Document Douglas_doc_74a78d2daa

Wyoming Region 2 Converse County Natrona County Niobrara County Regional Hazard Mitigation Plan September 2018 Developed by Converse County, Natrona County, and Niobrara County With professional planning assistance from Wood Environment & Infrastructure Solutions, Inc. Hazard Mitigation and Emergency Management Program ---PAGE BREAK--- Region 2 i Regional Hazard Mitigation Plan 2018 TABLE OF CONTENTS Chapters Chapter 1 – Introduction 1.1 Purpose 1.2 Background and Scope 1.3 Plan 1.4 Multi-Jurisdtional Planning Chapter 2 – Community Profile 2.1 Geography and Climate 2.2 Population 2.3 Economy Chapter 3 – Planning Process 3.1 Background on Mitigation Planning in the Region 3.2 Government Participation 3.3 The 10-Step Planning Process 3.3.1 Phase 1: Organize Resources 3.3.2 Phase 2: Assess Risks 3.3.3 Phase 3: Develop the Mitigation Plan 3.3.4 Phase 4: Implement the Plan and Monitor Progress Chapter 4 –Hazard Analysis and Risk Assessment 4.1 Hazard Identification 4.1.1. Results and Methodology 4.1.2 Disaster Declaration History 4.2 Hazard 4.2.1 Profile Methodology 4.2.2 Dam Failure 4.2.3 Drought 4.2.4 Earthquake 4.2.5 Expansive Soils 4.2.6 Flood 4.2.7 Hail 4.2.8 Hazardous Materials 4.2.9 High Winds and Downbursts 4.2.10 Landslide/Rockfall/Debris Flow 4.2.11 Lightning 4.2.12 Mine Subsidence 4.2.13 Severe Winter Weather ---PAGE BREAK--- Region 2 ii Regional Hazard Mitigation Plan 2018 4.2.14 Tornado 4.2.15 Wildfire Chapter 5 – Mitigation Strategy 5.1 Mitigation Strategy: Overview 5.2 Goals and Objectives 5.3 Identification and Analysis of Mitigation 5.3.1 Prioritization Process 5.4 Mitigation Action Plan 5.4.1 Progress on Previous Mitigation Actions 5.4.2 New Mitigation Actions 5.4.3 Continued Compliance with NFIP 5.4.4 Mitigation Action Plan Chapter 6 – Plan Adoption, Implementation, and 6.1 Formal Adoption 6.2 Implementation 6.2.1 Role of the Hazard Mitigation Planning Committee in Implementation and Maintenance 6.3 Maintenance 6.3.1 Maintenance Schedule 6.3.2 Maintenance Evaluation Process 6.3.3 Incorporation into Existing Planning Mechanisms 6.3.4 Continued Public Involvement ---PAGE BREAK--- Region 2 iii Regional Hazard Mitigation Plan 2018 Jurisdictional Annexes Converse County Annex Natrona County Annex Niobrara County Annex Appendixes Appendix A - Planning Process Documentation Appendix B – Records of Adoption (electronic) ---PAGE BREAK--- Region 2 iv Regional Hazard Mitigation Plan 2018 EXECUTIVE SUMMARY This plan is the product of a 2017-2018 planning process undertaken by the three counties in Wyoming Office of Homeland Security Region 2 – Converse, Natrona, and Niobrara Counties. The purpose is to meet the requirements of the Disaster Mitigation Act of 2000 (PL 106-390), and thereby maintain continued eligibility for certain Hazard Mitigation – or disaster loss reduction – programs from the Federal Emergency Management Agency (FEMA). This plan updates existing hazard mitigation plans for Converse, Natrona, and Niobrara Counties. The process followed a methodology that adheres to FEMA guidance for local hazard mitigation plans. It consisted of two levels of planning teams; a steering committee/coordinating planning team comprised of each county’s Emergency Management Coordinator, and a local Hazard Mitigation Planning Committee (HMPC) in each county. Every municipality within each county was invited to participate. The planning process examined the recorded history of losses resulting from natural hazards, and analyzed the future risks posed to each county and participating municipalities by these hazards. A hazard identification and risk assessment was updated for the following hazards: dam failure, drought, earthquake, expansive soils, flood, hailstorm, hazardous materials, high winds, landslide, lightning, mine subsidence, tornadoes, severe winter storms and wildfire. Where applicable, these profiles were built on existing information found in the previous hazard mitigation plans. The hazards were assessed for geographic extent, potential magnitude probability, vulnerability and given a rating for overall significance. Drought, wildfire, floods and winter storms tend to cause the most damage or economic loss in the Region. The plan’s mitigation strategy includes goals for each county in the planning area. The plan also puts forth county-specific recommendations for mitigation, based on the risk assessment, that are designed to reduce future losses in each county and the Region. Lastly, the plan includes an implementation strategy to ensure the plan is carried out in practice. ---PAGE BREAK--- Region 2 1-1 Regional Hazard Mitigation Plan 2018 CHAPTER 1 INTRODUCTION 1.1 Purpose Wyoming Region 2, encompassing Converse, Natrona, and Niobrara Counties and their municipalities, prepared this regional hazard mitigation plan to guide hazard mitigation planning and to better protect the people and property of the planning area from the effects of hazard events. This plan demonstrates the region’s commitment to reducing risks from hazards and serves as a tool to help decision makers direct mitigation activities and resources. This plan also maintains the eligibility of participating jurisdictions in the planning area for certain federal disaster assistance under the Federal Emergency Management Agency’s (FEMA) Hazard Mitigation Assistance (HMA) grant programs. 1.2 Background and Scope Each year in the United States, disasters take the lives of hundreds of people and injure thousands more. Nationwide, taxpayers pay billions of dollars annually to help communities, organizations, businesses, and individuals recover from disasters. These monies only partially reflect the true cost of disasters, because additional expenses to insurance companies and nongovernmental organizations are not reimbursed by tax dollars. Many disasters are predictable, and much of the damage caused by these events can be alleviated or even eliminated. Hazard mitigation is defined by FEMA as “any sustained action taken to reduce or eliminate long- term risk to human life and property from a hazard event.” The results of a three-year, congressionally mandated independent study to assess future savings from mitigation activities provides evidence that mitigation activities are highly cost-effective. According to the Natural Hazard Mitigation Saves: 2017 Interim Report released by the National Institute of Building Science, on average, each dollar spent on mitigation saves society an average of $6 in avoided future losses in addition to saving lives and preventing injuries. Hazard mitigation planning is the process through which hazards that threaten communities are identified, likely impacts of those hazards are determined, mitigation goals are set, and appropriate strategies to lessen impacts are developed, prioritized, and implemented. This plan documents the planning region’s hazard mitigation planning process, identifies relevant hazards and risks, and identifies the strategies that each participating jurisdiction will use to decrease vulnerability and increase resiliency and sustainability. This plan was prepared pursuant to the requirements of the Disaster Mitigation Act of 2000 (Public Law 106-390) and the implementing regulations set forth by the Interim Final Rule published in the Federal Register on February 26, 2002 (44 CFR §201.6) and finalized on October 31, 2007 (hereafter, these requirements and regulations will be referred to collectively as the Disaster Mitigation Act (DMA)). While the act emphasized the need for mitigation plans and more ---PAGE BREAK--- Region 2 1-2 Regional Hazard Mitigation Plan 2018 coordinated mitigation planning and implementation efforts, the regulations established the requirements that local hazard mitigation plans must meet in order for a local jurisdiction to be eligible for certain federal disaster assistance and hazard mitigation funding under the Robert T. Stafford Disaster Relief and Emergency Act (Public Law 93-288). Because the planning area is subject to many kinds of hazards, access to these programs is vital. Information in this plan will be used to help guide and coordinate mitigation activities and decisions for local land use policy in the future. Proactive mitigation planning will help reduce the cost of disaster response and recovery to communities and property owners by protecting critical community facilities, reducing liability exposure, and minimizing overall community impacts and disruption. The jurisdictions in the planning area have been affected by hazards in the past and are thus committed to reducing future disaster impacts and maintaining eligibility for federal funding. 1.3 Plan Organization The Wyoming Region 2 Regional Hazard Mitigation Plan is organized in alignment with the DMA planning requirements and the FEMA plan review tool as follows: • Chapter 1: Introduction • Chapter 2: Community Profile • Chapter 3: Planning Process • Chapter 4: Risk Assessment • Chapter 5: Mitigation Strategy • Chapter 6: Plan Adoption, Implementation, and Maintenance • County Annexes • Appendices County Annexes Each of the three counties has its own annex, which provides a more detailed assessment of each participating jurisdiction’s unique risks as well as its mitigation strategy to reduce long-term losses. Each annex contains the following: • Community profile summarizing geography and climate, history, economy, and population • Detailed, jurisdiction-specific hazard vulnerability information and unique risks, where applicable, for geographically specific hazards • Hazard map(s) at an appropriate scale for each jurisdiction, if available • Number and value of buildings, critical facilities, and other community assets located in hazard areas, if available • Capability assessments describing existing regulatory, administrative, and technical resources • Mitigation actions specific to the county and municipalities ---PAGE BREAK--- Region 2 1-3 Regional Hazard Mitigation Plan 2018 1.4 Multi-Jurisdictional Planning This plan was prepared as a regional, multi-jurisdictional plan. The planning region is comprised of three counties in Wyoming Region 2 (region), as established by the Wyoming Office of Homeland Security (WOHS); the region includes Converse, Natrona, and Niobrara Counties. All local units of government in each county were invited to participate in the planning process; the decision whether or not to participate in this process was a local decision, based on community needs. Communities have the options to not prepare a plan, to prepare a stand-alone plan for their jurisdiction, or to participate in a multi-jurisdiction or county-wide plan. All three counties in the region had previous multi-jurisdictional hazard mitigation plans prior to the development of this Regional Plan. The following table lists counties and their local governments that have opted to participate in this effort and are seeking FEMA approval of the 2018 version of this plan. All communities were updating a previously approved plan. Additional details about participation can be referenced in Chapter 3 and the county annexes. Table 1-1 Multi-Jurisdictional Participation 2018 Jurisdiction Participation Status Converse County Participated in 2011 original, 2018 county update, 2018 regional update City of Douglas Participated in 2011 original, 2018 county update, 2018 regional update Town of Glenrock Participated in 2011 original, 2018 county update, 2018 regional update Town of Lost Springs Participated in 2011 original, 2018 county update, 2018 regional update Town of Rolling Hills Participated in 2011 original, 2018 county update, 2018 regional update Natrona County City of Casper Participated in 2010 original, 2017 county update, 2018 regional update Town of Bar Nunn Participated in 2010 original, 2017 county update, 2018 regional update Town of Edgerton Participated in 2010 original, 2017 county update, 2018 regional update Town of Evansville Participated in 2010 original, 2017 county update, 2018 regional update Town of Midwest Participated in 2010 original, 2017 county update, 2018 regional update Town of Mills Participated in 2010 original, 2017 county update, 2018 regional update Niobrara County Town of Lusk Participated in 2018 update Town of Mansville Participated in 2018 update Town of Van Tassell Participated in 2018 update ---PAGE BREAK--- Region 2 2-1 Regional Hazard Mitigation Plan 2018 CHAPTER 2 COMMUNITY PROFILE The Community Profile provides a brief overview of the geography of the planning area. Additional geographic profiles of the participating jurisdictions are provided in the annexes. 2.1 Geography and Climate Wyoming Region 2 is comprised of three counties in the east-central part of the state; the three counties are Converse, Natrona, and Niobrara. The region encompasses 12,269 square miles. It is bordered in the east by the State of South Dakota; in the north by Wyoming’s Washakie, Johnson, Campbell and Weston Counties, in the south by Wyoming’s Carbon, Albany, Platte, and Goshen counties, and in the west by Wyoming’s Fremont County. The region stretches from the Granite Mountains and Laramie Mountains eastward across the Great Plains. The highest point in the region is the Twin Peaks in the Laramie Mountains at 9,165 feet; the region’s lowest point is near 3,000 feet in the northeast corner of Niobrara County. Most of the area between those two extremes consists of rolling grasslands between 3,000 and 600 feet. The North Platte River runs west-to-east across the length of the region; other major rivers include the Sweetwater River and the South Fork of the Powder River. Major highways include Interstate 25; US Highways 18, 20, 26, 85, 87, and 287; and Wyoming State highways 59, and 220. Multiple rail lines cross the region as well. Overall the region averages 27 days per year with temperatures above 90°F; during summer months, the average maximum temperature is 83.4°F, with a record high of 106°F. Growing season typically lasts 100-140 days a year. By contrast, the county averages 183 days a year with temperatures below 32°F; during winter months, the average minimum temperature is 13.5°F, with a record low of -43°F. The region averages 15 inches of precipitation and 60 inches of snow per year. A base map of the planning region is illustrated in Figure 2-1. Details of land type and ownership can be found in Table 2-1 through 2-3. ---PAGE BREAK--- Region 2 2.2 Regional Hazard Mitigation Plan 2018 Figure 2-1 Wyoming Region 2 ---PAGE BREAK--- Region 2 2-3 Regional Hazard Mitigation Plan 2018 The vast majority of land between the counties in the Region is grassland, forest or shrubland; cropland, water and urban development occurs on less than 1% of the total land area available. Table 2-1 Region 2 Land Types Land Type Acreage Percentage Total Acres (2006) 7,851,948 Forest 117,221 1.5% Grassland 7,219,656 91.9% Shrubland 358,960 4.6% Mixed Cropland 37,318 0.5% Water 16,555 0.2% Urban 2,965 0.0% Other 20,016 0.3% Source: NASA MODIS Land Cover Type Yearly L3 Global 1km MOD12Q1, 2006. The majority of land ownership in the Region is divided between private lands, federal lands and state lands, with private ownership making up the majority of land in the region. Table 2-2 Region 2 Land Ownership Land Ownership Acreage Percentage Total Acres 7,851,948 Private Lands 4,946,654 63.0% Conservation Easement 65,521 0.8% Federal Lands 2,092,460 26.6% Forest Service 306,221 3.9% BLM 1,682,428 21.4% National Park Service 0 0.0% Military 0 0.0% Other Federal 103,811 1.3% State Lands 808,506 10.3% State Trust Lands* 807,918 10.3% Other State 588 0.0% Tribal Lands 0 0.0% City, County, Other 4,327 0.1% Source: U.S. Geological Survey, Gap Analysis Program. 2016. Protected Areas Database of the United States (PADUS) Residential land use increased 34% between 2000 and 2010. Table 2-3 Region 2 Residential Land Use Residential Land 2000 2010 % increase Total Residential (acres) 38,579 58,370 34% Urban/Suburban 10,530 11,961 12% Exurban 28,049 46,410 40% Source: Theobald, DM. 2013. Land use classes for ICLUS/SERGoM v2013. Unpublished report, Colorado State University. ---PAGE BREAK--- Region 2 2-4 Regional Hazard Mitigation Plan 2018 2.2 Population Table 2-4 describes the population distribution and change for the region as a whole and for individual counties. 83% of the region’s population lives in Natrona County, 14% in Converse County, and the remaining 3% in Niobrara County. Table 2-4 Region 2 Population Distribution Jurisdiction 2017 Estimated Population % of Region Total Converse County 13,809 14% Natrona County 79,547 83% Niobrara County 2,397 3% Region 2 Total 95,753 Source: US Census Bureau Table 2-5 shows how the region’s population has changed since the 2010 Census. As a whole, the Region increased in population by above the state’s overall growth of However, this increase was almost entirely driven by Natrona County; the population of Converse County has stayed relatively flat, while Niobrara County saw a 4% decrease. Moreover, the region experienced an overall growth of 7.8% from 2010 through 2015, after which the population declined to its current level. Table 2-5 Region 2 Population Change 2010-2017 Jurisdiction 2010 Census 2011 2012 2013 2014 2015 2016 2017 % change Converse County 13,833 13,736 14,025 14,365 14,219 14,312 14,127 13,809 0% Natrona County 75,450 76,421 78,583 81,101 81,439 82,134 80,892 79,547 5% Niobrara County 2,484 2,483 2,476 2,544 2,489 2,496 2,470 2,397 Region 2 Total 91,767 92,640 95,084 98,010 98,147 98,942 97,489 95,753 4% Source: US Census Bureau Table 2-6 Region 2 Demographic Profile Population Population estimate, 2017 95,753 Age and Sex Median Age (US median age is 37.7) 36.6 Percent of population under 18 23,507 Percent of population 18-34 23,148 Percent of population 35-44 12,312 Percent of population 45-64 25,853 Percent of population 65 and over 12,772 Percent of population male 50.4% Percent of population female 49.6% Race and Ethnicity ---PAGE BREAK--- Region 2 2-5 Regional Hazard Mitigation Plan 2018 White alone 93.3% Black or African American alone 1.0% American Indian alone 1.0% Asian alone 0.9% Native Hawaiian & Other Pacific Islander alone 0.0% Some other race alone 1.1% Two or more races 2.7% White alone, not Hispanic or Latino 87.4% Hispanic or Latino (of any race) 8% Education High school graduate or higher, age 25 years+ 91.4% Bachelor's degree or higher, age 25 years+ 21.1% Vulnerable Populations Percent of population under 5 years old 6.7% Percent of population 80 years and older 1.8% Percent of population that speak English "not well" 0.7% Percent of population with disabilities 14.4% Percent of population without health insurance 13.9% Percent of population in poverty 10.3% Percent of population in deep-poverty (<1/2 federal poverty level) 4.4% Percent of population over 65 and in poverty 1.0% Source: U.S. Census Bureau, American Factfinder, *Hispanic or Latino is considered an ethnicity, not a race. People who identify as Hispanic or Latino can belong to one or more races. Therefore, the total percentage can be greater than 100%. 2.3 Economy The counties in Region 2 have a diverse economy: 63.5% of workers in the region are employed in the service sector, led by education, health care, and the retail trade. 18.9% of workers are employed in non-service jobs, with construction and mining being the largest employers. The remaining 16.7% work in government sector jobs, primarily city and county government. There is considerable variation within the region: mining accounts for more than 18% of employment in Converse County, but less than 3% in Niobrara; 67% of Natrona County jobs are in the service sector, while in Natrona it is less than 43%. Table 2-7 Employment Statistics Characteristic Region 2 Converse County Natrona County Niobrara County EMPLOYERS Total employer establishments, 2016 3490 448 2,953 89 Total annual payroll, 2016 ($1000) $1,707,695 $252,379 $1,443,465 $11,851 Paid employees 38161 4,811 32,937 413 Total Private 81.6% 72.1% 84.9% n/a Non-Services 18.9% 29.3% 17.7% n/a Natural Resources and Mining 7.9% 21.1% 6.0% 4.5% Ag., Forestry, Fishing, Hunting 0.7% 2.7% 0.4% 1.8% Mining 7.2% 18.3% 5.6% 2.8% Construction 7.8% 5.7% 8.3% n/a ---PAGE BREAK--- Region 2 2-6 Regional Hazard Mitigation Plan 2018 Characteristic Region 2 Converse County Natrona County Niobrara County Manufacturing (Incl. Forest Prod.) 3.3% 2.6% 3.5% n/a Services 63.5% 42.8% 67.2% 40.9% Trade, Transportation, Utilities 21.7% 17.6% 22.5% 16.2% Information 1.1% 0.9% 1.1% n/a Financial Activities 4.8% 3.5% 5.1% 2.8% Professional and Business 6.6% 4.4% 7.1% 1.9% Education and Health 14.4% 4.7% 16.0% 8.0% Leisure and Hospitality 11.2% 9.0% 11.8% n/a Other Services 3.4% 2.6% 3.6% n/a Unclassified 0.0% 0.0% 0.0% 0.0% Government 16.7% 27.9% 15.1% 13.1% Federal Government 1.6% 1.1% 1.6% 1.2% State Government 2.1% 2.4% 1.8% 11.9% Local Government 13.0% 24.3% 11.6% n/a Travel & Tourism related jobs as a percentage of total private employment 15.9% 12.4% 16.3% 31.2% Source: U.S. Census Bureau, American Factfinder, The number of jobs in the region has grown by 115% from 1970 to 2016. The most jobs added have been in services; finance, insurance and real estate; and construction. On average, job growth has kept pace with the region’s population growth. The last few decades saw the region’s unemployment rate decline steadily from 5.9% in 1990 to 2.6% in 2007; the Great Recession sent the county’s unemployment rate as high as 6.7% in 2010, after which it has whipsawed down to 3.9% in 2014, back up to 6.9% in 2016, and back down to 5.2% in 2017. Volatility in the mining sector has been a major contributor to this instability. Table 2-8 Economic Profile Characteristic Region 2 Converse County Natrona County Niobrara County EMPLOYMENT Total Employment, 2016 64,506 8,811 53,907 1,788 Unemployment Rate, as of 2017 (US average: 4.4%) 5.2% 4.4% 5.5% 2.8% Per capita income, 2016 (US average is $50,280) $67,260 $52,257 $70,538 $45,992 Average earning per job, 2016 (US average: $59,598) $68,726 $56,176 $71,787 $38,291 Population % change, 1970-2016 (US ave: 58.6%) 61.8% 133.7% 57.7% -15.1% Employment % change, 1970-2016 (US ave: 112.2%) 114.5% 218.9% 109.5% 13.7% Personal Income % change, 1970-2016 (US ave: 201.1%) 278.1% 404.6% 276.8% 54.7% Persons in poverty (US average is 15.1%) 10.3% 8.4% 10.5% 13.6% Families in poverty (US average is 11.0%) 6.7% 4.4% 7.0% 12.4% Source: U.S. Census Bureau, American Factfinder, ---PAGE BREAK--- Region 2 2-7 Regional Hazard Mitigation Plan 2018 The region’s per capita income is $67,260, well above the national average of $50,280; once again, there is considerable variability between the three counties in the region. Overall, per capita income grew by 134% from 1970 to 2016. Income from non-labor sources such as rents, dividends, or retirement income is 39% of total, which is close to the national average of 36.8%. 10.3% of county’s population lives below the poverty level, well below the national average of 15.1%. Table 2-9 Household Income Characteristic Region 2 Converse County Natrona County Niobrara County HOUSEHOLD INCOME Total Households 38,979 5,576 32,422 981 Less than $10,000 5.2% 3.6% 5.3% 8.2% $10,000 to $14,999 3.7% 3.8% 3.6% 5.8% $15,000 to $24,999 9.6% 7.7% 9.7% 17.2% $25,000 to $34,999 11.0% 12.2% 10.7% 14.0% $35,000 to $49,999 14.0% 11.9% 14.5% 10.9% $50,000 to $74,999 19.2% 17.4% 19.5% 19.0% $75,000 to $99,999 13.6% 14.3% 13.6% 10.6% $100,000 to $149,999 15.5% 21.5% 14.7% 10.3% $150,000 to $199,999 4.7% 5.1% 4.7% 1.1% $200,000 or more 3.5% 2.3% 3.8% 3.0% Median household income 57,967 $66,737 $56,983 $40,640 Median mortgage cost (US ave: $1,491) $1,298 $1,337 $1,298 $1,066 Median rent (US ave: $949) $806 $685 $832 $627 Mean Annual Household Earnings by Source, 2016 Labor earnings 81.6% 83.2% 81.6% 70.4% Social Security 27.0% 27.3% 26.7% 34.3% Retirement income 16.3% 18.1% 16.0% 18.5% Supplemental Security Income 5.9% 6.9% 5.7% 6.9% Cash public assistance income 2.5% 1.1% 2.8% 0.7% Food Stamp/SNAP 7.5% 7.8% 7.5% 8.9% Source: U.S. Census Bureau, American Factfinder, ---PAGE BREAK--- Region 2 3-1 Regional Hazard Mitigation Plan 2018 CHAPTER 3 PLANNING PROCESS Requirements §201.6(b) and §201.6(c)(1): An open public involvement process is essential to the development of an effective plan. In order to develop a more comprehensive approach to reducing the effects of natural disasters, the planning process shall include: 1) An opportunity for the public to comment on the plan during the drafting stage and prior to plan approval; 2) An opportunity for neighboring communities, local and regional agencies involved in hazard mitigation activities, and agencies that have the authority to regulate development, as well as businesses, academia, and other private and nonprofit interests to be involved in the planning process; and 3) Review and incorporation, if appropriate, of existing plans, studies, reports, and technical information. [The plan shall document] the planning process used to develop the plan, including how it was prepared, who was involved in the process, and how the public was involved. 