Big Horn County Pre-Disaster Mitigation Plan Basin, Burlington, Byron, Cowley, Deaver, Frannie, Greybull, Lovell, Manderson, and Big Horn County, WY
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Big Horn County Pre-Disaster Mitigation Plan Basin, Burlington, Byron, Cowley, Deaver, Frannie, Greybull, Lovell, Manderson, and Big Horn County, WY. Big Horn River Ice Jam, Greybull, Wyoming March 9, 2014 Prepared by: Big Horn County, WY., Beck Consulting AMEC Foster Wheeler DRAFT: October 2015 EXECUTIVE SUMMARY Bog Horn County, Wyoming, and the incorporated communities of Basin, Burlington, Byron, Cowley, Deaver, Frannie, Greybull, Lovell, and Manderson prepared and adopted a Pre-Disaster Mitigation Plan (PDM Plan) in 2010. This plan is a revision to ensure these ten local jurisdictions remain disaster- resistant. This revision was prepared by Big Horn County with the assistance of contractor, Beck Consulting, and subcontractor, AMEC Foster Wheeler. The content of the plan relies on the advice and guidance of the Local Emergency Planning Committee (LEPC) and Mayors and Clerks of the incorporated towns. Both the LEPC and Mayors and Clerks actively participated in the update by determining the status of projects from the 2010 plan, validating natural hazards of concern, reviewing draft products, and identifying and prioritizing mitigation projects. Information was available about the project through newspaper coverage and the county’s website. Meetings--all open to the public--were held in Basin, Burlington, Deaver, and Greybull. The draft plan was made available through town and county websites and the public library for a four-week period starting in late October 2015. The plan contains five chapters and several appendices with supporting information. The chapters include an introduction, a description of the planning process, the hazard profiles, mitigation actions, and monitoring and updating the plan. Local plans and sources were utilized as were state and national data bases. A total of nine natural hazards were prioritized and profiled for the county. The hazard profiles included information about past occurrences, vulnerability, potential impact, and future development. The nine hazards include; dam failure, drought, earthquakes, floods, hail, tornadoes, wildland fire, wind and winter storms. The goals and action items in this plan revision were developed after consideration of: the projects identified in the 2010 PDM Plan, research of past disasters, the risks and vulnerabilities, and available resources and capacities. Chapter IV contains the mitigation goals and actions--or projects. Ten goals (rewritten to address each local jurisdiction’s needs individually) with a total of 45 projects were either carried over and/or developed during this revision process. Projects that had not been accomplished from the 2010 plan, that were still appropriate and meaningful were incorporated into the revision. Goal One: Mitigate natural and human caused hazards to reduce the potential for property loss or damage, injury and loss of life for Big Horn County. Goals 2-10 contain this same wording except to name the each specific jurisdiction. i ii Table of Contents Chapter 1 INTRODUCTION ......................................................................................................................... 1-1 Purpose ...................................................................................................................................................... 1-1 Specific Jurisdictions Participating in the Plan Update .............................................................................. 1-1 Mitigation Goals ........................................................................................................................................ 1-1 Scope and Plan Organization ..................................................................................................................... 1-2 Appendices ................................................................................................................................................ 1-3 Authority .................................................................................................................................................... 1-3 Chapter 2 PLANNING PROCESS .................................................................................................................. 2-1 Process Followed to Update the Plan ........................................................................................................ 2-1 How the Jurisdictions Participated in the Plan Update ............................................................................. 2-1 Opportunity for Involvement by Other Interests ...................................................................................... 2-2 How the Planning Team Reviewed and Analyzed the Existing Plan .......................................................... 2-2 How the Public Was Involved in the Planning Process .............................................................................. 2-2 Review and Incorporation of Existing Plans .............................................................................................. 2-5 Chapter 3 RISK ASSESSMENT AND HAZARD PROFILES .............................................................................. 3-7 Introduction and Methodology ................................................................................................................. 3-8 Identified Hazards ...................................................................................................................................... 3-8 Vulnerability Overview .............................................................................................................................. 3-8 Structural Vulnerability ............................................................................................................................ 3-13 Vulnerable Populations ........................................................................................................................... 3-14 Critical Facilities ....................................................................................................................................... 3-14 Dam Failure .............................................................................................................................................. 3-20 Drought .................................................................................................................................................... 3-30 Earthquake ............................................................................................................................................... 3-44 Flooding ................................................................................................................................................... 3-54 Damaging Hail .......................................................................................................................................... 3-83 High Winds and Downbursts ................................................................................................................... 3-89 Tornado.................................................................................................................................................... 3-95 iii Wildfire .................................................................................................................................................. 3-101 Severe Winter Weather ......................................................................................................................... 3-112 Chapter 4 HAZARD MITIGATION GOALS AND PROJECTS ........................................................................... 4-1 How the goals and projects were developed ............................................................................................ 4-1 Project Costs .............................................................................................................................................. 4-1 Project Priorities ........................................................................................................................................ 4-1 Project Types ............................................................................................................................................. 4-3 Abbreviations used in table ..................................................................................................................... 4-11 Action Plan ............................................................................................................................................... 4-12 Use of Cost-Benefit Analysis .................................................................................................................... 4-12 Existing Authorities, Policies, Programs and Resources for Implementation ......................................... 4-12 Chapter 5 PLAN MONITORING, MAINTENANCE, REVISION AND COORDINATION ................................... 5-1 Responsible Parties .................................................................................................................................... 5-1 Plan Monitoring and Evaluation ................................................................................................................ 5-1 Plan Update Review Triggers ..................................................................................................................... 5-1 Revision Procedures .................................................................................................................................. 5-2 Incorporation