Attachment B - Orange County Hazard Mitigation Plan Page 1 of 219 County of Orange & Orange County Fire Authority Local Hazard Mitigation Plan November 2015 This page intentionally left blank. Attachment B - Orange County Hazard Mitigation Plan Page 2 of 219 County of Orange and Orange County Fire Authority Hazard Mitigation Plan Record of Changes Date of Revision Revision Description Section/Component Revision Completed By This page intentionally left blank. Page ii November 2015 Attachment B - Orange County Hazard Mitigation Plan Page 3 of 219 County of Orange and Orange County Fire Authority Hazard Mitigation Plan Board of Supervisors Resolution Page iii November 2015 Attachment B - Orange County Hazard Mitigation Plan Page 4 of 219 County of Orange and Orange County Fire Authority Hazard Mitigation Plan This page intentionally left blank. Page iv November 2015 Attachment B - Orange County Hazard Mitigation Plan Page 5 of 219 County of Orange and Orange County Fire Authority Hazard Mitigation Plan State OES Formal Review Letter Page v November 2015 Attachment B - Orange County Hazard Mitigation Plan Page 6 of 219 County of Orange and Orange County Fire Authority Hazard Mitigation Plan This page intentionally left blank. Page vi November 2015 Attachment B - Orange County Hazard Mitigation Plan Page 7 of 219 County of Orange and Orange County Fire Authority Hazard Mitigation Plan FEMA Letter of Acceptance Page vii November 2015 Attachment B - Orange County Hazard Mitigation Plan Page 8 of 219 County of Orange and Orange County Fire Authority Hazard Mitigation Plan This page intentionally left blank. Page viii November 2015 Attachment B - Orange County Hazard Mitigation Plan Page 9 of 219 County of Orange and Orange County Fire Authority Hazard Mitigation Plan Table of Contents Record of Changes ........................................................................................................................................ ii Board of Supervisors Resolution.................................................................................................................. iii State OES Formal Review Letter ................................................................................................................... v FEMA Letter of Acceptance ........................................................................................................................ vii Chapter 1 Introduction ................................................................................................................................. 1 Introduction .......................................................................................................................................... 1 Scope ..................................................................................................................................................... 1 Planning Process ................................................................................................................................... 1 Disabilities and Access and Functional Needs Working Group ............................................................. 6 Public Review ........................................................................................................................................ 6 Online Survey Results ........................................................................................................................... 7 Plan Meetings ....................................................................................................................................... 7 Related Documents and Resources ...................................................................................................... 8 Chapter 2 Community Profile ....................................................................................................................... 9 History ................................................................................................................................................... 9 Geography and the Environment........................................................................................................ 11 Land Use .............................................................................................................................................. 12 Population and Demographics ............................................................................................................ 13 Employment and Industry................................................................................................................... 15 History of Disasters ............................................................................................................................. 15 Chapter 3 Risk and Vulnerability Assessment ............................................................................................ 18 Overview of the Risk Assessment Process .......................................................................................... 18 Critical Facilities and Infrastructure .................................................................................................... 19 Hazard Identification ........................................................................................................................... 20 Profile of Hazard Events ...................................................................................................................... 23 3.1 Flood/Storm .................................................................................................................................. 23 3.2 Wildland/Urban Fire ..................................................................................................................... 50 3.3 Earthquake .................................................................................................................................... 71 3.4 Dam Failure ................................................................................................................................... 97 3.5 Landslide/Mud Flow/Debris Flow ............................................................................................... 104 Page ix November 2015 Attachment B - Orange County Hazard Mitigation Plan Page 10 of 219 County of Orange and Orange County Fire Authority Hazard Mitigation Plan 3.6 Tsunami ....................................................................................................................................... 113 3.7 Drought ....................................................................................................................................... 120 3.8 Climate Change ........................................................................................................................... 126 3.9 Epidemic ...................................................................................................................................... 131 Vulnerability Assessment .................................................................................................................. 143 Chapter 4 Hazard Mitigation Strategy ...................................................................................................... 147 Multi-Hazard Goals and Action Items ............................................................................................... 147 Hazard Mitigation Plan Action Items ................................................................................................ 148 National Flood Insurance Program ................................................................................................... 158 Prioritization ..................................................................................................................................... 160 Benefit Cost Review .......................................................................................................................... 160 Mitigation Action Items .................................................................................................................... 161 Chapter 5 Plan Maintenance .................................................................................................................... 168 Coordinating Body ............................................................................................................................ 168 Convener ........................................................................................................................................... 168 Adopting, Monitoring, and Updating the Hazard Mitigation Plan .................................................... 168 Incorporating Mitigation Into Existing Planning Mechanisms .......................................................... 169 Flood Event Post-Disaster Policies and Procedures / Action Items .................................................. 170 Continued Public Involvement .......................................................................................................... 173 Chapter 6 Local Capability Assessment .................................................................................................... 175 Chapter 7 Plan Resource Directory ........................................................................................................... 181 Chapter 8 Appendices ............................................................................................................................... 199 Appendix A – List of Acronyms ................................................................................................................