INITIAL STUDY RANCHO CALIFORNIA WATER DISTRICT VAIL DAM SEISMIC AND HYDROLOGIC REMEDIATION PROJECT PROJECT NO. D1911 RIVERSIDE COUNTY, CALIFORNIA (951) 296-6900 Post Office Box 9017 42135 Winchester Road Temecula, California 92589-9017 Temecula, California 92590 June 2020 This page intentionally left blank INITIAL STUDY RANCHO CALIFORNIA WATER DISTRICT VAIL DAM SEISMIC AND HYDROLOGIC REMEDIATION PROJECT PROJECT NO. D1911 RIVERSIDE COUNTY, CALIFORNIA Submitted to: Rancho California Water District 42135 Winchester Road Temecula, California 92590 Prepared by: LSA 703 Palomar Airport Road, Suite 260 Carlsbad, California 92011 (760) 931-5471 Project No. RCW1902 June 2020 This page intentionally left blank I NITIAL S TUDY V AIL D AM S EISMIC AND H YDROLOGIC R EMEDIATION P ROJECT J UNE 2020 R ANCHO C ALIFORNIA W ATER D ISTRICT P ROJECT N O . D1911 TABLE OF CONTENTS TABLE OF CONTENTS ............................................................................................................................... i FIGURES AND TABLES ............................................................................................................................. ii LIST OF ABBREVIATIONS AND ACRONYMS ............................................................................................ iii 1.0 INTRODUCTION ................................................................................................ 1-1 1.1 Project Information ........................................................................................................... 1-1 1.2 Project Description ............................................................................................................ 1-2 2.0 ENVIRONMENTAL FACTORS POTENTIALLY AFFECTED ........................................ 2-1 2.1 Determination ................................................................................................................... 2-1 3.0 EVALUATION OF ENVIRONMENTAL IMPACTS ................................................... 3-1 3.1 Aesthetics .......................................................................................................................... 3-3 3.2 Agriculture and Forestry Resources .................................................................................. 3-5 3.3 Air Quality ......................................................................................................................... 3-7 3.4 Biological Resources .......................................................................................................... 3-9 3.5 Cultural Resources .......................................................................................................... 3-12 3.6 Energy .............................................................................................................................. 3-14 3.7 Geology and Soils ............................................................................................................ 3-15 3.8 Greenhouse Gas Emissions ............................................................................................. 3-18 3.9 Hazards and Hazardous Materials................................................................................... 3-19 3.10 Hydrology and Water Quality ......................................................................................... 3-22 3.11 Land Use and Planning .................................................................................................... 3-25 3.12 Mineral Resources ........................................................................................................... 3-26 3.13 Noise................................................................................................................................ 3-27 3.14 Population and Housing .................................................................................................. 3-29 3.15 Public Services ................................................................................................................. 3-30 3.16 Recreation ....................................................................................................................... 3-32 3.17 Transportation ................................................................................................................ 3-33 3.18 Tribal Cultural Resources ................................................................................................ 3-35 3.19 Utilities and Service Systems ........................................................................................... 3-37 3.20 Wildfire ............................................................................................................................ 3-39 3.21 Mandatory Findings of Significance ................................................................................ 