for the shoreline protection wall and stockpiled above ground, (jrading associated with re-establishment of the maintenance access road and construction of the crib walls would also result in movement and stockpiling of soil. There is the potential for temporary soil erosion to occur during construction activities and the loss of soil and resulting sedimentation in the lagoon is considered a signiflcant impact requiring mitigation. Post-construction, runoff from adjacent bluffs will continue to flow into the lagoon via culverts. The amount of runoff from adjacent slopes is not anticipated to be greater than existing conditions. Runoff from the re-established maintenance access road would be directed to several catch basins before entering the lagoon. Debris and material would be filtered from the runoff and not How into the lagoon. The access road would be surfaced with decomposed granite, a pervious material that may result in an increase in runoff of sediment into the lagoon. Sedimentaflon into the lagoon would degrade lagoon water quality and is considered a significant impact requiring mitigation. Post-construction, all temporarily disturbed areas and crib walls would be promptly revegetated with a hydroseed application of native plant species to reduce soil erosion. However, soil erosion and resulting sedimentation into the lagoon may potentially occur before plant establishment. Soil erosion and sedimentation into the lagoon would degrade water quality and is considered a signiflcant impact requiring miUgation. The project's potential affect on soil erosion requires analysis in two manners: 1) potential increase in erosion causing sedimentation and ground instability and 2) potential decrease in 2798-03 February 2004 3-71 a! Ttami for Compiri Prnjedi 3.0 Environmentai Anaiysis erosion causing an interruption in the natural sand replenishment mechanisms. With regard to the first manner of analysis, soil erosion along the shoreline as a result of wave action would continue to occur at natural rates on the lagoon side of the shoreline protection wall. On the landward side of the wall, soil erosion caused by wave action would not occur. Based on the wave uprush study, a wave generated by 20 to 60 mph winds would not reach the top of the shoreline protection wall (TCG 2003b). Therefore, soil erosion via wave action on the landward side of the shoreline protection wall is not anticipated. In terms of ensuring the stability of soils in this area, these affects, landward and on the lagoon side, are positive and result in a conclusion of no significant hazardous impact. With regard to the second manner of analysis, wave, water, and wind driven erosion is a natural part of the lagoon environment and all contribute to the dynamic movement of sand along this shoreline. A major component of the project is the introduction of a structure to mitigate the effects of erosion and loss of shoreline. The shoreline protection wall will have an impact on sediment transport from the bluff to the lagoon, 'fhis impact is due lo the physical interruption of sand movement from the eroding bluffs to the shoreline due to the introduction of the wall. This affect is known as passive erosion. Current CEQA guidelines do not provide criteria to determine significance of these affects. Determination of significance for this project considers existing conditions and overall project affects on the lagoon beach. Historical records (based on 1965 and 1998 topographic surveys) of the shoreline show both shoreline erosion and accretion {i.e.. accumulation of sand), depending on the location along the alignment. The difference between the Agua Hedionda lagoon environment and a seawall project on an ocean facing beach should also be noted. Ongoing dredging operations conducted within the lagoon are atypical of the ocean coastal shoreline. It is difficult to quantify the affect these operations have on the rate of erosion or accretion of sand to the lagoon shoreline. Currently, the existing shoreline is inundated during average high tides; the sandy beach during low tides extends an average of 10 to 20 feet wide. Therefore the existing condition is one where an existing relatively thin beach is shifting in width due to various environmental factors. As documented by the California Coastal Commission (ref "Report on In-Lieu Fee Beach Sand Miflgaflon Program: San Diego County", January 1997, Sherilyn Sarb, California Coastal Commission, http://www.eoastal.ea.aov/pgd/sandl.html ), improved public access improvements provided by the project may offset adverse impacts on erosive mechanisms of sediment transport. The proposed project provides stable trail access to the lagoon coastline during all tide levels where currently there is no access during even average high tides. Thus the potenflal loss of recreational sand due to passive erosion is offset by the improvement of coastal recreational access and no significant impacts are anticipated. 2798-03 February 2004 3-72 nl Tiumi for Cumplti Ptojicli 3,0 Environmentai Anaiysis 3.4.4.2 Groundwater Groundwater levels along the shoreline of Agua Hedionda are relatively shallow and likely to be encountered during construction activities. Surface Hows were observed within the project study site during field visits and may also be encountered during construction. During excavation activities, groundwater or surface water may enter trenches and expose eonstrucflon workers to hazards associated with groundwater or surface water seepage. This is considered a significant impact and mifigation is required. Cut and flll slopes above the groundwater table are considered stable at inclinations of 2:1 (horizontal lo vertical) or flatter (TCG 2003a). The project does not propose construction of nicmufactured slopes greater than 2:1, therefore slope instability due to the proximity of groundwater is not anticipated and no significant impacts would occur. 3.4.4.3 Geologic Hazards The likelihood of a seismic event producing ground shaking and lateral spreading effects are moderate to high within the project study area. Potential impacts to people or struetures are not considered significant due to features incorporated into the project design, which provide for additional structural stability. The construction of the shoreline protection structure involves installation of piers into the bedrock formation. Embedment of the piers into the bedrock provides for greater stability than compared to other methods of shoreline protection, such as a gabion wall or conventional retaining wall, which rely on gravity mass. The stability of the existing sewer and retaining wall may be compromised by Uqueflable soils located in two areas within the project site: near manhole numbers 14 and 16. While most of the existing sewer is located on stable formafional materials, these two areas are supported by unconsolidated soils. As a resuh of a seismic event, liquefacfion of the unconsoHdatcd soils may potentially cause ground settlement beneath the pipeline (TCG 2003a). Near manhole number 14, up to one-half inch of ground settlement may occur and near manliole number 16, approximately one to three inches of ground settlement is possible. Ground settlement underneath the sewer may result in a breach of the pipeline. Impacts as a result of liquefaction are considered signiflcant and require mitigation. The likelihood of a landslide within the project site causing substanfial risk to human life or struetures is considered low (TCG 2003a). Any debris flow, which may occur during an extreme rainfall event, would be removed from the access road. Landslides would result in less than significant impacts to people and structures. 2798-03 & ASSOCIATES, INC. February 2004 3-73 Pto/iiiionul Tiiimi for Comlplet Proft- 3.0 Environmentai Anaiysis 3.4.5 Required Mitigation Measures 3.4.5.1 Soils In order to mitigate for impacts associated with unstable soils, the following measures would be implemented: • All grading and site preparation shall be performed under the observation of a geotechnical engineer and in accordance with the City's Grading Ordinance, Standard Specificafions for Public Works, and the 1997 Regional Supplemental Amendments. • All unconsolidated and loose soils shall be excavated to competent soils or formational soils and benched, as required by the City's grading ordinance. Structural fill soils shall be compacted to a minimum 90 percent of the maximum dry density, as determined by ASTM Test Method D 1557-91. Moisture content in the flll shall be maintained between the optimum moisture content and three percent over optimum. In order to mitigate for impacts associated with caving of trenches during excavation activifies, the following measure would be implemented: • All trenching acfivifles shall comply with OSHA and CALOSHA requirements. Excavated areas shall be shored or sloped back for stability. Trench shields may be used in place of shoring or sloping the excavation, provided that OSHA and CALOSHA requirements are followed. Any shoring designs would be reviewed by the geotechnical engineer or other qualified personnel. Excavafion conditions would be checked in the field and adjusted as necessary. In order to mitigate impacts associated with soil erosion during construction and post- construction, measures outlined in Section 3.5.5, Required Mitigation Measures for Hydrology and Water Quality Impacts, would be implemented. 3.4.5.2 Groundwater In order to mitigate for impacts associated with groundwater or surface water encountered during excavation activities, the following measures would be implemented: • Dewatering systems, such as well point systems, would be installed during excavation of trenches to maintain stability. In addition, placement of sheet pile cut-off wall systems or cofferdams would be required if avoidance of construction activifies during high tides is not feasible. & ASSOCIATES, INC. 2798-03 February 2004 3-74 Prnfasional Troiiu for Corapltr ProyecO 3-0 Environmentai Anaiysis It should be noted that dewatering activities would require appropriate permits from the RWQCB. Water quality impacts associated with dewatering are addressed through implementation of mitigation measures described in Section 3.5.5, Required Mitigation Measures for Hydrology and Water Quality Impacts. 3.4.5.3 Geologic Hazards In order to mifigate for impacts associated with liquefacfion, the following measure would be implemented: • Liquefiable soils onsite would be subject to densificafion tlirough vibro-replacement or compaction grouting methods or some other method that results in displacement of liquefiable soils and compaetion/cemenfing of soil around the sewer pipeline. 3.4.6 Significance of Impact After Mitigation and Rationale Although impacts to the various components of the proposed project, as well as potential impacts to people and other structures may occur as a result of exisfing geotechnical constraints and soil eondifions, all impacts would be mifigated to a level below significant with implementation of the required mitigation measures. 