Cunningham Flood Detention Facility Certification Project Final Initial Study and Mitigated Negative Declaration Project No. 40264011 January 2018 Prepared by: Santa Clara Valley Water District 5750 Almaden Expressway San Jose, CA 95118-3614 TABLE OF CONTENTS Page LIST OF ACRONYMS ................................................................................................................ III KEY TERMINOLOGY ................................................................................................................ V SECTION 1: INTRODUCTION ................................................................................................... 1 SECTION 2: PROJECT DESCRIPTION .................................................................................... 3 SECTION 3: ENVIRONMENTAL SETTING ............................................................................. 29 SECTION 4: ENVIRONMENTAL EVALUATION ...................................................................... 30 SECTION 5: REPORT PREPARATION ................................................................................. 115 SECTION 6: REFERENCES................................................................................................ 1165 TABLES TABLE 1.1: SUMMARY OF AGENCY APPROVALS ................................................................. 3 TABLE 2.1: CONSTRUCTION SCHEDULE ............................................................................. 16 TABLE 2.2: CONSTRUCTION OFF-SITE TRIPS ..................................................................... 16 TABLE 2.3: CONSTRUCTION HAUL TRIPS ........................................................................... 17 TABLE 2.4: PROPOSED CONSTRUCTION EQUIPMENT ...................................................... 17 TABLE 2.5: BEST MANAGEMENT PRACTICES AND SANTA CLARA VALLEY HABITAT PLAN CONDITIONS INCORPORATED INTO THE PROPOSED PROJECT ........ 20 TABLE 3.1: AIR QUALITY MONITORING SUMMARY ............................................................. 44 TABLE 3.2: SAN FRANCISCO AIR BASIN ATTAINMENT STATUS ........................................ 45 TABLE 3.3: BAAQMD THRESHOLDS OF SIGNIFICANCE...................................................... 47 TABLE 3.4: CRITERIA AIR POLLUTANT EMMISSIONS ......................................................... 50 TABLE 3.5: CONSTRUCTION AIR POLLUTANT EMISSIONS ................................................ 52 TABLE 4.1: SPECIAL STATUS SPECIES WITH POTENTIAL TO OCCUR AT THE PROJECT SITE ...................................................................................................................... 56 TABLE 4.2: TREES PROPOSED FOR REMOVAL AT THE PROJECT SITE .......................... 61 TABLE 7.1: DESCRIPTION OF GREENHOUSE GASES ...................................................... 754 TABLE 7.2: CONSTRUCTION GREENHOUSE GAS EMISSIONS .......................................... 78 TABLE 7.3: SCOPING PLAN MEASURES CONSISTENCY ANALYSIS ................................. 79 TABLE 9.1: NEW AND REPLACEMENT IMPERVIOUS AND SEMI-PERVIOUS SURFACES .......................................................................................................... 91 Page i FIGURES FIGURE 1: REGIONAL LOCATION MAP .................................................................................. 7 FIGURE 2: PROJECT VICINITY MAP ....................................................................................... 8 FIGURE 3A: PHOTOGRAPHS OF THE PROJECT SITE .......................................................... 9 FIGURE 3B: PHOTOGRAPHS OF THE PROJECT SITE ........................................................ 10 FIGURE 3C: PHOTOGRAPHS OF THE PROJECT SITE ........................................................ 11 FIGURE 4: SITE PLAN ............................................................................................................ 14 FIGURE 5A: PHOTOGRAPHS OF THE PROJECT SITE ........................................................ 36 FIGURE 5B: PHOTOGRAPHS OF THE PROJECT SITE ........................................................ 37 FIGURE 6: 100 YEAR FEMA FLOOD ZONE ........................................................................... 87 APPENDIX APPENDIX A: AIR QUALITY AND GHG ANALYSIS REPORT ............................................... A-1 APPENDIX B: ARBORIST REPORTS .................................................................................... B-1 APPENDIX C: RESPONSE TO COMMENTS .........................................................................C-1 APPENDIX D: MITIGATION MONITORING AND REPORTING PROGRAM ..........................D-1 Page ii LIST OF ACRONYMS AB Assembly Bill AQP Air Quality Plan ATCM Airborne Toxic Control Measure BAAQMD Bay Area Air Quality Management District BMPs Best Management Practices CAA Clean Air Act CARB California Air Resources Board CDFW California Department of Fish and Wildlife CEQA California Environmental Quality Act CESA California Endangered Species Act CCR California Code of Regulations CFR Code of Federal Regulations CIDH Cast in Drill Hole CO Carbon Monoxide CWA Federal Clean Water Act dB Decibel dBA A-weighted sound level District Santa Clara Valley Water District DPM Diesel Particulate Matter DTSC Department of Toxic Substances and Control EPA U.S. Environmental Protection Agency ESA Endangered Species Act FEMA Federal Emergency Management Agency GHGs Greenhouse Gases GP NPDES General Permit HCP Habitat Conservation Plan HSLA Hazardous Substance Liability Assessment LCP Lake Cunningham Park Ldn Day-Night Average Sound Level LOMR Letter of Map Revision IS Initial Study MBTA Migratory Bird Treaty Act MND Mitigated Negative Declaration MRP San Francisco Bay Region Municipal Regional Stormwater NPDES Permit MTCO Metric Ton of Carbon Dioxide Equivalent Per Year NAVD North American Vertical Datum of 1988 NOx Oxides of Nitrogen NPDES National Pollutant Discharge