City of Wasilla Hazard Mitigation Plan (Phase I – Natural Hazards) 2018 Update by: Wasilla Planning Commission Acknowledgements Wasilla City Council Bert Cottle, Mayor Glenda Ledford Tim Burney Stu Graham Mike Dryden Gretchen O’Barr James E. Harvey Wasilla Planning Commission Eric Bushnell Darrell L. Breese Jessica Dean Simon Brown Brian L. Mayer City Staff Tina Crawford, City Planner City of Wasilla Planning Office 290 E. Herning Avenue Wasilla, AK 99654 Phone: (907) 373-9020 Fax: (907) 373-9021 E-Mail: [email protected] Consultants LeMay Engineering & Consulting, Inc. Jennifer LeMay, PE, PMP John Farr, EIT 4272 Chelsea Way Anchorage, Alaska 99504 Phone: (907) 350-6061 Email: [email protected]; [email protected] Technical Assistance Brent Nichols, CFM, SHMO, Alaska State DHS&EM The preparation of this plan was financed by funds from a grant from the Alaska Division of Homeland Security and Emergency Management and the Federal Emergency Management Agency. ii City of Wasilla 2018 Hazard Mitigation Plan Acronyms °F Degrees Fahrenheit ADEC Alaska Department of Environmental Conservation AEIC Alaska Earthquake Information Center AFS Alaska Fire Service AHS Alaska Hydrologic Survey APA Approved Pending Adoption AS Alaska State Statute AKST Alaska Standard Time BCA Benefit-Cost Analysis BCR Benefit-Cost Ratio BLM Bureau of Land Management CFR Code of Federal Regulations DCCED Department of Commerce, Community, and Economic Development (State of Alaska) DHS&EM Department of Homeland Security and Emergency Management DMA Disaster Mitigation Act DOL Department of Labor EOC Emergency Operation Center EOP Emergency Operations Plan EQ Earthquake ER Erosion FEMA Federal Emergency Management Agency FL Flooding FMA Flood Mitigation Assistance Program HMA Hazard Mitigation Assistance HMP Hazard Mitigation Plan HMGP Hazard Mitigation Grant Program HW High Wind IA Individual Assistance LEPC Local Emergency Planning Committee M Magnitude MPH Miles Per Hour MSB Matanuska-Susitna Borough NFIP National Flood Insurance Program NMFS National Marine Fisheries Service NOAA National Oceanic & Atmospheric Administration NWS National Weather Service PA Public Assistance PDM Pre-Disaster Mitigation Grant Program PSA Public Service Announcement Risk MAP FEMA Risk Mapping, Assessment, and Planning Program SBA Small Business Administration SHMO State Hazard Mitigation Officer SOA State of Alaska SW Severe Weather USACE United States Army Corps of Engineers USC United States Code iii City of Wasilla 2018 Hazard Mitigation Plan USFS United States Forest Service USGS United States Geological Survey VAF Volcanic Ashfall WF/UF Wildland and Urban Fire iv City of Wasilla 2018 Hazard Mitigation Plan FEMA Approval Letter v City of Wasilla 2018 Hazard Mitigation Plan City Council Resolution vi City of Wasilla 2018 Hazard Mitigation Plan Table of Contents Acknowledgements ......................................................................................................................... ii Acronyms ....................................................................................................................................... iii FEMA Approval Letter ................................................................................................................... v City Council Resolution ................................................................................................................. vi List of Tables ................................................................................................................................. ix List of Figures ................................................................................................................................. x List of Maps .................................................................................................................................... x Chapter I – Planning Process and Methodology ............................................................................. 1 A. Introduction ...................................................................................................................... 1 Section 1. Purpose of the Plan ...................................................................................... 1 Section 2. Authority ...................................................................................................... 2 B. Plan Development ............................................................................................................ 3 Section 1. Project Staff ................................................................................................. 4 Section 2. Plan Research ............................................................................................... 4 Section 3. Public Involvement ...................................................................................... 4 Section 4. Incorporation of Existing Plans ................................................................... 5 C. Plan Maintenance ............................................................................................................. 6 Section 1. Incorporation into Existing Planning Mechanisms ...................................... 7 Section 2. Continued Public Involvement .................................................................... 7 Section 3. Monitoring, Evaluating and Updating the Plan ........................................... 8 Section 4. State and FEMA Review and Technical Assistance .................................... 8 Section 5. Formal Plan Adoption and Assurances ........................................................ 9 Chapter II – Community Profile .................................................................................................. 10 A. Location ......................................................................................................................... 11 B. History............................................................................................................................ 11 C. Population ...................................................................................................................... 12 D. Economy ........................................................................................................................ 13 E. Transportation ................................................................................................................ 13 F. Climate ........................................................................................................................... 14 G. Natural Environment ...................................................................................................... 14 H. Land Use and Development Trends ............................................................................... 14 Chapter III – Risk Assessment ...................................................................................................... 18 A. Requirements ................................................................................................................. 18 B. Vulnerability Assessment Methodology ........................................................................ 20 Section 1. Identifying Hazards .................................................................................... 23 Section 2. Assessing Vulnerability ............................................................................. 25 Overview ................................................................................................................ 25 Identification of Assets ........................................................................................... 25 Summary ................................................................................................................ 31 Section 3. Earthquake ................................................................................................. 33 Hazard Description ................................................................................................. 33 Location .................................................................................................................. 34 Extent ...................................................................................................................... 35 Impact ..................................................................................................................... 36 Probability .............................................................................................................. 36 vii City of Wasilla 2018 Hazard Mitigation Plan Previous Occurrences ............................................................................................. 37 Section 4. High Wind .................................................................................................. 39 Hazard Description ................................................................................................. 39 Location .................................................................................................................. 40 Extent ...................................................................................................................... 40 Impact ..................................................................................................................... 40 Probability .............................................................................................................. 40 Previous Occurrences ............................................................................................