3.5 HYDROLOGY AND WATER QUALITY The purpose of this section is to assess general surface water hydrology and water quality conditions and identify potential hydrology and water quality impacts in the project areas. The information used in this analysis is derived from the most readily available information found in applicable resource and plamiing documents. 3.5.1 Methodology 'fhe general surface water hydrology and water quality conditions of the project area were based on review of the Water Quality Control Plan for the San Diego Basin (State of California 1994), City of Carlsbad General Plan (1994) and General Plan Master EIR (1994), and the City and County of San Diego online geographical database (www.SanGIS.org) for floodplains. Aerial photography flown by Aerial Access in 2002 and vegetation cover mapped by DUDEK in 2001 and 2002 were also reviewed to determine existing land cover and vegetative cover, respectively. & ASSOCIATES, INC. Psofesiiona! Tf am. for Co-plc- Profrct: 2798-03 February 2004 3-75 3.0 Environmental Anaiysis 3.5.2 Existing Conditions 3.5.2.1 Hydrology '1 he project study site is located within the San Diego Hydrologic Region, which drains west into the Pacific Ocean. The San Diego Hydrologic Region encompasses approximately 3,900 square miles and is further subdivided into 11 major watersheds. The proposed project occurs primarily in the Carlsbad Watershed. The Carlsbad Watershed occupies approximately 210 square miles, extending from Lake Wohlford on the east to the Pacific Ocean on the west and from Vista on the north to Cardiff-by-the-Sea on the south, l^his watershed includes the cities of Oceanside, Carlsbad, Encinitas, Vista, and Escondido. The watershed is drained by Buena Vista, Agua Iledionda, San Marcos, and Escondido creeks and contains four coastal lagoons, including Buena Vista, Agua Hedionda, Bafiquitos, and San Elijo lagoons. The Carlsbad Watershed is comprised of the following six drainage basins: Loma Alta, Buena Vista Creek, Agua Hedionda, Eneinas, San Marcos, and Escondido Creek. The proposed project occurs within the Agua Hedionda drainage basin. 3.5.2.2 Floodplains The Federal Emergency Management Agency (FEMA) has mapped special flood hazard areas, which include land subject to the 100-year flood. A 100-year flood is defined as an area of land that would be inundated by a flood having a one percent chance of occurring in any given year (http://www.fema.gov, accessed April 2003). ThelOO-year flood is the standard used by most federal and state agencies and by the Nafionai Flood Insurance Program (NFIP) for floodplain management and for flood insurance purposes. The project site is located within the 100-year floodplain of Agua Hedionda Lagoon {Figure 3.5-1). 3.5.2.3 Surface Water Agua Hedionda Lagoon serves as the receiving water body for Agua Hedionda Creek. The lagoon ultimately drains into the Paeiflc Ocean. The RWQCB has identified beneflcial uses for Agua Hedionda Lagoon, including industrial, water recreation (contact and non-contact), commercial and sport fishing, estuarine habitat, wildlife habitat, threatened and endangered species, marine habitat, aquaculture, migration of aquatic organisms, and shellfish harvesting (RWQCB, San Diego Region, 1994 with revisions in 1995 and 1998). Current uses of the lagoon east of 1-5 primarily include recreational water sports. A commercial boat rental area is located at the western portion of the project site, and a boat launch and private marina associated with the Cove Drive residences are located at the eastern end of the project & ASSOCIATES, INC. 2798-03 February 2004 3-76 Piofeasipnol TCUTTIJ/ITT Compltx PTOJCCII North Agua Hedionda Sewer Western Segment EIR 100 Year Flood Plain FIGURE 3.5-1 3.0 Environmentai Anaiysis site. The lagoon also supports estuarine habitat, wildlife habitat and sensitive plant and wildlife species, as shown on Figures 3.2-1A through E. 3.5.2.4 Groundwater Groundwater is defined as subsurface water that occurs beneath the water table in fully saturated soils and geologic formations. Groundwater bearing formations sufflciently permeable to transmit and yield significant quantities of water are called aquifers. However, there arc groundwater bearing geologic formations within the area that do not meet the definition of an aquifer. As stated in the San Diego Basin Plan, principal groundwater basins in the San Diego Region are small and shallow. Only a small portion of the region is underlain by permeable geologic formations that can accept, transmit and yield appreciable quantities of groundwater (RWQCB, San Diego Region, 1994 with revisions in 1995 and 1998). A number of groundwater seeps or areas with the predominance of phreatic vegetation (plants that grow in saturated conditions) were observed near manhole numbers 11,16 and 17 during a geotechnical field visit, 'fhe groundwater table is relatively shallow and fluctuates with the lagoon tides. 3.5.2.5 Water Quality Water quality refers to the effect of natural and human activities on the composition of water. Water quality is expressed in terms of measurable physical and chemical qualities that can be related to planned water use. According to the San Diego Basin Plan, Agua Hedionda Lagoon has the following beneflcial uses: industrial, water recreation (contact and non-contact), commercial and sport fishing, estuarine habitat, wildlife habitat, threatened and endangered species, marine habitat, aquaculture, migration of aquatic organisms, and shellfish harvesting. Agua Hedionda Lagoon is listed on the Environmental Protection Agency (EPA)/RWQCB list of impaired water bodies (EPA/RWQCB1998). This list, compiled pursuant to Section 303(d) of the Clean Water Act, identifies all water bodies, which support pollutant levels in excess of those allowable for each beneflcial use outlined for the specific water body. Main pollutants/stress or s of Agua Hedionda Lagoon include high eoliform count and sedimentafion/siltation. 3.5.2.6 Applicable Plans and Policies The principle federal taw regulating surface water quality is the 1972 Clean Water Act. The Clean Water Act sets up a system of water quality standards, discharge limitations, and permits. Under Section 404 of the Clean Water Act, the ACOE regulates discharges of dredged or fill material into waters of the U.S. Activities that may result in the dredge or flll of waters of the & ASSOCIATES, INC. 2798-03 February 2004 3-78 Profn^iortal Tea™ for Camp\!x Proje 3.0 Environmentai Anaiysis U.S. require issuance of a Section 404 pemiit from the ACOE. Under Section 401 of the Clean Water Act, a state water quality certifleation must be obtained whenever an application for a federal permh for discharge of pollutants into waters of the U.S., such as a Section 404 permh, is submitted. The Section 401 certifleation requires any activity affecting waters of the U.S. be in compliance with all applicable water quality standards, limitations and restrictions. Division 7 of the California Water Code, commonly referred to as the state Porter-Cologne Water Quality Act, is the principal state law enacted to establish requirements for adequate planning, implementation, management, and enforcement for the control of water quality. This act established a regulatory program to protect water quality and beneficial uses of all state waters. The act also established the State Water Resources Control Board (SWRCB) and RWQCB as state agencies responsible for water quality control. For the San Diego Hydrologic Region, water quality is regulated by the RWQCB. Region 9 of the SWRCB. Conformance with the Clean Water Act and Porter-Cologne Water Quality Act is required for any discharges, including erosion, into waters of the U.S. through compliance with the SWRCB's NPDES General Construction Permit. Issuance of a NPDES Permit requires preparation of a Notice of Intent with the SWRCB and development of a SWPPP and monitoring program that incorporates applicable BMPs. Construction activity would also be subject to the erosion control requirements set forth in the City's Grading Ordinance. Other applicable regulations include Sections 1601-1603 of the California Fish and Game Code, 'fhe CDFG regulates wetland areas as defined by the Fish and Game Code. A Secfion 1601/1603 Streambed Alterafion Agreement is required from CDFG whenever CDFG jurisdictional wetlands are altered or fish or wildlife resources are adversely affected. Addifional information related to wetlands is found in Section 3.2, Biological Resources. 3.5.3 Criteria for Determining Significance A significant impact to hydrology or water quality would occur if the proposed project is determined to: Hydrology • Substantially aher the existing drainage pattern of the site or area, including through the alteration of the course of a stream or river, in a manner which would result in substantial erosion or siltafion on- or off-site; • Substantially alter the existing drainage pattern of the site or area, including through the alteration of the course of a stream or river, or substantially increase the flow rate or & ASSOCIATES, INC. 2798-03 February 2004 3-79 Environmentai Anaiysis amount (volume) of surface runoff in a manner, which would result in flooding on- or off-site; Create or contribute runoff water, which would exceed the capacity of existing or planned stormwater drainage systems or provide substantial additional sources of polluted runoff; • Result in inundation by seiche, tsunami, or mudflow; Floodplains Place within 100-year flood hazard area structures, which would impede or redirect flood flows; Expose people or structures to a signiflcant risk of loss injury or death involving flooding, including flooding as a resuh of the failure of a levee or dam; Surface Water Result in increased erosion (sediment) into receiving surface waters; Result in increased pollutant discharges (e.g., heavy metals, pathogens, petroleum derivatives, synthetic organics, nutrients, oxygen-demanding substances and trash) into receiving surface waters or other alteration of receiving surface water quality (e.g., temperature, dissolved oxygen or turbidity); Groundwater Substantially deplete groundwater supplies or interfere substantially with ground water recharge such that there would be a net deficit in aquifer volume or a lowering of the local ground water table level {i.e., the production rate of pre-existing nearby wells would drop to a level which would not support existing land uses or plamied uses for which permits have been granted); • Resuh in impacts to groundwater quality; Water Quality Violate any water quality standards or waste discharge requirements; • Otherwise substantially degrade water quality; & ASSOCIATES, INC. 2798-03 February 2004 3-80 [Vipfri-iionul Tromi for Complrx PtoircIS Environmentai Anaiysis Result in changes to receiving water quality (marine, fresh or wetland waters) during or following construction; Result in increases in any pollutant to an already impaired water body as listed on the Clean Water Act Section 303(d) list; or Result in the exceedanee of applicable surface or groundwater receiving water quality objectives or degradation of beneflcial uses. 3.5.4 Potential Impacts 3.5.4.1 Hydrology With implementation of the proposed project, surface flow from adjacent coastal bluffs would continue to drain into the lagoon. No feature of the project would substantially alter the existing drainage patterns in such a manner that would alter the course of any waterway or increase surface water flows into the Agua Hedionda drainage basin. No impacts to hydrology are anticipated to occur as a result of the proposed project. 