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 .................................................................................................................. 20 CHAPTER 4—DISTRICT PROFILE ......................................................................................... 26 AREA AT A GLANCE ................................................................................................................ 26 DEMOGRAPHICS ....................................................................................................................27 ECONOMIC TRENDS ............................................................................................................... 30 ENERGY INFRASTRUCTURE ................................................................................................. 31 EVACUATION ROUTES ........................................................................................................... 32 CHAPTER 5—HAZARD IDENTIFICATION, ANALYSIS, AND ASSESSMENT ....................... 34 HAZARD ANALYSIS ................................................................................................................. 34 HAZARD PRIORITIZATION ...................................................................................................... 36 SUMMARY OF PAST DISASTERS .......................................................................................... 39 HAZARD PROFILES................................................................................................................. 40 VULNERABILITY ASSESSMENT ............................................................................................. 93 R14163 i 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 ................................................................................... 116 IMPLEMENTATION, UPDATES, AND ENHANCEMENT ........................................................ 116 MONITORING......................................................................................................................... 117 CONTINUED PUBLIC INVOLVEMENT................................................................................... 118 LIST OF ACRONYMS AND ABBREVIATIONS ...................................................................... 120 APPENDIX A: RESOLUTION OF ADOPTION ...................................................................... 122 APPENDIX B: HAZARD MITIGATION PLANNING TEAM MEETING MATERIALS ............. 124 APPENDIX C: PUBLIC OUTREACH ..................................................................................... 128 APPENDIX D: PREVIOUS MITIGATION MEASURES .......................................................... 142 APPENDIX E: SOURCES...................................................................................................... 170 APPENDIX F: CRITICAL FACILITIES LIST .......................................................................... 176 LIST OF TABLES Table 2-1: 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 ..... 21 Table 3-3: Santa Clara Valley Water District Water Supplies ......................................... 22 Table 3-4: 2015 Groundwater Inflow and Outflow in the Santa Clara Valley Water District in Acre-Feet (AF)....................................... 23 Table 3-5: Watersheds in the Santa Clara Valley Water District..................................... 23 Table 3-6: Santa Clara Valley Water District Supply Facilities ....................................... 24 Table 4-1: Key Demographics, Santa Clara County (2015) ............................................. 27 R14163 ii Table 4-2: Racial and Ethnic Composition of Residents, Santa Clara County (2015) ... 28 Table 4-3: Educational Attainment of Residents 25+ Years of Age, Santa Clara County (2015) ............................................................................... 29 Table 4-4: Language Proficiency of Residents 5+ Years of Age, Santa Clara County (2015) ............................................................................... 29 Table 4-5: Top Ten Santa Clara County Employers (2016) ............................................. 30 Table 5-1: Santa Clara Valley Water District LHMP Hazard Evaluation ......................... 34 Table 5-2: Hazard Ranking Scores and Weighing Factors ............................................. 37 Table 5-3: Scores and Threat Levels by Hazard .............................................................. 39 Table 5-4: Dams in Santa Clara County ........................................................................... 41 Table 5-5: US Drought Monitor Classification Scheme .................................................. 48 Table 5-6: Landslide Events in Santa Clara County ........................................................ 59 Table 5-7: Modified Mercalli Intensity Scale .................................................................... 71 Table 5-8: Major Faults in and Near Santa Clara County ................................................ 73 Table 5-9: Earthquake Probabilities Near Santa Clara County ....................................... 82 Table 5-10: Selected Earthquake Scenarios ...................................................................... 82 Table 5-11: Beaufort Scale .................................................................................................. 84 Table 5-12: Number of District Facilities in Risk Assessment ......................................... 93 Table 5-13: Facilities within 500 feet of a Dam Inundation Zone ...................................... 93 Table 5-14: Assets Within 500 feet of the 100-Year Floodplain ........................................ 94 Table 5-15: Risk to District Facilities from Landslides ..................................................... 95 Table 5-16: Risk to District Facilities from Ground Shaking ............................................ 95 Table 5-17: Risk to District Facilities from Fault Rupture ................................................. 96 Table 5-18: Risk to District Facilities from Liquefaction ................................................... 96 Table 5-19: Risk to District Facilities from Land Subsidence .......................................... 97 Table 5-20: Risk to District Facilities from Sea Level Rise ............................................... 97 Table 5-21: Risk to District Facilities from Wildfire ........................................................... 99 R14163 iii Table 6-1: STAPLE/E Review and Selection Criteria ..................................................... 103 Table 6-2: Mitigation Actions .........................................................................................