3.1 Background on Mitigation Planning in Region 2 While Region 2 has never had a regional hazard mitigation plan prior to 2018, though all three counties in the region have adopted county-specific hazard mitigation plans in the past. Converse, Natrona and Niobrara Counties each have county-specific plans and this Regional Plan builds upon and updates those efforts. The following is a short description of those efforts by county. Converse County. The Converse County components of this Regional Plan have their roots in the 2017-2018 planning process to update the Converse County Hazard Mitigation Plan. The planning process began in September of 2017 with a kick-off meeting at the Converse County Courthouse as well as being broadcasted online. All incorporated jurisdictions participated in the update process. Three meetings in total were held between September 2017 and January 2018. Pending FEMA approval, the Plan will be approved in 2018. Natrona County. Natrona County began the planning process to update the County’s Hazard Mitigation Plan in January of 2017. The Local Emergency Planning Commission (LEPC) reviewed and evaluated existing information, while clarifying the purpose and process of creating a hazard mitigation plan. The commission met three times between January 2017 and March 2017 and the Plan was ultimately approved in August 2018. Niobrara County. The Niobrara County Hazard Mitigation Plan was approved in December of 2015. The planning process for the Regional Plan gave the county and its participating jurisdictions an opportunity to review their existing goals and proposed mitigation actions from the 2015 plan. During the Regional Planning process, the County’s Hazard Mitigation Planning ---PAGE BREAK--- Region 2 3-2 Regional Hazard Mitigation Plan 2018 Committee (HMPC) met two times between January 2018 and June 2018 to review the existing plan and provide the consulting team with local information that was not included in the 2015 Plan. Regional Planning. In Wyoming, the Wyoming Office of Homeland Security (WOHS) utilizes a regional support structure to assist the counties with all aspects of emergency management including planning. The counties that comprise Region 2 include Converse, Natrona and Niobrara. In 2016, the WOHS began supporting the development of regional hazard mitigation plans statewide, based on existing homeland security regions. This initiative recognized that the process of facilitating, developing, or updating multi-jurisdictional hazard mitigation plans compliant with the Disaster Mitigation Act of 2000 is often beyond local capabilities and expertise. Instead of each county hiring consultants, the WOHS took the lead in procuring and funding a professional hazard mitigation planning consultant through a competitive bid process. Wood Environment and Infrastructure, Inc. (Wood) (formally Amec Foster Wheeler) of Boulder, Colorado was selected in late 2017 to provide assistance to the Region. Prior to initiating the development of this regional hazard mitigation plan, a substantial coordination effort took place to ensure the participation of all three counties within Region 2. The WOHS received letters of commitment from each county (copies included in Appendix A) indicating their interest in and willingness to participate in the regional planning process. Each county has an Emergency Management Coordinator who was designated as the primary point of contact. Each Coordinator was required to undertake a coordination role within their respective counties to help fulfill the Disaster Mitigation Act of 2000 (DMA) planning requirements. The county Emergency Management Coordinators then contacted each of the incorporated communities, offering them the opportunity to participate in the development of the Region 2 Hazard Mitigation Plan. Every incorporated community within the counties chose to participate in the development of this Regional Plan. Each Emergency Management Coordinator led a Hazard Mitigation Planning Committee (HMPC) working in concert with the hazard mitigation planning consultant. As the planning consultant, Wood’s role was to: • Provide guidance on a planning organization for the entire planning area representative of the participants; • Ensure the plan meets all of the DMA requirements as established by federal regulations, following FEMA’s most recent planning guidance; • Facilitate the entire planning process; • Identify the data requirements that the participating counties and municipalities could provide, and conduct the research and documentation necessary to augment that data; • Develop and help facilitate the public input process; • Produce the draft and final plan documents; and • Ensure acceptance of the final Plan by WOHS and FEMA Region VIII ---PAGE BREAK--- Region 2 3-3 Regional Hazard Mitigation Plan 2018 3.2 Government Participation The DMA planning regulations and guidance stress that each local government seeking FEMA approval of their mitigation plan must participate in the planning effort in the following ways: • Participate in the process as part of the Hazard Mitigation Planning Committee (HMPC), • Detail areas within the planning area where the risk differs from that facing the entire area, • Identify specific projects to be eligible for funding, and • Have the governing board formally adopt the plan. For the Region 2 Hazard Mitigation Plan’s “participation” meant: • Establishing or reconvening a HMPC; • Attending and participating in HMPC meeting(s); • Providing available data requested by the HMPC coordinator and Wood.; • Providing and updating the hazard profile and vulnerability details specific to jurisdictions; • Developing, updating, and providing input on the local mitigation strategy (action items and progress); • Advertising and assisting with the public input process; • Reviewing and commenting on plan drafts; and • Coordinating the formal adoption of the plan by the governing boards. This Regional Plan includes the participation of the counties and municipalities in Region 2 as noted in Chapter 1 and detailed further in Section 3.3.1. Documentation of participation is included in Appendix A in the form of meeting sign-in sheets, meeting summaries, and more. 3.3 The 10-Step Planning Process Wood established the planning process for the Region 2 plan using the DMA planning requirements and FEMA’s associated guidance. This guidance is structured around a four-phase process: 1) Organize Resources 2) Assess Risks 3) Develop the Mitigation Plan 4) Implement the Plan and Monitor Progress Into this four-phase process, Wood integrated a more detailed 10-step planning process used for FEMA’s Community Rating System (CRS) and Flood Mitigation Assistance (FMA) programs. Thus, the modified 10-step process used for this plan meets the requirements of six major programs: FEMA’s Hazard Mitigation Grant Program, Pre-Disaster Mitigation Program, Community Rating System, Flood Mitigation Assistance Program, Severe Repetitive Loss Program, and flood control projects authorized by the U.S. Army Corps of Engineers. FEMA’s ---PAGE BREAK--- Region 2 3-4 Regional Hazard Mitigation Plan 2018 March 2013 Local Mitigation Planning Handbook recommends a nine-task process within the four-phase process. Table 3-1 summarizes the four-phase DMA process, the detailed CRS planning steps and the work plan used to develop the plan, the nine handbook planning tasks from FEMA’s 2013 Local Mitigation Planning Handbook, and where the results are captured in the Plan. The sections that follow describe each planning step in more detail. Table 3-1 Mitigation Planning Process Used to Develop the Regional Hazard Mitigation Plan FEMA 4 Phase Guidance Community Rating System (CRS) Planning Steps (Activity 510) and Wood Work Plan Steps FEMA’s Local Mitigation Planning Handbook Tasks (44 CFR Part 201) Location in Plan Phase I: Organize Resources Step 1. Organize Resources 1: Determine the Planning Area and Resources Chapters 1, 2 and 3 2: Build the Planning Team 44 CFR 201.6(c)(1) Chapter 3, Section 3.3.1 Step 2. Involve the public 3: Create an Outreach Strategy 44 CFR 201.6(b)(1) Chapter 3, Section 3.3.1 Step 3. Coordinate with Other Agencies 4: Review Community Capabilities 44 CFR 201.6(b)(2) & Chapter 3, Section 3.3.1 and annexes Phase II: Assess Risks Step 4. Assess the hazard 5: Conduct a Risk Assessment 44 CFR 201.6(c)(2)(i) 44 CFR 201.6(c)(2)(ii) & (iii) Chapter 4 and annexes Step 5. Assess the problem Chapter 4 and annexes Phase III: Develop the Mitigation Strategy Step 6. Set goals 6: Develop a Mitigation Strategy 44 CFR 201.6(c)(3)(i); 44 CFR 201.6(c)(3)(ii); and 44 CFR 201.6(c)(3)(iii) Chapter 5, Section 5.2 Step 7. Review possible activities Chapter 5, Section 5.3 Step 8. Draft an action plan Chapter 5, Section 5.4 and annexes Phase IV: Adopt and Implement the Plan Step 9. Adopt the plan 8: Review and Adopt the Plan Chapter 6 Step 10. Implement, evaluate, revise 7: Keep the Plan Current Chapter 6 9: Create a Safe and Resilient Community 44 CFR 201.6(c)(4) Chapter 6 ---PAGE BREAK--- Region 2 3-5 Regional Hazard Mitigation Plan 2018 3.3.1 Phase 1: Organize Resources Planning Step 1: Organize the Planning Effort With each jurisdiction’s commitment to develop a Regional Plan, Wood worked with WOHS and each county Emergency Management Coordinator to establish the framework and organization for the process. Organizational efforts were initiated with each county to inform and educate the plan participants of the purpose and need for a regional hazard mitigation plan. During the development of this Regional Plan, the planning process was directed through a regional planning committee comprised of Emergency Management Coordinators for Converse, Natrona, and Niobrara counties. The planning consultant held an initial Uberconference call/webinar to discuss the organizational aspects of the planning process with the county coordinators. Using FEMA’s planning guidance, representative participants for each county’s HMPC base membership were established, with additional invitations extended as appropriate to other federal, state, local stakeholders, and the public throughout the planning process. The list of agencies and individuals invited to participate is provided in the following table. More details with documentation of participation included are in Appendix A. Table 3-2 HMPC Members and Stakeholders by County Converse County Jurisdictions and Stakeholders Representatives Converse County County Emergency Management Coordinator Public Health Response Coordinator, Public Health Department City of Douglas Mayor Director of Public Works Chief of Fire Department Town of Glenrock Glenrock Health Center Town of Lost Springs Mayor Town of Rolling Hills Chief Water Operator, Public Works State and Other Local Agencies WOHS Federal Agencies None Private Industry/Stakeholders Safety and Regulations Compliance, Sinclair Transportation Company Safety Specialist, The Williams Company, Inc. Reporter, Douglas Budget Natrona County Jurisdictions and Stakeholders Representatives Natrona County Emergency Management Coordinator Public Health Preparedness Manager, Casper- Natrona County Health Department GIS Specialist, GIS Department ---PAGE BREAK--- Region 2 3-6 Regional Hazard Mitigation Plan 2018 City of Casper Deputy Chief, Fire Department Town of Bar Nunn Mayor Town of Edgerton Mayor Town of Evansville Mayor Town of Midwest Mayor Town of Mills Mayor State Agency Stakeholders WOHS Federal Agencies Stakeholders Deputy State Director, Congresswoman Liz Cheney Private Industry/Stakeholders Operation Supervisor, Black Hills Energy Gas Operations Supervisor, Black Hills Energy Utility Construction, Black Hills Energy Ambulance Manager, Wyoming Medical Center Disaster Specialist, Wyoming Medical Center Safety and Regulations, Sinclair Transportation Company Niobrara County Jurisdictions and Stakeholders Representatives Niobrara County Emergency Management Coordinator County Commissioners Deputy, County Sheriff Public Health Response Coordinator, Niobrara Public Health Town of Lusk Mayor Officer, Police Department City Council Member EMS Town of Manville Mayor Town of Van Tassell Mayor State or Local Agencies Stakeholders Lieutenant, Department of Corrections, Wyoming Women’s Center Wood and each Emergency Management Coordinator identified key county, municipal, and other local government and stakeholder representatives. Letters of invitation were sent to invite them to participate as members of the HMPC and to attend a series of planning workshops. During the plan development process communication amongst the county planning teams occurred through a combination of face-to-face meetings, conference calls, a web-based meeting, phone interviews, mail and email correspondence. Following the initial kickoff Uberconference call/webinar on February 20, 2018, a planning workshop with each county HMPC was held during the plan’s development between February and June 2018. The meeting schedule and topics are listed below. The sign-in sheets and agendas for each meeting are documented in Appendix A. In addition, ---PAGE BREAK--- Region 2 3-7 Regional Hazard Mitigation Plan 2018 conference calls were held as needed with the Emergency Management Coordinators, WOHS and Wood as needed to discuss the process, including upcoming milestones and information needs. Kickoff Meeting During the kickoff call/webinar, Wood presented information on the scope and purpose of the regional plan, participation requirements of HMPC members, and the proposed project work plan and schedule. A plan for public involvement (Step 2) and coordination with other agencies and departments (Step 3) was discussed. The HMPC reviewed the hazard identification information for the county as well as the Region and refined the list of identified hazards to mirror that of the Wyoming Hazard Mitigation Plan. In follow-up to the meeting, participants were provided a Geographic Information Systems (GIS) data needs worksheet to facilitate the collection of information needed to support the plan update. Following the kickoff meeting a planning workshop was held with each county HMPC and scheduled as follows: June 19, 2018 - Natrona County June 20, 2018 - Converse County June 21, 2018 - Niobrara County The purpose of these workshops was to review the results of the risk assessment, review and update goals and update each county’s mitigation strategy. Each HMPC workshop was followed by a public meeting in the evening (see the discussion under Planning Step 2: Involve the Public for further information on the public meetings). Shortly after the adoption of the Niobrara County plan in 2015 the county experienced a major flood event. This planning process was an opportunity for the Niobrara HMPC to discuss how mitigation actions and strategies recommended in the 2015 plan worked or did not work during the flood event and brainstorm new mitigation actions that were not included in the existing plan. See Chapter 5 for further information on new, ongoing and deleted or deferred actions for Niobrara, Natrona, and Converse counties and the other participating jurisdictions. In some cases, HMPC meetings were supplemented with additional meetings, emails and telephone discussions to further engage the municipalities in the process. During August 2018, Converse, Natrona and Niobrara Counties engaged communities that were not able to be represented at the in-person meetings. Summaries of these interactions are detailed in the Planning Process Appendix. ---PAGE BREAK--- Region 2 3-8 Regional Hazard Mitigation Plan 2018 Planning Step 2: Involve the Public The 2018 planning process informed and involved the public throughout the process. In some cases, the HMPC meetings included members of the public and/or local media. Public outreach included press releases, social media notices, a survey and newspaper postings. Converse County had already released a public survey months earlier as part of their county- specific planning process; these results were incorporated during the development of their mitigation strategy. The results of the regional public survey indicated that respondents were most interested in more information regarding the hazards they were vulnerable to and what they could do about them; this led directly to at least one new/updated mitigation action regarding public information on hazards that can affect each jurisdiction. Public meetings were held in each county as part of the 2018 planning process. The meetings were an opportunity for the public to be active participants in the planning process and share anecdotes with the HMPC and planning consultant on how they have, or their community has been impacted by hazard events in the past. Meeting topics included, explaining what hazard mitigation is, an overview of the planning process, sharing the results of the hazard identification risk assessment and an overview of existing and potential mitigation actions. The first public meeting was held on June 19, 2018 at the Natrona County Sheriff’s Office. Wood Project Manager Kyle Karsjen and Natrona County Emergency Management Coordinator John Harlin were present to facilitate the meeting. One member of the public was present, as well as a representative for Congresswoman Liz Cheney. Following the Converse County meeting, a public meeting was held at the Douglas City Hall in Converse County on June 20, 2018. The Project Manager, County Emergency Management Coordinator Russ Dalgarn and Assistant Emergency Management Coordinator Mary Schell were present to facilitate the meeting. In addition to the facilitators, one member of the public was present as well as representatives for Congresswoman Cheney and Senator Enzi. The Niobrara County public meeting on June 21, 2018 was the final workshop in the region. The Wood Project Manager and County Emergency Management Coordinator James Santistevan facilitated the meeting. One member of the public was in attendance. 2018 Public Survey During this regional planning process and drafting stage, a public survey was developed as a tool to gather public input. The survey enabled the public to provide feedback to the planning teams on topics related to hazard concerns and reducing hazard impacts. The survey provided an opportunity for public input during the planning process, prior to finalization of the plan update. The survey gathered public feedback on concerns about hazards and solicited input on strategies ---PAGE BREAK--- Region 2 3-9 Regional Hazard Mitigation Plan 2018 to reduce their impacts. The highest rated hazards in Region 2 were wind, wildfire, and winter storm. The highest rated mitigation strategies were indoor/outdoor warning systems, public education/awareness, and evacuation planning. This input is consistent with many of the mitigation strategies identified by each county and can be found in their respective annexes. The survey was released as both an online tool and a hardcopy form on or around May 3, 2018 and closed on July 1, 2018. The counties provided links to the public survey by distributing it using social media, email, and posting the link on websites. The survey received 106 responses and was shared with the county planning committees to inform the process. Summarized results of the survey are included in Appendix A, Planning Process Documentation. Prior to finalizing, a draft of the regional plan was made available to the public for review and comment. The plan was placed on the WOHS’s website and the counties used social media and email blasts to announce the public comment period. An online feedback form was provided to collect specific comments. Placeholder for review comment discussion… This accomplished task three in the FEMA Local Mitigation Planning Handbook (Create an outreach strategy). Planning Step 3: Coordinate with Other Departments and Agencies Early in the planning process, the HMPC determined that data collection, mitigation strategy development, and plan approval would be greatly enhanced by inviting state and federal agencies and organizations to participate in the process. Neighboring communities and regional agencies involved in hazard mitigation activities, agencies that have the authority to regulate development, as well as other interests, businesses, academia and other private and non-profit interests were also invited to provide feedback. Based on their involvement in hazard mitigation or emergency management activities in the Region, representatives from several state and federal agencies and local businesses were included in the in 2018 and are noted in Table 3-2. Many of these stakeholders participated in planning meetings or were provided an opportunity to review the draft plan before it was finalized. Other Community Planning Efforts and Hazard Mitigation Activities Coordination with other community planning efforts is an important aspect of mitigation planning. Hazard mitigation planning involves identifying existing policies, tools, and actions that will reduce a community’s risk and vulnerability from natural hazards. Most of the counties and municipalities in the Region use a variety of comprehensive planning mechanisms, such as master plans and ordinances to guide growth and development. Integrating existing planning efforts and mitigation policies and action strategies into this plan establishes a credible and comprehensive plan that ties into and supports other community programs. The development of this plan incorporated information from the following existing plans, studies, reports, and initiatives as well ---PAGE BREAK--- Region 2 3-10 Regional Hazard Mitigation Plan 2018 as other relevant data from neighboring communities and other jurisdictions. Examples of this include: • County Comprehensive Plans • Community Wildfire Protection Plans • Wyoming Hazard Mitigation Plan (2016) During the development of this Regional Hazard Mitigation Plan, Niobrara County was also beginning the planning process for their County Comprehensive Community Development Plan. The idea for a county-wide comprehensive plan came from the Wyoming Business Council, which was designated as the coordinating agency for the State of Wyoming’s recovery efforts following the 2015 flood. The Council recognized that a county-wide comprehensive plan would be vital for not only the recovery efforts for Niobrara but also to guide the area’s growth and development. In future updates, opportunities to integrate and coordinate both the Regional Hazard Mitigation Plan and the Niobrara County Comprehensive Community Development Plan should and will be explored. Other documents were reviewed and cited, as appropriate, during the collection of data to support Planning Steps 4 and 5, which include the hazard identification, vulnerability assessment and capability assessment. 3.3.2 Phase 2: Assess Risks Planning Steps 4 and 5: Identify the Hazards and Assess the Risks Wood led each HMPC to review, identify and document all the hazards that have, or could, impact the planning area. The existing hazard mitigation plans, and the Wyoming Hazard Mitigation Plan provided a basis for many of the hazard profiles. Where data permitted, GIS was used to display, analyze and quantify hazards and vulnerabilities. Sophisticated analyses for flood, landslide and wildfire hazards were performed by Wood that included an analysis of flood risk based on the Digital Flood Insurance Rate Maps (DFIRMs), where available. A more detailed description of the risk assessment process and the results are included in Chapter 4. Also included in the 2018 plan is a capability assessment to review and document the planning area’s current capabilities to mitigate risk and vulnerability from natural hazards. By collecting information about existing government programs, policies, regulations, ordinances and emergency plans, the HMPC can assess those activities and measures already in place that contribute to mitigating some of the risks and vulnerabilities identified. The results of this assessment are captured in each annex. ---PAGE BREAK--- Region 2 3-11 Regional Hazard Mitigation Plan 2018 3.3.3 Phase 3: Develop the Mitigation Plan Planning Steps 6 and 7: Set Goals and Review Possible Activities Wood facilitated discussion sessions with the that described the purpose and the process of developing planning goals, a comprehensive range of mitigation alternatives, and a method of selecting and defending recommended mitigation actions using a series of selection criteria. This process was used to update and enhance the mitigation action plan, which is the essence of the planning process and one of the most important outcomes of this effort. The action plans are detailed in each county annex; the process used to identify and prioritize mitigation actions is described in greater detail in Chapter 5. Planning Step 8: Draft an Action Plan Based on input from the regarding the draft risk assessment and the goals and activities identified in Planning Steps 6 and 7, Wood produced a complete first draft of the Regional Plan. This complete draft was shared for the to review and comment by email from the consultant and posted on the project cloud-based share drive. The HMPC comments were integrated into the second draft, which was advertised and distributed to collect public input and comments. Other agencies and neighboring county emergency managers were invited to comment on this draft as well. Wood integrated comments and issues from the public, as appropriate, along with additional internal review comments and produced a final draft for the Wyoming Office of Homeland Security and FEMA Region VIII to review and approve, contingent upon final adoption by the governing boards of each participating jurisdiction. 3.3.4 Phase 4: Implement the Plan and Monitor Progress Planning Step 9: Adopt the Plan In order to secure buy-in and officially implement the plan, the plan was adopted by the governing boards of each participating jurisdiction. As the adoption process follows the FEMA plan review and approval, copies of the adoption resolution will be included electronically in Appendix B Records of Adoption. Planning Step 10: Implement, Evaluate, and Revise the Plan The true worth of any mitigation plan is in the effectiveness of its implementation. Each recommended action includes key descriptors, such as a lead /agency and possible funding sources, to help initiate implementation. Progress on the implementation of specific actions identified in the plan is captured in the mitigation action plan summary table in Chapter 5: Mitigation Strategy. An overall implementation strategy is described in Chapter 6: Plan Adoption, Implementation and Maintenance. ---PAGE BREAK--- Region 2 3-12 Regional Hazard Mitigation Plan 2018 Finally, there are numerous organizations within the Region 2 planning area whose goals and interests interface with hazard mitigation. Coordination with these other planning efforts, as addressed in Planning Step 3, is important to mitigation in Region 2 and the ongoing success of this plan; further information on coordination efforts can be found in Chapter 6. A plan update and maintenance schedule and a strategy for continued public involvement are also included in Chapter 6 and specifics can also be found in the annexes for the three counties. ---PAGE BREAK--- Region 2 4-1 Regional Hazard Mitigation Plan 2018 CHAPTER 4 HAZARD ANALYSIS AND RISK ASSESSMENT 44 CFR Requirement 201.6(c)(2): [The plan shall include] a risk assessment that provides the factual basis for activities proposed in the strategy to reduce the losses from identified hazards. Local risk assessments must provide sufficient information to enable the jurisdiction to identify and prioritize appropriate mitigation actions to reduce losses from identified hazards. 44 CFR Requirement 201.7(c)(2): [The plan shall include] a risk assessment that provides the factual basis for activities proposed in the strategy to reduce losses from identified hazards. Tribal risk assessments must provide sufficient information to enable the Indian tribal government to identify and prioritize appropriate mitigation actions to reduce losses from identified hazards. As defined by the Federal Emergency Management Agency (FEMA), risk is a combination of hazard, vulnerability, and exposure. “It is the impact that a hazard would have on people, services, facilities, and structures in a community and refers to the likelihood of a hazard event resulting in an adverse condition that causes injury or damage.” The risk assessment process identifies and profiles relevant hazards and assesses the exposure of lives, property, and infrastructure to these hazards. The process allows for a better understanding of a jurisdiction’s potential risk to hazards and provides a framework for developing and prioritizing mitigation actions to reduce risk from future hazard events. This risk assessment builds upon the methodology described in the 2013 FEMA Local Mitigation Planning Handbook, which recommends a four-step process for conducting a risk assessment: 1) Describe Hazards 2) Identify Community Assets 3) Analyze Risks 4) Summarize Vulnerability Data collected through this process has been incorporated into the following sections of this chapter: Section 4.1 Hazard Identification identifies the hazards that threaten the planning area and describes why some hazards have been omitted from further consideration. Section 4.2 Hazard Profiles discusses the threat to the planning area and describes previous occurrences of hazard events, the likelihood of future occurrences, and the Region’s vulnerability to particular hazard events. ---PAGE BREAK--- Region 2 4-2 Regional Hazard Mitigation Plan 2018 County Annexes include summaries of community assets including population, building stock, critical facilities, and historic, cultural and natural resources. Additional details on vulnerability to specific hazards where they vary from those of the Region are noted in the annexes, with more details including maps, where appropriate. 