3-41 4.0 REFERENCES ..................................................................................................... 4-1 Q:\RCW1902 - Vail Dam\CEQA\Initial Study\Vail Dam IS June 2020.docx (06/16/20) i V AIL D AM S EISMIC AND H YDROLOGIC R EMEDIATION P ROJECT I NITIAL S TUDY R ANCHO C ALIFORNIA W ATER D ISTRICT J UNE 2020 P ROJECT N O . D1911 FIGURES AND TABLES FIGURES Figure 1-1: Project Vicinity .................................................................................................................. 1-3 Figure 1-2: Project Location ................................................................................................................ 1-5 Figure 1-3: Surrounding Land Use ....................................................................................................... 1-9 Figure 1-4: Existing Vail Dam and Spillway ....................................................................................... 1-13 Figure 1-5: Existing and Proposed Dam Cross Section with Elevation .............................................. 1-17 Figure 1-6: Vail Lake Inundation Area ............................................................................................... 1-19 Figure 1-7: Vail Lake Historic Water Levels ....................................................................................... 1-21 Figure 1-8: Proposed Gravity Dam Plan and Profile ......................................................................... 1-25 Figure 1-9: Proposed Gravity Dam Section ....................................................................................... 1-27 Figure 1-10: Existing Dam Partial Demolition ................................................................................... 1-31 Figure 1-11: Staging and Disposal Areas and Access Roads ............................................................. 1-35 TABLE Table 1.A: Summary of Anticipated Construction Equipment .......................................................... 1-39 Table 1.B: Anticipated Permits and Authorizations .......................................................................... 1-41 ii Q:\RCW1902 - Vail Dam\CEQA\Initial Study\Vail Dam IS June 2020.docx (06/16/20) I NITIAL S TUDY V AIL D AM S EISMIC AND H YDROLOGIC R EMEDIATION P ROJECT J UNE 2020 R ANCHO C ALIFORNIA W ATER D ISTRICT P ROJECT N O . D1911 LIST OF ABBREVIATIONS AND ACRONYMS AAQS ambient air quality standards AB Assembly Bill ac-ft acre-feet AQMP Air Quality Management Plan BMPs Best Management Practices California Register California Register of Historical Resources CDFW California Department of Fish and Wildlife CEQA California Environmental Quality Act CFR Code of Federal Regulations County County of Riverside CWA Clean Water Act cy cubic yard(s) DSOD (California Department of Water Resources) Division of Safety of Dams EIR Environmental Impact Report FGC California Fish and Game Code ft foot/feet GHG greenhouse gas H:V horizontal to vertical (ratio) I-15 Interstate 15 MBTA Migratory Bird Treaty Act NCCP/HCP Natural Communities Conservation Plan/Habitat Conservation Plan MCE Maximum Credible Earthquake MSHCP Multiple Species Habitat Conservation Plan NEPA National Environmental Policy Act NHPA National Historic Preservation Act NPDES National Pollutant Discharge Elimination System PMF Probable Maximum Flood PMP Probable Maximum Precipitation PRC Public Resources Code Project Vail Dam Seismic and Hydrologic Remediation Project RCC Roller Compacted Concrete RCWD Rancho California Water District RWQCB Regional Water Quality Control Board SB Senate Bill SCAQMD South Coast Air Quality Management District SCE Southern California Edison SHPO State Historic Preservation Officer SR-79 State Route 79 SWPPP Storm Water Pollution Prevention Plan USACE United States Army Corps of Engineers USC United States Code USFWS United States Fish and Wildlife Service VDC Valle De Los Caballos VMT vehicle miles traveled WQMP Water Quality Management Plan WRC RCA Western Riverside County Regional Conservation Authority Q:\RCW1902 - Vail Dam\CEQA\Initial Study\Vail Dam IS June 2020.docx (06/16/20) iii V AIL D AM S EISMIC AND H YDROLOGIC R EMEDIATION P ROJECT I NITIAL S TUDY R ANCHO C ALIFORNIA W ATER D ISTRICT J UNE 2020 P ROJECT N O . D1911 This page intentionally left blank iv Q:\RCW1902 - Vail Dam\CEQA\Initial Study\Vail Dam IS June 2020.docx (06/16/20) I NITIAL S TUDY V AIL D AM S EISMIC AND H YDROLOGIC R EMEDIATION P ROJECT J UNE 2020 R ANCHO C ALIFORNIA W ATER D ISTRICT P ROJECT N O . D1911 1.0 INTRODUCTION In accordance with the California Environmental Quality Act (CEQA), the State CEQA Guidelines, and Rancho California Water District (RCWD)’s CEQA Guidelines 2019: Local Guidelines for Implementing the California