Hinsdale County Hazard Mitigation Plan 2019 Update November 2019 Hinsdale County Hazard Mitigation Plan 2019 Update November 2019 Table of Contents TABLE OF CONTENTS SECTION 1 - INTRODUCTION ............................................................................................................................ 1-1 1.1 Purpose .................................................................................................................................................................................... 1-1 1.2 Background and Scope ...................................................................................................................................................... 1-1 1.3 Multi-Jurisdictional Planning ........................................................................................................................................... 1-2 1.4 Plan Organization ................................................................................................................................................................. 1-2 SECTION 2 – COMMUNITY PROFILE ................................................................................................................................... 2-1 2.1 Geography and Climate ..................................................................................................................................................... 2-1 2.2 History ...................................................................................................................................................................................... 2-4 2.3 Population ............................................................................................................................................................................... 2-6 2.4 Government ............................................................................................................................................................................ 2-7 2.4.1 Hinsdale County Government .............................................................................................................................. 2-7 2.4.2 Town of Lake City Government ........................................................................................................................... 2-8 2.5 Economy .................................................................................................................................................................................. 2-8 2.6 Capability Assessment ........................................................................................................................................................ 2-9 2.6.1 Planning and Regulatory Mitigation Capabilities ......................................................................................... 2-9 2.6.2 Administrative and Technical Mitigation Capabilities ............................................................................. 2-14 2.6.3 Financial Mitigation Capabilities ...................................................................................................................... 2-16 2.6.4 Public Education and Outreach Mitigation Capabilities ......................................................................... 2-17 2.6.5 Special Districts, Stakeholder Agencies, and Other Mitigation partnerships ................................. 2-19 2.6.6 Opportunities for Enhancement ....................................................................................................................... 2-22 SECTION 3 – PLANNING PROCESS .............................................................................................................. 3-1 3.1 Background on Mitigation Planning in Hinsdale County ..................................................................................... 3-1 3.1.1 What’s New in the Plan Update .......................................................................................................................... 3-1 3.1.2 2014 Plan Section Review and Analysis ........................................................................................................... 3-2 3.2 Local Government Participation ..................................................................................................................................... 3-2 3.3 The 10-Step Planning Process ........................................................................................................................................ 3-2 3.3.1 Phase 1: Organize Resources ................................................................................................................................ 3-4 3.3.2 Phase 2: Assess Risks ............................................................................................................................................... 3-9 3.3.3 Phase 3: Develop the Mitigation Plan ............................................................................................................ 3-10 3.3.4 Phase 4: Implement the Plan and Monitor Progress ............................................................................... 3-10 SECTION 4 – RISK ASSESSMENT .................................................................................................................. 4-1 4.1 Hazard Identification and Prioritization ...................................................................................................................... 4-2 4.1.1 Methodology and Results...................................................................................................................................... 4-2 4.1.2 Disaster Declaration History ................................................................................................................................. 4-4 4.1.3 Overview of Hazard Identification and Risk Assessment .......................................................................... 4-6 4.2 Assets Summary .................................................................................................................................................................. 4-7 4.2.1 Methodology .............................................................................................................................................................. 4-7 4.2.2 Assets Exposure ......................................................................................................................................................... 4-7 4.2.3 Development and Population Trends ............................................................................................................ 4-17 4.3 Hazard Analysis and Risk Assessment ...................................................................................................................... 4-19 4.3.1 Avalanche ................................................................................................................................................................ 4-19 4.3.2 Dam Incidents .......................................................................................................................................................... 4-29 4.3.3 Drought ...................................................................................................................................................................... 4-40 4.3.4 Earthquake ................................................................................................................................................................ 4-50 Hinsdale County Hazard Mitigation Plan | September 2019 Page i Table of Contents 4.3.5 Flooding ..................................................................................................................................................................... 4-66 4.3.6 Landslides, Debris Flow, and Rockfall ............................................................................................................ 4-83 4.3.7 Severe Thunderstorm Activity ........................................................................................................................... 4-92 4.3.8 Severe Winter Storms ......................................................................................................................................... 4-104 4.3.9 Wildfires ................................................................................................................................................................... 4-111 4.3.10 Imminent Threat/Terrorism ........................................................................................................................... 4-126 4.3.11 Hazardous Materials Incidents ..................................................................................................................... 4-129 4.3.12 Pandemic Influenza ........................................................................................................................................... 4-135 4.3.13 Utility Failure ........................................................................................................................................................ 4-140 4.3.14 Transportation Accidents................................................................................................................................ 4-146 SECTION 5 – MITIGATION STRATEGY ......................................................................................................... 5-1 5.1 Mitigation Strategy: Overview........................................................................................................................................