4.1 Hazard Identification Requirement §201.6(c)(2)(i): [The risk assessment shall include a] description of the type of all natural hazards that can affect the jurisdiction. Requirement §201.7(c)(2)(i): [The risk assessment shall include a] description of the type, location, and extent of all natural hazards that can affect the tribal planning area. The Hazard Mitigation Planning Committee (HMPC) from each county in the Region conducted a hazard identification study to determine the hazards that threaten the planning area. 4.1.1 Results and Methodology Using existing hazards data, plans from participating jurisdictions, and input gained through planning, the of Converse, Natrona, and Niobrara Counties agreed upon a list of hazards that could affect the Region. Hazards data from FEMA, the Wyoming Office of Homeland Security (including the 2016 State of Wyoming Multi-Hazard Mitigation Plan), the National Oceanic and Atmospheric Administration, the Spatial Hazard Events and Losses Database for the United States (SHELDUS), and many other sources were examined to assess the significance of these hazards to the planning area. The hazards evaluated in this plan include those that have occurred historically or have the potential to cause significant human and/or monetary losses in the future. The final list of hazards identified and investigated for the 2018 Region 2 Multi-Hazard Mitigation Plan includes: • Dam Failure • Drought • Earthquake • Expansive Soils • Flood • Hail • Hazardous Materials • High Winds and Downbursts • Landslide/Rockfall/Debris Flow • Lightning • Mine and Land Subsidence • Severe Winter Weather ---PAGE BREAK--- Region 2 4-3 Regional Hazard Mitigation Plan 2018 • Tornado • Wildland Fire Members of each HMPC used a hazards worksheet to rate the significance of hazards that could potentially affect the region. They measured significance in general terms, focusing on key criteria such as the likelihood of the event, past occurrences, spatial extent, and damage and casualty potential. Table 4-1 represents the worksheet used to identify and rate the hazards, and is a composite that includes input from all the participating jurisdictions. Note that the significance of the hazard may vary from jurisdiction to jurisdiction. The county annexes include further details on hazard significance by county and municipality. Expansive soils and land subsidence hazards were added during the 2018 planning process to be consistent with the Wyoming Multi-Hazard Mitigation Plan. Other changes in the hazard identification list are noted with an asterisk in Table 4-1. ---PAGE BREAK--- Region 2 4-4 Regional Hazard Mitigation Plan 2018 Table 4-1 Region 2 Hazard Significance Table Converse Natrona Niobrara Dam Failure Medium Medium Low Drought High High High Earthquake Medium High Low Expansive Soils Low Low Low* Flood Medium High Medium Hail Medium Medium Medium Hazardous Materials Medium Medium Low High Winds and Downbursts Medium Medium Medium Landslide, Rockfall and Debris Flow Low Medium Low Lightning Low* Medium Medium Mine and Land Subsidence Low Low* Low* Severe Winter Weather High High High Tornado Medium Medium Medium Wildfire High High High Significance based on a combination of Geographic Extent, Potential Magnitude/Severity and Probability as defined below. * Indicates hazard was not identified prior to 2018 in the county. Geographic Extent Negligible: Less than 10% of planning area or isolated single- point occurrences Limited: 10 to 25% of the planning area or limited single-point occurrences Significant: 25 to 75% of planning area or frequent single-point occurrences Extensive: 75 to 100% of planning area or consistent single-point occurrences Potential Magnitude/Severity Negligible: Less than 10% of property is severely damaged, facilities and services are unavailable for less than 24 hours, injuries and illnesses are treatable with first aid or within the response capability of the jurisdiction. Limited: 10 to 25% of property is severely damaged, facilities and services are unavailable between 1 and 7 days, injuries and illnesses require sophisticated medical support that does not strain the response capability of the jurisdiction, or results in very few permanent disabilities. Critical: 25 to 50% of property is severely damaged, facilities and services are unavailable or severely hindered for 1 to 2 weeks, injuries and illnesses overwhelm medical support for a brief period of time, or result in many permanent disabilities and a few deaths. Catastrophic: More than 50% of property is severely damaged, facilities and services are unavailable or hindered for more than 2 weeks, the medical response system is overwhelmed for an extended period of time or many deaths occur. Probability of Future Occurrences Unlikely: Less than 1% probability of occurrence in the next year, or has a recurrence interval of greater than every 100 years. Occasional: Between a 1 and 10% probability of occurrence in the next year, or has a recurrence interval of 11 to 100 years. Likely: Between 10 and 90% probability of occurrence in the next year, or has a recurrence interval of 1 to 10 years Highly Likely: Between 90 and 100% probability of occurrence in the next year, or has a recurrence interval of less than 1 year. Overall Significance Low: Two or more of the criteria fall in the lower classifications or the event has a minimal impact on the planning area. This rating is also sometimes used for hazards with a minimal or unknown record of occurrences/impacts or for hazards with minimal mitigation potential. Medium: The criteria fall mostly in the middle ranges of classifications and the event’s impacts on the planning area are noticeable but not devastating. This rating is also sometimes utilized for hazards with a high impact rating but an extremely low occurrence rating. High: The criteria consistently fall along the high ranges of the classification and the event exerts significant and frequent impacts on the planning area. This rating is also sometimes utilized for hazards with a high impact or for hazards that the jurisdiction identifies as particularly relevant. Hazards considered but not profiled further include avalanche, volcanism and windblown deposits. The HMPC concluded that avalanche is not a significant hazard in Region 2 due to the lack of steep terrain and minimal past impacts. The region is significantly vulnerable to an eruption of ---PAGE BREAK--- Region 2 4-5 Regional Hazard Mitigation Plan 2018 the Yellowstone Caldera due to its proximity to Yellowstone National Park. A large-scale eruption would have catastrophic global impacts. Because of the overly long expected occurrence of frequency (greater than 10,000 years) for explosive volcanism at Yellowstone, and the fact that a good response or mitigation plan is not possible for an event of this magnitude, it was not analyzed in this document. Windblown deposits include sands that can be mobilized by wind during extended drought. The did not consider this to be a significant hazard in the region and thus did not profile it further. 4.1.2 Disaster Declaration History As part of the hazard identification process, the HMPC researched past events that triggered federal and/or state emergency or disaster declarations in the planning area. Federal and/or state disaster declarations may be granted when the severity and magnitude of an event surpasses the ability of the local government to respond and recover. Disaster assistance is supplemental and sequential. When the local government’s capacity has been surpassed, the state may declare a state disaster, allowing for the provision of state assistance. Should the disaster be so severe that both the local and state governments’ capacities are exceeded, the state can request a federal emergency or disaster declaration, to allow for the provision of federal assistance. The federal government may issue a disaster declaration through FEMA, the U.S. Department of Agriculture (USDA), and/or the Small Business Administration (SBA). FEMA also issues emergency declarations, which are more limited in scope and without the long-term federal recovery programs of major disaster declarations. The quantity and types of damage are the determining factors. A USDA declaration will result in the implementation of the Emergency Loan Program through the Farm Services Agency. This program enables eligible farmers and ranchers in the affected county as well as contiguous counties to apply for low interest loans. A USDA declaration will automatically follow a major disaster declaration for counties designated major disaster areas and those that are contiguous to declared counties, including those that are across state lines. As part of an agreement with the USDA, the SBA offers low interest Economic Injury Disaster Loans for eligible businesses that suffer economic losses in declared and contiguous counties that have been declared by the USDA. Table 4-2 provides information on federal emergencies and disasters declared in Wyoming between 1963 and 2017. ---PAGE BREAK--- Region 2 4-6 Regional Hazard Mitigation Plan 2018 Table 4-2 Major Disaster Declarations in Wyoming that Included Region 2: 1963 – 2016 Event/ Hazard Year Declaration Type Remarks/Description Severe storms, flooding, mudslides 1978 Presidential – Major Disaster Declaration Converse, Natrona & Niobrara Counties included in Declaration Severe winter storm 1999 Presidential – Major Disaster Declaration Niobrara County included in Declaration Dead Horse Fire 2000 Fire Mgmt Assistance Declaration Natrona County included in Declaration Hensel Fire 2002 Fire Mgmt Assistance Declaration Converse County included in Declaration Jackson Canyon Fire 2006 Fire Mgmt Assistance Declaration Natrona County included in Declaration Arapahoe Fire 2012 Fire Mgmt Assistance Declaration Converse County included in Declaration Sheep Herder Hill Fire 2012 Fire Mgmt Assistance Declaration Natrona County included in Declaration Severe Storms and Flooding 2015 Presidential-Major Disaster Declaration Niobrara County included in Declaration Station Fire 2015 Fire Mgmt Assistance Declaration Natrona County included in Declaration Source: FEMA, From 1963 through 2017, Wyoming experienced 26 additional disaster incidents that didn’t include one of the three counties in Region 2. These included nine Presidential Disaster Declarations, two Presidential Emergency Declarations, four USDA Declarations and eleven Fire Management Assistance declarations. 4.2 Hazard Profiles Requirement §201.6(c)(2)(i): [The risk assessment shall include a] description of the…location and extent of all natural hazards that can affect the jurisdiction. The plan shall include information on previous occurrences of hazard events and on the probability of future hazard events. Requirement §201.7(c)(2)(i): [The risk assessment shall include a] description of the type, location, and extent of all natural hazards that can affect the tribal planning area. The plan shall include information on previous occurrences of hazard events and on the probability of future hazard events. This section profiles each of the hazards identified in Section 4.1, Identifying Hazards. Much of the profile information came from the same sources used to initially identify the hazards. ---PAGE BREAK--- Region 2 4-7 Regional Hazard Mitigation Plan 2018 4.2.1 Profile Methodology Hazard profiles follow this format: Hazard/Problem Description This subsection gives a description of the hazard and associated problems, followed by details on the hazard specific to the Region. Geographical Area Affected This subsection discusses which areas of the Region are most likely to be affected by a hazard event. Limited: Less than 10% of the planning area Significant: 10 to 50% of the planning area Extensive: 50 to 100% of the planning area Past Occurrences This subsection contains information on historic incidents, including impacts where known. The subsection includes information provided by the HMPC, along with information from other data sources, including the National Oceanic and Atmospheric Administration (NOAA) National Centers for Environmental Information (NCEI – formerly the National Climatic Data Center (NCDC)) and SHELDUS where available. SHELDUS is a county-level data set for the United States that tracks 18 types of natural hazard events along with associated property and crop losses, injuries, and fatalities. In 2014 this formerly free database transitioned into a fee-based service. Due to this and the availability of similar data in NCEI databases, it was not used as a resource during the 2018 regional plan development except for when the data was already available. When available, tables showing county-specific data from the NCEI and SHELDUS databases may be found in each hazard profile. Frequency/Likelihood of Occurrence The frequency of past events is used in this section to gauge the likelihood of future occurrences. Based on historical data, the likelihood of future occurrences is categorized into one of the following classifications: • Highly Likely—Near 100% chance of occurrence in next year or happens every year. • Likely—Between 10 and 100% chance of occurrence in next year or has a recurrence interval of 10 years or less. ---PAGE BREAK--- Region 2 4-8 Regional Hazard Mitigation Plan 2018 • Occasional—Between 1 and 10% chance of occurrence in the next year, or has a recurrence interval of 11 to 100 years. • Unlikely—Less than 1% chance of occurrence in next 100 years, or has a recurrence interval of greater than every 100 years. The frequency, or chance of occurrence, was calculated where possible based on existing data. Frequency was determined by dividing the number of events observed by the number of years and multiplying by 100. Stated mathematically, the methodology for calculating the probability of future occurrences is: # of known events x100 years of historic record This gives the percent chance of the event happening in any given year. An example would be three droughts occurring over a 30-year period which equates to 10% chance of that hazard occurring any given year. Potential Magnitude This subsection discusses the potential magnitude of impacts, or extent, from a hazard event. Magnitude classifications are as follows: • Catastrophic— More than 50% of property severely damaged, and/or facilities are inoperable or closed for more than 30 days. More than 50% agricultural losses. Multiple fatalities and injuries. Critical indirect impacts. • Critical— 25 to 50% of property severely damaged, and/or facilities are inoperable or closed for at least 2 weeks. 10-50% agricultural losses. Injuries and/or illnesses result in permanent disability and some fatalities. Moderate indirect impacts. • Limited— 10 to 25% of area affected. Some injuries, complete shutdown of critical facilities for more than one week, more than 10% of property is severely damaged. • Negligible— Less than 10% of area affected. Minor injuries, minimal quality-of-life impact, shutdown of critical facilities and services for 24 hours or less, less than 10% of property is severely damaged. Vulnerability Assessment Vulnerability is the measurement of exposed structures, critical facilities or populations relative to the risk of the hazard. For most hazards, vulnerability is a best-estimate. Some hazards, such as flood, affect specific areas so that exposure can be quantified, and vulnerability assessments result in a more specific approximation. Other hazards, such as tornados, are random and unpredictable in location and duration that only approximate methods can be applied. ---PAGE BREAK--- Region 2 4-9 Regional Hazard Mitigation Plan 2018 Assets Summary Assets inventoried for the purpose of determining vulnerability include people, structures, critical facilities, and natural, historic, or cultural resources. For the regional planning process locally- available GIS databases were utilized. Parcel and assessor data for all counties was obtained from the Wyoming Department of Revenue. This information provided the basis for building exposure and property types. This information provided the basis for building exposure and property types. A critical facility is defined as one that is essential in providing utility or direction either during the response to an emergency or during the recovery operation. Much of this data is based on GIS databases associated with the 2015 and 2017 Homeland Security Infrastructure Program (HSIP) Freedom dataset. Where applicable, this information was used in an overlay analysis for hazards such as flood and landslide. More detail on assets potentially exposed to hazards can be found in the county and reservation annexes. Future Development This section describes how the hazard could impact future development. Summary The summary section summarizes risk by county according to the area affected, likelihood, and magnitude of impacts. If the hazard has impacts on specific towns or cities in the region they are noted here, where applicable. 4.2.2 Dam Failure Hazard/Problem Description Dams are man-made structures built for a variety of uses, including flood protection, power, agriculture, water supply, and recreation. Dams typically are constructed of earth, rock, concrete, or mine tailings. Dams and reservoirs serve a very important role for Wyoming residents and industry. While dam failures are rare, should a complete or partial failure occur it will create a significant hazard for those Dam failure is the uncontrolled release of impounded water resulting in flooding, which can affect life and property. Factors that influence the potential severity of a full or partial dam failure are the amount of water impounded and the density, type, and value of development and infrastructure located Dam failure occurs when the retention function of the dam is compromised partially or entirely. Damage to a dam structure that results in a failure may be caused by any of the following sources: • Prolonged periods of rainfall and flooding resulting in overtopping • Earthquake ---PAGE BREAK--- Region 2 4-10 Regional Hazard Mitigation Plan 2018 • Inadequate spillway capacity resulting in excess overtopping flows • Internal erosion caused by embankment, foundation leakage, piping or rodent activity • Improper design • Age • Improper maintenance • Negligent operation • Failure of upstream dams on the same waterway • Vandalism or terrorism Failure is not the only type of emergency associated with dams. Other types of emergencies may include spillway discharges that are large enough to cause flooding in areas or flooding in upstream areas due to backwater effects or high pool levels. Both are considered dam emergencies that could lead to significant property damage or loss of life. (Source: U.S. Army Corps of Engineers Flood Emergency Plans: Guidelines for Corps Dams. Hydrologic Engineering Center, June 1980, p Dam failures can be grouped into four classifications: overtopping, foundation failure, structural failure, and other unforeseen failures. Overtopping failures result from the uncontrolled flow of water over, around, and adjacent to the dam. Earthen dams are most susceptible to this type of failure. According to the Wyoming State Hazard Mitigation Plan, hydraulic failures account for approximately 28 percent of all dam failures. Foundation and structural failures are usually tied to seepage through the foundation of the main structure of the dam. Deformation of the foundation or settling of the embankment can also result in dam failure. According to the same plan, structural failures account for approximately 28% of all dam failures, and foundation problems account for another 25%. Earthquakes or sabotage account for 12% of all dam failures, while inadequate design and construction account for the remaining 7% of failures. The State of Wyoming has adopted FEMA’s risk classifications as set forth in FEMA’s Federal Guidelines for Dam Safety: Hazard Potential Classification System for Dams, which classifies dams into three classes: high, significant and low hazard classes. These guidelines define High Hazard (Class I) dams as those rated based on an expected loss of human life should the dam fail. Significant Hazard (Class II) dams as those rated based on expected significant damage but not loss of human life. Significant damage refers to damage to structures where humans live, work, or play or public or private facilities, exclusive of unpaved roads and picnic areas, that are made inhabitable or inoperable. Failure of a low hazard dam would have minimal impacts. Geographical Area Affected In 1981, the U.S. Army Corps of Engineers completed an inspection program for nonfederal dams under the National Dam Inspection Act (P.L. 92-367). This was a four-year effort that included compiling an inventory of about 50,000 dams and conducting a review of each state’s capabilities, practices, and regulations regarding design, construction, operation, and maintenance of dams. Part of the inspection included evaluating the dams and assigning a hazard classification based on ---PAGE BREAK--- Region 2 4-11 Regional Hazard Mitigation Plan 2018 the effects dam failure would have on areas. The dams were rated High, Significant, and Low hazard. The Corps of Engineers based the hazard potential designation on such items as acre-feet capacity of the dam, distance from nearest community, population density of the community, and age of the dam. There were 1,458 dams in Wyoming that were reviewed by the Corps of Engineers in the 1981 inspection program. Of that number 38 were rated high hazard, 56 were rated significant hazard, and the remaining 1,364 were rated low hazard. The Wyoming State Engineers Office (WSEO) inspects dams over 20 feet high or with a storage capacity of 50 acre-feet or more, as well as smaller dams in highly populated areas. According to the Association of State Dam Safety Officials web site, as of 2016 the WSEO regulates 1,544 dams. As a part of the regulatory process the WSEO inspects these dams once every five years. Of these dams, 87 are rated high hazard, 107 are rated significant hazard, and 1,350 are rated low hazard potential Figure 4-1 shows the dams affecting Region 2. Nine are classified as High Hazard (Class I) and eighteen are classified as Significant Hazard (Class II). below provides details of the High and Significant Hazard Dams sorted by the county. ---PAGE BREAK--- Region 2 4-12 Regional Hazard Mitigation Plan 2018 Figure 4-1 Locations of High and Significant Hazard Dams Affecting Region 2 ---PAGE BREAK--- Region 2 4-13 Regional Hazard Mitigation Plan 2018 Table 4-3 High and Significant Hazard Dams in Region 2 Hazard Dam River Maximum Storage (Acre Ft) Nearest City Distance to Nearest Community (Mi.) EAP Converse County H LaPrele LaPrele CR, TR N Platte River 26850 Douglas 14 Y S Antelope No. 1 Antelope Creek N. 202 Douglas 3 N S Chamberlain No.1 LaPrele Creek 727 Douglas 16 N S Douglas Fishing Lake No.1 Six Mile Creek 193 Douglas 4 N S East Side No. 3 Five Mile Creek 200 Douglas 6 N S Elsie Moss Agate Creek 51 Douglas 28 N S Reservoir 26-SR-1* - Wright - N S Werner Ranch Werner Draw 113 Unnamed Ranch 15 N Natrona County H Alcova North Platte River 184,300 Casper 30 Y H Eastdale Creek Detention No. 2 Holman Draw 83 Casper 0 Y H Eastgate Jones Draw 717 Hat Six Road 1 Y H Pathfinder North Platte River 1,016,500 Casper 45 Y H Pathfinder Dike North Platte River 1,016,500 Casper 46 Y H Pathfinder Dike* North Platte River Off stream 1,128,087 Casper 45 Y H Seminoe* North Platte River 1,017,279 Red Buttes 64 Y H Spring Creek*(Enlargement) Spring Creek 58 Leo 7 N S Basin No. 2 Flood Detention Pond Airport Draw 0 Casper 1 N S Bates Creek Dry Fork Bates Creek 8,885 Casper 44 N S Cardine Keith Skeen Creek 169 Glenrock 23 N S Casper Parks No. 2 Holman Draw 48 Casper 1 N S Casper Sage Creek Sage Creek 165 Casper 2 N S East Fork Wolfe Creek East Fork Wolf Creek 45 Casper 5 N S Gothberg Dobbins Spring Creek 0 Casper 1 N S Kortes* North Platte River 4,739 None 0 Y S McFarland No. 3 East Fork Webb Creek 20 Hwy 220 0.5 N S Nicolaysen Dry Muddy Creek 475 Big Muddy Oil Field 10 N S Spicer Lower Holman Draw Off stream 0 Casper 0 N Source: National Inventory of Dams; *Located outside County but dam failure would have significant impact on County. There are 79 dams located in Niobrara County, all of which are earthen dams used for irrigation or stock fish ponds. All are rated as low hazard dams according to the National Inventory of Dams. ---PAGE BREAK--- Region 2 4-14 Regional Hazard Mitigation Plan 2018 Despite this low hazard rating from NID, the Niobrara County Emergency Operations Plan rates three dams, the Duel Reservoir on Cow Creek, the Field Reservoir on Cottonwood Draw and Pfister no. 2 Reservoir on Oat Creek, as dams that could be a significant hazard. Past Occurrences According to the 2016 Wyoming State Mitigation Plan, there has been a minimal history of dam failures that have led to a loss of life or damage to property in the state’s history. One of the most significant dam failure events, in terms of loss of life, occurred in Natrona County on March 1, 1906. Flooding due to snow and ice melt along the North Platte River near Casper led to a diversion dam to fail. The flooding caused a stream to return to its natural channel with a culvert that was too small to handle the increased amount of water. The water began to rise against a railroad embankment causing it to fail. The failure led to a railroad bridge to be damaged causing a train wreck that resulted in twelve individuals to lose their lives. All counties within Region 2 have experienced a dam failure event in the past. On July 22, 1983 a dam connected to the LaPrele Range Drainage Basin in Converse County collapsed after a heavy thunderstorm event that caused intense flooding and runoff to inundate the dam. A wall of water estimated to be 10-15 feet high rushed through a nearby ranch southwest of Douglas. No damage information is available from the incident and HMPC members have confirmed that the impact of the failure was isolated to that single ranch. In addition to the 1906 dam failure event, Natrona County experienced another significant dam failure in 1984. Snow melt flooding caused a dam to fail leading to dozens of residences, businesses, and farms to be impacted and resulted in a total of $5 million in damages to the area. Natrona County’s 2017 HMP also noted a dam failure event that occurred on September of 1982. The Shriner Reservoir Dam located along South Casper Creek was reported as having completely failed. No impacts were recorded from this failure. The State HMP identifies two dam failure events that took place within Niobrara County. On August 10, 1955 heavy rains caused several dams to break resulting in one ranch losing twenty- one heads of cattle. The second identified dam failure event took place on July 21, 1973 and affected both Niobrara and Weston counites. Torrential rainfall accompanied by hail caused flash flooding to damage bridges, make roads impassable in some areas and result in several earthen dams to fail. Crop and property damaged was substantial with an estimated $225,000 in property damage. The Niobrara HMP identifies an additional dam failure event that occurred in July of 1969. Although the dam failure took place in nearby Platte County it had a substantial impact on Niobrara County. The dam break resulted in a wall of water that was 50 feet high that damaged crops, killed livestock and forced evacuations. Property damage is estimated to be over $1 million. Frequency/Likelihood of Occurrence It is estimated that the counties in Region 2 will be affected by dam failure occasionally in the future, or a probability between 1% and 10% of occurring in any given year. The structural ---PAGE BREAK--- Region 2 4-15 Regional Hazard Mitigation Plan 2018 integrity of dams depends on regular inspections and maintenance, which do not always occur. Additionally, a number of the dam failures in Wyoming and other Rocky Mountain states occurred because of snow melt flooding that exceeded the capacity and strength of levees and dams. Wyoming’s dams will continue to be tested by snow melt, heavy rains, and other types of floods every year, continuing the potential of dam failure for the foreseeable future. Potential Magnitude Potential impacts of a dam failure may include injury, loss of life, property damage, damage to infrastructure, water contamination, loss of crops and livestock, evacuations and sheltering, interruption of commerce and transportation, search, and clean-up costs. In addition, dam failure and associated flooding can cause damage to and loss of irrigation structures such as headgates and ditches. Loss or damage to water structures would negatively impact agricultural producers of crops and livestock, and can be costly to repair. The severity and magnitude of a given dam failure will vary by county and case-by-case basis. Information on potential impacts of specific dam failures is not detailed in this plan due to Homeland Security concerns. Emergency management coordinators have access to inundation maps contained in the emergency action plans for the High Hazard dams in the state. High Hazard (Class I) dams, by definition, would merit a magnitude/severity rating of catastrophic, whereas Significant Hazard (Class II) dams rate as critical and Low Hazard dams fall into the limited rating. The magnitude/severity rating for the hazard in Converse and Natrona counties is considered mostly critical, due to the number of Class I dams that could impact highly populated communities such as Douglas in Converse County and Casper in Natrona County. The low hazard classification of the dams located in Niobrara and the low population density in the county result in the magnitude/severity ratings for the hazard in in the county to be limited. Vulnerability Assessment As noted in Table 4-2 , Converse and Natrona counties both contain high hazard dams that could affect areas and communities. Jurisdictions should consult dam EAPs to ensure that they recognize the potential impacts from the failure of these dams and plan for them. The previous hazard mitigation plan for the Converse and Natrona counties note the following information on the impacts of failures of specific dams: Converse County LaPrele Dam The LaPrele Dam, the only high hazard classified dam in Converse County, is a 135-foot tall concrete dam located 14 miles southwest of Douglas along LaPrele Creek. The dam was constructed in 1909 for the purpose of irrigation and as part of a federal campaign to promote western settlement. After falling into disrepair in the 1970’s, the dam was modified in the 1980’s, ---PAGE BREAK--- Region 2 4-16 Regional Hazard Mitigation Plan 2018 even winning the “Outstanding Civil Engineering Achievement of 1979”. According to the Wyoming Irrigation Systems Report by Wyoming Water Development Commission, the LaPrele Dam irrigates 14,612 acres of land. Although the probability of dam failure is low, a failure could be catastrophic and would result in hundreds of millions of dollars in damage to communities. Areas of inundation may include, Natural Bridger Park recreation area, City of Douglas, nearby unincorporated areas, rural ranches, and portions of Interstate 25. Although the area experienced high traffic volumes with the 2017 solar eclipse, the HMPC voiced concerns of the possibility of