OCTOBER 2017 Local Hazard Mitigation Plan 1 THIS PAGE INTENTIONALLY LEFT BLANK TABLE OF CONTENTS Page CHAPTER 1—INTRODUCTION ................................................................................................. 1 PURPOSE AND BACKGROUND................................................................................................ 1 PLAN AUTHORITY ..................................................................................................................... 2 PLAN ADOPTION ....................................................................................................................... 3 PLAN USE .................................................................................................................................. 3 CHAPTER 2—PLANNING PROCESS ....................................................................................... 5 PROCESS OBJECTIVES ........................................................................................................... 5 PLANNING TEAM ....................................................................................................................... 5 COMMUNITY ENGAGEMENT PROCESS ................................................................................. 7 SUPPORTIVE RESOURCES ..................................................................................................... 9 CHAPTER 3—CAPABILITY ASSESSMENT ........................................................................... 11 RELEVANT PLANS AND PROGRAMS .................................................................................... 11 STRATEGY IMPLEMENTATION CAPACITIES ........................................................................ 15 PREVIOUSLY IMPLEMENTED MITIGATION MEASURES ...................................................... 16 DISTRICT ASSETS .................................................................................................................. 19 CHAPTER 4—DISTRICT PROFILE ......................................................................................... 25 AREA AT A GLANCE ................................................................................................................ 25 DEMOGRAPHICS .................................................................................................................... 26 ECONOMIC TRENDS ............................................................................................................... 29 ENERGY INFRASTRUCTURE ................................................................................................. 30 EVACUATION ROUTES ........................................................................................................... 31 CHAPTER 5—HAZARD IDENTIFICATION, ANALYSIS, AND ASSESSMENT ....................... 33 HAZARD ANALYSIS ................................................................................................................. 33 HAZARD PRIORITIZATION ...................................................................................................... 35 SUMMARY OF PAST DISASTERS .......................................................................................... 38 HAZARD PROFILES................................................................................................................. 39 VULNERABILITY ASSESSMENT ............................................................................................. 95 R14163 i Page CHAPTER 6—MITIGATION AND ADAPTATION STRATEGY .............................................. 101 MITIGATION GOALS .............................................................................................................. 101 UPDATES FROM PREVIOUS PLAN ...................................................................................... 101 INTEGRATION ....................................................................................................................... 102 ANALYSIS OF MITIGATION ACTIONS .................................................................................. 102 PRIORITIZATION ................................................................................................................... 104 COST ESTIMATES ................................................................................................................. 104 MITIGATION ACTIONS .......................................................................................................... 104 CHAPTER 7—PLAN MAINTENANCE ................................................................................... 115 IMPLEMENTATION, UPDATES, AND ENHANCEMENT ........................................................ 115 MONITORING......................................................................................................................... 116 CONTINUED PUBLIC INVOLVEMENT................................................................................... 117 LIST OF ACRONYMS AND ABBREVIATIONS ...................................................................... 119 APPENDIX A: RESOLUTION OF ADOPTION ...................................................................... 121 APPENDIX B: HAZARD MITIGATION PLANNING TEAM MEETING MATERIALS ............. 123 APPENDIX C: PUBLIC OUTREACH ..................................................................................... 127 APPENDIX D: PREVIOUS MITIGATION MEASURES .......................................................... 141 APPENDIX E: SOURCES...................................................................................................... 171 APPENDIX F: CRITICAL FACILITIES LIST .......................................................................... 177 LIST OF TABLES Table 2-1: Planning Team Meeting Topics ........................................................................ 7 Table 3-1: District Resources to Support Hazard Mitigation Activities .........................11 Table 3-2: Santa Clara Valley Water District Projected 2020 Demand by Customer .....20 Table 3-3: Santa Clara Valley Water District Water Supplies .........................................21 Table 3-4: 2015 Groundwater Inflow and Outflow in the Santa Clara Valley Water District in Acre-Feet (AF).......................................22 Table 3-5: Watersheds in the Santa Clara Valley Water District.....................................22 Table 3-6: Santa Clara Valley Water District Supply Facilities .......................................23 Table 4-1: Key Demographics, Santa Clara County (2015) .............................................26 Table 4-2: Racial and Ethnic Composition of Residents, Santa Clara County (2015) ...27 R14163 ii Page Table 4-3: Educational Attainment of Residents 25+ Years of Age, Santa Clara County (2015) ...............................................................................28 Table 4-4: Language Proficiency of Residents 5+ Years of Age, Santa Clara County (2015) ...............................................................................28 Table 4-5: Top Ten Santa Clara County Employers (2016) .............................................29 Table 5-1: Santa Clara Valley Water District LHMP Hazard Evaluation .........................33 Table 5-2: Hazard Ranking Scores and Weighing Factors .............................................36 Table 5-3: Scores and Threat Levels by Hazard ..............................................................38 Table 5-4: Dams in Santa Clara County ...........................................................................40 Table 5-5: US Drought Monitor Classification Scheme ..................................................48 Table 5-6: Landslide Events in Santa Clara County ........................................................61 Table 5-7: Modified Mercalli Intensity Scale ....................................................................74 Table 5-8: Major Faults in and Near Santa Clara County ................................................76 Table 5-9: Earthquake Probabilities Near Santa Clara County .......................................83 Table 5-10: Selected Earthquake Scenarios ......................................................................83 Table 5-11: Beaufort Scale ..................................................................................................85 Table 5-12: Number of District Facilities in Risk Assessment .........................................95 Table 5-13: Facilities within 500 feet of a Dam Inundation Zone ......................................95 Table 5-14: Assets Within 500 feet of the 100-Year Floodplain ........................................96 Table 5-15: Risk to District Facilities from Landslides .....................................................97 Table 5-16: Risk to District Facilities from Ground Shaking ............................................97 Table 5-17: Risk to District Facilities from Fault Rupture .................................................98 Table 5-18: Risk to District Facilities from Liquefaction ...................................................98 Table 5-19: Risk to District Facilities from Land Subsidence ..........................................99 Table 5-20: Risk to District Facilities from Sea Level Rise ...............................................99 Table 5-21: Risk to District Facilities from Wildfire ......................................................... 100 R14163 iii Page Table 6-1: STAPLE/E Review and Selection Criteria ..................................................... 103 Table 6-2: Mitigation Actions .........................................................................................