3.5.4.2 Floodplains The proposed project >s located tn the 100-year floodplain, as defined by FEMA. The proposed nroiect involves re-establ,shmcnt, construction of a shoreline protection structure, relocation ol a portion of sewer pipeline, rehabilitation of manholes, and development of trail amenities. It is unlikely that the project components occurring within the 100-year floodplain would impede or redirect flow because the majority of the project components would be placed underground or be placed relatively flush with existing contours. Therefore, impacts associated with placement of structures in a 100-year floodplain arc considered less than sigmficant. 3.5.4.3 Surface Water The beneficial uses of Agua Iledionda lagoon would not be affected by the proposed project. No change in the capacity of the lagoon as a result of the project would occur; therefore, recreational uses will not be impacted. The project does not propose a change in land use or resuh m degradation of water quality (see discussion regarding water quality) such that existing functions and values of the lagoon supporting estuarine habitat, wildlife habitat, threatened and endangered species marine habitat, aquaculture, migration of aquatic organisms, and shellfish harvesting would be impacted. Therefore, less than significant impacts to the beneficial uses of Agua I ledionda Lagoon would occur. & ASSOCIATES, INC. February 2004 Prolrsiiotal Tearni for Ctmplrx Projt 3.0 Environmentai Anaiysis 3.5.4.4 Groundwater Groundwater will likely be encountered during excavation for construction of the shoreline protection wall and sewer pipeline improvements. As previously stated in Section 3.4.5 Required Mitigation Measures for Geology and Soils, dewatering will be required in order to mitigate for impacts associated with groundwater seepage into excavation areas and help maintain stability of trenches. Dewatering activities would not substantially deplete groundwater supply, as such activities would be temporary. Therefore, impacts to groundwater supplies as a result of dewatering activities would be less than significant. Groundwater recharge would not be affected by the proposed project. The project is not introducing a substantial amount of impervious surfaces and decomposed granite, a pervious material, would be used for the access road surface. Constmction of the shoreline protection wall would require thai the wall be embedded approximately two feet below ground and piers be installed up to 30 feet deep. The below ground portions of the shoreline protection wall and the relocated pipeline would not alter groundwater integrity or characteristics as a relatively small area would be affected. Therefore, impacts associated with groundwater recharge or quality would be less than significant. 3.5.4.5 Water Quality During construction, soil will be temporarily removed from excavated and graded areas and stockpiled above ground. Potential turbidity effects may occur to the lagoon as a result of sediment-laden runolTfrom the construction site. The influx of sediment into the lagoon would increase the total dissolved solids. Degradation of existing water quality is considered a significant impact requiring mifigation. As previously mentioned in Section 3.4.5, Required Mitigation Measures for Geology and Soils, in order to mitigate for impacts associated with the seepage of groundwater or surface water during excavation activities, dewatering is required. Because the composition of the groundwater is unknown, the water quality of the lagoon may be altered as a result of dewatering. Potential degradation of existing water quality is considered a significant impact and requires mhigation. Post-construction, runoff from adjacent bluffs will continue to flow into the lagoon via culverts. The amount of runoff from adjacent slopes is not anticipated to be greater than existing conditions. Runoff from the re-established maintenance access road would be directed to several catch basins before entering the lagoon. Debris and material would be filtered from the runoff and not flow into the lagoon. The access road would be surfaced with decomposed granite, a pervious material that may result in an increase in runoff of sediment into the lagoon. & ASSOCIATES', INC. Praftjjional Tiomi fa, Complu Ptoifcl. 2798-03 February 2004 3-82 3.0 Environmentai Anaiysis Sedimentation into the lagoon would degrade lagoon water quality and is considered a signiflcant impact requiring mitigation. Post-construction, all temporarily disturbed areas and crib walls would be promptly revegetated with a hydroseed application of native plant species to reduce soil erosion, flowever, soil erosion and resuhing sedimentation into the lagoon may potentially occur before plant establisliment. Soil erosion and sedimentation into the lagoon would degrade water quality and is considered a significant impact requiring mhigation. Equipment required for construction will include cranes, excavators, front end loaders, delivery (dump) trucks, soil compactors, pumps for dewatering, desilting tanks and/or graders. During maintenance and operation activities, equipment would include Vactor and haul trucks. Although all equipment and vehicles would be stored within staging areas during construction and restricted to the access road during maintenance activities, there is a potential for accidental spills of hazardous materials to occur adjacent to the lagoon. Potenfial impacts associated with a hazardous materials spill are considered significant and require mitigafion. 3.5.5 Required Mitigation Measures In order to mitigate for impacts to water quality during project construction, the following measures would be implemented: • Stockpiles of soils and materials shall be placed such that they cause minimal interference with onsite drainage patterns. In the event of rain, all stockpiles shall be covered with an impermeable tarp. Stockpiles of brush, loose soil or other similar debris shall not be placed within any stream channel or on its banks. • Drainage control devices will be constructed to direct surface water runoff away from slopes and waterways; hay bale barriers or sandbags would be placed along the toes of graded slopes to help reduce sedimentation during grading operations. • A silt curtain or other drainage control device will be placed around construction areas to protect natural drainage channels from sedimentation. In order to mitigate for impacts to water quality associated with dewatering, the following measures would be implemented: • Dewatering would be conducted in accordance vv'ith the standard regulations of the RWQCB. A permit to discharge water from dewatering activities will be required. & AySOCIATES, INC, 2798-03 February 2004 3-83 Pxi/ciiLDnal Tfuml/m Complrx Projtcti 3.0 Environmentai Anaiysis • The City shall obtain a NPDES General Storm Water Permit. The permit will require the City to outline all BMPs planned in order to reduce potential water quality impacts. At a minimum the BMPs would include discharging water through silt fencing or other pervious materials to remove silt prior to entry into the lagoon. • The City shall prepare and implement a SWPPP that describes the site-specific implementafion of the BMPs. In order to mitigate for long-term water quality impacts, the following measures would be implemented: • The City would comply with its JURMP. Compliance with the JURMP shall include proper engineering design and construefion of drainage control devices to collect and direct surface water runoff to natural drainage features present along the alignment. Culverts designed into the project to collect and channel drainage from areas upstream of the road shall also be properly sized to handle storm water volumes. • During the plant establisliment period, silt fencing, hay bale barriers or sandbags would be placed along the toes of temporarily disturbed slopes to reduce soil erosion and sedimentation into the lagoon. In order to mitigate for impacts associated with potenfial hazardous materials spills, the following measures would be implemented: • All equipment and vehicles required for construction, maintenance and operafion shall be refueled or maintained within paved roadways or designated staging areas. All stationary equipment, such as motors or generators, would be stored on the existing access road or designated staging areas. When equipment is being utilized along the access road, drip pans shall be placed under all potenfial discharge conduits or leaks. All connections and fittings of hoses would be periodically cheeked for leaks. • All project related spills of hazardous materials shall be reported to the appropriate enfifies, including the USFWS, CDFG, RWQCB, and shall be cleaned up immediately. Contaminated soils shall be removed to approved disposal areas. 3.5.6 Significance of Impact After Mitigation and Rationale Impacts to water quality associated with grading, dewatering and maintenance aefivities can be mitigated to less than signiflcant by implemenfing the mitigation measures described above. & ASSOCIATES, INC. T=u.n> for Complr, Proj.cl, 2798-03 February 2004 3-84 SECTION 4.0 ALTERNATIVES 4.1 PURPOSE Section 15126.6 of the CEQA Guidelines states that the purpose of the Project Altematives section of an EIR is to assess a range of reasonable altematives to the project which would reasonably attain most of the basic objectives of the project, but which would avoid or substantially lessen any of the significant effects of the proposed project. The purpose of this section is also to evaluate the comparative merits of each alternative. According to the CEQA Guidelines, discussion of each altemative should be sufficient "to allow meaningful evaluation, analysis and comparison with the proposed project." Therefore, the significant effects of each alteniafive are discussed in less detail than those of the project, but in enough detail to provide decision-makers perspective and a reasoned choice among altematives to the proposed project. 