high volumes of traffic if an evacuation were to take place due to an unexpected failure of the LaPrele Dam. Natrona County Alcova and Pathfinder Dam The Alcova and Pathfinder Dams, both located close to active faults, are classified as high hazard dams in Natrona County. Failure of either dam may result in hundreds of millions of dollars in damage to communities including Casper, Evansville and Mills. Alcova Dam is a 265-foot tall earthfill dam that is operated by the U.S. Bureau of Reclamation for the purpose of water and hydroelectric power generation. The Pathfinder Dam is a cyclopean masonry dam located on the North Platte River. The dam was completed in June of 1909 and was immediately tested with unusual summer rains that overtaxed the spillways and threatened to overtop an unfinished auxiliary dike south of the dam. The potential overtopping led to sensational stories in Denver newspapers and caused annual nervousness in Casper for years following. The reservoir exceeded capacity in 1984, 2010, and 2011 causing overflow water to divert into the spillway immediately north of the dam. The dam’s spillway overflowed in June 2016 as a result of snowmelt runoff, making this the fourth time in three decades overflow has occurred. Seminoe Dam The Seminoe Dam is a 295-foot tall concrete thick-arch dam that covers more than 20,000 acres. It is located in a narrow, isolated canyon formed by the North Platte and cutting through the Semione Mountains and is the uppermost dam located on the North Platte River. The dam is owned and operated by the U.S. Bureau of Reclamation and is used to store water for irrigation and generate hydroelectricity. Although the dam is located outside the county, due to its classification as a high hazard dam and being located upstream from other dams classified as significant and high hazard, if the Seminoe Dam was to fail it may result in serious property damage to communities Aging dams is another factor to consider when assessing the vulnerability of dams. According to the State Hazard Mitigation Plan, of the 1,548 dams in the state inventory, 860 dams or 56% were constructed before 1965 and are over fifty years old. In Converse County, of the eight aging dams that could impact the county, four were constructed before 1965 and are over fifty years old. However, the Converse County 2018 Hazard Mitigation Plan notes that two of those four dams have been modified in the last forty years. Within Natrona County, there are 19 aging dams that ---PAGE BREAK--- Region 2 4-17 Regional Hazard Mitigation Plan 2018 could impact the county, thirteen of which were constructed before 1965 and are over fifty years old. Future Development As communities or unincorporated areas grow, previously lower-classified dams may pose greater risks, leading to their hazard classification to be elevated. Inundation maps and emergency action plans should be consulted in the planning of new development, where applicable to ensure that risks from a potential dam failure are recognized. Growth rates in the region do not indicate that risk is increasing substantially. Summary Overall, dam failure significance in the Region ranges from low to medium depending upon its location. Due to the number of dams classified as high and significant hazard, the greatest risk of dam failure in the Region is in Converse (1 high; 7 significant) and Natrona (8 high; 11 significant) counites. Although the probability of a dam failure event to occur in Converse or Natrona counties is unlikely, if a high hazard dam such as LaPrele in Converse or Alcova in Natrona were to fail it would have a significant impact on either county due to the highly populated communities in Casper and Douglas that would be affected. Table 4-4 Dam Failure Hazard Risk Summary 4.2.3 Drought Hazard/Problem Description Drought is described as a protracted period of deficient precipitation resulting in extensive damage to vegetation. Of all the natural weather-related disasters, drought is by far the costliest to our society. It indirectly kills more people, animals, and plants than the combined effects of hurricanes, floods, tornadoes, blizzards, and wildfires. And, unlike other disasters that quickly come and go, drought's long-term unrelenting destruction has been responsible in the past for mass migrations and lost civilizations. The 1980 and 1988 droughts in the U.S. resulted in approximately 17,500 heat-related deaths and an economic cost of over $100 billion. Drought occurs in four stages and is defined as a function of its magnitude (dryness), duration, and regional coverage. Severity, the most commonly used term for measuring drought, is a combination of magnitude and duration. County Geographic Extent Probability of Future Occurrence Potential Magnitude/ Severity Overall Significance Converse Limited Occasional Significant Medium Natrona Limited Occasional Significant Medium Niobrara Limited Low Limited Low ---PAGE BREAK--- Region 2 4-18 Regional Hazard Mitigation Plan 2018 The first stage of drought is known as a meteorological drought. The conditions at this stage include any precipitation shortfall of 75% of normal for three months or longer. The second stage is known as agricultural drought. Soil moisture is deficient to the point where plants are stressed and biomass (yield) is reduced. The third stage is the hydrological drought. Reduced stream flow (inflow) to reservoirs and lakes is the most obvious sign that a serious drought is in progress. The fourth stage is the socioeconomic drought. This final stage refers to the situation that occurs when physical water shortage begins to affect people. As these stages evolve over time, the impacts to the economy, society, and environment converge into an emergency situation. Without reservoir water to irrigate farms, food supplies are in jeopardy. Without spring rains for the prairie grasslands, open range grazing is compromised. Without groundwater for municipalities, the hardships to communities can result in increases in mental and physical stress as well as conflicts over the use of whatever limited water is available. Without water, wetlands disappear. Other animal and plant species also suffer from lack of (or degraded) proper food, nutrients, water, and habitat. The quality of any remaining water decreases due to its higher salinity concentration. There is also an increased risk of fires, and air quality degrades as a result of increased soil erosion particles in strong winds (blowing dust). Geographical Area Affected According to estimates by the Region 2 Hazard Mitigation Plan Committee, the Region is at high risk to drought events over an extensive spatial area which covers all three counties in the region. Since droughts are often regional events that impact multiple counties and states simultaneously, given the climate of the planning area being contiguous, it is reasonable to assume that a drought will impact the entire planning region and affect a large geographic extent, so that the hazard proves significant across the counties. According to the Wyoming State Climate Office, Wyoming is the 5th driest state in the United States and since 1999, moderate to severe droughts have been normal occurrences in much of the state due to its natural climate. The Region primarily falls within three major river drainage basins in the state (North Platte, Cheyenne, and Powder-Tongue Basins). The Laramie Mountains, on the eastern edge of the Rocky Mountains of the Wyoming side, provide some snowpack during the winter months that discharge flow through major local streams South Fork Powder River, North Platte River, Cheyenne River). However, as of 2018, parts of the Powder River and the North Platte River were declared as impaired waters by the Wyoming Water Resources Data System & Wyoming State Climate Office services (WRDS-UWY, 2018); streams falling under this impairment criteria are considered threatened, significantly degraded, or too contaminated to meet the water quality standards set by the Environmental Protection Agency’s Clean Water Act (EPA, 2017). Given the Region’s lack of widespread access to large amounts of fresh water locally, and because some major streams contain segments deemed impaired, effects from droughts may be exacerbated and the areas impacted may be quite large within the three region counties. ---PAGE BREAK--- Region 2 4-19 Regional Hazard Mitigation Plan 2018 Past Occurrences The Region 2 area has experienced several multi-year droughts over the past century. The most significant statewide drought in recent history began in earnest in the spring of 2000 and endured through 2004. 2005 was a wetter year, technically signifying the end of the drought period. Dry conditions returned in the following years and became severe between 2006 and 2007. According to the Wyoming State Climate Office, “conditions [had] eased somewhat in mid-2008, but a near decade with warm temperatures and relatively little precipitation has left [Wyoming] very vulnerable” (http://www.wrds.uwyo.edu/sco/drought/drought.html). The driest year to date occurred in 2012, with only 10.9 inches of precipitation, or 69.06% of the normal precipitation observed across the state. The 2000-2004 drought is considered by many to be the most severe in collective memory. However, some older residents have indicated that they remember streams drying up in the 1930s and 1950s. According to instrument records, since 1895 there have been only six multi-year (three years or longer) statewide droughts. Based on deficit precipitation totals (negative departures from the long-term average), they are ranked statewide. Refer to Table 4-5 for a summary of the years that suffered drought, their average precipitation records, and the percent of those years’ precipitation compared to the average annual records average precipitation in the range of years, which corresponds to an average annual precipitation of 15.87). Table 4-5 Significant Multi-Year Wyoming Droughts since 1895 (Modern Instrumented Era) Years Average Annual Precipitation (inches) Percent of 1895-2017 Average Annual Precipitation (15.87”) 1900-1903 13.53 85.28% 1931-1935 13.43 84.65% 1952-1956 12.93 81.47% 1958-1960 13.23 83.36% 1987-1990 14.17 89.29% 2000-2004 13.44 84.67% Source: NOAA – National Centers for Environmental Information Overall, Wyoming's precipitation record from 1895-2017 reveals that, for the first half of the 20th century (except for the Dust Bowl years of the 1930s and the localized event in the mid-1950s), there was generally a surplus of moisture. During the second half of the 20th century and into the 21st century there was a trend of increased periods of drought (Figure 4-2Figure 4-2). The dry years are denoted by the binomial filter troughs red line dips). ---PAGE BREAK--- Region 2 4-20 Regional Hazard Mitigation Plan 2018 Figure 4-2 Wyoming Annual Precipitation: 1895-2017 Source: NOAA – National Centers for Environmental Information (http://www.ncdc.noaa.gov/cag/time-series/) The U.S. Drought Monitor is another useful source related to drought, and it provides a general summary of current drought conditions. The U.S. Department of Agriculture (USDA), the National Oceanic and Atmospheric Administration (NOAA), and the National Drought Mitigation Center (University of Nebraska-Lincoln) collaborate on this weekly product, which is released each Thursday. Multiple drought indicators, including various indices, outlooks, field reports, and news accounts are reviewed and In addition, numerous experts from other agencies and offices across the country are consulted. The result is the consensus assessment presented on the U.S. Drought Monitor map (with Wyoming’s current drought conditions portrayed in The image is color-coded for six levels of drought intensity. The first drought category, “Abnormally Dry,” is used to show areas that might be moving into a drought, as well as those that have recently come out of one. The last category is called “Exceptional Drought”, and is reserved to classify the most severe drought events. The remaining four categories define droughts ranging from less to more severe, while a lack of yellow-red coloring indicates no drought conditions are present (Source: As of May 8, 2018, no drought conditions were identified in any parts of the Region. Nevertheless, some “Abnormally Dry” and “Moderate Drought” areas are present in the southwestern parts of the state. Since no part of the Region is currently impacted by drought, the three counties are displayed in white by Figure 4-3 (found within the green square below). ---PAGE BREAK--- Region 2 4-21 Regional Hazard Mitigation Plan 2018 Figure 4-3 U.S. Drought Monitor Source: U.S. Drought Monitor; Region 2 counties highlighted in green square A particularly useful resource to determine the impacts of drought is the Drought Impact Reporter (DIR), launched by the National Drought Mitigation Center in July 2005 as the nation’s first comprehensive database accounting for a range of drought impacts. The Drought Impact Reporter is an interactive web-based mapping tool designed to compile and display impact information across the United States in near real-time. Information within the DIR is collected from a variety of sources including the media, government agencies and reports, and citizen observers. Each of these sources provides different types of information at different spatial and temporal scales. (Source: http://drought.unl.edu/monitoringtools/droughtimpactreporter.aspx) A search of the database for the entire State of Wyoming from 1999 to 2017 (which includes the most recent severe droughts) shows a total of 145 reported impacts. Figure 4-4 below contains the breakdown of reported impacts by county, with color-coding ranging from fewest (yellow) to most reported impacts (reds). The majority of reported impacts fall within the Agriculture Category. Drought effects associated with agriculture include damage to crop quality; income loss for farmers due to reduced crop yields; reduced productivity of cropland; reduced productivity of rangeland; forced reduction of foundation stock; and closure/limitation of public lands to grazing, ---PAGE BREAK--- Region 2 4-22 Regional Hazard Mitigation Plan 2018 among others. Note that the three counties in Region 2 account for 54 out of the total (145) drought reports in the time period queried: 23 for Natrona, 19 for Converse, and 12 for Niobrara County. Figure 4-4 Number of Reported Drought Impacts from 1999 to 2017 in Region 2 Source: http://droughtreporter.unl.edu/map/ All areas in Region 2 have, at various times, been included in county or regional USDA disaster declarations for droughts (by either Secretarial and/or Presidential Disaster Declarations). In 2016 specifically, all three counties were included in the Secretarial Drought Designation statement as a primary disaster designated county. In 2017, only Converse County received a Secretarial Disaster Declaration for drought. The occurrence of drought in the Region, however, is frequent and expected, as can be seen from the various records and declarations. More details on drought frequency are discussed below. Region 2 Counties ---PAGE BREAK--- Region 2 4-23 Regional Hazard Mitigation Plan 2018 Frequency/Likelihood of Occurrence Figure 4-5 indicates that the Region 2 planning area spent approximately 15-20% of the 100-year span from 1895 to 1995 in severe or extreme drought. This is consistent with the data in the Past Occurrences subsection which highlights that severe multi-year droughts have occurred roughly every twenty years, since the beginning of precipitation data collection in 1895. In addition, single year or partial year drought events are also common in each of the three region counties. An occurrence interval of roughly once every twenty years for the Region until 1995 may not seem like a frequent interval, but given more recent data records since then, the trend has changed From 1996 to 2017, including both of those years, Region 2 has experienced ten additional years of drought, averaging to a drought (of at least one year) every 2.2 years. Figure 4-5 Palmer Drought Severity Index Time Series for the Continental U.S.: 1895- 1995 Potential Magnitude In order to calculate a magnitude and severity rating for comparison with other hazards, and to assist in assessing the overall impact of the hazard on the planning area, information from the event of record is used. Impacts can help understand the effects of a hazard, and potentially assist in preparing for and preventing against said hazard drought). In some cases, the event of record represents an anticipated worst-case scenario, and in others, it is a reflection of a common occurrence. Based upon Table 4-7, the drought of 2000-2004 was more significant, in terms of ---PAGE BREAK--- Region 2 4-24 Regional Hazard Mitigation Plan 2018 losses and changes in productivity, than some of the other droughts in the last 100 years for the entire state. The droughts noted previously in Table 4-5, derived from NOAA’s National Center for Environmental Information database, indicate that the most significant droughts in the last century, in terms of precipitation deficit, were in 1952-1956, 1958-1960, 1931-1935, and 1999- 2004. To determine how the drought periods had significant negative impacts on Wyoming, crop production and livestock inventory data for the driest period (1952-1956) and the latest multi-year drought period (2000-2004) were compared. 1957 and 2005 were wetter years, with annual statewide precipitation totals above the 1895-2017 average. Those two years were used as endpoints for the droughts that started in 1952 and 2000 respectively. In both cases, the years following saw a return to drier conditions. Because of this, the most recent drought impacts were also calculated for 2005 and 2006, and are included in summary tables. Table 4-6 and Table 4-7 show peak decline in one or more production categories during drought compared to the 5- year pre-drought production averages for various commodities. A comparison of Table 4-6 and Table 4-7 indicate that drought impacts to the entire Wyoming agricultural community were greater in the 2000-2004 drought than in the 1952-1956 drought. With the exception of dry beans, all commodities in the worst years of the 2000-2004 drought showed a greater percentage decline in production than in the 1952-1956 drought. As a result, the 2000-2004 drought will be used as the drought of historic record to calculate dollar impacts. (Note that the abbreviation ‘Bu.’ means bushel, and ‘cwt’ stands for hundredweight.) Table 4-6 Peak Commodity Production Changes from Pre-Drought (1947-1951) to Drought (1952-1956) Commodity 5-Year Pre- Drought Production Average (1947-1951) Units Lowest Production During Drought (1952-1956) Year of Lowest Production (1952-1956) Percent Change Winter Wheat 5,072 1,000 bu. 2,346 1954 -54% Spring Wheat 1,579 1,000 bu. 600 1954 -62% Barley 4,414 1,000 bu. 2,700 1956 -39% Oats 4,577 1,000 bu. 2,470 1954 -46% Dry Beans 1,009 1,000 cwt. 589 1955 -42% Sugarbeets 413 1,000 tons 421 1955 Corn 227 1,000 bu. 161 1953 -29% Alfalfa Hay 490 1,000 tons 675 1954 +38% Other Hay 674 1,000 tons 442 1954 -34% Cattle/ Calves Inventory 1,050 1,000 head 1,096 1954 Source: USDA ---PAGE BREAK--- Region 2 4-25 Regional Hazard Mitigation Plan 2018 Table 4-7 Peak Commodity Production Changes from Pre-Drought (1994-1998) to Drought (2000-2004) Commodity 5-Year Pre- Drought Production Average (1994-1998) Units Lowest Production During Drought (1999-2006) Year of Lowest Production (1999-2006) Percent Change Winter Wheat 6,029 1,000 bu. 2,375 2002 -61% Spring Wheat 648 1,000 bu. 96 2002 -84% Barley 8,383 1,000 bu. 4,680 2002 -44% Oats 1,648 1,000 bu. 600 2005 -64% Dry Beans 691 1,000 cwt. 514 2001 -26% Sugarbeets 1,151 1,000 tons 659 2002 -43% Corn 6,328 1,000 bu. 4,165 2002 -34% Alfalfa Hay 1,581 1,000 tons 1,150 2002 -27% Other Hay 817 1,000 tons 450 2002 -45% Cattle/ Calves Inventory 1,536 1,000 head 1,300 2004 -16% Source: USDA Economic Impacts Agricultural dollar impacts can also be used to show the effects of drought. For Wyoming, historic data from the 2000-2004 drought and the two subsequent years was obtained from the U.S. Department of Agriculture (USDA) Quick Stats database The data below represent changes in production value for crops, and changes in inventory value for cattle and calves. As such, the data should be considered to summarize impact value versus economic loss value. For example, with cattle and calves inventory (Table 4-8 through Table 4-14), the inventory decreased during the drought. Therefore, the value of inventory on hand decreased. The inventory decreased, however, because of the reduced sales in cattle and calves, due to hardships in raising the cattle, feeding, etc. The net result, therefore, is an overall decrease in inventory value, which is a negative impact stemming from drought. Although these summaries have been obtained state-wide, they serve as a good indicator of how drought can affect a specific industry or business over time. ---PAGE BREAK--- Region 2 4-26 Regional Hazard Mitigation Plan 2018 Table 4-8 2000 Production and Inventory Value Impact Commodity 5-Year Pre-Drought Production Average (1994-1998) Units 2000 Production Value (USD) Production and Inventory Value Impact (USD) Winter Wheat 6,029 1,000 bu. 4,080 $2.70/bu - $ 5,262,300 Spring Wheat 648 1,000 bu. 232 $2.70/bu - $ 1,124,280 Barley 8,383 1,000 bu. 7,885 $3.08/bu - $ 1,533,840 Oats 1,648 1,000 bu. 1,156 $1.55/bu - $ 252,650 Dry Bean 691 1,000 cwt. 762 $16.80/cwt + $ 1,196,160 Sugar Beet 1,150 1,000 tons 1,556 $32.50/ton + $ 195,000 Corn 6,328 1,000 bu. 7,656 $2.02/bu + $ 2,682,560 Alfalfa Hay 1,581 1,000 tons 1,449 $85.00/ton - $ 11,220,000 Other Hay 817 1,000 tons 650 $80.00/ton - $ 13,392,000 Cattle/Calves Inventory 1,536 1,000 head 1,550 $780.00/head +$10,920,000 TOTAL -$17,791,350 Source: USDA Table 4-9 2001 Production and Inventory Value Impact Commodity 5-Year Pre-Drought Production Average (1994-1998) Units 2001 Production Value (USD) Production and Inventory Value Impact (USD) Winter Wheat 6,029 1,000 bu. 2,880 $2.70/bu - $ 8,502,300 Spring Wheat 648 1,000 bu. 168 $2.90/bu - $ 1,393,160 Barley 8,383 1,000 bu. 6,970 $3.32/bu - $ 4,691,160 Oats 1,648 1,000 bu. 1,344 $1.65/bu - $ 501,600 Dry Bean 691 1,000 cwt. 514 $23.00/cwt - $ 4,066,400 Sugar Beet 1,150 1,000 tons 794 $39.70/ton - $ 14,133,200 Corn 6,328 1,000 bu. 6,375 $2.30/bu + $ 108,100 Alfalfa Hay 1,581 1,000 tons 1,276 $110.00/ton - $ 33,550,000 Other Hay 817 1,000 tons 605 $105.00/ton - $ 22,302,000 Cattle/Calves Inventory 1,536 1,000 head 1,470 $780.00/head - $ 51,480,000 TOTAL -$140,511,720 Source: USDA ---PAGE BREAK--- Region 2 4-27 Regional Hazard Mitigation Plan 2018 Table 4-10 2002 Production and Inventory Value Impact Commodity 5-Year Pre-Drought Production Average (1994-1998) Units 2002 Production Value (USD) Production and Inventory Value Impact (USD) Winter Wheat 6,029 1,000 bu. 2,375 $3.70/bu - $ 13,519,800 Spring Wheat 648 1,000 bu. 96 $3.90/bu - $ 2,154,360 Barley 8,383 1,000 bu. 4,680 $3.23/bu - $ 11,960,690 Oats 1,648 1,000 bu. 750 $2.20/bu - $ 1,975,600 Dry Bean 691 1,000 cwt. 624 $18.30/cwt - $ 1,222,440 Sugar Beet 1,150 1,000 tons 659 $42.30/ton - $ 20,769,300 Corn 6,328 1,000 bu. 4,165 $2.60/bu - $ 5,623,800 Alfalfa Hay 1,581 1,000 tons 1,150 $111.00/ton - $ 47,841,000 Other Hay 817 1,000 tons 450 $106.00/ton - $ 38,944,400 Cattle/Calves Inventory 1,536 1,000 head 1,320 $760.00/head - $164,160,000 TOTAL -$308,171,390 Source: USDA Table 4-11 2003 Production and Inventory Value Impact Commodity 5-Year Pre-Drought Production Average (1994-1998) Units 2003 Production Value (USD) Production and Inventory Value Impact (USD) Winter Wheat 6,029 1,000 bu. 3,915 $3.40/bu 7,187,600 Spring Wheat 648 1,000 bu. 180 $3.15/bu 1,474,200 Barley 8,383 1,000 bu. 6,975 $3.46/bu 4,871,680 Oats 1,648 1,000 bu. 1,104 $1.80/bu 979,200 Dry Bean 691 1,000 cwt. 645 $17.40/cwt 800,400 Sugar Beet 1,150 1,000 tons 752 $41.20/ton -$16,397,600 Corn 6,328 1,000 bu. 6,450 $2.50/bu $ 305,000 Alfalfa Hay 1,581 1,000 tons 1,625 $80.00/ton $ 3,520,000 Other Hay 817 1,000 tons 770 $73.00/ton 3,431,000 Cattle/Calves Inventory 1,536 1,000 head 1,350 $890.00/head 165,540,000 TOTAL 196,856,680 Source: USDA ---PAGE BREAK--- Region 2 4-28 Regional Hazard Mitigation Plan 2018 Table 4-12 2004 Production and Inventory Value Impact Commodity 5-Year Pre-Drought Production Average (1994-1998) Units 2004 Production Value (USD) Production and Inventory Value Impact (USD) Winter Wheat 6,029 1,000 bu. 3,510 $3.20/bu 8,060,800 Spring Wheat 648 1,000 bu. 240 $3.25/bu 1,326,000 Barley 8,383 1,000 bu. 7,050 $3.41/bu 4,545,530 Oats 1,648 1,000 bu. 795 $1.55/bu 1,322,150 Dry Bean 691 1,000 cwt. 541 $25.90/cwt 3,885,000 Sugar Beet 1,150 1,000 tons 812 $41.70/ton 14,094,600 Corn 6,328 1,000 bu. 6,550 $2.48/bu $ 550,560 Alfalfa Hay 1,581 1,000 tons 1,305 $74.50/ton 20,562,000 Other Hay 817 1,000 tons 756 $69.50/ton 4,239,500 Cattle/Calves Inventory 1,536 1,000 head 1,300 $1020.00/head 240,720,000 TOTAL 298,205,020 Source: USDA Table 4-13 2005 Production and Inventory Value Impact Commodity 5-Year Pre-Drought Production Average (1994-1998) Units 2005 Production Value (USD) Production and Inventory Value Impact (USD) Winter Wheat 6,029 1,000 bu. 4,350 $3.50/bu 5,876,500 Spring Wheat 648 1,000 bu. 315 $3.19/bu 1,062,270 Barley 8,383 1,000 bu. 5,580 $3.28/bu 9,193,840 Oats 1,648 1,000 bu. 600 $1.60/bu 1,676,800 Dry Bean 691 1,000 cwt. 776 $18.70/cwt $ 1,589,500 Sugar Beet 1,150 1,000 tons 801 $42.80/ton 14,937,200 Corn 6,328 1,000 bu. 6,860 $2.45/bu $ 1,303,400 Alfalfa Hay 1,581 1,000 tons 1,560 $75.00/ton 1,575,000 Other Hay 817 1,000 tons 756 $72.00/ton 4,392,000 Cattle/Calves Inventory 1,536 1,000 head 1,400 $1140.00/head 155,040,000 TOTAL 190,860,710 Source: USDA ---PAGE BREAK--- Region 2 4-29 Regional Hazard Mitigation Plan 2018 Table 4-14 2006 Production and Inventory Value Impact Commodity 5-Year Pre-Drought Production Average (1994-1998) Units 2006 Production Value (USD) Production and Inventory Value Impact (USD) Winter Wheat 6,029 1,000 bu. 3,645 $4.58/bu 10,918,720 Spring Wheat 648 1,000 bu. 234 $3.80/bu 1,573,200 Barley 8,383 1,000 bu. 4,845 $3.32/bu 11,746,160 Oats 1,648 1,000 bu. 684 $2.15/bu 2,072,600 Dry Bean 691 1,000 cwt. 590 $22.00/cwt 2,222,000 Sugar Beet 1,150 1,000 tons 798 $46.80/ton 16,473,600 Corn 6,328 1,000 bu. 5,805 $2.64/bu 1,380,720 Alfalfa Hay 1,581 1,000 tons 1,400 $101.00/ton 18,281,000 Other Hay 817 1,000 tons 715 $103.00/ton 10,506,000 Cattle/Calves Inventory 1,536 1,000 head 1,400 $1010.00/head 137,360,000 TOTAL 212,534,000 Source: USDA Table 4-15 Production and Inventory Value Impact for Worst Year of Drought Commodity 5-Year Pre- Drought Production Average (1994-1998) Units Worst Yearly Production of Drought Year Value (USD) Production and Inventory Value Impact (USD) Winter Wheat 6,029 1,000 bu. 2,375 2002 $3.70/bu -$13,519,800 Spring Wheat 648 1,000 bu. 96 2002 $3.90/bu -$2,152,800 Barley 8,383 1,000 bu. 4,505 2007 $3.62/bu -$14,038,360 Oats 1,648 1,000 bu. 376 2007 $2.82/bu -$3,587,040 Dry Bean 691 1,000 cwt. 514 2001 $23.00/cwt -$4,071,000 Sugar Beet 1,150 1,000 tons 658 2007 $40.20/ton -$19,778,400 Corn 6,328 1,000 bu. 4,165 2002 $2.60/bu -$5,623,800 Alfalfa Hay 1,581 1,000 tons 1,150 2002 $111.00/ton -$47,841,000 Other Hay 817 1,000 tons 450 2002 $106.00/ton -$38,902,000 Cattle/Calves Inventory 1,536 1,000 head 1,300 2004 $1,020/head -$240,720,000 TOTAL -$390,234,200 Source: USDA – National Agricultural Statistics Service ---PAGE BREAK--- Region 2 4-30 Regional Hazard Mitigation Plan 2018 The 2000-2004 drought made historical record impacts in Wyoming, with significant negative ramifications particularly on the agricultural industry. The worst-case year was 2002, with a negative dollar impact of $308,171,390 statewide. The counties of Region 2 comprise 12.52% of the State of Wyoming in land area. While drought impacts are not always equally distributed across the state, the potential drought impact in Region 2 could nevertheless be estimated to be over $120 million for the five-year period, based on the region’s size alone. The total impact statewide for the 2000-2004 drought was $961,536,160. The 2002 year alone caused Region 2 roughly $38,521,423 in production losses. Another tool provided by the USDA and used to assess commodity and crop losses is the Risk Management Agency’s indemnity summaries, which highlight insurance payments to counties based on damages caused to different crops, by specific hazards (such as drought). From 2007 to 2017, the Region 2 counties experienced drought-caused damages to 22,529 acres of land, totaling $816,288 in indemnity payments. Table 4-16 below breaks down the drought impacts by county, acreage, and commodity type. Table 4-16 Indemnities Paid for