Elimination System NRCS Natural Resources Conservation Service OEHHA Office of Health Hazard Assessment PM Fine particulate matter less than 10 micrometers 10 PM2.5 Fine particulate matter less than 2.5 micrometers PRNS City of San Jose Parks and Neighborhood Services Department ROG Reactive Organic Gases RWQCB Regional Water Quality Control Board SAA Streambed Alteration Agreement SCE State Candidate for listing as Endangered SCVWD Santa Clara Valley Water District SSC CDFW Species of Special Concern TAC Toxic Air Contaminants Page iii TPZ Traffic Pattern Zone USFWS United States Fish and Wildlife Service VHP Valley Habitat Plan WDR Waste Discharge Requirements Page iv Key Terminology Beneficial Impact: A project impact is considered beneficial if it would result in the enhancement or improvement of an existing physical condition in the environment – no mitigation is required when an impact is determined to be beneficial. Best Management Practices: Measures typically derived from standardized District operating procedures. These practices have been identified as methods, activities, procedures, or other management practices for the avoidance or minimization of potential adverse environmental effects. They have been designed for routine incorporation into project designs and represent the “state of the art” impact prevention practices. Less-than-significant Impact: This is indicated in the Initial Study checklist where the impact does not reach the standard of significance set for that factor and the project would therefore cause no substantial change in the environment (no mitigation needed). Less-than-significant Impact with Mitigation: This is indicated in the Initial Study checklist where the impact is determined to exceed the applicable significance criteria, but for which feasible mitigation measure(s) are available to reduce the impact to a level of less-than-significant. Mitigation Measures: Mitigation includes: (a) avoiding the impact altogether by not taking a certain action or parts of an action; (b) minimizing impacts by limiting the degree or magnitude of the action and its implementation; (c) rectifying the impact by repairing, rehabilitating, or restoring the impacted environment; (d) reducing or eliminating the impact over time by preservation and maintenance operations during the life of the action; and (e) compensating for the impact by replacing or providing substitute resources or environments.* No Impact: This is indicated in the Initial Study where, based on the environmental setting, the stated environmental factor does not apply to the proposed project. Potentially Significant Impact: This is indicated in the Initial Study where the project impact may cause a substantial adverse change in the environment, but for which (1) no feasible mitigation is available to reduce the impact to a less-than-significant level, or (2) feasible mitigation has been identified but the residual impact remains significant after mitigation is applied. Significance Criteria: A set of criteria used by the lead agency to determine whether an impact would be considered significant. The District relied upon the significance criteria set forth in the CEQA Guidelines and criteria based on the regulatory standards of local, state and federal agencies. * Authority cited: Sections 21083 and 21087, Public Resources Code; Reference: Sections 21002, 21002.1, 21081, and 21100(c), Public Resources Code. Page v SECTION 1: INTRODUCTION Organization of This Document This document is organized to assist the reader in understanding the potential impacts that the proposed project may have on the environment and to fulfill the requirements of the California Environmental Quality Act (CEQA) (Public Resources Code Section 21000 et seq.). Section 1 indicates the purpose under CEQA, sets forth the public participation process, and summarizes applicable state and federal regulatory requirements. Section 2 describes the location as well as features of the proposed plan and Section 3 describes the environmental setting. Section 4 evaluates the potential impacts through the application of the CEQA Initial Study Checklist questions to project implementation. Section 5 lists the contributors, and Section 6 supplies the references used in its preparation. The air quality and greenhouse gas report is located in Appendix A and the arborists reports are located in Appendix B. Responses to public comments received during the 30-day public review period are provided in Appendix C, and a Mitigation Monitoring and Reporting Program summary table is provided in Appendix D. Purpose of the Initial Study The Santa Clara Valley Water District (District), acting as the Lead Agency under CEQA, prepared this Initial Study (IS) and Mitigated Negative Declaration (MND) to provide the public, responsible agencies and trustee agencies with information about the potential environmental effects of the Cunningham Flood Detention Facility Certification Project (hereinafter “proposed project”). This Mitigated Negative Declaration was prepared consistent with CEQA, the CEQA Guidelines (Title 14 Code of Regulations 15000 et seq.), and District procedures for implementation of CEQA (Environmental Planning Guidance Q520D01 and W520M01). CEQA requires that public agencies such as the District identify significant adverse environmental effects from their discretionary actions and mitigate those adverse effects through feasible mitigation measures or through selection of feasible alternatives. In addition to acting as the CEQA Lead Agency for its projects, the District’s mission includes objectives to conduct its activities in an environmentally sensitive manner as a steward of Santa Clara Basin watersheds. The District strives to preserve the natural qualities, scenic beauty and recreational uses of Santa Clara Valley’s waterways by using methods that reflect an