County of Orange & Orange County Fire Authority Local Hazard Mitigation Plan May 2021 DRAFT FOR PUBLIC REVIEW County of Orange and Orange County Fire Authority Local Hazard Mitigation Plan This page intentionally left blank. Page ii May 2021 County of Orange and Orange County Fire Authority Local Hazard Mitigation Plan Table of Contents Chapter 1 Introduction and Planning Process .............................................................................................. 1 Plan Description .................................................................................................................................... 1 Purpose ................................................................................................................................................. 1 Hazard Mitigation Planning During a Pandemic ................................................................................... 1 2020 Plan Updates ................................................................................................................................ 2 Plan Development ................................................................................................................................. 3 Plan Meetings ....................................................................................................................................... 6 Public Involvement and Review ............................................................................................................ 7 Related Documents and Resources ...................................................................................................... 8 Chapter 2 Community Profile ..................................................................................................................... 10 Orange County Overview .................................................................................................................... 10 Orange County Fire Authority Overview ............................................................................................. 10 Geography and the Environment ........................................................................................................ 10 Land Use .............................................................................................................................................. 11 Population and Demographics ............................................................................................................ 12 Employment and Industry ................................................................................................................... 13 History of Disasters ............................................................................................................................. 14 Chapter 3 Risk and Vulnerability Assessment ............................................................................................. 19 Overview of the Risk Assessment Process .......................................................................................... 19 Hazard Identification ........................................................................................................................... 20 Profile of Hazard Events ...................................................................................................................... 23 3.1 Earthquake .................................................................................................................................... 24 3.2 Flood-Storm .................................................................................................................................. 30 3.3 Wildland and Urban Fire ............................................................................................................... 36 3.4 Climate Change ............................................................................................................................. 40 3.5 Dam Failure ................................................................................................................................... 46 3.6 Epidemic ........................................................................................................................................ 53 3.7 Drought ......................................................................................................................................... 64 3.8 Tsunami ......................................................................................................................................... 71 3.9 Landslide ....................................................................................................................................... 75 Identification of Community Assets and Critical Infrastructure ......................................................... 81 Page iii May 2021 County of Orange and Orange County Fire Authority Local Hazard Mitigation Plan Vulnerability Assessment .................................................................................................................... 81 Chapter 4 Hazard Mitigation Strategy ........................................................................................................ 85 Multi-Hazard Goals ............................................................................................................................. 85 Hazard Mitigation Plan Action Items .................................................................................................. 86 Previous Action Items ......................................................................................................................... 87 National Flood Insurance Program ..................................................................................................... 98 Prioritization...................................................................................................................................... 100 Mitigation Action Item Summary ...................................................................................................... 102 Chapter 5 Plan Maintenance .................................................................................................................... 106 Coordinating Body ............................................................................................................................ 106 Convener ........................................................................................................................................... 106 Adopting, Monitoring, and Updating the Hazard Mitigation Plan .................................................... 106 Incorporating Mitigation Into Existing Planning Mechanisms .......................................................... 107 Flood Event Post-Disaster Policies and Procedures / Action Items .................................................. 107 Continued Public Involvement .......................................................................................................... 110 Chapter 6 Local Capability Assessment .................................................................................................... 112 Planning and Regulatory Resources .................................................................................................. 112 Administrative and Technical Resources .......................................................................................... 113 Financial Resources ........................................................................................................................... 115 Education and Outreach Resources .................................................................................................. 116 Chapter 7 Appendices ............................................................................................................................... 117 Appendix A – List of Acronyms ............................................................................................................. 118 Appendix B - Table of Maps .................................................................................................................. 122 Appendix C - List of Tables .................................................................................................................... 123 Chapter 8 Attachments ............................................................................................................................. 124 Page iv May 2021 County of Orange and Orange County Fire Authority Local Hazard Mitigation Plan Chapter 1 Introduction and Planning Process Plan Description The 2020 County of Orange and Orange County Fire Authority Local Hazard Mitigation Plan (LHMP) was developed collaboratively with emergency management staff, County and external partners, and Orange County residents. The document is an update to the 2015 LHMP and is a critical step in continuing Orange County’s commitment to hazard mitigation as one component of its comprehensive emergency management program. The mission of the LHMP is to promote sound public policy designed to protect residents, critical facilities, infrastructure, key resources, private property, and the environment from natural hazards in unincorporated areas, fire hazards in the Fire Authority service area, and County and Fire Authority owned facilities. This contribution to Orange County’s hazard mitigation efforts will increase public awareness, document resources for risk reduction and loss prevention, and identify activities to guide the County toward building a safer,