Local Hazard Mitigation Plan Five Year Update 2018–2023
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CITY OF SANTA CRUZ Local Hazard Mitigation Plan Five Year Update 2018–2023 Hazard Mitigation is any action taken to reduce or eliminate the long-term risk to human life and property from hazards. ~ Title 44 Code of Federal Regulations (§206.401) Adopted by the City Council xxxx xx, 201x Table of Contents APPENDICES .......................................................................................................................................................... II MAPS AND FIGURES ................................................................................................................................................ II TABLES ................................................................................................................................................................ III HOW TO USE THIS PLAN ......................................................................................................................................... IV PART 1 — INTRODUCTION AND ADOPTION .................................................................................................... 1 INTRODUCTION...................................................................................................................................................... 2 ACKNOWLEDGEMENTS ............................................................................................................................................ 4 SUMMARY ............................................................................................................................................................ 5 CLIMATE ADAPTATION ............................................................................................................................................. 6 CHAPTER 1: ADOPTION BY CITY COUNCIL ....................................................................................................... 8 ADOPTION ............................................................................................................................................................ 9 CHAPTER 2: COMMUNITY PROFILE ............................................................................................................... 10 PART 2 — THE PLANNING PROCESS ............................................................................................................... 23 CHAPTER 3: THE PLANNING PROCESS ........................................................................................................... 24 PROJECT TEAMS: THEN AND NOW .......................................................................................................................... 25 PART 3 — HAZARD IDENTIFICATION AND RISK ASSESSMENT ........................................................................ 33 IDENTIFICATION AND PROFILING OF HAZARDS ............................................................................................................ 34 CHAPTER 4: EARTHQUAKES AND LIQUEFACTION .......................................................................................... 39 CHAPTER 5: WILDFIRES ................................................................................................................................. 60 CHAPTER 6: FLOODS AND ASSOCIATED COASTAL STORMS ............................................................................ 70 CHAPTER 7: DROUGHT .................................................................................................................................. 84 CHAPTER 8: TSUNAMI ................................................................................................................................. 102 CHAPTER 9: COASTAL EROSION ................................................................................................................... 113 CHAPTER 10: DAM FAILURE LESSER RISK .................................................................................................. 123 CHAPTER 11: LANDSLIDE ............................................................................................................................. 128 CHAPTER 12: MULTI-HAZARD SUMMARY .................................................................................................... 140 PART 4 — MITIGATION STRATEGY ................................................................................................................ 141 CHAPTER 13: MITIGATION STRATEGY .......................................................................................................... 142 IDENTIFICATION AND ANALYSIS OF MITIGATION ACTIONS ........................................................................................... 144 PART 5 — PLAN MAINTENANCE PROCESS ................................................................................................... 163 CHAPTER 14: PLAN MAINTENANCE PROCESS .............................................................................................. 164 CHAPTER 15: PUBLIC OUTREACH AND PLAN DEVELOPMENT ...................................................................... 170 ENDNOTES ........................................................................................................................................................ 204 CITY OF SANTA CRUZ LOCAL HAZARD MITIGATION PLAN 20187–2023 UPDATE i Appendices Appendix Subject A Hazards That Are Not a Significant Risk B Acronyms and Abbreviations C Glossary of Terms D Critical Facilities E Public Schools F Private Schools G Day Care Facilities H Senior Residence and Care Facilities I City of Santa Cruz Facilities J References for Tsunami Run Up K Successful Programs and Projects L Water Shortage Contingency Plan: Executive Summary M Census Characteristics N Critical Structures Overview O Emergency Operations Plan 2012 P Climate Adaptation Plan Q City of Santa Cruz Local Hazard Mitigation Plan Update: Project Team Local Emergency Management Agency and Jurisdictional Partners Review of R this LHMP Update Maps and Figures Map/Figure Subject 1 City Limits of Santa Cruz with Surrounding Greenbelts 2 City of Santa Cruz Location within the State of California 3 Key Transportation Routes to and within Santa Cruz Critical Structures within the City of Santa Cruz and Unincorporated 4 Surrounding Area 5 Public and Private Schools, Day Care and Senior Facilities 6 Areas in Santa Cruz Potentially Vulnerable to Liquefaction Intensity and Magnitude of the 1989 Loma Prieta Earthquake in 7 Santa Cruz 8 Scenario N-9 Repeat of 1906 Earthquake 9 Scenario N-9 Repeat of 1906 Earthquake — Bldg. Economic Loss by County 10 Scenario N-9 Repeat of 1906 Earthquake Loss by Census Tract 11 Scenario N-7 Santa Cruz Mountains 12 Scenario N-7 Santa Cruz Mountains — Building Economic Loss by County 13 Scenario N-7 Santa Cruz Mountains — Bldg. Economic Loss by Census Tract 14 Wildfire Hazard Areas within the City of Santa Cruz 15 FEMA Flood Map showing 100-year flood zone 16 Water Service Area CITY OF SANTA CRUZ LOCAL HAZARD MITIGATION PLAN 20187–2023 UPDATE ii Map/Figure Subject 17 US Drought Monitor, late 2015 18 Water Year Classification Total Annual Runoff San Lorenzo River (acre feet) 19 Tsunami Inundation Area 20 Areas Susceptible to Coastal Erosion 21 Slides and Earth Flows in Santa Cruz County 22 Potential Slide Threats to Santa Cruz Tables Table Subject 2-1 Temperature Averages for Santa Cruz City of Santa Cruz Population and Household Growth — 2-2 U.S. Census 2011–2015 American Community Survey 5-Year Estimates 3-1 List of Meetings A-1 Review of All Hazards A-2 Hazard Screening for City of Santa Cruz 4-1 Modified Mercalli Intensity Scale 4-2 Ten Most Likely Damaging Earthquake Scenarios in California 4-3 Earthquake Potential Loss Inventory 5-1 Wildfire Potential Loss Inventory 6-1 Flood Probability Terms 6-2 Flood Potential Loss Inventory 7-1 Single Dry Year Supply and Demand Assessment 7-2 Multiple Dry Year Supply and Demand Assessment Relationship of Water Shortages with Various Recurrence Intervals 7-3 to the Probability of Occurrence over Time 8-1 Locally Generated Tsunami Source 8-2 Tsunami Potential Loss Inventory 9-1 Coastal Erosion Potential Loss Inventory 11-1 Landslide Potential Loss by Structure CITY OF SANTA CRUZ LOCAL HAZARD MITIGATION PLAN 20187–2023 UPDATE iii How to Use This Plan FEMA has defined very specific requirements for Local Hazard Mitigation Plans and this plan follows those guidelines. The organization of the Plan follows FEMA’s structural requirements and includes the following four organizational levels: ♦ Parts ♦ Chapters ♦ Sections ♦ Subsections This LHMP Five Year Update [2018–2023] is organized into five primary Parts and fifteen Chapters (and, Appendices A–R), that track the phases of the plan’s development as follows: ♦ Part 1 — Prerequisites — Introduction and Adoption Acknowledgements • Summary Adoption by City Council ......................................... Chapter 1 Community Profile.................................................... Chapter 2 ♦ Part 2 — The Planning Process ..................................................... Chapter 3 ♦ Part 3 — Risk Assessment ..................................................... Chapters 4–12 ♦ Part 4 — Mitigation Strategies — Goal, Objectives, Actions Mitigation Strategy ................................................. Chapter 13 ♦ Part 5 — Plan Maintenance Process Plan Maintenance Process....................................... Chapter 14 Public Outreach and Plan Development ................. Chapter 15 Risk Assessment (Part 3) is organized into specific hazards by chapter (Chapter 4 through Chapter