ongoing commitment to conserving the environment. This MND is intended to allow the public to fully understand the environmental consequences of the proposed project, the significance of those consequences, feasible measures to reduce or eliminate project impacts, and the effectiveness of those measures. Decision to Prepare a Mitigated Negative Declaration The Initial Study (Section 4) for the proposed project indicates that the proposed project could result in significant environmental impacts, but those impacts would be reduced to less than significant level through application of feasible mitigation measures. Implementation of the proposed project would not result in significant impacts to the environment after implementation of mitigation measures identified herein. A Mitigated Negative Declaration is consistent with CEQA Guidelines §15070, which indicates that a Mitigated Negative Declaration is appropriate when: Page 1 a) Revisions to the project plan are made that would avoid, or reduce the effects to a point where clearly no significant effects would occur, and b) There is no substantial evidence that the project, as revised, may have a significant effect on the environment. Public Review Process This IS/MND will be circulated to local, state and federal agencies, interested organizations and individuals who may wish to review and provide comments on the project description, the proposed mitigation measures or other aspects of the report. The publication commenced a minimum 30-day public review period consistent with CEQA Guidelines §15105(b) beginning began on June 28 July 20, 2017 and ending ended on July 28 August 21, 2017. The draft IS/MND and all supporting documents are were available for review at: • Santa Clara Valley Water District 5750 Almaden Expressway San Jose, CA 95118 • At the local library reference desks: San Jose Public Library Evergreen Branch Library 2635 Aborn Road San Jose, CA 95121 San Jose Public Library Hillview Branch Library 1600 Hopkins Drive San Jose, CA 95122 • Posted on the District website: www.valleywater.org, or • Via written request for a copy from the District. Written comments or questions regarding the draft IS/MND should be were submitted to: Tim Tidwell Santa Clara Valley Water District 5750 Almaden Expressway San Jose, CA 95118-3614 e-mail: [email protected] Submittal of written comments via e-mail will greatly facilitate the response process. The District will considered all comments and make made any necessary changes to the document prior to adopting the final IS/MND and approving the project. Interagency Collaboration and Regulatory Review The CEQA review process is intended to provide both trustee and responsible agencies with an opportunity to provide input into the project. Trustee agencies are agencies having jurisdiction Page 2 by law over natural resources affected by a project which are held in trust for the state. Responsible agencies are those agencies, other than the lead agency, that have some responsibility or authority for carrying out or approving a project; in many instances these public agencies must make a discretionary decision to issue a permit; provide right-of-way, funding or resources to the project. In this instance the California Department of Fish and Wildlife (CDFW), State Water Resources Control Board (SWRCB), San Francisco Bay Regional Water Quality Control Board (RWQCB), Santa Clara Valley Habitat Agency, and the City of San Jose would be considered responsible agencies. The District will work with CDFW, SWRCB, RWQCB, Santa Clara Valley Habitat Agency, and City of San Jose to ensure that the proposed project meets applicable policies and requirements. This IS/MND is intended to assist state and local agencies to carry out their responsibilities for permit review or approval authority over the proposed project. Implementation of the proposed project would likely require specific permitting as summarized in Table 1.1: Summary of Agency Approvals below. Table 1.1: Summary of Agency Approvals Agency Permit/Review Required CDFW Fish and Game Code §1602 Lake and Streambed Alteration Agreement (LSAA) SWRCB NPDES General Construction Permit RWQCB Waste Discharge Requirements (WDR) Santa Clara Valley Habitat Agency Santa Clara Valley Habitat Plan Reporting Form for Public Projects City of San Jose Traffic Control Permit for Lane Closure on Cunningham Avenue and South White Road SECTION 2: PROJECT DESCRIPTION Project Objectives Lower Silver Creek flows from south to north through Lake Cunningham Park (LCP or Park) in San Jose, CA. Flint and Ruby Creeks are tributary streams rising in the hills east of the park and flowing westward to the eastern portion of LCP, then join together and empty into Lower Silver Creek within the park. Lower Silver Creek carries the combined flows from all three creeks northwards out of the Park to its confluence with Coyote Creek, located about 4.2 miles downstream from the LCP. During high flows, Lower Silver Creek and Flint Creek overtop weirs located within LCP and are temporarily stored within LCP, which was designed and constructed in the late 1970s and early 1980s to serve as both a detention basin for overflow water from Lower Silver, Flint, and Ruby creeks and a recreational facility. The storage of water at LCP reduces the flows of Lower Silver Creek downstream of LCP. To reduce flow hazards to urbanized areas along Lower Silver Creek downstream of LCP, the District reconstructed the channel of Lower Silver Creek between LCP and Coyote Creek confluence between 2005 and 2016. The reconstructed channel has a design flow conveyance capacity of 2,810 cubic feet per second (cfs) at the Cunningham Avenue Bridge crossing (i.e. the upstream terminus of the Lower Silver Creek Flood Protection Project). Flows greater than 2,8160 cfs would cause Lower Silver Creek to overflow its banks downstream of LCP and Page 3