Commodities that Suffered from Drought in Region 2, 2007-2017 Commodity Counties Affected Acres Damaged Indemnity Amount Forage Production Niobrara 14,988 $422,739 Forage Seeding Niobrara 318 $36,294 Oats Converse, Niobrara 127 $3,009 Wheat Converse, Niobrara 684 $69,028 All Other Crops Converse, Natrona 6,412 $285,218 TOTAL 22,529 $816,288 Source: USDA – Risk Management Agency In addition to hurting the agricultural industry as well as ranching businesses, drought can exacerbate the risk of wildfires, increase the cost of municipal water usage, and deplete water resources used for recreation and tourism, hence negatively affecting the economy in various ways. Vulnerability Assessment The vulnerability of the people, buildings, and economy of Region 2 to drought is very difficult to quantify. Typically, people and structures are not directly vulnerable to drought, though secondary or indirect impacts may eventually increase vulnerability ratings. However, some areas are more vulnerable overall than others and, therefore, benefit from adequate mitigation planning and implementation. For Region 2, the agricultural sector is the most vulnerable to drought and will benefit the most from mitigation efforts. Economic resources tied to agricultural production are extremely vulnerable to drought. Water supply and quality issues are also of concern during times of drought, as are relief, response, and restriction efforts. Outdoor recreation, which is important ---PAGE BREAK--- Region 2 4-31 Regional Hazard Mitigation Plan 2018 to the region’s economy, is vulnerable to drought too. The geographic extent of the hazard is considered extensive. The probability of future occurrences is considered likely, and the potential magnitude/severity is critical. In addition, the HMPC considers the hazard to have an overall impact rating of high for the entire Region. Vulnerability is tempered somewhat for Natrona and Niobrara counties with the Laramie Mountains being a headwaters area. The snowpack in the Laramie Mountains typically helps contribute to streamflow during normal years, but can be affected by drier, low snowpack winters. Future Development Future development in the Region is not anticipated to change its vulnerability to drought in a significant way. Summary Drought is considered a high significance hazard for all counties in the Region due to the extensive economic and environmental impacts. Drought can be widespread and pervasive for several years. Table 4-17 Drought Hazard Risk Summary 4.2.4 Earthquake Hazard/Problem Description An earthquake is generally defined as a sudden motion or trembling in the Earth caused by the abrupt release of strain accumulated within or along the edge of the earth’s tectonic plates. The most common types of earthquakes are caused by movements along faults and by volcanic forces, although they can also result from explosions, cavern collapse, and other minor causes not related to slowly accumulated strains. The amount of energy released during an earthquake is usually expressed as a Richter magnitude and is measured directly from the earthquake as recorded on seismographs. The moment magnitude scale (abbreviated as MMS and sometimes denoted as MW or M) is used by seismologists to measure the size of earthquakes in terms of the energy released. The scale was developed in the 1970s to succeed the Richter magnitude scale. Even though the formulas are different, the new scale retains a similar continuum of magnitude values to that defined by the older one. Another measure of earthquake severity is intensity. Intensity is an expression of the County Geographic Extent Probability of Future Occurrence Potential Magnitude/ Severity Overall Significance Converse Significant Likely Critical High Natrona Significant Likely Critical High Niobrara Significant Likely Critical High ---PAGE BREAK--- Region 2 4-32 Regional Hazard Mitigation Plan 2018 amount of shaking at any given location on the ground surface as felt by humans or based on the resulting damage to structures. Intensity is defined in the Modified Mercalli Scale, or MMI, shown in Table 4-18 along with the relevant Peak Ground Acceleration, or PGA (expressed as gravitational/g force percentages). Seismic shaking is typically the greatest cause of losses to structures during earthquakes. Table 4-18 Modified Mercalli Intensity (MMI) Scale MMI Felt Intensity Acceleration (PGA) I Not felt except by a very few people under special conditions. Detected mostly by instruments. <0.17 II Felt by a few people, especially those on upper floors of buildings. Suspended objects may swing. 0.17 – 1.4 III Felt noticeably indoors. Standing automobiles may rock 0.17 – 1.4 IV Felt by many people indoors, by a few outdoors. At night, some people are awakened. Dishes, windows, and doors rattle. 1.4 – 3.9 V Felt by nearly everyone. Many people are awakened. Some dishes and windows are broken. Unstable objects are overturned. 3.9 – 9.2 VI Felt by everyone. Many people become frightened and run outdoors. Some heavy furniture is moved. Some plaster falls. 9.2 – 18 VII Most people are alarmed and run outside. Damage is negligible in buildings of good construction, considerable in buildings of poor construction. 18 – 34 VIII Damage is slight in specially designed structures, considerable in ordinary buildings, great in poorly built structures. Heavy furniture is overturned. 34 – 65 IX Damage is considerable in specially designed buildings. Buildings shift from their foundations and partly collapse. Underground pipes are broken. 65 – 124 X Some well-built wooden structures are destroyed. Most masonry structures are destroyed. The ground is badly cracked. Considerable landslides occur on steep slopes. >124 XI Few, if any, masonry structures remain standing. Rails are bent. Broad fissures appear in the ground. >124 XII Virtually total destruction. Waves are seen on the ground surface. Objects are thrown in the air. >124 Source: USGS. http://earthquake.usgs.gov/learn/topics/mercalli.php; Modified Mercalli Intensity and peak ground acceleration (PGA) (Wald, et al 1999). Earthquakes can cause structural damage, injury, and loss of life, as well as damage to infrastructure networks such as water, power, communication, and transportation lines. Other damaging effects of earthquakes include surface rupture, fissuring, ground settlement, and permanent horizontal and vertical shifting of the ground. Secondary impacts can include landslides, seiches, liquefaction, fires, and dam failure, which in turn could lead to flooding. The combination of widespread primary and secondary effects from large earthquakes make this hazard potentially devastating. ---PAGE BREAK--- Region 2 4-33 Regional Hazard Mitigation Plan 2018 Part of what makes earthquakes so destructive is that they generally occur without warning. The main shock of an earthquake can usually be measured in seconds, and rarely lasts for more than a minute. Aftershocks can occur within the days, weeks, and even months following a major earthquake. By studying the geologic characteristics of faults, geoscientists can often determine when the fault last moved and estimate the magnitude of the earthquake that produced the last movement. Because the occurrence of earthquakes is relatively infrequent in Region 2 and the historical earthquake record is short, accurate estimations of magnitude, timing, or location of future dangerous earthquakes in the Region are difficult to estimate. Liquefaction During an earthquake, near surface (within 30 feet), relatively young (less than 10,000 years old), water-saturated sands and silts may act as a viscous fluid. This event is known as liquefaction (quicksand is a result of liquefaction). Liquefaction occurs when water-saturated materials are exposed to seismic waves. These seismic waves may compact the material silts and sands), increasing the interior pore water pressure within the material mass. When the pore pressure rises to about the pressure of the weight of the overlying materials, liquefaction occurs. The result of the saturated soil’s loss in strength and stiffness from ground moving and shaking ends up making that soil/sand behave like a liquid. If the liquefaction occurs near the surface, the soil bearing strength for buildings, roads, and other structures may be lost. Buildings can tip on their side, or in some cases sink. Roads can shift and become unstable to drive on. If the liquefied zone is buried beneath more competent material, cracks may form in the overlying material, and the water and sand from the liquefied zone can eject through the cracks as slurry. Geographical Area Affected Most Wyoming earthquakes outside of Yellowstone National Park occur as a result of movement on faults. If the fault has moved within the Quaternary geological period, or last 1.6 million years, the fault is considered to be active. Active faults can be exposed at the surface or deeply buried with no significant surface expression. Historically, no earthquakes in Wyoming have been associated with exposed active faults. The exposed active faults, however, have the potential to generate the largest earthquakes. As a result, it is necessary to understand both exposed and buried active faults in order to generate a realistic seismological characterization of the state. As shown in Figure 4-6, there are approximately 80 Quaternary faults mapped in Wyoming, with 26 considered active. ---PAGE BREAK--- Region 2 4-34 Regional Hazard Mitigation Plan 2018 Figure 4-6 Exposed Known or Suspected Active Faults in Wyoming Source: Wyoming Geological Survey - www.wsgs.wyo.gov Blue square denotes the Region 2 planning area The only known active fault in Region 2 is the Cedar Ridge-Dry Fork fault system in northern Natrona county, which is believed to be capable of generating a magnitude 6.5+ earthquake. The 35-mile long Cedar Ridge fault comprises the western portion of the fault system, and the 15-mile long Dry Fork fault makes up the eastern portion. After various assessments, the Geomatrix Corporation concluded that it is not possible to conduct a reliable deterministic analysis on the fault system; however, general estimates can be made. Although there is no compelling reason to believe that the Dry Fork fault system is currently active, if it did activate as an isolated system, it could potentially generate up to a magnitude 6.7 earthquake. Additional fault lines in Region 2 that are not confirmed as being active include the Wheatland- Whelen fault system that runs from southern Niobrara County south through Goshen and Platte Counties. The South Granite Mountains fault system south of Natrona County (across north ---PAGE BREAK--- Region 2 4-35 Regional Hazard Mitigation Plan 2018 Carbon County and running into Fremont County) is in very close proximity, and could affect said county or even the Region were it to cause an earthquake, though an area sparsely populated. Figure 4-7 shows areas in Wyoming that could experience liquefaction during an intense earthquake. Areas shown as black lines have sands and coarse silts that are less than 10,000 years in age and are within 30 feet of the surface. Region 2 does not contain any areas susceptible to liquefaction; however, there is liquefaction potential in neighboring Fremont, Hot Springs, and Washakie Counties. Overall, the geographic extent of this hazard across the Region is limited. Figure 4-7 Wyoming Liquefaction Coverage Source: Wyoming Geological Survey - www.wsgs.wyo.gov Blue square denotes Region 2 planning area Past Occurrences Prior to the 1950s, most earthquakes were detected and located by personal reports. After the Hebgen Lake earthquake in 1959 near Yellowstone Park, monitoring in Wyoming started to improve and earthquakes were more commonly located by seismometers. Since 1871, the state has logged some 47,000 earthquakes, with the majority of the events taking place in the western third of the state (see Figure 4-8) where the majority of the active, or Quaternary Period faults, are identified. ---PAGE BREAK--- Region 2 4-36 Regional Hazard Mitigation Plan 2018 Figure 4-8 Wyoming Historic Earthquake Occurrences Statewide 1963- 2010 Source: Wyoming Geological Survey - Wyoming Earthquake Hazard and Risk Analysis: HAZUS-MH Loss Estimations for 16 Earthquake Scenarios Report Blue square denotes Region 2 planning area Historically, earthquakes have occurred in every county in Wyoming, to varying magnitude and intensity degrees. The first was reported in Yellowstone National Park in 1871. Data on instrumentally recorded earthquakes is available from the USGS Earthquake Hazards Program dating back to 1973. Thirty-two earthquakes of magnitude 2.5 and greater have been recorded in the Region’s recent history (since 1889), with seven of these events taking place in Natrona County, sixteen in Converse County, and nine in Niobrara County. These earthquakes are noted in the tables below, along with discussions of notable events by county. For more details on the specific events, and previous (older) historical record of earthquakes in any of the three counties, please refer to the individual County Plans included in the annex. ---PAGE BREAK--- Region 2 4-37 Regional Hazard Mitigation Plan 2018 Converse County There have been sixteen earthquake events recorded in Converse County since 1947. Most of these events fall in the IV intensity category, ranging from a magnitude of 2.9 to 5.5. These events are presented in Table 4-19, with the most recent described further in the following text. Table 4-19 Converse County Seismic Events, 1947 – 2018 Location Date Magnitude / Intensity Damage, Injuries, Additional Information LaPrele Creek, southwest of Douglas 1947-04-14 V The earthquake was felt by everyone in a ranch house and by a few outdoors. Windows were rattled, chairs were moved, and buildings shook 7 miles north-northeast of Esterbrook 1952-04-21 IV Felt by several people in the area and was reportedly felt 40 miles to the southwest of Esterbrook 7 miles north-northeast of Esterbrook 1952-19-02 N/A Small magnitude event; no damage reported 7 miles north-northeast of Esterbrook 1957-01-05 III No damage reported 7 miles north-northeast of Esterbrook 1964-03-31 IV No damage reported About 2.5 miles northeast of Esterbrook, near Sunset Hill 1978-01-16 3.0 No damage reported About 11.5 miles northwest of Glenrock, and 6 miles east of the boundary with Natrona County 1983-11-15 3.0 No damage reported 4 miles west of Toltec in norther Albany County, 21 miles south of Esterbrook 1984-10-18 5.5 Felt in Wyoming, South Dakota, Nebraska, Colorado, Utah, Montana, and Kansas. It cracked buildings and shook items from shelves in grocery stores in Douglas. About 0.7 miles north of the boundary with Albany, on Chimney Ridge and northwest of Coverdale Basin (half a mile east of Campbell Creek) 1984-12-06 2.9 No damage reported About 11 miles northeast of Orpha, 5.7 miles west of Highway 59, and 5 miles south of Highland Loop Rd 1993-06-30 3.0 No damage reported About 3.2 miles north of the boundary with Albany County, running parallel to Old Fort Fetterman Rd (between Reed and Jackson Creeks) 1993-07-23 3.7 The event was felt as far away as Laramie Almost 9 miles southeast of Esterbrook, between Esterbrook Rd and Horseshow Creek 1993-12-13 3.2 No damage reported About 29 miles northwest of Glenrock, and 1 mile east of the boundary with Natrona County 1996-10-19 4.2 No damage reported ---PAGE BREAK--- Region 2 4-38 Regional Hazard Mitigation Plan 2018 Location Date Magnitude / Intensity Damage, Injuries, Additional Information About 7.6 miles northeast of Orpha, and 9.7 miles north of the Converse Airport 2004-02-15 3.5 n/a About 2.3 miles northeast of Orpha, and 7.5 miles northwest of the Converse Airport 2004-08-29 3.8 n/a On Bill Hall Rd. 0.4 miles west of the intersection with the train rail tracks 2008-11-03 3.5 n/a Source: http://earthquake.usgs.gov and Wyoming Geological Survey The latest earthquake in the County occurred early November of 2008, with its epicenter about 11.3 miles northeast of Douglas, 11.8 miles north of Orin, and 10.25 miles northwest of Shawnee, right on Bill Hall Rd. It had a magnitude of 3.5, and a reported depth of 5 kilometers (about 3.1 miles). The previous most recent event was a 3.8 earthquake on August 29, 2004, with the epicenter approximately 11 miles northwest of Douglas. There was no reported damage, but the earthquake was felt throughout the city and even on nearby highways. Members from the HMPC commented on this event, remarking that this quake occurred in the middle of vacant land and there was no damage reported because there were no structures or infrastructure near the epicenter. Natrona County Natrona County has record of 7 earthquakes since 1993. These earthquakes are detailed in Table 4-20, with key events described further in the following text. Table 4-20 Natrona County Seismic Events, 1993 – 2018 Location Date Magnitude / Intensity Damage or Injuries About 4 miles southwest of Devils Monument, and 11.7 miles west of Interstate 25 1993-03-10 3.2 No damage reported About 1.6 miles south of the northwest corner of the county, and 2.9 miles east of the same corner 1999-11-09 3.1 No damage reported About 5.3 miles west of the boundary with Converse County, and 12.7 miles south of the Naval Petroleum Reserve 2003-02-01 3.7 n/a About 5.6 miles west of Mile Rd, near the Big Sulfur Draw 2012-11-30 3.1 n/a 11.2 miles SSW of Midwest 2015-11-30 3.1 n/a 8.7 miles WSW of Midwest 2015-12-27 2.5 n/a 17.4 miles SSE of Mills 2016-08-22 3.2 n/a Source: http://earthquake.usgs.gov and Wyoming Geological Survey ---PAGE BREAK--- Region 2 4-39 Regional Hazard Mitigation Plan 2018 The seven earthquakes in Natrona County range from magnitudes of 2.5 to 3.7. The event of highest magnitude took place February 1, 2003, about 5.3 miles west of the boundary with Converse County, and 12.7 miles south of the Naval Petroleum Reserve. It was a 3.7 magnitude earthquake, but no damage information was available in the USGS database. In late November of 2015 another earthquake was reported, of magnitude 3.1. Its epicenter was located about 11.2 miles south-southwest of Mills. The latest took place August 22 of 2016, being a magnitude 3.2 quake. No damage details were available from the USGS database for this event, but its epicenter was found about 17.4 miles south-southeast of Mills. Four other earthquakes were reported in the County’s recent history, ranging from 1993 to 2015, and 2.5 to 3.2 in M magnitude. Niobrara County Niobrara County has experienced eleven seismic events since 1889. They are identified in Table 4-21, with key events described further in the following text. Table 4-21 Niobrara County Seismic Events, 1889 – 2018 Location Date Magnitude / Intensity Damage or Injuries Lusk, Manville, and Muskrat Canyon 1889-10-08 ? Unknown 18 miles south of Lusk 1942-02-25 V No damage reported near Guernsey, approximately 38 miles south-southwest of Lusk 1954-10-03 IV Event felt from Douglas to Wheatland, but no damage reported. Train traffic between Douglas and Wheatland temporarily halted 21 miles southeast of Lusk 1964-03-28 V No damage reported 17 miles northwest of Lusk 1964-08-22 4.5 / V Much of the town was attending a concern. When attendees felt the tremor, they thought the furnace had blown up. However, no damage was reported Few miles south of Lusk 1992-11-02 3.0 Little damage reported 26 miles northeast of Lusk 1996-04-09 3.7 Quake felt in Lusk but no damage reported. Southwestern corner of South Dakota 1996-05-03 3.1 No damage reported 19 miles outside of Lance Creek 2008-08-22 3.1 No damage reported Lusk and much of the county 2008-12 ? No damage reported 13 miles away from Van Tassell 2011-03-10 2.9 No damage reported Source: http://earthquake.usgs.gov and Wyoming Geological Survey The earthquakes on record for Niobrara ranged from intensity IV-V, with magnitudes of 2.9 to 4.5. None of the events resulted in damages or injuries. The earliest recorded earthquake in Niobrara County occurred on October 8, 1889. The event was felt in Lusk, Manville, and Muskrat Canyon and traveled in a northeasterly direction (Case, 1993). The most recent earthquake took place March 10 of 2011, about 13 miles away from Van Tassell. Its magnitude was of 2.9 M. For a more detailed history of these earthquakes in Niobrara County, please visit the County Annex. ---PAGE BREAK--- Region 2 4-40 Regional Hazard Mitigation Plan 2018 Regional Summary Table 4-22 Earthquakes Greater than 2.5 in Region 2: 1889 – 2018 County Magnitude 2.5-2.9 Intensity I Magnitude 3.0- 3.9 Intensity II-III Magnitude 4.0- 4.9 Intensity IV-V Magnitude 5.0- 5.9 Intensity VI-VII Not Rated Total Converse 1 9 4 1 1 16 Natrona 1 6 7 Niobrara 1 4 2 2 2 11 Total 3 19 6 3 3 34 Source: Analysis of data from USGS Earthquake Hazards Program and Wyoming Geological Survey Table 4-23 Top Ten Highest Magnitude* Earthquakes in Region 2: 1942 – 2018 County Magnitude/Intensity Date Converse 5.5 1984-10-18 Niobrara 4.5 / V 1964-08-22 Converse 4.2 1996-10-19 Converse 3.8 2004-08-29 Converse 3.7 1993-07-23 Natrona 3.7 2003-02-01 Niobrara 3.7 1996-04-09 Converse 3.5 2004-02-15 Converse 3.5 2008-11-03 Converse 3.2 1993-12-13 Natrona 3.2 1993-03-10 Natrona 3.2 2016-08-22 *Based on instrumentally recorded earthquakes. Source: USGS Earthquake Hazards Program and Wyoming Geological Survey Frequency/Likelihood of Occurrence With a total of 34 recorded earthquakes with a magnitude greater than 2.5 in the last 130 years, the Region is likely to experience an earthquake almost every three years; or an occasional occurrence rating. Considering past occurrences, however, the earthquakes are likely to cause little to no damage. To determine the likelihood of damaging earthquakes, the U.S. Geological Survey (USGS) publishes probabilistic ground acceleration maps for 500-, 1000-, and 2,500-year time frames. The maps show what accelerations may be met or exceeded in those time frames by expressing the probability that the accelerations will be met or exceeded in a shorter time frame. For example, a 10% probability that ground acceleration may be met or exceeded in 50 years is roughly equivalent to a 100% probability of exceedance in 500 years. The 2,500-year probability of exceedance in 50 years) map is shown in the figure below. The International Building Code uses a 2,500-year map as the basis for building design. The maps reflect current ---PAGE BREAK--- Region 2 4-41 Regional Hazard Mitigation Plan 2018 perceptions on seismicity in Wyoming based on available science. In many areas of Wyoming, ground accelerations shown on the USGS maps can be increased further due to local soil conditions. For example, if the ground/soil is fairly soft, saturated sediments are expected to be present at the surface, and seismic waves passed through them, so that surface ground accelerations will usually be greater than would be experienced if only bedrock solid ground mass/rock) was present. In this case, the ground accelerations shown on the USGS maps would underestimate the local hazard, as they are based upon accelerations that would be expected if firm soil or rock were present at the surface. As the historic record is limited, it is nearly impossible to determine when a 2,500-year event last occurred in the county. Because of the uncertainty involved and based upon the fact that the new International Building Code utilizes 2,500-year events for building design, it is suggested that the 2,500-year probabilistic maps be used for regional and county analyses. This conservative approach is in the interest of public safety. Figure 4-9 2,500-year Probabilistic Acceleration Map Probability of Exceedance in 50 years) Source: Wyoming Geological Survey Purple square denotes Region 2 planning area ---PAGE BREAK--- Region 2 4-42 Regional Hazard Mitigation Plan 2018 Potential Magnitude Very limited damages have been documented in the Region from historic earthquakes. Because of the limited historic record, however, it is possible to underestimate the seismic hazard in the Region if historic/reported earthquakes are used as the sole basis for analysis. Earthquake and ground motion probability maps give a more reasonable estimate of damage potential in areas with or without exposed active faults at the surface. Current earthquake probability maps that are used in the newest building codes suggest a scenario that would result in moderate damage to buildings and their contents, with ground shaking potential higher in Natrona and Converse counties. Overall, however, the potential magnitude/severity of earthquakes to the Region could be critical. Vulnerability Assessment The Wyoming State Geological Survey conducted a study in 2011 to model loss estimations for 16 earthquake scenarios, in order to quantify the magnitude of earthquake impacts around the state. The scenarios included four random event scenarios run on the basis of data from historic earthquakes that occurred near Casper, Gillette, Laramie Peak, and Estes Park, Colorado. Each of the historic, random event earthquake scenarios registered a 6.0 magnitude. The Estes Park Scenario was based on an event occurring in 1882, the Casper area event in 1897, and the Gillette and Laramie Peak events in 1984 (Source: Wyoming Geological Survey, “Wyoming Earthquake Hazard and Risk Analysis: HAZUS-MH Loss Estimations for 16 Earthquake Scenarios, 2011). HAZUS (Hazards U.S.) is a nationally standardized, GIS-based risk assessment and loss estimation computer program that was originally designed in 1997 to provide the user with an estimate of the type, extent, and cost of damages and losses that may occur during and following an earthquake. It was developed for FEMA by the National Institute of Building Sciences (NIBS). There have been a number of versions of HAZUS generated by FEMA since then, with HAZUS- MH 4.2 (HAZUS Multi-Hazard version 4.2) being the most recent release. The study included information regarding the likelihood of damage to local and regional infrastructure, including fire stations, police stations, sheriffs’ departments, schools, and hospitals. The scenarios reflect anticipated functionality of each infrastructure system immediately following the scenario earthquake, on day seven following the earthquake as well as one month after the earthquake. Additional information provided includes anticipated households displaced or seeking temporary shelter, electrical outages predicted, number of households without potable water, debris generated by the scenario, and economic losses resulting from three categories: buildings, transportation, and utilities. The map in Figure 4-10 shows epicenter locations of the scenarios, sized by total loss. Epicenters on the map are labeled with their total loss and, if applicable, life-threatening injuries and fatalities. ---PAGE BREAK--- Region 2 4-43 Regional Hazard Mitigation Plan 2018 Figure 4-10 AZUS-MH Earthquake Scenarios for Wyoming, 2011 (Source: Wyoming Multi-Hazard Mitigation Plan, 2014) Note that a more focused Hazus Earthquake model was run specifically for Converse County, and is included in the recent Converse County Hazard Mitigation Plan attached in the county annexes. In addition, more information on general earthquake vulnerability, potential losses estimated by the Wyoming State Geological Survey, and Hazus derived results can also be found in the respective County Plans (included in the annexes) as well as in the Wyoming State Hazard Mitigation Plan from 2016. Casper Area Historic Random Earthquake Event Scenario The Casper Area “random event” scenario, which was based on a repeat of the November 14th, 1897 earthquake, had the most impact on the counties in Region 2, with significant effects felt in Natrona and Converse Counties. The earthquake scenario was modeled at magnitude 6.0. Scenario results estimate a total economic loss of $564.11 million dollars in the Region. $545.38M of the loss was in building losses and 8 casualties. The regional direct economic loss for utilities would be 15.302 million dollars. Natrona County would expect the highest losses at $15.137 million dollars. The losses reflect damage to potable water, waste water, and natural gas pipelines; ---PAGE BREAK--- Region 2 4-44 Regional Hazard Mitigation Plan 2018 as well as losses to waste water, oil system, natural gas, electrical power, and communication facilities. The scenario results show that 7,832 of those would sustain at least moderate damage from the earthquake. The earthquake would generate 266,000 tons of debris. Schools in the Casper area, with the exception of Red Creek Elementary, would be between 29-72% functional the day of the earthquake, with those closest to the epicenter having the lowest functionality. The schools would be between 44-93% functional on day 7 and over 74% functional on day 30. Fault Based Scenario – South Granite Mountains System Of the 16 fault-based scenarios modeled by the Wyoming Geological Survey, the South Granite Mountains fault system had the most impact on the region, primarily affecting Natrona County. The earthquake scenario was modeled at magnitude 6.75. The earthquake would also cause damage in Carbon, Fremont, and Sweetwater Counties, though. Scenario results estimate that very light damage would be expected up to 45 miles from the epicenter. Light damage would be expected as far as 30 miles, including the town of Alcova. The total population in the scenario region is 16,732 based on the 2000 census. In this assessment, only 3 households would be displaced, and one person would seek temporary shelter. There are 12,197 buildings in the area, and scenario results show that 437 of those would sustain at least moderate damage from the earthquake. The earthquake would generate 6,000 tons of debris. The modeled earthquake would cause a total economic loss of $22.387 million dollars for the region. Direct economic losses are estimated in three categories: buildings, transportation, and utilities. Buildings Direct economic losses for buildings, which include structural and content damage, would total $14.245 million dollars for the South Granite Mountains fault region. Natrona County is modeled to have $2.992 million dollars in direct economic losses for buildings. Transportation Direct transportation losses for the region are expected to be $1.145 million dollars. Natrona County would be expected to see $144,000 in damage to bridges and airports. Utilities The South Granite Mountains fault regional direct economic loss for utilities would be $6.997 million dollars. Natrona County’s losses are predicted to be $586,000 from damage to wastewater and natural gas pipelines and facilities, as well as electrical facilities. Essential Facilities Essential facilities include fire stations, hospitals, police stations, and schools. Several details on the estimated impacts to these facilities can be referenced in the WYGS report. As a general consensus, damage to essential facilities in Natrona is projected to be minimal to non-existent. ---PAGE BREAK--- Region 2 4-45 Regional Hazard Mitigation Plan 2018 Probabilistic Scenario In the Wyoming Multi-Hazard Mitigation Plan, HAZUS 2.1 was used to develop losses associated with a 2,500-year probabilistic earthquake scenarios for each county in the State of Wyoming. This scenario uses USGS probabilistic seismic contour maps to model ground shaking with a 2% probability of being exceeded in 50 years (or a 2,500-year event). Total losses include building, contents, inventory, and income-related losses. The following table lists total loss, loss ratio (total loss/total building inventory value), and ranges of casualties within severity levels. HAZUS provides casualty estimates for 2 am, 2 pm, and 5 pm to represent periods of the day that different sectors of the community are at their peak occupancy loads. The casualty ranges represent the lowest to highest casualties within these times of day. Casualty severity levels are described as follows: • Level 1: Injuries will require medical attention but hospitalization is not needed • Level 2: Injuries will require hospitalization but are not considered life-threatening • Level 3: Injuries will require hospitalization and can become life-threatening if not treated • Level 4: Victims are killed by the earthquake The table is sorted and ranked by total loss, with the Region 2 counties highlighted in light orange. There are two methods for ranking counties to determine where earthquake impacts may be the greatest. Either loss ratios or total damage figures can be used. The loss ratio is determined by dividing the sum of the structural and non-structural damage by the total building value for the county. The loss ratio is a better measure of impact for a county, since it gives an indication of the percent of damage to buildings. ---PAGE BREAK--- Region 2 4-46 Regional Hazard Mitigation Plan 2018 Table 4-24 2500-Year Probabilistic Scenario Loss Estimates Rank County Total Loss Loss Ratio Casualties Level 1 Casualties Level 2 Casualties Level 3 Casualties Level 4 1 Teton $654 27% 150-300 40-90 0-20 10-30 2 Lincoln $528 63% 190-220 50-60 0-20 10-20 3 Natrona $268 11% 50-60 10 0 0 4 Uinta $247 18% 90-120 20-30 0-10 0-10 5 Sweetwater $181 19% 50 10 0 0 6 Fremont $115 25% 20 0 0 0 7 Laramie $105 4% 20 0 0 0 8 Sheridan $84 9% 20 0 0 0 9 Albany $81 21% 20 0 0 0 10 Campbell $79 14% 20 0 0 0 11 Park $79 1% 20 0 0 0 12 Sublette $74 6% 20 0-10 0 0 13 Carbon $64 1% 10 0 0 0 14 Converse $50 28% 10 0 0 0 15 Washakie $28 1% 10 0 0 0 16 Big Horn $26 4% 0-10 0 0 0 17 Johnson $25 1% 0-10 0 0 0 18 Platte $20 3% 0 0 0 0 19 Hot Springs $20 1% 0 0 0 0 20 Goshen $11 1% 0 0 0 0 21 Weston $7 0% 0 0 0 0 22 Crook $5 1% 0 0 0 0 23 Niobrara $4 1% 0 0 0 0 Total $2,755 Source: Wyoming State Hazard Mitigation Plan 2016 The total damage figure by itself does not reflect the percentage of building damage, since small damage to a number of valuable buildings may result in a higher total damage figure than may be found in a county with fewer, less expensive buildings with a higher percentage of damage. Liquefaction Vulnerability There have been little, if any, reported damages from liquefaction in Wyoming. Given that ground motions associated with Intensity VIII or larger are usually needed to trigger liquefaction, and that only small areas of the region would experience that level of shaking during the 2% event ---PAGE BREAK--- Region 2 4-47 Regional Hazard Mitigation Plan 2018 probability of exceedance in 50 years), liquefaction would be a rare occurrence in the Region. The 2016 Wyoming State Hazard Mitigation Plan notes that all three counties in the region have $0 in exposure to liquefaction. Future Development Future development in the Region is not anticipated to change vulnerability to earthquake hazards significantly. Summary Due to the Cedar Ridge-Dry active fault in the region and the South Granite Mountains system just south of Natrona County, as well as previous occurrence data, there is an indication for potential for damaging seismic activity in the Region. Within Region 2, the two counties that have the highest level of susceptibility and exposure are Natrona and Converse, respectively. In addition, and although the probability is low, WSGS studies indicate the possibility that a 6.5 magnitude could occur anywhere in the state. For more details on each county’s earthquake studies and the state-wide assessment performed by the WSGS, refer to individual county annexes or the 2016 Wyoming State Hazard Mitigation Plan. Table 4-25 Earthquake Hazard Risk Summary 4.2.5 Expansive Soils Hazard/Problem Description Expansive soils contain clay which causes the material to increase in volume when exposed to moisture and shrink as it dries. They are also commonly known as expansive, shrinking and swelling, bentonitic, heaving, or unstable soils. The clay materials in swelling soils are capable of absorbing large quantities of water and expanding 10% or more as the clay becomes wet. The force of expansion is capable of exerting pressures of 15,000 pounds per square foot or greater on foundations, slabs, and other confining structures. (Ibid., p 17.) The amount of swelling (or potential volume of expansion) is linked to five main factors: the type of mineral content, the concentration of swelling clay, the density of the materials, moisture changes in the environment, and the restraining pressure exerted by materials on top of the swelling soil. Each of these factors impact how much swelling a particular area will experience, but may be modified, for better or worse, by development actions in the area. County Geographic Extent Probability of Future Occurrence Potential Magnitude/ Severity Overall Significance Converse Limited Occasional Critical Medium Natrona Significant Occasional Critical High Niobrara Limited Occasional Limited Low ---PAGE BREAK--- Region 2 4-48 Regional Hazard Mitigation Plan 2018 • Low—this soils class includes sands and silts with relatively low amounts of clay minerals. Sandy clays may also have low expansion potential, if the clay is kaolinite. Kaolinite is a common clay mineral. • Moderate—this class includes silty clay and clay textured soils, if the clay is kaolinite, and also includes heavy silts, light sandy clays, and silty clays with mixed clay minerals. • High—this class includes clays and clay with mixed montmorillonite, a clay mineral which expands and contracts more than kaolinite. Geographical Area Affected Expansive soils occur throughout the Region. Figure 4-11 and Figure 4-12 illustrate possible expansive soils locations in Wyoming. Figure 4-12is based on select geologic formations that have characteristics that could lead to expansive soils where they outcrop. The reported that the U.S. Bureau of Land Management is working with the Wyoming Department of Transportation (DOT) to update expansive soils mapping. ---PAGE BREAK--- Region 2 4-49 Regional Hazard Mitigation Plan 2018 Figure 4-11 Expansive Soil Potential in Region 2 ---PAGE BREAK--- Region 2 4-50 Regional Hazard Mitigation Plan 2018 Figure 4-12 Wyoming Mapped Formations with Potential for Expansive Soils Source: State of Wyoming Multi-Hazard Mitigation Plan 2016 Table 4-26 Percentage of Land Area Estimated to be Susceptible to Expansive Soils County % Expansive Soils based on Total Area Converse 1.2% Natrona 29.5% Niobrara 2.0% Region 2 13.5% Data Source: WY Geospatial Hub Based on the figures above, expansive soils have the potential to affect a limited portion of the planning area. Note however that there is a significant variation between counties. The geographic extent of any individual expansive soil incident is likely to be extremely localized. Past Occurrences Very little data exists on expansive soil problems and damages in Wyoming. Studies on the issue have not been performed and no database exists to catalog occurrences. The 2016 State of Wyoming Multi-Hazard Mitigation Plan states “Although there have been instances in the Casper area where foundations and other concrete work have fractured and been displaced, historical accounts of actual damaging events caused by expansive soils have been difficult to locate.” Damages due to expansive soils such as foundation cracks, parking lot/sidewalk cracks, etc. do ---PAGE BREAK--- Region 2 4-51 Regional Hazard Mitigation Plan 2018 occur but are generally handled by individual property owners. Other damages to supply lines, roads, railways, bridges and power lines typically occur over time and are not attributed to or reported as an event. Frequency/Likelihood of Occurrence Historical data on expansive soils issues was not readily available, making frequency difficult to extrapolate. Based on HMPC discussions, expansive soils are likely to continue to be an occasional problem for the jurisdictions in Region 2. Potential Magnitude The potential magnitude of expansive soils events and damages is estimated to be negligible for the counties in the Region, with limited and isolated impacts. Because damages from expansive soils are difficult to track due to limited reporting, it is difficult to estimate the potential severity of a problem. Expansive soils can create localized damage to individual structures and supply lines, such as roads, railways, bridges and power lines, but no significant impacts have been reported. Vulnerability Assessment According to the Wyoming State Multi-Hazard Mitigation Plan there are two measurements used for calculating potential impacts: historic dollar damages and building exposure values. There is not enough current data to accurately estimate historic damages. The Wyoming State Geological Survey (WSGS) calculated the building exposure values for buildings that may occur within the areas of expansive soils. All expansive soils mapped have been digitized and the expansive soil layer was then digitally crossed with the Census block building values. In the event of an expansive soil boundary dissecting a census block, the proportional value of the buildings in the census block will be assigned to the expansive soil. In a case where a census block is within an expansive soil, the combined values of all the buildings in the census block are assigned. The values for each county are shown in the map below. ---PAGE BREAK--- Region 2 4-52 Regional Hazard Mitigation Plan 2018 Figure 4-13 Wyoming Building Exposure to Shrinking-Swelling Clays Source: Wyoming State Hazard Mitigation Plan 2016 These values represent exposure and the potential for damage, not a true loss estimate. Natrona County is the highest in the state ($1.1B) for value of buildings at risk due to expansive soils. The risk in Converse and Niobrara Counties is several orders of magnitude lower at $54,641 and $148,248 respectively. Critical facilities within expansive soils areas include emergency response facilities (police, fire, EMS, etc.), infrastructure nodes (transmission towers, electric substations, refineries), and community resources (schools, nursing homes, daycare facilities). Damage from these soils will be individual events, which will cause damage to a small number of buildings or road segments over time. Table 4-27 Critical Facilities Vulnerable to Mapped Expansive Soil Hazards County Jurisdiction Critical Facility Type Facility Count Converse Unincorporated Bridge 4 Converse County Total 4 County Jurisdiction Critical Facility Type Facility Count Natrona Bar Nunn Day Cares 3 EPA FRS Location 1 Fire Department 1 National Shelter System Facility 2 School 1 Total 8 ---PAGE BREAK--- Region 2 4-53 Regional Hazard Mitigation Plan 2018 County Jurisdiction Critical Facility Type Facility Count Casper Air Facility 1 Assisted Living 7 Bridge 3 College/University 1 Community Support 16 Day Cares 74 EPA FRS Location 102 Fire Department 4 Hospital 1 Law Enforcement 1 Medical Facility 1 National Shelter System Facility 25 Nursing Home 7 Private School 3 School 21 Special Medical Facility 27 Tier II 4 Urgent Care Facility 2 Total 300 Edgerton Community Support 1 Total 1 Evansville Day Cares 2 Total 2 Midwest Fire Department 1 Law Enforcement 1 National Shelter System Facility 1 School 1 Total 4 Mills Day Cares 4 EPA FRS Location 10 EPA Regulated Facility 3 Law Enforcement 1 Tier II 8 Total 26 Unincorporated Air Facility 2 Bridge 46 Day Cares 4 Electrical Facility 1 EPA FRS Location 158 EPA Regulated Facility 6 Fire Department 1 Law Enforcement 2 National Shelter System Facility 2 Non-Union Communications 6 School 2 Substation 7 Tier II 24 Union Communications 5 Total 266 Natrona County Total 607 County Jurisdiction Critical Facility Type Facility Count Niobrara NA None 0 Region Total = 611 Source: Homeland Infrastructure Foundation-Level Data (HIFLD) ---PAGE BREAK--- Region 2 4-54 Regional Hazard Mitigation Plan 2018 Future Development Modern building practices incorporate mitigation techniques, provided proper geotechnical testing is employed to identify expansive soils. If areas prone to expansive soils are identified, future areas for development will need to take this hazard into account. Summary While there are areas of potential risk from expansive soils identified in the county, expansive soils are a low significance hazard for the counties in the region overall. Table 4-28 Expansive Soil Hazard Risk Summary County Geographic Extent Probability of Future Occurrence Potential Magnitude/ Severity Overall Significance Converse Negligible Likely Negligible Low Natrona Negligible Likely Negligible Low Niobrara Significant Likely Negligible Low 4.2.6 Flood Hazard/Problem Description Floods can and have caused significant damage in Region 2, and are one of the more significant natural hazards in the Region. Certain flood events have even caused millions of dollars in damage in just a few hours or days. A flood, as defined by the National Flood Insurance Program, is a general and temporary condition of partial or complete inundation of two or more acres of normally dry land area, or of two or more properties from: overflow of waters; unusual and rapid accumulation or runoff of surface waters from any source; or, a mudflow. Floods can be slow or fast rising, but generally develop over a period of hours or days. Causes of flooding relevant to the Region include: • Rain in a general storm system • Rain in a localized intense thunderstorm • Melting snow • Rain or melting snow • Urban stormwater drainage • Ice Jams • Dam failure • Levee Failure • Rain on fire damaged watersheds ---PAGE BREAK--- Region 2 4-55 Regional Hazard Mitigation Plan 2018 The area adjacent to a river channel is its floodplain. In its common usage, “floodplain” most often refers to any area that is inundated by the 100-year flood, or a flood that has a 1% chance in any given year of being equaled or exceeded. The 100-year flood is the national standard to which communities regulate their floodplains through the National Flood Insurance Program. Region 2 is susceptible to multiple types of floods including riverine flooding, flash floods, slow rise floods, ice jams, and possibly dam or levee failure. Riverine flooding occurs when a watercourse exceeds its “bank-full” capacity; this is usually the most common type of flood event. Riverine flooding generally occurs as a result of prolonged rainfall, or rainfall that is combined with soils already saturated from previous rain events. Slow rise floods associated with snowmelt and sustained precipitation usually are preceded with adequate warning, though the event can last several days. Floods can also occur with little or no warning and can reach full peak in only a few minutes. Such floods are called flash floods. A flash flood usually results from intense storms dropping large amounts of rain within a brief period. Flash floods, by their nature, occur very suddenly but usually dissipate within hours. Even flash floods are usually preceded with warning from the National Weather Service, in terms of flash flood advisories, watches, and warnings. Floods can occur for reasons other than precipitation or rapidly melting snow. They can also occur because of ice jams. An ice jam is a stationary accumulation of ice that restricts flow. Ice jams can cause considerable increases in upstream water levels, while at the same time water levels may drop. Types of ice jams include freeze up jams, breakup jams, or combinations of both. Floods arising from these types of ice jams can be slow or fast rising, but generally develop over a period of many hours or days. Levee failure can also cause a flash flood and poses a risk in the region. A levee is an earthen embankment constructed along the banks of rivers, canals, and coastlines to protect adjacent lands from flooding by reinforcing the banks. By confining the flow, levees can also increase the speed of the water, however. Levees can be natural or man-made. A natural levee is formed when sediment settles on the river bank, raising the level of the land around the river. To construct a man-made levee, workers pile dirt or concrete along the river banks, creating an embankment. This embankment is flat at the top, and slopes at an angle down to the water. For added strength, sandbags are sometimes placed over dirt embankments. Natural disasters such as Hurricane Katrina demonstrate that, although levees can provide strong flood protection, they are not failsafe. Levees can reduce the risk to individuals and structures behind them, but they do not eliminate risk entirely. Levees are designed to protect against a specific flood level; severe weather could create a higher flood level that the levee cannot withstand. Levees can fail by either overtopping or breaching. Overtopping occurs when floodwaters exceed the height of a levee and flow over its crown. As the water passes over the top, it may erode the levee, worsening the flooding and potentially causing an opening, or breach, in the levee. A levee breach occurs when part of a levee gives way, creating an opening through which floodwaters may pass. A breach may occur ---PAGE BREAK--- Region 2 4-56 Regional Hazard Mitigation Plan 2018 gradually or suddenly. The most dangerous breaches happen quickly during periods of high water. The resulting torrent can quickly swamp a large area behind the failed levee with little or no warning. Unfortunately, in the rare occurrence when a levee system fails or is overtopped, severe flooding can occur due to increased elevation differences associated with levees and the increased water velocity that is created. It is also important to remember that no levee provides protection from events for which it was not designed, and proper operation and maintenance are necessary to reduce the probability of failure. The potential for flooding can also change and increase through various land use changes and changes to land surface. A change in the built environment can create localized flooding problems inside and outside of natural floodplains, by altering or confining watersheds or natural drainage channels. These changes are commonly created by human activities. Flooding in the communities in Region 2 could be exacerbated by inadequate drainage and channel systems that would not stand up to the 1% annual chance flood. Inadequate culverts and drainage systems can flood and adjacent properties. Refer to the specific county annexes for a description of localized problems. Increased flooding can also be created by other hazards such as wildfires. Wildfires create hydrophobic soils, a hardening or “glazing” of the earth’s surface that prevents rainfall from being absorbed into the ground; this effect increases runoff, erosion, and sedimentation of channels. Geographical Area Affected All counties within the planning region have the potential for flooding. The extent of the flooding varies based on the location of the county, and on what part of the county is being examined. Detailed geographic flood assessments are provided in each attached county annex. The counties of Region 2 are predominantly located in the North Platte, Cheyenne, and Powder- Tongue River Basins. However, the northwest corner of Natrona County crosses onto the Big Horn Basin, while the southeast portion of Niobrara County falls within the Niobrara Basin. The part of the North Platte River Basin in the region encompasses the North Platte River, Casper Creeks, Box Elder Creek, Dry Creek, and the Sweetwater River, among other smaller streams. The Cheyenne River Basin contains the Cheyenne River primarily, which crosses Niobrara on the northeast portion of the county. Finally, the Powder-Tongue Basin area in the region contains primarily the South Fork Powder River, Cottonwood Creek, Salt Creek, Castle Creek, and Wallace Creek, among others. The North Platte River is over 700 miles in length. It is a tributary of the Platte River, and originates in Jackson County, Colorado. From northern Colorado it flows up through Carbon County in Wyoming, entering the Region via the south of Natrona County. It then moves northeast through to Converse County, making its way south again and out of the state just south of Torrington, Goshen County. ---PAGE BREAK--- Region 2 4-57 Regional Hazard Mitigation Plan 2018 The Cheyenne River originates north of the Region, on the edge of Converse County. The river flows east to South Dakota, and north onto the Missouri River. The Cheyenne River is approximately 295 miles long, and drains over 24 thousand square miles into the basin named after it. The river has some major tributaries including Dry Fork Creek and Antelope Creek. From Converse it flows through Niobrara before leaving the state. The South Fork Powder River is a major tributary of the Powder River, which feeds to its main vein just north of north-central Natrona County. The South Fork, along with the other two Powder River forks (North and Middle Forks), meet on the foothills east of the Bighorn Mountains, which then join the larger Yellowstone River in Montana. The Powder River is about 375 miles long. The geographic extent rating for Region 2 ranges from limited to significant, meaning that a flood event could impact 10-50% of the planning area due the presence of major rivers/streams across the three counties. The following sections detail the extent and history of flood hazards in the Region. Figure 4-14 below shows the Region 2 Flood Hazards, highlighting both the available Digital Flood Insurance Rate Maps (DFIRM) layers from FEMA, for parts of Converse and Natrona, as well as Hazus-derived flooding area estimates (portrayed in purple) to supplement those provided by the federal agency. Both DFIRM and Hazus derived datasets are utilized in the maps to follow, as only limited parts of the region contain updated flooding study information. ---PAGE BREAK--- Region 2 4-58 Regional Hazard Mitigation Plan 2018 Figure 4-14 Region 2 Flood Hazards ---PAGE BREAK--- Region 2 4-59 Regional Hazard Mitigation Plan 2018 Past Occurrences A brief history of significant floods is presented below by county, while a more extensive summary is included in the county annexes. A damaging flood occurs in the area every year or two on average, based upon the historical data presented below. Table 4-29 Flood Events in Converse County, 1941-2017 Location Date Property Damage Crop Damage 7/27/1941 Esterbrook 6/26/1952 Esterbrook 7/24/1955 Douglas, Antelope, East Antelope 01/00/1962 Glenrock, Deer Creek 5/14/1965 $175,000 Bill 6/16/1965 $2,250 Glenrock, Deer Creek 6/12/1970 $1,000,000 5/1/1978 Laramie Range drainage, eastward southwest of Douglas near LaPrele Reservoir 7/22/1983 Glenrock 8/1/1984 $2,250 5/1/1991 50 NW Douglas to 30 N Douglas 7/1/1998 $2,000 7/1/2008 Douglas 7/12/2009 6/1/2010 8/9/2013 5/7/2016 TOTAL $1,181,500 $0 Source: NCEI Table 4-30 Flood Events in Natrona County, 1895-2017 Location Date Property Damage Crop Damage Casper, Garden Creek 07/00/1895 Casper, North Platte River 3/1/1906 Big Horn River, Powder River, North Platte River, North Platte River tributaries near Casper 9/27/1923 North Platte River, near Glendo 5/1/1935 Southeast, Central Wyoming 9/1/1938 Casper and vicinity 7/6/1961 $225,000 Big Horn, North Platte, and Tongue Rivers, Beaver Creek 2/00/1962 Casper 30 NW 6/15/1962 $225,000 Glendo 6/1/1965 Casper 7/15/1967 $1,000,000 Casper 7/16/1968 $22,500 West of Casper 7/6/1971 Casper 6/23/1974 $225,000 Casper 6/19/1986 $2,250,000 ---PAGE BREAK--- Region 2 4-60 Regional Hazard Mitigation Plan 2018 Location Date Property Damage Crop Damage Casper 5/8/1995 1/29/1996 $2,000 $0 3/13/1996 $0 $0 Midwest 5/29/2001 $0 $0 Midwest 5/29/2001 $0 $0 Midwest 5/29/2001 $0 $0 9 SW Casper 6/16/2003 10 W Casper 7/13/2004 Casper 7/25/2005 $500,000 Casper 8/3/2005 $85,000 MILLS 7/19/2007 $50,000 $0 GOOSE EGG 7/19/2007 $5,000 $0 MILLS 7/25/2007 $300,000 $0 (CPR)NATRONA CO ARPT 8/2/2007 $500,000 $0 CASPER 8/3/2007 $50,000 $0 CASPER 8/3/2007 $15,000 $0 CASPER 6/13/2009 $2,000 $0 MOUNTAIN VIEW 7/3/2009 $5,000,000 $0 BROOKHURST 7/29/2013 $200,000 $0 BADWATER 8/9/2013 $17,000 $0 BISHOP 8/9/2013 $0 $0 ARMINTO 8/5/2014 $200,000 $0 SALT CREEK COLUMBINE 5/24/2015 $100,000 $0 BAR NUNN 5/24/2015 $0 $0 (CPR)NATRONA CO ARPT 6/5/2015 $0 $0 ARMINTO 10/2/2015 $40,000 $0 RED BUTTES VILLAGE 6/5/2017 $0 $0 TOTAL $11,013,500 $0 Source: NCEI Table 4-31 NCEI Flood Events in Niobrara County, 1938-2018 Location Date Property Damage Crop Damage Cheyenne River 6/1/1938 6/7/1945 4 miles north of old Whitman Post Office 8/10/1955 South of Lusk 6/11/1960 $2,250 $2,250 Lusk and county-wide 6/1/1962 County wide 7/1/1973 state wide 5/1/1978 Lusk 7/1/1980 Niobrara River Spring 1990 Niobrara River Spring 1991 County wide 5/7/1995 Redbird 8/6/2006 $40,000 County wide Spring 2008 Keeline, Lusk 9/29/2014 WEST LANCE CREEK 5/26/2015 KEELINE 6/3/2015 VAN TASSELL 6/4/2015 $1,500,000 ---PAGE BREAK--- Region 2 4-61 Regional Hazard Mitigation Plan 2018 Location Date Property Damage Crop Damage TOTAL $1,542,250 $2,250 Source: NCEI Figure 4-15 and Figure 4-16 were created by Western Water Assessment based on their analysis of NCEI data; they show the number of flood and flash flood events in Wyoming per county from 1996-2017. Figure 4-15 Flood Events in Wyoming, 1996-2017 ---PAGE BREAK--- Region 2 4-62 Regional Hazard Mitigation Plan 2018 Figure 4-16 Flash Flood Events in Wyoming, 1996-2017 Converse County The principal flooding sources in the county are heavy rains and rapid snowmelt, which turn into flash flooding often in a matter of just hours. River flooding is also common, particularly overflowing of the North Platte River and major tributaries in the county Deer Creek, Sand Creek, Box Elder Creek). The largest USGS gage-recorded flood took place on the North Platte River, May 15, 1965, with around 16,000 cubic feet per second (cfs) of flow eight miles down of