4.2 BACKGROUND Altematives to the proposed project were developed that considered the objectives of the project. The project objectives, described in Section 2.3, Project Objectives, include protection of the sewer pipeline from future failure, collapse, or leakage resulting from shoreline erosion; establishment of access to conduct regular maintenance; providing reliable sewer sen'icc to existing and planned development; development of a portion of the regional trail system; avoidance of impacts to biological resources to the maximum extent possible during constmction and future maintenance and operation activities; and preservation of lagoon aesthetics and passive recreation opportunifies. Various design concepts for the shoreline protection and access road components of the project were considered in the course of project design. These designs differ from the proposed project in terms of construction methodology, structural integrity, and size of overall development footprint. A description of the various design opfions for the shoreline protection method and access road that were eliminated from further consideration due to their failure to meet the basic project objectives is provided in Section 4.2.T Section 4.3 describes the project altematives that could potenfially meet the project objectives. 2798-03 lATES, INC.] February 2004 4-1 4.0 Alternatives 4.2.1 Design Concepts Eliminated for Shoreline Protection and Access Road 4.2.1.1 Shoreline Protection Methods Various types of shoreline protection were considered to protect the gravity sewer from future failure, collapse, or leakage resulting from shoreline erosion. These alternatives include • Gabion/Terramesh wall system • Conventional retaining wall with carved concrete facade • Sheet pile wall with carved concrete facade A detailed discussion of each construction method of shoreline protection is provided in the Geotechnical Investigation Report (Appendix D). Provided below is a short description of each type of shoreline protection with an emphasis on construction limitations and overall integrity. Gabion/Terramesh Wall System The Gabion/Terramesh wall system consists of cobble, rock, and gravel-filled wire mesh baskets that are generally stacked and connected together. This wall alternative has the ability to support vegetation growth but may not support a sculpted facade due to the flexibility of the wall itself I he construction footprint for the Ciabion/'I erramesh wall would require access on both side of the seawall. In order to provide adequate support, the permanent footprint of the Gabion/Terramesh wall (or the width of the wall) would be, at a minimum, equal to the height of the wall. Because the permanent footprint of this type of wall is based on the height of the wall, it is likely that the width of the wall system would extend beyond the centerline of the sewer alignment. Access to these portions of the sewer alignment would be precluded; therefore this alternative would not meet a project objective and the City has eliminated this shoreline protection alternative from further consideration. Conventional Retaining Wall with Carved Concrete Facade The conventional retaining wall with carved concrete facade would consist of a wall with a minimum width based on the height of the wall and a wall face that could be colored and textured to simulate adjacent coastal bluffs. fhis wall would be more rigid than the Gabion/Terramesh structure, which would present problems of cracking when settlement occurs over time. Although expansion joints can be designed into the wall to reduce this effect, the construction of this detail would be expensive. Similar to the Gabion/Terramesh wall system, in order to provide adequate support, it is likely that this wall system would extend beyond the centerline of the sewer aligimient. Access to these portions of the sewer alignment would be & ASSOCIATES, INC. 2798^03 February 2004 4-2 Pro/cijional Ttains (or CompXrx I'Tofiiiti 4.0 Alternatives precluded; therefore this alternative would not meet a project objective and the City has eliminated this shoreline protection alternative from further consideration. Sheet Pile Wall with Carved Concrete Facade Construction of the sheet pile wall with carved concrete facade involves embedment of sheet pile into the underlying bedrock for stability. The wall face could be colored and textured to simulate adjacent coastal bluffs with this wall alternative. Because the sheet pile wall is embedded into the bedrock for stability, the issue of the wall width extending into the sewer alignment is not a concern. However, along certain portions of the alignment, embedding the sheet pile is not possible due to variability in the depth to bedrock. Therefore this alternative could not be used for the entire length of the project, fhis alternative alone would not meet the shoreline protection objective of the project and therefore the City has eliminated the sheet pile wall from further consideration. 4.2.1.2 Elevated Access Road Design The Elevated Access Road design is a typical road construction method that provides a level road over the entire sewer aligmnent. This type of road would extend from approximately Hoover Street to Cove Drive. In order to achieve a level road surface, the topography in certain areas would be filled in or "elevated". In areas where a steep slope currently exists adjacent to the sewer alignment, a 2:1 cut slope would be necessary for ground stability. The Elevated Access Road would not reduce or avoid any significant impacts and would result in greater impacts to sensitive biological resources when compared to the Non-elevated Access Road and Segmented Access Road. For this reason, the City has eliminated this access road design from further consideration. 4.3 ANALYSIS OF PROJECT ALTERNATIVES Based on the preliminary evaluation of the various options for shoreline protection, access road and NAHI alignment, a total of four project alternatives have been identified for further analysis in the EIR. The four alternatives include the No Project Altemative, Sand Replenishment Alternative, Segmented Road Alternative, and the Pump Station/Forcemain Alternative. These four project alternatives are considered to represent a reasonable range of alternatives. A description of the alternatives and comparative analysis of the merits of each altemative are provided below. 4.3.1 No Project Alternative The No Project Alternative would consist of continued use of the existing NAHI. No direct impacts to aesthetics, biological resources, cultural resources, geology/soils and water quality 2798-03 & ASSOCIATES, INC. February 2004 4-3 ProfeJiif nal Teunu for Compl« Prnjfctj 4,0 Alternatives would occur. City public works staff would attempt to conduct maintenance to the manholes that are accessible; however, due to the inability to reach various portions of the sewer aligmnent with maintenance vehicles and equipment, a number of manlioles would not be maintained. The NAHI sewer would continue to be subject to wave action and shoreline erosion, as shoreline protection would not occur with this alternative, 'fhe No Project Alternative would not fulfill any of the project objectives as described in Section 2.3. 4.3.2 Sand Replenishment Alternative This alternative involves the re-establishment of an access road identical to the proposed project. The entire sewer alignment and associated manholes would be accessible for ongoing maintenance and operation activities. The access road and sewer would be protected from shoreline erosion through placement of sand on the lagoon side of the road. A 2:1 slope would be created and ongoing sand replenishment activity would be required as the placed sand gradually erodes into the lagoon. Figure 4.3-1 illustrates the overall footprint of the access road and the area where sand replenishment w^ould occur. The City considered sand replenishment as a means of shoreline protection in order to avoid the visual impacts that are typically associated with permanent structures, like a sea wall. However, maintenance efforts would be greater with the sand replenishment alternative, as the sand would need to be continually replenished. In addition, greater wetlands impacts would be incurred due to the placement of sand in areas currently supporting wetlands habitats. 4.3.2.1 Aesthetics Impacts to aesthetics associated with the Sand Replenishment Alternative would be less than the proposed project, as shoreline protection under this alternative would be provided through sand replenishment. The areas that would be replenished with sand would be contiguous with the existing sandy beach along Agua Hedionda Lagoon. Impacts associated with re-establishment of the access road would be the same as the proposed project. However, no signiflcant unmitigable impacts were identifled for the proposed project. Therefore, Sand Replenishment Alternative does not provide for mitigation of significant impacts that could not be achieved under the proposed project. 4.3.2.2 Biology This alternafive would result in greater impacts to biological resources due to the placement of sand on sensitive wetkmds habitats occurring on the lagoon side of the sewer pipeline. Although sand would have some biological function, and certainly more funcfion than a sea wall, the ongoing maintenance required to replenish sand, limits its biological value and requires that the sand placement be considered a permanent impact. This alternative would result in an increase in permanent impacts to southern coastal salt marsh, intertidal mudflat, and intertidal rocky 2798-03 & ASSOCIATES, INC. February 2004 Profrssio-nitl Trains for Cumplti Proitdi OW VEGETATION TYPES/LANDCOVERS: AGL Annual Grassland DH Disturbed Habitat ORN Ornamental CSM Coastal Salt Marsh EClC I Eucalyptus Woodland OW I Open Water / \ ' Study Area Limit of Grading CSS I Coastal Sage Scrub IM Intertidal Mudflat ROD Ruderal DEV I Developed Und IRB Intertidal Rocky Beach SWS Southern Willow Scrub NOTE: A lower case'd' in front of a vegetation type designator indicates that it is disturbed. An upper case 'J' following a vegetation type designator indicates that it is jurisdictional. Scale in Feet BASE PHOTO SOURCE: CITY OF CARLSBAD North Agua Hedionda Sewer Western Segment EIR Access Road with Sand Replenishment Alternative FIGURE 4.3-1 4.0 Alternatives beach from 0.14 acre to 0.51 acre. For this reason, this alternafive is not consistent with federal and state policies related to avoidance and minimization of impacts to wetlands. Mitigation for this alternative, consisting of creation of tidal wetlands habitats, would be substantially greater (0.56 acre under the proposed project and 2.04 acres under this altemative) and may not be achievable within existing disturbed habitat in Agua Hedionda Lagoon. In addition, the increase maintenance activity associated with this alternative would result in greater long-term indirect impacts to both upland and wetland species. 