Denali Borough and City of Anderson Multi‐Jurisdictional Hazard Mitigation Plan Update Prepared by the Denali Borough and the City of Anderson Mitigation Planning Team In Collaboration with: September 2020 This page was intentionally left blank. ii Table of Contents 1.0 Introduction ................................................................................................................ 1 1.1 Hazard Mitigation Planning ......................................................................................... 1 1.2 Local Mitigation Plans ................................................................................................. 1 1.3 Grant Programs with Mitigation Plan Requirements ................................................... 2 1.4 HMA Unified Programs ................................................................................................ 2 1.5 Plan Description .......................................................................................................... 3 2.0 Prerequisites ............................................................................................................... 5 3.0 Community Description ............................................................................................... 6 3.1 Location, Geography, Climate, Community Types, and History ................................... 6 3.2 Demographics ............................................................................................................. 9 3.3 Economy ...................................................................................................................... 9 3.4 Transportation ........................................................................................................... 11 4.0 Planning Process ........................................................................................................ 12 4.1 Overview of Planning Process ................................................................................... 12 4.2 Hazard Mitigation Planning Team ............................................................................. 14 4.3 Public Involvement & Opportunity for Interested Parties to Participate ................... 16 4.4 Incorporation of Existing Plans and Other Relevant Information .............................. 20 5.0 Hazard Profiles .......................................................................................................... 21 5.1 Overview of a Hazard Analysis................................................................................... 21 5.2 Hazard Identification and Screening .......................................................................... 21 5.3 Hazard Profile ............................................................................................................ 23 5.3.1 Changes in the Cryosphere ........................................................................................ 23 5.3.2 Earthquakes ............................................................................................................... 35 5.3.3 Flooding ..................................................................................................................... 43 5.3.4 Ground Failure........................................................................................................... 49 5.3.5 Severe Weather ......................................................................................................... 54 5.3.6 Wildfire and Conflagration Fires ................................................................................ 67 6.0 Vulnerability Analysis ................................................................................................ 86 6.1 Overview of a Vulnerability Analysis ......................................................................... 86 6.2 Vulnerability Analysis: Specific Steps ......................................................................... 87 6.2.1 Asset Inventory ......................................................................................................... 87 6.2.2 Population and Building Stock ................................................................................... 87 6.2.3 Repetitive Loss Properties ......................................................................................... 88 6.2.4 Existing Critical Facilities and Infrastructure .............................................................. 88 6.2.5 Methodology ............................................................................................................. 89 6.2.6 Data Limitations ........................................................................................................ 89 6.2.7 Vulnerabilities ........................................................................................................... 99 6.3 Land Use and Development Trends ......................................................................... 101 7.0 Mitigation Strategy .................................................................................................. 105 7.1 Developing Mitigation Goals ................................................................................... 106 7.2 Identifying Mitigation Actions ................................................................................. 106 7.3 Evaluating and Prioritizing Mitigation Actions ......................................................... 107 iii 7.4 Implementing a Mitigation Action Plan ................................................................... 108 8.0 Plan Maintenance.................................................................................................... 122 8.1 Monitoring, Evaluating, and Updating the Plan ....................................................... 122 8.2 Implementation Through Existing Planning Mechanisms ........................................ 124 8.3 Capability Assessment ............................................................................................. 124 8.4 Continued Public Involvement ................................................................................ 126 8.5 Federal Resources ................................................................................................... 127 9.0 References ............................................................................................................... 133 Table of Tables Table 1. Community Types in the Denali Borough ....................................................................... 7 Table 2. Hazard Mitigation Planning Team .................................................................................. 14 Table 3. Public Involvement Mechanisms ................................................................................... 16 Table 4. Identification and Screening of Borough and City of Anderson Hazards ....................... 22 Table 5. Glaciers within the Denali Borough ............................................................................... 33 Table 6. Perceived Shaking, Potential Damage, and Peak Ground Acceleration ......................... 38 Table 7. Historical Earthquakes within a 150‐Mile Radius of the Center of the Borough ............ 39 Table 8. Landslide Types ............................................................................................................. 49 Table 9. Severe Weather Events ................................................................................................. 55 Table 10. Denali Borough Community Weather Summary .......................................................... 66 Table 11. Largest Wildfire Locations Since 1995 within 100‐Miles of the Healy ......................... 74 Table 12. Largest Wildfire Locations within 100‐Miles of Anderson ........................................... 76 Table 13. Hazard Identification by Area ...................................................................................... 87 Table 14. Estimated Population and Building Inventory ............................................................. 87 Table 15. Alaska’s Critical Infrastructure ..................................................................................... 88 Table 16. Hazard Vulnerabilities for Critical Facilities & Infrastructure for Government, Medical, and Emergency Services .............................................................................................................. 90 Table 17. Hazard Vulnerabilities for Critical Facilities and Infrastructure for Education, Community, and Utilities ............................................................................................................ 90 Table 18. Hazard Vulnerabilities for Critical Facilities and Infrastructure for Transportation and Essential Businesses .................................................................................................................... 91 Table 19. Borough Land Ownership .......................................................................................... 102 Table 20. Mitigation Goals ........................................................................................................ 106 Table 21. Potential Mitigation Actions ...................................................................................... 107 Table 22. Evaluation Criteria for Mitigation Actions .................................................................. 108 Table 23. Community’s Mitigation Action Plan Matrix .............................................................. 110 Table 24. Community’s Regulatory Tools