Glenrock and 23,800 cfs near Orin. A following flood, just a month after the May event, took place near Bill, reportedly taking one life in its path, though details on the incident are not available. One of the financially costliest flood event in the history of Converse County then occurred June 12 of 1970, when high flows occurred in the North Platte River again and caused about $1,000,000 in property damages near Glenrock and Deer Creek areas. Another notable flood event in Converse County was in May of 1978, when a severe thunderstorm produced up to 4.5 inches of rain overnight. Bridges and sections of roads were washed out, power lines were downed, and there was extensive damage to homes, property, crops, and livestock. Damages throughout the entire flooded area, including outside counties, were estimated at approximately $15.5 million (information from Converse County). ---PAGE BREAK--- Region 2 4-63 Regional Hazard Mitigation Plan 2018 Other floods that resulted in property damages include a Glenrock/Deer Creek area flood in May 14, 1965, accruing $175,000 in losses; a flood near Bill on June 16, 1965, costing $2,250; a flood of the same cost but taking place near Glenrock August of 1984; and an early July 1998 flood, causing $2,000 in damages. The most recent reported flood in the county happened May 7th of 2016 but did not incur any property or crop damages. Figure 4-17 though Figure 4-21 are maps of FEMA and HAZUS designated floodplains in Converse County, overlaid by the parcels/infrastructure at risk of flooding (displayed as yellow or red dots, depending on the type of floodplain they intersect), if applicable. Converse County is shown first with flooding only, then its jurisdictions with the parcels/structures on top (if present). ---PAGE BREAK--- Region 2 4-64 Regional Hazard Mitigation Plan 2018 Figure 4-17 Converse County Flood Hazards ---PAGE BREAK--- Region 2 4-65 Regional Hazard Mitigation Plan 2018 Figure 4-18 Douglas Flood Hazards and Parcels/Structures at Risk ---PAGE BREAK--- Region 2 4-66 Regional Hazard Mitigation Plan 2018 Figure 4-19 Glenrock Flood Hazards and Parcels/Structures at Risk ---PAGE BREAK--- Region 2 4-67 Regional Hazard Mitigation Plan 2018 Figure 4-20 Lost Springs Flood Hazards ---PAGE BREAK--- Region 2 4-68 Regional Hazard Mitigation Plan 2018 Figure 4-21 Rolling Hills Flood Hazards ---PAGE BREAK--- Region 2 4-69 Regional Hazard Mitigation Plan 2018 Natrona County Natrona County has suffered a total of $11,013,500 in property losses since the first recorded flood event, which took place in 1895. A major flood took place around mid-June of 1986, causing $2,250,000 in property damages. Smaller storms leading to flood also occurred in the mid-1990s. Some notable floods have occurred in the last 18 or so years, however. For example, a July 2005 flash flood which originated as strong thunderstorms from the Bighorn Mountains hit Casper, shutting down portions of Interstate 25 and blocking areas around the city, ultimately causing damages to storage sheds and other properties (incurring $500,000 in damages). Another storm in August of the same year also caused heavy rainfall, leading to flash flooding. Basement flooding occurred in many houses in Casper, causing sinkholes as well. Property damages totaled $85,000. In July of 2007, Strong and severe thunderstorms spread south along the eastern slopes of the Bighorn Mountains. These storms produced long periods of hail and very heavy rain. Additional thunderstorms brought heavy rain to areas west and southwest of Casper, including the area near the Jackson Canyon fire burn scar. Property damage reached $105K. Later in the month, copious moisture was brought north into Wyoming in strong monsoonal flow. Rainfall estimated by radar to be three inches or more fell in a swath from Emigrant Gap to Bar Nunn. The heavy rain caused flash flooding along Poison Spider Road and other nearby roads as culverts could not handle the large volume of water. Portions of a ranch along Poison Spider Road were under several feet of water. A mobile home park south of Bar Nunn was flooded as water flowed from surrounding higher terrain. The lower floor of the rural Poison Spider Elementary School sustained flood damage as the water poured in through several doorways. Damages incurred were $585,000. Several storms in August were of similar nature, causing inundation in rural and urban areas alike. Natrona County International Airport was affected, as were portions of Interstate highways and personal properties. Overall, around $65,000 in damages were incurred. The summer of 2009 brought about notable storms that caused flooding as well, both flash- and river-based. Damages were caused near Mountain View and Casper in July of that year, totaling $5,200,000. From 2013 onward, there are nine reported flood events across the county, often causing property damages that range from $40,000 to $200,000. The latest recorded event took place near Red Buttes Village in June 5, 2017, but no damages were reported. Figure 4-22 through Figure 4-27 are maps of FEMA and HAZUS designated floodplains in Natrona County, overlaid by the parcels/infrastructure at risk of flooding (displayed as yellow or red dots, depending on the type of floodplain they intersect), if applicable. Natrona County is shown first with flooding only, then its jurisdictions with the parcels/structures on top (if present). ---PAGE BREAK--- Region 2 4-70 Regional Hazard Mitigation Plan 2018 Figure 4-22 Natrona County Flood Hazards ---PAGE BREAK--- Region 2 4-71 Regional Hazard Mitigation Plan 2018 Figure 4-23 Bar Nunn Flood Hazards and Parcels/Structures at Risk ---PAGE BREAK--- Region 2 4-72 Regional Hazard Mitigation Plan 2018 Figure 4-24 Casper Flood Hazards and Parcels/Structures at Risk ---PAGE BREAK--- Region 2 4-73 Regional Hazard Mitigation Plan 2018 Figure 4-25 Evansville Flood Hazards and Parcels/Structures at Risk ---PAGE BREAK--- Region 2 4-74 Regional Hazard Mitigation Plan 2018 Figure 4-26 Midwest and Edgerton Flood Hazards ---PAGE BREAK--- Region 2 4-75 Regional Hazard Mitigation Plan 2018 Figure 4-27 Mills Flood Hazards and Parcels/Structures at Risk ---PAGE BREAK--- Region 2 4-76 Regional Hazard Mitigation Plan 2018 Niobrara County Niobrara County has experienced multiple flooding events dating back to 1938. While not all have incurred property damages, many have. For example, an earlier flood on June 11, 1960 accrued a recorded $2,250 in damages, and another $2,250 in recorded crop losses (the highest crop damages incurred to date in Niobrara County). A more recent event took place on June 4, 2015 and involved flash flooding of homes, businesses and a highway bridge in Lusk and surrounding areas, becoming the flood of record in the county due to high losses. Heavy rain of six inches sent the Niobrara River over its banks. The Niobrara County Emergency Management Coordinator reported that water covered approximately four city blocks and knocked out the town's drinking water system, resulting in a boil order from the Environmental Protection Agency (EPA). In addition to damaging and forcing closedowns on highways and roads, towns lost power, homes destroyed, and businesses received heavily damages, leading to both Governor and Presidential Disaster Declarations in early July. Overall, this flood caused around $1,500,000 in property damages. Figure 4-28 through Figure 4-31 are maps of FEMA and HAZUS designated floodplains in Niobrara County, overlaid by the parcels/infrastructure at risk of flooding (displayed as yellow or red dots, depending on the type of floodplain they intersect), if applicable. Niobrara County is shown first with flooding only, then its jurisdictions with the parcels/structures on top (if present). ---PAGE BREAK--- Region 2 4-77 Regional Hazard Mitigation Plan 2018 Figure 4-28 Niobrara County Flood Hazards ---PAGE BREAK--- Region 2 4-78 Regional Hazard Mitigation Plan 2018 Figure 4-29 Manville Flood Hazards and Parcels/Structures at Risk ---PAGE BREAK--- Region 2 4-79 Regional Hazard Mitigation Plan 2018 Figure 4-30 Lusk Flood Hazards and Parcels/Structures at Risk ---PAGE BREAK--- Region 2 4-80 Regional Hazard Mitigation Plan 2018 Figure 4-31 Van Tassell Flood Hazards and Parcels/Structures at Risk ---PAGE BREAK--- Region 2 4-81 Regional Hazard Mitigation Plan 2018 Table 4-32 Flood Occurrences per County County Events Total Property Damage Total Crop Damage Period of Record Converse 17 $1,181,500 $0 1941-2016 Natrona 41 $11,013,500 $0 1895-2017 Niobrara 17 $1,542,250 $2,250 1938-2015 TOTAL 75 $13,737,250 $2,250 1895-2017 Source: NCEI Frequency/Likelihood of Occurrence and Spatial Coverage Judging by the historical flood record for the Region, a flood of at least minimal magnitude occurs once or twice every year or two, on average, within the planning area. Most of these floods’ extents were less than the 100-year flood; however, the chance of a 100-year flood occurring in any 100- year period is approximately 50%, or a chance that flooding will affect the region to some extent (spatially speaking). Using the guidelines outlined in Section 4.2, this yields a 10-100 % probability. This corresponds to a likely occurrence rating, meaning that a flood has a 10-100% chance of occurrence in the next year somewhere in the Region. Potential Magnitude Magnitude and severity can be described or evaluated in terms of a combination of the different levels of impact that a community sustains from a hazard event. Specific examples of negative impacts from flooding on Region 2 span a comprehensive range and are summarized as follows: • Floods cause damage to private property that often creates financial hardship for individuals and families; • Floods cause damage to public infrastructure resulting in increased public expenditures and demand for tax dollars; • Floods cause loss of personal income for agricultural producers that experience flood damages; • Floods cause emotional distress on individuals and families; and • Floods can cause injury and death. Floods present a risk to life and property, including buildings, their contents, and their use. Floods can affect crops and livestock. Floods can also affect lifeline utilities water, sewerage, power), transportation, jobs, tourism, the environment, and the local and regional economies. The impact of a flood event can vary based on geographic location to waterways, soil content and ground cover, and construction. The extent of the damage of flooding ranges from very narrow to widespread based on the type of flooding and other circumstances such as previous rainfall, rate of precipitation accumulation, current conditions in the infrastructure and landscapes, the time of year, and emergency response preparedness. ---PAGE BREAK--- Region 2 4-82 Regional Hazard Mitigation Plan 2018 The magnitude and severity of the flood hazard is usually determined by both the extent of impact it has on the overall geographic area, and by identifying the most catastrophic event in the previous flood history (as an example of the losses that could be incurred during such an event). Sometimes this “example” of a catastrophic event is referred to as the “event of record.” The flood of record is almost always correlated to a peak discharge at a gage, because it usually also comes with the worst impacts in terms of property damage, loss of life, etc. The most damaging event in the Region is used to set the “event of record”, in terms of injuries/deaths and/or property/agricultural damages. An event of record could be the flood in summer of 2009 impacted Natrona County with over $5,000,000; nevertheless, an earlier flood in May of 1978 has been among the most damaging in the history of the region, inflicting roughly $15.5 million in damages, especially around Niobrara. However, given this event affected 12 counties in the Rocky Mountain region as a whole, it is difficult to calculate the event’s damages for Region 2 alone. As such, a single “event of record” for Region 2 may not be clearly defined, given the various similarly damaging events. The potential magnitude for a flood event in the Region is overall estimated to be limited. An event of limited magnitude can result in some injuries, a shutdown of critical facilities for over a week, and/or damages to more than 10% of the planning area (in terms of property and agricultural losses). This is consistent with the flood event history in the Region. The flood history indicates that damaging floods have occurred consistently in the planning area. Vulnerability Assessment Population Vulnerable populations in Region 2 include residents living in known flood prone areas or near areas vulnerable to flash floods. Certain populations are particularly vulnerable. This may include the elderly and very young; those living in long-term care facilities; mobile homes; hospitals; low- income housing areas; temporary shelters; people who do not speak English well; tourists and visitors; and those with developmental, physical, or sensory disabilities. These populations may be more vulnerable to flooding due to limitations in mobility and accessibility, income, challenges in receiving and understanding warnings, or unfamiliarity with surroundings. As part of this Plan’s preparation, an estimate of the population exposed to flooding was created using a GIS overlay of existing Digital Flood Insurance Rate Maps (DFIRMs) on potentially flooded parcels. The flood-impacted population for each county in the region was then calculated by taking the number of residential units in the 100-year and 500-year floodplains and multiplying that number by the average household size based on the Census Bureau’s estimate for the counties. The average household factor was 2.54 for Converse County, 2.44 for Natrona, and 2.24 for Niobrara. The results are displayed below in Table 4-33 below. ---PAGE BREAK--- Region 2 4-83 Regional Hazard Mitigation Plan 2018 Table 4-33 Flood Vulnerable Population Estimates in Region 2 Type of Flood Total # of Parcels Vulnerable Population Estimate 100 yr. flood 1,544 2,751 500 yr. flood 3,401 6,231 TOTAL 4,945 8,982 Source: FEMA NFHL, HAZUS analysis, and Census Bureau average household estimates for 2012-2016 Property and Economic Losses GIS analysis was used to estimate Region 2’s potential property and economic losses. The county parcel layers were used as the basis for the inventory of developed parcels. GIS was used to create a centroid, or point, representing the center of each parcel polygon, which was overlaid on the best available floodplain layers. For the purposes of this analysis, the flood zone that intersected the centroid was assigned as the flood zone for the entire parcel (so either 1% or 0.2% annual chance flood). Another assumption with this model is that every parcel with an improvement value greater than zero was assumed to be developed in some way. Only improved parcels, and the value of those improvements, were analyzed and aggregated by jurisdiction, property type, and flood zone. The summarized results for the Region are shown below, followed by the summarized results for each community affected by flooding. Table 4-34 and Table 4-35 show the count and improved value of all the parcels in the Region, broken up by each county and their jurisdictions, by flood zone. Only those parcels which fall within the 100-year/Hazus derived or 500-year floodplains are summarized. The tables also show loss estimate values which are calculated based upon the improved value and estimated contents value. The estimated contents value is 50% of the improved value for residential properties, 150% for industrial, and 100% for all other non-residential properties; the Total Exposure Value is the sum of the improved and estimated contents values; the potential loss estimate is 25% of the total value based on FEMA’s depth-damage loss curves. For example, a two-foot flood generally results in about 25% damage to the structure (which translates to 25% of the structure’s replacement value). Table 4-34 Region 2 Hazus Flood Risk and FEMA 1% Annual Chance Flood Risk Summaries Jurisdiction Parcel Count Improved Value Est. Content Value Total Exposure Potential Loss Population Converse 239 $46,981,829 $31,043,591 $78,025,420 $19,506,355 462 Natrona 1,131 $108,230,726 $70,102,695 $178,333,421 $44,583,355 2,161 Niobrara 174 $18,551,147 $16,866,250 $35,417,397 $8,854,349 128 TOTAL 1,544 $173,763,702 $118,012,535 $291,776,237 $72,944,059 2,751 ---PAGE BREAK--- Region 2 4-84 Regional Hazard Mitigation Plan 2018 Table 4-35 Region 2 FEMA 0.2% Annual Chance Flood Risk Summaries Jurisdiction Parcel Count Improved Value Est. Content Value Total Exposure Potential Loss Population Converse 274 $43,265,330 $28,188,399 $71,453,729 $17,863,432 551 Natrona 3,127 $327,118,206 $215,701,005 $542,819,211 $135,704,803 5,680 Niobrara TOTAL 3,401 $370,383,536 $243,889,404 $614,272,940 $153,568,235 6,232 Table 4-36 Converse County FEMA 1%/Hazus and 0.2% Annual Chance Flood Risk Summary 1% Annual Chance Flood Risk Jurisdiction Property Type Parcel Count Improved Value Est. Content Value Total Exposure Potential Loss Population Unincorporated Agricultural 46 $13,907,736 $13,907,736 $27,815,472 $6,953,868 Commercial 4 $4,945,256 $2,472,628 $7,417,884 $1,854,471 Residential 106 $20,515,693 $10,257,846 $30,773,539 $7,693,385 269 Total 156 $39,368,685 $26,638,210 $66,006,895 $16,501,724 269 Douglas Commercial 5 $1,020,034 $1,020,034 $2,040,068 $510,017 Residential 51 $4,552,469 $2,276,234 $6,828,703 $1,707,176 130 Total 56 $5,572,503 $3,296,268 $8,868,771 $2,217,193 130 Glenrock Commercial 2 $177,586 $177,586 $355,172 $88,793 Residential 25 $1,863,055 $931,527 $2,794,582 $698,646 64 Total 27 $2,040,641 $1,109,113 $3,149,754 $787,439 64 Grand Total 239 $46,981,829 $31,043,591 $78,025,420 $19,506,355 462 0.2% Annual Chance Flood Risk Jurisdiction Property Type Parcel Count Improved Value Est. Content Value Total Exposure Potential Loss Population Unincorporated Commercial 1 $59,828 $59,828 $119,656 $29,914 Total 1 $59,828 $59,828 $119,656 $29,914 Douglas Commercial 50 $11,902,160 $11,902,160 $23,804,320 $5,951,080 Exempt 5 $1,013,168 $1,013,168 $2,026,336 $506,584 Industrial 1 $68,156 $102,234 $170,390 $42,598 Residential 217 $30,222,018 $15,111,009 $45,333,027 $11,333,257 551 Total 273 $43,205,502 $28,128,571 $71,334,073 $17,833,518 551 Grand Total 274 $43,265,330 $28,188,399 $71,453,729 $17,863,432 551 ---PAGE BREAK--- Region 2 4-85 Regional Hazard Mitigation Plan 2018 Table 4-37 Natrona County FEMA 1%/Hazus and 0.2% Annual Chance Flood Risk Summary 1% Annual Chance Flood Risk Jurisdiction Property Type Parcel Count Improved Value Est. Content Value Total Exposure Potential Loss Population Casper Commercial 84 $5,051,721 $5,051,721 $10,103,442 $2,525,861 Exempt 18 $0 $0 $0 $0 Res Vacant Land 2 $0 $0 $0 $0 Residential 565 $50,281,259 $25,140,630 $75,421,889 $18,855,472 1,379 Total 669 $55,332,980 $30,192,351 $85,525,331 $21,381,333 1,379 Evansville Commercial 3 $1,758,803 $1,758,803 $3,517,606 $879,402 Exempt 1 $0 $0 $0 $0 Residential 1 $214,208 $107,104 $321,312 $80,328 2 Total 5 $1,973,011 $1,865,907 $3,838,918 $959,730 2 Mills Commercial 8 $763,194 $763,194 $1,526,388 $381,597 Exempt 3 $0 $0 $0 $0 Residential 5 $76,673 $38,337 $115,010 $28,752 12 Total 16 $839,867 $801,531 $1,641,398 $410,349 12 Unincorporated Com Vacant Land 5 $0 $0 $0 $0 Commercial 73 $5,117,428 $5,117,428 $10,234,856 $2,558,714 Exempt 3 $0 $0 $0 $0 Industrial 9 $9,198,301 $13,797,452 $22,995,753 $5,748,938 Multi-Use 10 $886,915 $886,915 $1,773,830 $443,458 Res Vacant Land 26 $0 $0 $0 $0 Residential 315 $34,882,224 $17,441,112 $52,323,336 $13,080,834 769 Total 441 $50,084,868 $37,242,907 $87,327,775 $21,831,944 769 Grand Total 1,131 $108,230,726 $70,102,695 $178,333,421 $44,583,355 2,161 0.2% Annual Chance Flood Risk Jurisdiction Property Type Parcel Count Improved Value Est. Content Value Total Exposure Potential Loss Population Casper Com Vacant Land 8 $0 $0 $0 $0 Commercial 256 $69,544,805 $69,544,805 $139,089,610 $34,772,403 Exempt 108 $1,095,930 $1,095,930 $2,191,860 $547,965 Industrial 5 $2,107,754 $3,161,631 $5,269,385 $1,317,346 Multi-Use 13 $2,978,567 $2,978,567 $5,957,134 $1,489,284 Res Vacant Land 89 $0 $0 $0 $0 Residential 1,593 $164,544,092 $82,272,046 $246,816,138 $61,704,035 3,887 Total 2,072 $240,271,148 $159,052,979 $399,324,127 $99,831,032 3,887 Evansville Commercial 3 $355,402 $355,402 $710,804 $177,701 Exempt 4 $0 $0 $0 $0 Res Vacant Land 29 $0 $0 $0 $0 Residential 239 $23,417,500 $11,708,750 $35,126,250 $8,781,563 583 Vacant Land 2 $1,245 $1,245 $2,490 $623 ---PAGE BREAK--- Region 2 4-86 Regional Hazard Mitigation Plan 2018 Jurisdiction Property Type Parcel Count Improved Value Est. Content Value Total Exposure Potential Loss Population Total 277 $23,774,147 $12,065,397 $35,839,544 $8,959,886 583 Mills Com Vacant Land 21 $0 $0 $0 $0 Commercial 21 $1,388,874 $1,388,874 $2,777,748 $694,437 Exempt 7 $0 $0 $0 $0 Industrial 1 $3,912,380 $5,868,570 $9,780,950 $2,445,238 Res Vacant Land 62 $0 $0 $0 $0 Residential 267 $9,870,584 $4,935,292 $14,805,876 $3,701,469 651 Total 379 $15,171,838 $12,192,736 $27,364,574 $6,841,144 651 Unincorporated Com Vacant Land 2 $0 $0 $0 $0 Commercial 155 $11,089,932 $11,089,932 $22,179,864 $5,544,966 Exempt 1 $0 $0 $0 $0 Industrial 3 $2,694,324 $4,041,486 $6,735,810 $1,683,953 Multi-Use 4 $400,133 $400,133 $800,266 $200,067 Res Vacant Land 5 $0 $0 $0 $0 Residential 229 $33,716,684 $16,858,342 $50,575,026 $12,643,757 559 Total 399 $47,901,073 $32,389,893 $80,290,966 $20,072,742 559 Grand Total 3,127 $327,118,206 $215,701,005 $542,819,211 $135,704,803 5,680 Table 4-38 Niobrara County FEMA 1%/Hazus Annual Chance Flood Risk Summary 1% Annual Chance Flood Risk Jurisdiction Property Type Parcel Count Improved Value Content Value Total Exposure Potential Loss Population Lusk Commercial 3 $65,326 $65,326 $130,652 $32,663 Exempt 1 $21,174 $21,174 $42,348 $10,587 Ind. Vacant Land 2 $16,545 $16,545 $33,090 $8,273 Industrial 1 $41,900 $62,850 $104,750 $26,188 Res Vacant Land 6 $42,285 $42,285 $84,570 $21,143 Residential 32 $1,456,790 $728,395 $2,185,185 $546,296 72 Com Vacant Land 1 $12,500 $12,500 $25,000 $6,250 Total 46 $1,656,520 $949,075 $2,605,595 $651,399 72 Manville Residential 5 $180,032 $90,016 $270,048 $67,512 11 Res Vacant Land 8 $30,242 $30,242 $60,484 $15,121 Total 13 $210,274 $120,258 $330,532 $82,633 11 Unincorporated Agricultural 73 $14,168,147 $14,168,147 $28,336,294 $7,084,074 Com Vacant Land 2 $14,897 $14,897 $29,794 $7,449 Commercial 5 $574,269 $574,269 $1,148,538 $287,135 Ind Vacant Land 4 $77,468 $77,468 $154,936 $38,734 Res Vacant Land 6 $23,647 $23,647 $47,294 $11,824 Residential 19 $1,632,334 $816,167 $2,448,501 $612,125 43 Total 109 $16,490,762 $15,674,595 $32,165,357 $8,041,339 43 Van Tassell Residential 1 $142,539 $71,270 $213,809 $53,452 2 Agricultural 3 $43,387 $43,387 $86,774 $21,694 Res Vacant Land 2 $7,665 $7,665 $15,330 $3,833 Total 6 $193,591 $122,322 $315,913 $78,978 2 ---PAGE BREAK--- Region 2 4-87 Regional Hazard Mitigation Plan 2018 Jurisdiction Property Type Parcel Count Improved Value Content Value Total Exposure Potential Loss Population Grand Total 174 18,551,147 16,866,250 35,417,397 8,854,349 128 Niobrara County does not have FEMA mapped floodplains in a digital format, so 0.2% annual chance floodplain losses were not calculated in this plan. Based on this analysis, the Region 2 planning area has significant assets at risk to the 100-year and greater floods. There are 1,544 improved parcels within the 100-year floodplain annual chance), for a total improved value of $173,763,702. There are 3,401 improved parcels within the 500-year floodplain (0.2% annual chance), for a total improved value of $370,383,536. Overall, Region 2 counties potentially face over $226 million in potential losses from flooding both the 100-year and 500-year floodplain estimations. Approximately $72.94 million of that total is based on damage estimates from the 1% annual chance flood alone, with the remaining $153.57 million in damages resulting from the 0.2% annual chance flood. NFIP Claims Analysis Another method of examining the magnitude and severity of flooding in the Region is to examine the historic damage losses and payments from the National Flood Insurance Program, or NFIP. This information is not comprehensive, because it only reflects the communities which participate in the NFIP and have made claims, but it is a useful overview of flood damages in the region. The information below represents the composite of unincorporated and community-specific policies, claims and payments. According to statistics from the National Flood Insurance Program there have been a total of 60 flood insurance claims filed between 1/1/1978 and 03/31/2018 in the Region. The total of the payments made on these claims was $137,694.55. As of 02/07/2018, however, there were 290 flood insurance policies in force in the Region, for a total coverage of $66,208,100. More details on National Flood Insurance Program participation can be found within the county annexes. Most of Niobrara County is neither participating nor has effective FEMA Flood Insurance Rate Maps (with the exception of the Town of Lusk). As such, there are no NFIP policies available for most jurisdictions in the county, including unincorporated areas. Certain communities of Converse and Natrona Counties are also not mapped or part of the NFIP (indicated by “N/A” in Table 4-39 below). ---PAGE BREAK--- Region 2 4-88 Regional Hazard Mitigation Plan 2018 Table 4-39 NFIP Policy and Insurance Claim Data for Region 2 Location Policies Coverage "Insurance in Force" # of Claims "Closed Paid Losses" Paid Losses of closed paid losses" Repetitive Losses Substantial Damage claims # of Policies in A Zones # of Policies in Non A Zones Converse County 17 $4,750,400 1 $2,032.60 2 15 Glenrock 4 $675,700 4 $7,350.78 2 2 Douglas 10 $2,729,000 0 10 Rolling Hills N/A N/A N/A N/A N/A N/A N/A N/A Lost Springs N/A N/A N/A N/A N/A N/A N/A N/A Natrona County 42 $12,919,500 1 $2,725.67 0 42 Casper 211 $43,728,500 20 $125,585.50 4 207 Mills 4 $875,000 0 4 Evansville 2 $530,000 0 2 Bar Nunn N/A N/A N/A N/A N/A N/A N/A N/A Midwest N/A N/A N/A N/A N/A N/A N/A N/A Edgerton N/A N/A N/A N/A N/A N/A N/A N/A Niobrara County N/A N/A N/A N/A N/A N/A N/A N/A Manville N/A N/A N/A N/A N/A N/A N/A N/A Lusk 5 $828,300 N/A N/A N/A N/A 0 5 Van Tassell N/A N/A N/A N/A N/A N/A N/A N/A TOTAL 295 $67,036,400 26 $137,695 0 0 8 287 Source: FEMA Policy and Claim Statistics , State of Wyoming Department of Homeland Security, NFIP Coordinator - current as of 2/07/2018 The only communities in the Region currently eligible for enrollment in the National Flood Insurance Program's Community Rating System (CRS) are Casper in Natrona County and Douglas in Converse County. The CRS is a voluntary incentive program that recognizes and encourages community floodplain management activities that exceed the minimum NFIP requirements. As a result, flood insurance premium rates are discounted to reflect the reduced flood risk resulting from the community actions. For more details please visit the CRS document accessible here: Critical Facilities and Community Assets GIS analysis of flood hazards in Region 2 indicates that there are 48 critical facilities and/or community assets that are potentially exposed to flood hazards. There are 19 facilities in the 100- year floodplain (including the Hazus-derived floodplains) and 29 in the 500-year floodplain. The majority of these facilities are microwave service towers. Table 4-40 and Table 4-41 below summarize the facilities that are potentially at risk in the 1% and 0.2% annual chance floods. One limitation to the HSIP dataset, however, is a lack of water facilities (water and wastewater), for example. Gaining access to this type of information would enhance the results of the critical facility risk analysis in future endeavors. ---PAGE BREAK--- Region 2 4-89 Regional Hazard Mitigation Plan 2018 Table 4-40 Critical Facilities within the Hazus Flood Zones 1% Chance FEMA Flood Hazard and Hazus Flood Zones Source County Jurisdiction Facility Type Count Hazus 100-year CONVERSE Unincorporated Microwave Service Towers 1 NATRONA Unincorporated Electric Substations 3 Power Plants 1 NIOBRARA Lusk Electric Substations 1 Microwave Service Towers 2 1% Annual Chance FEMA CONVERSE Unincorporated Electric Substations 1 EPA FRS Power Plants 1 Fire Stations 1 Microwave Service Towers 1 Paging Transmission Towers 1 Power Plants 1 NATRONA Casper Microwave Service Towers 1 WWTP 1 Unincorporated Microwave Service Towers 2 Natural Gas Plants 1 GRAND TOTAL 19 Table 4-41 Critical Facilities within the 0.2% Chance FEMA Flood Zone County Jurisdiction Facility Type Count CONVERSE Douglas AM Transmission Towers 1 Nursing Homes 1 Public Schools 1 NATRONA Casper Day Care Facilities 3 EMS