4.3.2.3 Cultural Impacts to cultural resources would be less than the proposed project under this altemative. While potential impacts to buried cultural resources may occur during re-establishment of the access road, no impacts are anticipated to occur as a result of sand replenishment activities. No excavation or trenching will be required for sand replenishment and maintenance of the sand would not likely affect buried cultural resources. 4.3.2.4 Geology/Soils Impacts related to the loss of soil during construction of the access road are anticipated to be the same as the proposed project. Sand replenishment activities would have a greater potential to result in long-term impacts associated with sand erosion and sedimentation to the lagoon. Additional mitigation measures would be necessary to reduce significant impacts. 4.3.2.5 Hydrology and Water Quality Water quality impacts associated with this alternative would be greater than the proposed project. Over time, it is anticipated that wave action will erode the shoreline and transport the replenished sand into the lagoon. The rate of sediment transport would need to be evaluated; however, any increase in turbidity is considered a significant impact to water quality. The proposed project does not result in any significant post-construction water quality impacts, therefore additional mitigation measures would need to be provided to reduce water quality impacts associated with the Sand Replenishment Altemative to less than significant. 4.3.3 Segmented Access Road Alternative Under this alternative, the City would constmct a total of four perpendicular spur roads from Adams Street to conduct maintenance on the manholes and sewer pipeline. Each spur road would be a 12-foot wide paved road with a turnaround area at each terminus. Temporary impacts resulting from cut/fill slopes would occur but cannot be identified without detailed engineering design. The City considered this type of access road design in order to reduce the lineal feet of road required to maintain the NAHI and to shift the road away from the lagoon 2798-03 UDEK &ASSCX:iATES, INC. February 2004 4-6 Proffsjicmal Teaim for Complex Projects 4.0 Alternatives shoreline. This altemative would provide City maintenance crews with direct access to 15 of 20 existing/new manlioles, which would allow cleaning of the entire sewer alignment. The five manholes, which would not be directly accessible, would require one-time temporary access for rehabilitation but would not be further maintained. The City would also need to constmct a cast- in-drilled-hole (CIDH) pier wall similar to the one identified for the proposed project, as a means of shoreline protection. Figure 4.3-2 depicts the location of the segmented access road and the shoreline protection structure. 4.3.3.1 Aesthetics Potential impacts to aesthetics associated with the Segmented Access Road Alternative would be greater than the proposed project due to the visibility of the paved spur roads from public roadways and other public view points. Views of the paved spur roads would be available to motorists traveling along Adams Street, which is designated as a scenic corridor in the City of Carlsbad General Plan. These spur roads would also be visible from Cannon Road, 1-5 northbound, and by recreational users of Agua Hedionda Lagoon. Constmction of the shoreline protection wall would result in similar impacts as the proposed project. As previously described, the face of the wall would be colored and textured to blend in with the adjacent coastal bluffs. Additional mitigation to reduce the visual impacts of the paved spur roads to motorists traveling along designated scenic roadways would be required under this altemative. 4.3.3.2 Biology Potential impacts to biological resources associated with the segmented road alternative include an increase in the permanent loss of coastal sage scrub (from 0.3 acre to 0.5 acre) and a decrease in the permanent loss of tidal wetlands (0.10 acre to 0.04 acre) when compared with the proposed project. The permanent loss of coastal sage scmb would be approximately 67% greater, whereas the permanent loss of tidal wetlands would be approximately 60% less. The segmented roads under this alternative would have a greater impact on California gnatcatcher and other upland wildlife due to the increase in edge effects associated with four spur roads compared with one linear road. Temporary impacts associated with road cut/fill slopes would result in a temporal loss of coastal sage scmb between the time of impact and successful revegetation. This altemative would require greater upland mitigation but reduced wetlands mitigation. 4.3.3.3 Cultural Cultural resource impacts associated with the Segmented Access Road Alternative are anticipated to be similar to those of the proposed project, as both the proposed project and the Segmented Access Road Altemative are generally located in the same area. Therefore, the Segmented Access Road Wall Alternative does not provide for mitigation of significant impacts that could not be achieved under the proposed project. 2798-03 DUDEK & ASSOCIATES, INC. February 2004 4-7 Pro/tsJionol Ttam5 for Complex Pro/rcli VEGETATION TYPES/LANDCOVERS I AGL I Annual Grassland DH Disturbed Habitat ORN Ornamental CSM Coastal Salt Marsh / '\ /' Study Area Limits of Grading EaC I Eucalyptus Woodland OW I Open Water CSS I Coastal Sage Scrub IM Intertidal Mudflat RUD Ruderal DEV I Developed Land IRB I Intertidal Rocky Beach SWS I Southern Willow Scnjb NOTE: A lower case'd' in front of a vegetation type designator indicates that it is disturbed. An upper case 'J' following a vegetation type designator indicates that it is jurisdictional. 200 Scale in Feet BASE PHOTO SOURCE: CITY OF CARLSBAD North Agua Hedionda Sewer Western Segment EIR Segmented Access Road with Shoreline Protection Wall FIGURE 4.3-2 4.0 Alternatives 4.3.3.4 Geology/Soils Impacts to geology and soils that would be associated with the Segmented Access Road Alternative are anticipated to be similar to those of the proposed project, as both the proposed project and the Segmented Access Road Altemative are generally located in the same area. No significant unmitigable impacts were identified for the proposed project. Therefore, the Segmented Access Road and CIDH Wall Altemative does not provide for mitigation of significant impacts that could not be achieved under the proposed project. 4.3.3.5 Hydrology and Water Quality Impacts to hydrology and water quality would be greater under the Segmented Access Road Altemative. The spur roads would occupy a slightly larger area than the proposed linear road (1.0 acre of spur roads vs. 0.80 acre of linear access road). In addition, the spur roads would be steeper and paved. The paved surface would introduce a new impervious surface adjacent to the lagoon and any petrochemicals/pollutants collected on the paved road may be transported towards the lagoon. For this reason, post-construction water quality impacts are more likely to occur with this alternative than with the proposed project. Mitigation that included post- constmction BMPs to reduce potential water quality impacts would be required under this alternative. 4.3.4 Pump Station/Forcemain Alternative The NAHI is a gravity sewer pipeline and is located at a lower elevation than its surrounding service area. It would be possible to avoid conveying sewage through the portion of NAHI within the project study area by pumping and conveying sewage flows through an altemative route. A pump station, forcemain, and numerous individual residential pumps would be required and these facilities could be constructed in roadways or other developed or disturbed areas (Figure 4.3-3). The locations for both the pump station and forcemain tie-in are based on existing land uses and the absence of sensitive biological resources. For purposes of this analysis, it was presumed that a pump station would be located at Cove Drive and the forcemain tie-in would occur at Hoover Street near manhole number 10 (Figure 4.3-3). Other pump station and forcemain tie-in locations may be available, yet all locations would result in a similar set of environmental impacts and therefore only one scenario is analyzed. A portion of the existing gravity sewer would be retained and require ongoing maintenance; however, this portion would be small and the majority of the gravity sewer alignment, including all portions subject to severe shoreline erosion, would be abandoned. Abandonment would require repair of existing corroded manholes and sealing of the sewer pipeline. These activities would require one-time temporary access of the various manholes on the gravity sewer alignment. 2798-03 February 2004 4-9 Pro/cisionol Ttotm for Complti Pro/cct> •••••••••••••••••••1 VEGETATION TYPES/LANDCOVERS: AGL I Annual Grassland DH Disturt>ed Habitat ORN CSM Coastal Salt Marsh ECIC I Eucalyptus Woodland OW CSS I Coastal Sage Scrub DEV I Developed Land IM Intertidal Mudflat RUD IRB Intertidal Rocky Beach SWS Ornamental Open Water Ruderal Southern Willow Scrub 7 / N / Study Area Approximate Limits of Grading/Trenchiing NOTE: A lower case'd' in front of a vegetation type designator indicates that it is disturbed. An upper case 'J' following a vegetation type designator indicates that it is jurisdictional. Scale in Feet BASE PHOTO SOURCE: CITY OF CARLSBAD North Agua Hedionda Sewer Western Segment EIR Pump Station/Forcemain Alternative FIGURE 4.3-3 4.0 Alternatives 4.3.4.1 Aesthetics Aesthetic impacts would occur with this ahernative as the pump station would be constructed in a public right-of-way. However, these aesthetic impacts would be less than the proposed project because the pump station would be the only permanent above-ground structure and would occupy a smaller footprint when compared to the shoreline protection wall and crib walls included as part of the proposed project. The pump station would be constructed in developed or disturbed areas and would he visible to motorists traveling on Cove Drive. As such, fewer sensitive receptors would he affected when compared to the proposed project, which is visible IVom 1-5 and other prominent public viewpoints. Mitigation under this alternative to reduce impacts may include landscaping or construction of a perimeter wall to minimize views of the pump station. Construction related visual impacts would occur during trenching and installation of the forcemain; however, no permanent impacts associated with the forcemain would occur as it would be located underground. Aesthetic impacts of the access road and shoreline protection structure would be avoided. Temporary impacts associated with rehabilitating and abandoning the shoreline gravity sewer would occur. No significant and unmitigable aesthetic impacts are anticipated with this alternative. 4.3.4.2 Biology Impacts to sensitive biological resources would be less than the proposed project because construction of the pump station, sewer pipeline and tie-in would generally occur in non- sensitive areas, including roadways and other developed or disturbed areas. Impacts to sensitive resources are limited to 0.05 acre of tidal wetlands associated with the tie-in and access road extending from Hoover Drive south and west (Figure 4.3-3). No significant unmitigable impacts to sensitive biological resources are anticipated. 4.3.4.3 Cultural Resources Impacts to sensitive cultural resources would be less than the proposed project because the pump station, sewer pipeline and tie-in would generally occur in areas previously disturbed. No significant unmitigable impacts to buried cultural resources are expected. 4.3.4.4 Geology/Soils Construction related impacts associated with soil erosion would be slightly less with this alternative due to the reduced amount of grading that would be necessary when compared to the proposed project. No significant umnitigable impacts were identified for the proposed project. & ASSOCIATES, JNC. 2798-03 February 2004 ^-'^'^ Proinsiovd Ttoms fur Cinnplei Proifctj 4 0 Alternatives Therefore, the Pump Station/Forcemain Alternative does not provide for mitigation of significant impacts that could not be achieved under the proposed project. 4.3.4.5 Hydrology and Water Quality Construction related impacts associated with soil erosion would be slightly less with this alternative due to the reduced amount of grading that would be necessary when compared to the proposed project. No significant unmitigable impacts were identified for the proposed project. Therefore, the Pump Station/Forcemain Alternative does not provide for mitigation of significant impacts that could not be achieved under the proposed project. In summary, this alternative would generally avoid impacts to sensitive biological and cultural resources; however, other impacts associated with this ahernative that were not previously identified for the proposed project may occur, including air quality, hazardous waste, land use, and noise Long-term air quality impacts are anticipated due to the greater consumption oi energy required to pump sewage and for the burning of diesel fuel to power emergency generators during a power loss. The transport and storage of chemicals and other hazardous materials, which pose a risk to human health, would occur under this alternative. Additional acquisition of rights-of-way solely for the pump station facility would be required and land uses adjacent to the pump station may be affected. Greater noise impacts would also be anticipated with this alternative as a result oJ' the operation of the pumps. While none of these impacts would be considered significant and unmitigable, they do represent an overall increase m environmental impacts when compared to the proposed project. 2798-03 & ASS0CIAT1ES, INC. ^ 4-12 February 2004 ProffilinnnC Teaini for Complex Prrvieclj 5.0 Growth Inducement SECTION 5.0 GROWTH INDUCEMENT Induced growth is that which exceeds the planned growth (City of Carlsbad General Plan) and results from new developments that would not have taken place in the absence of the project. Growth inducement impacts can result in accelerated economic or population growth, or the construction of new housing, that cither directly or indirectly resulted from building a project. Section 15126 (0 of the CEQA Guidelines requires that EIRs discuss whether a proposed project could: " foster economic or population growth, or the construction of additional housing, either directly or indirectly, in the surrounding environment. Included in this are projects which would remove obstacles to population growth. Increases in the population may further tax existing community service facilities, so consideration must be given to this impact. Also (the environmental analysis must) discuss the characteristics of some projects which may encourage and facilitate other activities that could significantly affect the enviromnent, either individually or cumulatively. It must not be assumed that growth in any area is necessarily beneficial, detrimental, or of little sigmficance to the environment." The proposed North Agua Hedionda Interceptor project involves the following: (1) re- establishment of the sewer maintenance access road; (2) construction of a shoreline protection wall, (3) relocation of 300 feet of the sewer pipehne; (4) rehabilitation of manholes; (5) future maintenance and operation activities (6) development of a portion of a regional trail. The proposed project is intended to ensure that the North Agua Hedionda interceptor sewer does not rupture, collapse or fail as a resuh of shoreline erosion. The proposed project is not considered to be growth inducing for several reasons: The capacity for the portion of the Agua Hedionda interceptor sewer within the project study area is not proposed to be increased as part of this project. The capacity of the interceptor sewer will continue to accommodate sewer flows from existing development and planned development that has been approved by the City. No features of the proposed project would provide wastewater collection service in a manner that would make lands available for development that aren't currently available. The proposed project does not provide for facilities or capacity that would induce growth. & ASSOCIATES, INC. February 2004 2798-03 5-1 Pro(fniono( Tianu for Complrx Pinjecli SECTION 6.0 CLMUIATIVE IMPACTS 6.1 PURPOSE The purpose of this section is to explain the methodology for the cumulative project analysis presented in this EIR. This section is important because, in many cases, the impact of a single project may not be significant, but when combined with other projects, the "cumulative" impact may be significant. Section 15355 of the CEQA Guidelines defines "cumulative impacts" as two or more individual effects which, when considered together, are considerable or which compound or increase other enviromiiental impacts." CEQA Guidelines Section 15130(b) states that "the discussion [of cumulative impacts] need not provide as great of detail as is provided of the effects attributable to the project alone." Section 15130(b) further states that a cumulative impacts discussion should be guided by the standards of practicality and reasonableness. Cumulative impacts can occur from the interactive effects of a single project. For example, the combination of noise and dust generated during construction activities can be additive and can have a greater impact than either noise or dust alone. However, substantial cumulative impacts more often result from the combined effect of past, present and future projects that are located in proximity to the project under review. For example, the wastewater treatment demand generated by a proposed project may not be significant when analyzed alone; however, when analyzed in combination with the wastewater demands of approved or proposed projects, the wastewater demands may exceed the resource capabilities of the service agency, resulting in a significant cumulative impact. Therefore, it is important for a cumulative impacts analysis to be viewed over time and in conjunction with other related past, present and reasonably foreseeable future developments, which may have impacts that might compound or inteiTclate with those of the project under review. 6.2 CUMULATIVE FORECASTING METHODOLOGY Section 15130 (b)(1)(A) of the CEQA Guidelines allows for the preparation of a list of past, present, and reasonably anticipated future project as a viable method of determining cumulative impacts. This EIR relies on the list of projects approach to provide a current assessment of the status of projects within a reasonable geographic scope of influence of the proposed project. For purposes of the cumulative analysis, the study area for each environmental resource has been expanded geographically in order to delineate an area in which the proposed project's effects may overlap with other projects. For aesthetics, the viewshed of Agua Hedionda lagoon was considered appropriate for the evaluation of cumulative impacts to scenic resources associated 2798-03 & ASSOCIATES, INC. February 2004 6-1 I'rii/iiiional Tf ami far Ci}mplrx Proitcli 6.0 Cumulative impacts with the lagoon. Similarly for cultural resources, the areas adjacent to the lagoon were considered appropriate for evaluation of cumulative impacts to cultural resources associated with the lagoon. For cumulative impacts to biological resources, geology/soils, and hydrology and water quality, the City evaluated all projects within the Agua Hedionda watershed. Areas beyond the City boundaries that were within the watershed were excluded from the cumulative analysis as those areas were considered geographically remote and the overlapping effects too speculative for evaluation. 6.3 LIST OF RELATED PROJECTS Several development proposals have been submitted for consideration or have been recently approved in proximity to the proposed project corridor that together with the proposed project would result in an increase in environmental impacts. These developments are depicted on Figure 6.3-1 and listed in Table 6. FT In addition to the development proposals, the City has prepared a Master Water and Sewer Plan, which identifies future improvement to existing facilities, capacity improvements, and expansion needs. The projects described below represent surrounding past, present, and reasonably foreseeable future projects within the area where the proposed project's effects could be considered to overlap with the effects of existing and future projects. All the projects below are generally located within 5 miles from the proposed project site. The project list below was developed through review of the City of Carlsbad General Plan EIR, examining ElR's that have been recently certified, and the City of Carlsbad Draft Program Master Water and Sewer Plans EIR. Additionally, cumulative projects were provided by the City's Planning Department. 2798-03 & ASSOCIATES, INC. February 2004 6-2 Profcjiiimiil Tiamj for Corapict Projf cli I r. I I I I I c c I D I I I I, North Agua Hedionda \/\festern Segment EIR Related Projects FIGURE 6.3-1 6.0 Cumulative Impacts Table 6.1-1. List of Related Projects ID PRGJECl NAME LOCAriON DESCRIPTIOiy STATUS Development Projects A Kelly Ranch- 432 acres east of proposed project and south of El Camino Real single family residential and associated infrastructure EIR certified 5/99; under construction B Calavera Hills Master Plan Amendment- 819 acres south of SR-78, north of the Rancho Carlsbad mobile home park, east of Carlsbad Village Drive and west of Lake Calavera modification of land uses, rearrangement of residential densities, construction of portions of College Boulevard and Cannon Road, installation of two detention basins EIR certified 1102 C Carlsbad Oaks North Specific Plan-414 acres Faraday Avenue and El Fuerte Road industrial park on 194 acres and 220 acres of designated open space EIR certified 10/02 D Cantarini-Holly Springs - 255 acres southeast of the College Boulevard and Cannon Road intersection residential development Joint EIR pending E Carlsbad Raceway- 146 acres north of Palomar Airport Road and east of Melrose Drive industrial business park MND adopted 12/01 F Palomar Forum Business Park - 71 acres north of Palomar Airport Road and east of Melrose Drive industrial business park MND adopted 12/01 G Hub Park/SDG&E Property south of Agua Hedionda Lagoon, north of Cannon Road, west of Kelly Ranch Regional park N/A H Robertson Ranch - 403 acres east of El Camino Real between Tamarack and Cannon Road master planned community with residential commercial, educational, recreational, and open space. EIR in process Carlsbad Master Sewer Plan Improvements 1 N. Agua Hedionda Interceptor Rehabilitation - Eastern Segment north shore of Agua Hedionda lagoon and creek from Cove Drive to El Camino Real rehabiliate/repair manholes NOE 2 N. Agua Hedionda Trunk Sewer Tamarack Avenue from El Camino Real to Calavera Hills Treatment Plant remove existing forcemain and construct 5,000 feet of gravity sewer pipeline Program EIR in process 3 El Camino Sewer El Camino Real from Tamarack Avenue to Chestnut Avenue construct 4,200 feet of gravity sewer pipeline Program EIR in process 4 Sewer Lift Station Repairs/Upgrades Terramar, Villas, and Gateshead Lift Stations various improvements Program EIR in process 5 Gateshead Lift Station Located on Gateshead Road just north of the Robertson Ranch development south of Tamarack Ave Remove Gateshead Sewer Lift Station. 200 feet of 8-inch lines to be installed adjacent to lift station to connect to residential development projects. Program EIR in process & ASSOCIATES, INC. February 2004 2798-03 6-4 Profdiinnol Ttomi/in Complrx Pro,ccU 6.0 Cumulative Impads Table 6.1-1. List of Related Projects ID >ltnJECT NAME LOCATION UESCKIPTION SFATUS 6 Woodstock Lift Station On Woodstock Street, south of Tamarack Avenue adjacent the Calavera Hills development project Remove Woodstock Lift Station. 400 feet of 8-inch lines lo be installed adjacent to lift station to connect to residential development projects. Program EIR in process 7 Vista/Carlsbad Interceptor Sewer Reach 11B Cross over (in a bridge structure} Agua Hedionda Lagoon in existing NCTD right-of-way. Replace existing Reach 11B and bridge with 915 feet of 54-inch pipeline and new concrete bridge. Program EIR in process 8 Agua Hedionda Lift Station South of the Agua Hedionda Lagoon adjacent the Cabrillo Power Plant Upgrade and slightly relocate lift station within existing property. Project includes five new pumping units for a firm pumping capacity of 36 mgd, and a new headworks, wet well, control building, 2.5 MG emergency storage basin, and 200 feet of 36-inch diameter forcemain. Program EIR in process 9 South Agua Hedionda/Kelly Ranch Lift Station Along Cannon Road within Kelly Ranch Temporary lift station to be replaced with permanent South Agua Hedionda Lift Station and new 5,380 feet of 14-inch forcemain. Program EIR in process 6.4 IMPACTS TO ENVIRONMENTAL FACTORS Implcmenlation of the proposed project has the potential to result in cumulative impacts to aesthetics, biological resources, cultural resources, geology/soils, and hydrology/water quality. A discussion of potential cumulative effects associated with the proposed project in conjunction with surrounding projects is provided below. 6.4.1 Aesthetics The proposed project is located along the northern shore of Agua Hedionda lagoon, where a number of other projects, including Kelly Ranch and other City of Carlsbad water and sewer projects, are proposed for implementation or are in progress, hiiplementation of the proposed project, in conjunction with other projects, would contribute to cumulative short-term construction related visual impacts. However, due to the temporary nature of the construction phase of the proposed project and other projects, views of construction activities and equipment would not be permanent. With implementation of the proposed project and surrounding projects, current views of the project site would change from a natural sandy shoreline to a shoreline built-up with a structure. & ASSOCIATES, INC. 2798-03 February 2004 6-5 Proit: 1 for Campla Projtcli 6.0 Cumulative Impacts The proposed project would introduce a shoreline protection wall and re-establish an access road. Because the wall is colored and textured to match adjacent bluffs and all temporarily disturbed areas will be revegetated with native plant species, the proposed project would not contribute to significant cumulative aesthetic impacts. 6.4.2 Biological Resources linplcmentation of proposed project, in conjunction with other projects, would contribute to significant cumulative loss of biological resources by converting vacant areas supporting natural habitat into urban land uses. It is anticipated that cumulative impacts to sensitive biological resources would be mitigated on a project-by-projcct basis by preservation and revegetation within project boundaries and compliance with appropriate permit conditions as determined by resource agencies, including the CDFG, ACOE, the LJSFWS, and CCC. The City has prepared an HMP, a comprehensive citywide program that identifies how the City, in cooperation with the resource agencies, will preserve diverse habitats and protect sensitive biological resources, while permitting development consistent with the City's General Plan. The HMP identifies specific preserve areas, core biological areas, wildlife linkages, implementation tecliniques and a preserve management strategy. With the respect to the Agua Hedionda watershed, the HMP identifies Core #3, 4, and 5, Linkage B and D, and Special Resource Area 1. These areas are targeted for conservation due to the presence of core populations of sensitive species, habitats, or corridor/linkage functions. By preserving habitat, plaiming land uses consistent with the goals and objectives of the HMP, and limiting impacts in accordance with the HMP's conservation strategy, the City would be able to mitigate for cumulative biological resource impacts. The proposed project's conformance with the HMP is evaluated in the Biological Resources Technical Report (Appendix B). hiiplementation of the proposed project and associated mitigation would be in conformance with the HMP and therefore would reduce potential cumulative biological impact to below a level of significance. 6.4.3 Cultural Resources Agua Hedionda Lagoon is known to support potential cultural resources due to the likely historical collection of shell fish and other aquatic resources by Native Americans. In addition, the underlying Santiago soil formation has a moderate potential to support invertebrate and vertebrate fossils {i.e., paleontologial resources). The project site itself traverses a known cultural resource site. A testing program was conducted for this site and it was determined that the resources within the proposed project area are not considered significant. However, other projects in the vicinity of the lagoon, including Kelly Ranch and Hub Park, have the potential to impact cultural resources which may be considered significant. Although the cultural resources site within the project corridor was tested and determined to not be significant, a project design measure for the City to commit to entering into a pre-excavation agreement with the local 2798-03 & ASSOCIATES, INC. February 2004 6-6 1 Tmm! for Complti Proff di 6.0 Cumulative Impacts band of Native Americans further reduces the potential for impacts. For potential paleontological resources, monitoring of excavation by a qualified paleontologist will be conducted to ensure proper collection of any significant resources. Therefore, although impacts to cultural resources in the region may occur, the proposed project will not contribute to any potentially significant cumulative loss of resources. 6.4.4 Geology and Soils Geologic and soils hazards associated with surrounding development projects and water and sewer improvement projects would be sitc-speeitlc. Impacts related to geologic and soil hazards and required mitigation would be evaluated based on the respective project sites on a project-by- projeet basis, 't herefore, with implementation of required mitigation measures, no significant cumulative significant impacts would occur from project implementation. 6.4.5 Hydrology and Water Quality The proposed project, in conjunction with surrounding projects, may contribute to a significant increase in construction runoff and sediment transport. It is expected that construction related water quality impacts would be mitigated to a level below significant with implementation of mitigation measures and compliance with the Clean Water Act. Conformance with the Clean Water Act may involve meeting the requirements of the State Water Resources Control Board's NPDES, including implementation of the City's Jurisdictional Urban Runoff Management Plan (JURMP) and preparation of a SWPPP. The JURMP is intended to control long-term storm- water pollutants and maintain appropriate storm water discharge volumes and velocities. The SWPPP is intended to control short-term construction related storm water pollutant discharge including sediment transport. Because the proposed project would mitigate for short-term water quality impacts to less than significant with implementation of mitigation measures described in Section 3.5.5, comply with the Clean Water Act, and not result in significant long-tenii storm water impacts, the proposed project would not contribute significant cumulative impacts to water quality. 2798-03 & ASSOCIATES, INC. February 2004 6-7 Professional Team, for Complrx PiojEi SECTION 7.0 ErrECTS rouND NOT TO BE SIGNIFICANT 7.1 PURPOSE Section 15128 of the CEQA Guidelines requires that an EIR briefly describe any potential environmental effects that were determined not to be significant during the initial project scoping and, therefore, were not discussed in detail in the EIR. 7.2 INTRODUCTION This section contains a brief discussion of the rationale for the determination that certain enviromiiental effects identified at the initial scoping phase of the proposed project would not be significant. The initial scoping process for the Draft EIR concluded that the proposed project would not result in significant impacts in the following environmental categories. Therefore, those issues received no further consideration in the EIR. 7.3 AGRICULTURAL RESOURCES No impacts to farmland, or land zoned for agricultural use, would result from implementation of the proposed project. There are no agricultural resources located within the proposed project corridor as the area of anticipated impact would be confined to the northern shore of Agua Hedionda Lagoon. Therefore, impacts to agricultural resources would not occur as a rcsuU of the proposed project. 7.4 AIR QUALITY The project would involve minimal short-term emissions associated with grading and construction. Such emissions would be minimized through standard construction measures such as the use of properly tuned equipment and watering the site for dust control. Long-tenii emissions associated with travel to and from the project will be minimal. Although air pollutant emissions would be associated with the project, they would neither resuh in the violation of any air quality standard {comprising only an incremental contribution to overall air basin quality readings), nor contribute substantially to an existing or projected air quahty violation. The San Diego Air Basin is currently a non-attainment region for ozone according to state and federal regulations and a non-attainment region for PMio according to state regulations. The project would contribute to these pollutant levels during construction activities. However, due to • ^^w^SS^f^ 2798-03 SOCIATES,INC.| February 2004 7-1 at Tcttnu for Cimiplci Prujeclj 7,0 Effects round Not to be Significant the short duration of the construction activities, emissions produced would be minimal and dispersed without significant eflects; i.e., would not be considered substantial contributions to regional air quality problems. Due to the insignificant level of maintenance vehicle-related traffic that would be associated with the proposed project, implementation of the project would not result in a cumulatively considerable net increase of any criteria pollutant. 7.5 HAZARDS AND HAZARDOUS MATERIALS The proposed project would not result in the routine transport, use or disposal of hazardous materials. Compliance with all applicable health and safety requirements would be implemented by the onsite maintenance supervisors. Any chemicals involved in the maintenance program would be handled by qualified personnel affiliated with the proposed project. No storage of chemicals onsite would occur. 7.6 LAND USE AND PLANNING 'Ihe proposed project is located along the northeastern shoreline of Agua Hedionda Lagoon within the City of Carlsbad. Agua Hedionda Lagoon is designated as a special resource area and zoned as open space in the City of Carlsbad General Plan (1994). The lagoon lies within Facilities Management Zone 1 as addressed in the City's Open Space and Conservation Resource Management Plan (1992). Agua Hedionda Lagoon is also regulated by the City's Agua Hedionda Land Use Plan and LCP (1982). The proposed project would not be inconsistent with the goals and polices of these applicable land use plans. 7.7 MINERAL RESOURCES The proposed project would not result in the loss of availability of a known mineral resource that would be of value to the immediate region or the residents of the state. The proposed project would not involve the disruption of existing mineral extraction operations. Locally-important mineral resource recovery sites have not been identified within the General Plan of the city of Carlsbad. Implementation of the proposed project would therefore not interfere with the extraction of any mineral resource of local importance. 7.8 NOISE Project construction would raise current noise levels within the immediate vicinity of the project. However, construction activities would comply with the City of Carlsbad Noise Ordinance which states that construction may not occur between the hours of sunset and 7a.m. Monday through Friday. Future maintenance and operation activities will not generate significant noise as a total of four maintenance visits per year is anticipated. & ASSOCIATES, INC. Pnifrs<i"na[ Teams for Compla Froltct! 2798-03 February 2004 7-2 7.0 Effects round Not to be Significant 7.9 POPULATION AND HOUSING The proposed project consists of rehabilitation of an existing sewer maintenance access road, shoreline stabilization and ongoing maintenance of a portion of the North Agua Hedionda interceptor sewer pipeline. The proposed project will not result in future development; therefore, the proposed project will not resuh in a demand for additional housing nor increase population. 7.10 PUBLIC SERVICES The proposed project would not require the development of new or physically ahered government facilities, 'fhe proposed project would not constitute an additional demand on current fire or police protection services as the project would not result in a population increase. 7.11 RECREATION The proposed project would not alter existing recreational facilities within the project vicinity. The proposed project would not increase demand on surrounding recreational facilities, nor would it cause substantial physical deterioration to these facilities. Because the proposed project would not increase population, the proposed project would not cause the demand for the construction of new recreational facilities. 7.12 TRANSPORTATION/TRAFFIC During project construction, traffic will be generated. The primary sources of construction traffic would be workers, delivery of materials and removal of excess material. Approximately eight to 15 workers are expected on a daily basis. The project will generate approximately 10 Average Daily Trips (ADT) during construction. This traffic will utilize the following roadways: Adams Street, Tamarack Avenue, Hoover Street, Cove Drive and possibly 1-5. Staging areas are proposed outside of public roadways, 'fhe proposed project is not expected to cause an increase in traffic that is substantial in relation to the existing traffic load and capacity of the street system, fhe addition of these daily trips to nearby roadways would not significantly effect current traffic flow rates. During maintenance activities, adequate vehicle parking would be provided at the terminus of Hoover Street, immediately north of the project area. 2798-03 & ASSOCIATES, INC. February 2004 7-3 Pyufessional Teams for Complex Protects 7.0 Effects round Not to be Significant 7.13 UTILITIES AND SERVICE SYSTEMS The proposed project consists of rehabilitation of an existing sewer maintenance access road, shoreline stabilization and maintenance of a portion of the North Agua Hedionda interceptor sewer pipeline and would not result in additional needs for new public utility or service systems nor expansion of existing faciliUes. Disposal of solid waste generated during project construction would be disposed of in a manner consistent with federal, state and local statutes and regulations. Therefore, the proposed project would not result in impacts to utilities or service systems. 2798-03 February 2004 7-4 SECTION 8.0 RErERENCES Associated Engineers. 1965. Plans for the Construction of Agua Hedionda Interceptor Sewer and Down Town Force Main. Califomia Coastal Commission. 1997. Report on In-Lieu Beach Sand Mitigation Program: San Diego County Website, www.coastal.ca.gov/pgd/sandl.html. Cahfomia Department of Fish and Game (CDFG). 2002a. At the Crossroads: A Report on the Status of California's Endangered and Rare Fish and Wildlife. State of California Resources Agency, Sacramento. California. California Department of Fish and Game (CDFG). 2002b. Endangered, Rare, and Threatened Animals of California. State of Califomia Resources Agency, Sacramento, Califomia. Cahfomia Department of Fish and Game (CDFG). 2002c. Cahfornia Natural Diversity Database, Special Animals. The Resources Agency, Wildlife and Habitat Data Analysis Branch. Califomia Native Plant Society (CNPS). 2001. Inventory of Rare and Endangered Plants of California (sixth edition). Rare Plant Scicnfific Advisory Committee, David P. Tibor, Convening Editor. Califomia Nafive Plant Society. Sacramento, CA x+388pp. Califomia, State of 1994. Water Quality Control Plan for the San Diego Basin. Carlsbad, City of 1982. Agua Hedionda Local Coastal Program. Carlsbad, City of 1994. General Plan. Carlsbad, City of 1994. General Plan Master Environmental hnpact Report. Carlsbad, City of 1999. Citywide Trails Program Report. Dudek & Associates. 2001. North Agua Hedionda Sewer Manhole Inspection Report. Prepared for the City of Carlsbad. & ASSOCIATES, INC. 2798-03 February 2004 8-1 Praftssional Ten™ far Complrx ProjcirU 8.0 References Dudek & Associates. 2004. Biological Resources Technical Report for the North Agua Hedionda Western Segment Sewer Maintenance, Access Road and Shoreline Protection Wall. Prepared for the City of Carlsbad. Eckcrt, Matt. 2003. TerraCosta Consuhing Group. Personal communication. Everett, W. T. 1979. Sensitive, threatened and declining bird species of San Diego County. San Diego Audubon Society Sketches 29:2-3. Holland, R. F. 1986. Preliminary descriptions of the terrestrial natural communities of California. Nonganie-Heritage Program, California Department of Fish and Game. 156 pp. McGurty- B. M. 1980. Si^rvey and status of endangered and threatened species of reptiles natively occurring in San Diego. California. San Diego flerpetological Society. Murphy, D. D. 1990. A report on the California butterflies listed as candidates for endangered .status by the United Stales Fish and Wildlife Service. Draft Report for California Department of Fish and Game, Contract No. C-1755. 60 pp. SANDAG. 2003. Floodplains website. w\\av.sangis.org. accessed December 2003. SAND AG (San Diego Associafion of Governments). 2001 Multiple Habitat Conservation Program. CD-ROM. ferraCosta Consulting Group. 2003a. Preliminary Geotechnical Investigation Preferred Wall Alternative North Agua Hedionda Interceptor Access Road & Shoreline Protection. TerraCosta Consulting Group. 2003b. Wave Uprush Study North Agua Hedionda Interceptor Access Road & Shoreline Protection. United States Fish and Wildlife Service (USFWS). 2001. Federally Listed and Candidate Species that May Occur within the Jurisdiction of the Carlsbad Fish and Wildlife Office. Microsoft Excel Spreadsheet. Provided by: Carlsbad Fish and Wildlife Office. October 23. Carlsbad, California. & ASSOCIATES, INC. 2798-03 February 2004 3-2 Vrofntivnal Trams for Coraplcl Projeco SECTION 9.0 LIST or PREPARERS City of Carlsbad Elaine Blackburn, Senior Planner Don Ridcout, Principal Planner Terry Smith, Senior Civil Engineer Mark Biskup, Associate Engineer Dudek & Associates, Inc. Vipul Joshi, Biologist/Project Manager Myloc Nguyen, M.S., Environmental Plamier Joe Monaco, A.I.C.P., Senior Project Manager Sherri Miller, M.S., Senior Biologist Ed Mathews, P.E., Senior Project Manager Anita Hayworth, Ph.D., Senior Wildhfe Biologist Mike Sweesy, M.S., Senior Habitat Restoration Specialist Michelle Balk, M.S., Biologist Andy Thompson, M.S., Habitat Restoration Specialist Annabelle Cuypers, Word Processing Lesley Terry, GIS Analyst Paul Cahgiuri, Senior Designer Gailegos & Associates Deimis Gailegos Terra Costa Walt Crampton 2798-03 & ASSOCIATES, INC. February 2004 Pro/iiiiona[Tfaifij/i>rCDmplEi Prufr