Stations 1 Fire Stations 1 Local Law Enforcement 3 Microwave Service Towers 12 Paging Transmission Towers 1 Public Schools 1 Evansville Day Care Facilities 1 Microwave Service Towers 1 Mills Public Schools 1 Natrona Paging Transmission Towers 1 GRAND TOTAL 29 Natural, Historic, and Cultural Resources Natural resources are generally resistant to flooding, except where natural landscapes and soil compositions have been altered for human development or after periods of previous disasters such ---PAGE BREAK--- Region 2 4-90 Regional Hazard Mitigation Plan 2018 as drought and fire. Wetlands, for example, exist because of natural flooding incidents. Areas that are no longer wetlands may suffer from oversaturation of water, as will areas that are particularly impacted by drought. Areas recently suffering from wildfire damage may erode because of flooding (as has been the case in previous floods in Natrona and Converse Counties), which could permanently alter an ecological system. Tourism and outdoor recreation is an important part of the Region’s economy as well. If part of the planning area were significantly damaged by flooding, tourism and outdoor recreation could potentially suffer. Future Development For NFIP participating communities, floodplain management practices implemented through local floodplain management ordinances are designed to mitigate the flood risk to new development in floodplains. The lack of comprehensive flood hazard mapping in Niobrara County, for example, makes floodplain management challenging in some areas of the County. No major growth or development in the Region is expected to significantly alter the general area flood risk, but good planning, zoning, and general hazard mitigation practices are always necessary to prevent future development from being heavily impacted by flooding. Summary Overall, flooding is a medium to significant hazard in parts of the region, particularly in Natrona and Converse Counties. The Region floods, on average, once or twice every year or two, having damaged homes, infrastructure (roads, railroads, bridges, culverts), and causing general property and sometimes agricultural losses in the past. Flood risk varies by jurisdiction and this risk is detailed further in the county annexes. Table 4-42 below summarizes the specific hazard risks by county. Table 4-42 Flood Hazard Risk Summary in Region 2, by County County Geographic Extent Probability of Future Occurrence Potential Magnitude/ Severity Overall Significance Converse Limited Likely Limited Medium Natrona Significant Likely Significant High Niobrara Limited Likely Limited Medium ---PAGE BREAK--- Region 2 4-91 Regional Hazard Mitigation Plan 2018 4.2.7 Hail Hazard/Problem Description Hail causes more than a billion dollars of property damage nationally each year. Damaging hail events occur sporadically throughout Region 2, usually associated with severe summer storms and wind events. Hailstones form when a super-cooled droplet collects a layer of ice and continues to grow, sustained by an updraft. Once the hailstone cannot be held up any longer by the updraft, it falls to the ground. Hail up to 3.5 inches in diameter has been recorded by the NCEI in the Region. Most of this damage is to crops, but hail can also decimate structural sidings, shatter windows, peel paint, and severely damage automobiles and equipment not protected or stored inside. Geographical Area Affected Hail can strike anywhere in the Region, and when they do occur hail storms can impact a Significant portion of the Region. Past Occurrences A comprehensive history of damaging hailstorms historically affecting the counties in Region 2 is included in Table 4-42. The data was derived from the Storm Data reports generated and released by the National Oceanic and Atmospheric Administration’s (NOAA) National Climate Center. NOAA records any hail events with hailstones that are 0.75 inch or larger in diameter, or any hail of a smaller diameter which causes property and/or crop damage, or casualties. According to the NOAA definition, there have been 371 separate hail incidents in the region since 1950, or an average of 5.54 incidents per year. However, only fourteen of those incidents resulted in damage or injuries, for a total of two injuries, $320,500 of property damage, and no reported crop damage. No deaths have been associated with these storms in the region during this timeframe. Most public and personal property damage from hail is insured under private property insurance or crop insurance policies, serviced by multiple insurance providers; it is very difficult to get a true cumulative estimate of damage costs caused by hail events. Nationwide, most hail-related injuries are suffered by people caught unsheltered when hail begins to fall. Most hail-related injuries are minor and go unreported. The figures and tables below display past occurrences of hail in the Region. ---PAGE BREAK--- Region 2 4-92 Regional Hazard Mitigation Plan 2018 Table 4-43 Summary Hail History, Region 2 (1950-2016) County Events Deaths Injuries Property Damage Crop Damage Total Damage Converse 104 0 1 $100,000 $0 $100,000 Natrona 126 0 1 $125,000 $0 $125,000 Niobrara 141 0 0 $95,500 $0 $95,500 Total: 371 0 2 $320,500 $0 $320,500 Source: NOAA Figure 4-32 was created by Western Water Assessment based on their analysis of NCEI data; shows the number of hail events in Wyoming per county from 1955-2017. Figure 4-32 Hail Events in Wyoming, 1955-2017 ---PAGE BREAK--- Region 2 4-93 Regional Hazard Mitigation Plan 2018 Figure 4-33 Region 2 Hail Events ---PAGE BREAK--- Region 2 4-94 Regional Hazard Mitigation Plan 2018 Table 4-44 Region 2 History with Damaging Hail County Date Hail Size Deaths Injuries Property Damage Crop Damage Natrona 2000-07-20 1.75 0 1 $110,000 $0 Converse 1989-08-18 0.75 0 1 $50,000 $0 Niobrara 1992-07-12 1.75 0 0 $50,000 $0 Converse 1996-08-15 1.75 0 0 $30,000 $0 Niobrara 1996-08-28 3.5 0 0 $10,000 $0 Niobrara 1996-08-28 1.75 0 0 $10,000 $0 Niobrara 1996-08-28 1.25 0 0 $10,000 $0 Niobrara 1996-08-28 1.75 0 0 $10,000 $0 Converse 1998-07-01 2.75 0 0 $10,000 $0 Converse 2009-07-12 1.25 0 0 $10,000 $0 Natrona 2013-06-22 2.75 0 0 $10,000 $0 Niobrara 1992-07-23 1.75 0 0 $5,000 $0 Niobrara 1990-07-04 0.75 0 0 $500 $0 Niobrara 1992-07-23 1.75 0 0 $5,000 $0 Source: NOAA Figure 4-34 Number of Region 2 Hail Events by Month, 1950-2016 Source: NOAA Hail events in Region 2 are most common during the months of May through August, most often between 1 pm and 10 pm Hail with a diameter less than two inches is most common, although hail up to 3.5 inches has been recorded in the Region. While most historical hail storms in the Region 0 20 40 60 80 100 120 140 APR MAY JUN JUL AUG SEP ---PAGE BREAK--- Region 2 4-95 Regional Hazard Mitigation Plan 2018 don’t result in major damage, recordable damage to property and crops could be in the hundreds of thousands of dollars, while extreme events could result in millions of dollars of damage. Insured loss related to hail storms could be in the millions, depending on the location and parameters of the storm. Figure 4-35 Number of Region 2 Hail Events by Time of Day, 1950-2016 Source: NOAA Frequency/Likelihood of Occurrence Based on available historical NOAA data, the Region has experienced 14 separate damaging hail events between 1950 and 2016, which is roughly one incident every 4-5 years. Thus, the Region is Likely to suffer damaging hail storms in the future. Potential Magnitude Most public and personal property damage from hail is insured under private property insurance or crop insurance policies, serviced by multiple insurance providers; it is very difficult to get a true cumulative estimate of damage costs caused by hail events. Data collection regarding dollar damage to public and personal property holds significant gaps for this reason. There have been no FEMA disaster or state declarations for the counties in the Region related to damaging hail, and no USDA disaster declarations as a result of hail damage were found. Agricultural losses and claims met by crop insurance carriers due to hail damage are difficult to determine. Since most hail damage is insured, the overall impact long-term for most of the Region is Negligible. 0 10 20 30 40 50 60 70 ---PAGE BREAK--- Region 2 4-96 Regional Hazard Mitigation Plan 2018 Vulnerability Assessment Hail can strike anywhere in the region, and all structures are vulnerable. Hail can damage roofs, shingles, windows, siding, unsheltered vehicles and any other property unprotected from the storm. People without shelter can also be injured by exposure to hail storms, though there is very little historical reference for this occurring in the Region. Most injuries caused by hail are minor, and go unreported. Higher levels of property damage are expected in more urban areas, and higher levels of crop damage would be expected in rural areas with more farmland. Future Development Hail can strike anywhere in the Region, so any growth or new development in the counties will increase exposure to hail damage. Insurance will be an important tool to offset the potentially substantial dollar losses associated with hail. Summary The counties in Region 2 will continue to experience on a regular basis. Hail damage to property is expected to be highest in the municipalities; much of the damage to both property and crops is covered under insurance policies. Table 4-45 Hail Hazard Risk Summary County Geographic Extent Probability of Future Occurrence Potential Magnitude/ Severity Overall Significance Converse Significant Likely Limited Medium Natrona Significant Likely Limited Medium Niobrara Significant Likely Limited Medium 4.2.8 Hazardous Materials Hazard Description Generally, a hazardous material is a substance or combination of substances which, because of quantity, concentration, or physical, chemical, or infectious characteristics, may either cause or significantly contribute to, an increase in mortality or an increase in serious, irreversible, or incapacitating reversible, illness; or pose a substantial present or potential hazard to human health or environment when improperly treated, stored, transported, disposed of, or otherwise managed. Hazardous material incidents can occur while a hazardous substance is stored at a fixed facility, or while the substance is being transported. ---PAGE BREAK--- Region 2 4-97 Regional Hazard Mitigation Plan 2018 The U.S. Department of Transportation, U.S. Environmental Protection Agency (EPA) and the Occupational Safety and Health Administration (OSHA) all have responsibilities regarding hazardous materials and waste. The U.S. Department of Transportation has identified the following classes of hazardous materials: • Explosives • Compressed gases: flammable, non-flammable compressed, poisonous • Flammable liquids: flammable (flashpoint below 141 degrees Fahrenheit) combustible (flashpoint from 141 - 200 degrees) • Flammable solids: spontaneously combustible, dangerous when wet • Oxidizers and organic peroxides • Toxic materials: poisonous material, infectious agents • Radioactive material • Corrosive material: destruction of human skin, corrodes steel The counties in Region 2 are home to several gas plants, refineries and mines, and numerous pipelines, highways, and rail lines run across the Region, creating a likely potential for hazardous materials releases. Geographical Area Affected Hazmat incidents can occur at a fixed facility or during transportation. Hazardous materials facilities are identified and mapped by the counties they reside in, along with the types of materials stored there; facilities generally reside in and around communities. Some facilities contain extremely hazardous substances; these facilities are required to generate Risk Management Plans (RMPs), and resubmit these plans every five years. RMP facility information can be found within individual jurisdiction annexes. In transit, hazardous materials generally follow major transportation routes where possible (including road, rail and pipelines), creating a risk area immediately adjacent to these routes. Past Occurrences There are a variety of mechanisms to get an idea of the number and types of historical hazardous materials spills in the Region. One such repository is the catalog of hazardous materials spill and accident reports at the National Response Center (NRC) as part of the Right to Know Network (RTK NET). The figure below shows a ten-year record for reported incidents in Region 2. ---PAGE BREAK--- Region 2 4-98 Regional Hazard Mitigation Plan 2018 Figure 4-36 Hazardous Materials Spills/ Accidents Reported to the NRC Region 2: 2007- 2016 Source: http://www.rtk.net/#rmp The data shows that from 2007 through 2016, the number of NRC-reported incidents in Converse and Niobrara Counties stayed fairly consistent, averaging 4.5 per year in Converse and 1.2 per year in Niobrara. Natrona County, however, saw a steep drop in the number of incidents, falling from 84 per year in 2007 to only 7 per year in 2015 and 2016, a 92% reduction. This led to a Region-wide reduction of 90% in the number of NRC-reported incidents Region. Since 2012, the Region has averaged 18.2 incidents per year, which means that all counties can reasonably expect multiple hazardous materials responses annually. The county data is further broken down in the table below: Table 4-46 NRC-Reported Incidents by County: 2007-2016 Year Converse Natrona Niobrara Total 2007 7 84 0 91 2008 4 73 1 78 2009 4 35 1 40 2010 4 35 1 40 2011 2 26 0 28 2012 4 17 1 22 2013 5 17 2 24 2014 4 8 3 15 2015 9 7 5 21 2016 2 7 0 9 Ten-Year Total 45 309 14 368 Source: http://www.rtk.net/#rmp 0 10 20 30 40 50 60 70 80 90 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 Converse Natrona Niobrara ---PAGE BREAK--- Region 2 4-99 Regional Hazard Mitigation Plan 2018 The NRC also tracks incidents by type. The following figure shows the percentage of each type of incident over the 10-year period between January 2007 and December 2016. Fixed sites and storage tanks make up 84% of all incidents in Region 2; this is mainly due to the large number of facilities in Natrona County. In Converse and Niobrara Counties, motor vehicle incidents account for 48% of spills. Figure 4-37 Hazmat Incidents Reported to the NRC, Region 2: 2007-2016 Source: http://www.rtk.net/#rmp An analysis of NRC-reported incidents from 2000 through 2016 shows that hazardous materials incidents occur year-round, with a slight increase in the warmer months. Similarly, hazardous materials incidents can happen at any time of day, but are far more common between the hours of 5:00am and 6:00pm, peaking historically in the 9 AM hour. Fixed Site 33% Continuous Release 1% Storage Tank, Drilling Platform, or Pipeline 51% Unknown Sheen on Water 1% Mobile Vehicle 9% Other or Unknown 5% ---PAGE BREAK--- Region 2 4-100 Regional Hazard Mitigation Plan 2018 Figure 4-38 Region 2 Hazardous Materials Incidents by Month: 2000-2016 Source: http://www.rtk.net/#rmp Figure 4-39 Region 2 Hazardous Materials Incidents by Time of Day: 2000-2016 Source: http://www.rtk.net/#rmp In addition to local first responders, eight Regional Emergency Response Teams (RERT) across the State of Wyoming respond to a variety of incidents, including those incidents involving hazardous materials. The Region 2 RERT is located in Casper, in Natrona County. The following table shows records of Region 2 RERT mission assignments pertaining to hazardous materials releases, according the 2016 Wyoming State Hazard Mitigation Plan. 0 10 20 30 40 50 60 70 80 90 100 JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC 0 20 40 60 80 100 120 140 12am 1am 2am 3am 4am 5am 6am 7am 8am 9am 10am 11am 12pm 1pm 2pm 3pm 4pm 5pm 6pm 7pm 8pm 9pm 10pm 11pm ---PAGE BREAK--- Region 2 4-101 Regional Hazard Mitigation Plan 2018 Table 4-47 Region 2 RERT Mission Assignments, Hazardous Materials: 2004-2015 Type Number Fixed Facility 5 Truck/Highway 16 Rail 0 Pipeline 0 Aircraft 2 Orphan Drum 1 Total 24 Source: 2016 Wyoming State Hazard Mitigation Plan Frequency/Likelihood of Occurrence The Region experiences multiple hazardous materials incidents each year, with various degrees of impact; there is effectively a 100% chance that the Region will see a hazardous materials incident in any given year. Hazardous material spills and releases, both from fixed facilities and during transport, will continue to occur in each county in Region 2 annually. Potential Magnitude Impacts that could occur from hazardous waste spills or releases include: • Injury • Loss of life (human, livestock, fish and wildlife) • Evacuations • Property damage • Air pollution • Surface or ground water pollution/contamination • Interruption of commerce and transportation Numerous factors go into the ultimate impacts of a hazardous materials release, including method of release, the type of material, location of release, weather conditions, and time of day. This makes it difficult to nail down precise impacts. Materials found in Region 2 will have at least one of the impacts listed above, and probably more. Vulnerability Assessment Region 2 has energy pipelines, railroad tracks which carry many types of hazardous materials, and both state and Interstate highways running through its boundaries. A variety of hazardous materials originating in the Region or elsewhere are transported along these routes, and could be vulnerable to accidental spills. Consequences can vary depending on whether the spill affects a populated area vs an unpopulated but environmentally sensitive area. ---PAGE BREAK--- Region 2 4-102 Regional Hazard Mitigation Plan 2018 The Right-to-Know Network lists 46 licensed hazardous waste handlers in Region 2, as broken down in Table 4-48. There are 12 Risk Management Plan (RMP) facilities located in Region 2, as noted in Table 4-49. Note that while Natrona County has a larger number of facilities overall, it has fewer RMP facilities than Converse County. Some of these sites are discussed in more detail in the Annexes. Table 4-48 Hazardous Materials Handlers in Region 2 County Treatment, Storage or Disposal Large Quantity Generator Transporter Total Converse 0 1 9 10 Natrona 1 7 23 31 Niobrara 0 0 5 5 Total 1 8 37 46 Source: http://www.rtknet.org/db/erns Table 4-49 RMP Facilities in Region 2 County Community Number of Facilities Converse Douglas 6 Converse Glenrock 2 Natrona Casper 2 Natrona Evansville 1 Natrona Midwest 1 Niobrara County 0 Total 12 Source: http://www.rtknet.org/db/erns No specific hazardous materials routes or route restrictions are designated in Region 2. Any routes used to carry hazardous materials introduce an element of risk of materials release to the area immediately adjacent to them. Potential losses can vary greatly for hazardous material incidents. For even a small incident, there are cleanup and disposal costs. In a larger scale incident, cleanup can be extensive and protracted. There can be deaths or injuries requiring doctor’s visits and hospitalization, disabling chronic injuries, soil and water contamination can occur, necessitating costly remediation. Evacuations can disrupt home and business activities. Large-scale incidents can easily reach $1 million or more in direct damages. Future Development Stationary facilities with hazardous materials are identified and mapped throughout the Region. Transportation routes are also identified. Special care should be taken to cross-reference any new ---PAGE BREAK--- Region 2 4-103 Regional Hazard Mitigation Plan 2018 development areas with identified sources for potential hazardous materials incidents. The downturn in oil and gas has resulted in lower growth and loss of tax revenues throughout the Region. Summary Table 4-50 Hazardous Materials Hazard Risk Summary County Geographic Extent Probability of Future Occurrence Potential Magnitude/ Severity Overall Significance Converse Significant Highly Likely Limited Medium Natrona Significant Highly Likely Limited Medium Niobrara Limited Likely Limited Low 4.2.9 High Winds and Downbursts Hazard Description Wind is a nearly constant presence in Wyoming, and can often be overlooked as a hazard. Wyoming’s wind is also becoming a positive economic factor, as renewable wind energy is developed around the state. This profile examines the hazard that high winds present including downbursts, a subcategory of high winds. A downburst is a strong down draft which causes damaging winds on or near the ground. Downbursts are much more frequent than tornadoes, and for every one tornado there are approximately 10 downburst damage reports. Downbursts can be associated with either a heavy precipitation or non-precipitation thunderstorm (dry or wet downbursts), and often occur in the dissipating stage of a thunderstorm. Microbursts and macrobursts are categories of downbursts, classified by length of duration, velocity of wind, and radius of impact. Microbursts generally last between five and 15 minutes, and impact an area less than three miles wide. Macrobursts can last up to 30 minutes with winds up to 130 miles per hour, and can impact areas larger than three miles in radius. Microbursts and macrobursts may induce dangerous wind shears, which can adversely affect aircraft performance, cause property damage and loss of life. A downburst can occur when cold air begins to descend from the middle and upper levels of a thunderstorm (falling at speeds of less than 20 miles an hour). As the colder air strikes the Earth's surface, it begins to ‘roll’ outward. As this rolling effect happens, the air expands causing further cooling and having the effect of pulling the shaft of air above it at higher and higher speeds. ---PAGE BREAK--- Region 2 4-104 Regional Hazard Mitigation Plan 2018 Figure 4-40 Schema of Microburst and Tornado Source: www.erh.noaa.gov Downbursts can be mistaken for tornadoes by those that experience them since damages and event characteristics are similar. Tornado winds can range from 40 mph to over 300 mph. Downbursts can exceed winds of 165 mph and can be accompanied by a loud roaring sound. Both downbursts and tornadoes can flatten trees, cause damage to homes and upend vehicles. In some instances, aerial surveying is the best method to determine what kind of event has taken place. In the following photograph, trees are blown down in a straight line - a very strong indication of a downburst as opposed to a tornado. Figure 4-41 Aerial Image of Downburst Damage Source: T. Fujita ---PAGE BREAK--- Region 2 4-105 Regional Hazard Mitigation Plan 2018 Geographical Area Affected High winds are common throughout the planning area. Figure 4-42 and Figure 4-43 were created by Western Water Assessment based on their analysis of NCEI data; they show the number of high wind and thunderstorm wind events in Wyoming per county from 1996-2017. Note that while the number of wind events reported in the counties of Region 2 appear to be relatively moderate, the residents of the area are used to high winds and may be less likely to report them as an “event” compared to other parts of the country. Figure 4-42 High Wind Events in Wyoming, 1996-2017 ---PAGE BREAK--- Region 2 4-106 Regional Hazard Mitigation Plan 2018 Figure 4-43 Thunderstorm Wind Events in Wyoming, 1996-2017 Past Occurrences In the counties in Region 2, most documented wind events causing damage typically range between 50 and 65 knots; max wind speeds of up to 71 knots have been recorded. It should be noted that the data is limited by what the NCEI is able to record, and what equipment was in place at the time, and that the timespan of available records for each county differs. ---PAGE BREAK--- Region 2 4-107 Regional Hazard Mitigation Plan 2018 Figure 4-44 NCEI-Recorded Wind Events, 1950-2016 Source: NOAA ---PAGE BREAK--- Region 2 4-108 Regional Hazard Mitigation Plan 2018 Table 4-51 Summary of Recorded Wind Weather Events and Impacts Region 2 (1950-2016) Total Number of Wind Events* Total Property Damage Total Crop Damage Total Fatalities Total Injuries Average Recorded Wind Speed Max Recorded Wind Speed 131 $270,500 $0 0 0 51.5 knots 71 knots Converse County (1950-2016) 19 $60,000 $0 0 0 52.4 knots 71 knots Natrona County (1950-2016) 93 $145,500 $0 0 0 52.9 knots 70 knots Niobrara County (1950-2016) 19 $65,000 $0 0 0 43.3 knots 61 knots Source: NCEI *It’s important to note that more than one event may be associated with a single storm While high winds can occur anytime, they are most common in the Region during the months of June, July and August, between 2:00 and 10:00 pm. Figure 4-45 Number of Region 2 High Wind Events by Month, 1950-2016 Source: NOAA 0 5 10 15 20 25 30 35 40 45 APR MAY JUN JUL AUG SEP ---PAGE BREAK--- Region 2 4-109 Regional Hazard Mitigation Plan 2018 Figure 4-46 Number of Region 2 High Wind Events by Time of Day, 1950-2016 Source: NOAA Frequency/Likelihood of Occurrence NOAA records 131 confirmed and documented high wind incidents specifically impacting the Region, or zones tied to the Region since 1950; it should be noted that as technology has improved, the number of incidents recorded in more recent years have gone up dramatically. Total recorded data for Region 2 since 1950 averages to 1.96 recorded incidents per year. This trend is expected to continue, and the region can expect high wind incidents every year for the foreseeable future. Potential Magnitude The 2016 Wyoming State Hazard Mitigation Plan cites SHELDUS and NCEI data to record 199 total damaging wind events between 1960-2015 in Region 2, with $273,165 in damage and two injuries recorded in Converse County from 58 events; $703,250 in damage, fourteen injuries and one death recorded in Natrona County from 84 events; and $266,326 and five injuries in damage recorded in Niobrara County from 57events during this timeframe. Per NCEI, the most damaging event in the Region caused $50,000 damage to property; NCEI does not record any crop damage in the Region due to high winds. These incidents can be used as worst- case scenarios, though more damage could occur with the right combination of factors. The following maps show annual average wind speeds across the US and across Wyoming (Figure 4-47 and Figure 4-48). The blue box corresponds to the planning area. Wyoming has some of the 0 5 10 15 20 25 30 11am 12pm 1pm 2pm 3pm 4pm 5pm 6pm 7pm 8pm 9pm 10pm 11pm 12am ---PAGE BREAK--- Region 2 4-110 Regional Hazard Mitigation Plan 2018 highest annual average wind speeds in the nation. While the threat varies across the planning area, all parts of the Region are susceptible to damaging wind events. Figure 4-47 Annual Average Wind Speed – United States ---PAGE BREAK--- Region 2 4-111 Regional Hazard Mitigation Plan 2018 Figure 4-48 Annual Average Wind Speed – Wyoming Vulnerability Assessment Vulnerability as it relates to location is mostly random, as damaging winds have occurred everywhere in the Region. Damage from high winds is often described in regional or broad areas, but downburst damage will impact a small area most generally less than three miles in diameter. Because state or presidential emergency or disaster declarations have not been necessary in the aftermath of wind events in the Region, and because damage to personal property is dealt with by numerous private insurance companies, it is difficult to estimate actual monetary impacts that have occurred due to damaging winds. See section on Potential Losses for loss estimates based on reported damage. Specific vulnerabilities from high wind events include damage to poorly constructed buildings, building collapse and damage, flying debris, semi rollovers and car accidents, and downed power lines and electric system damage. Cascading hazards caused by high winds can include power loss; depending on the time of year, winds can also exacerbate snow and blizzards by creating deep snow drifts over roads and affecting the normal flow of traffic. Damages recorded by the NCEI for the county include downed power lines, torn off roofs and building damage, and downed tree limbs and debris. ---PAGE BREAK--- Region 2 4-112 Regional Hazard Mitigation Plan 2018 Future Development Historical data demonstrates that the most critical area of the state for high wind hazards is the eastern one third, including much of Region 2. Future residential or commercial buildings built to code should be able to withstand wind speeds of at least 150 miles per hour. Summary Many areas of the United States are prone to damaging wind events, and while the counties of Region 2 may not be counted in a high category for occurrences across the nation, it does have a history of such episodes which should be anticipated for the future. Primary damage is structural and utility-borne. Although minimal deaths and injuries have been reported, the frequency of occurrence is due consideration, as well as the hazard to rural citizens and town populations from falling trees, power poles, and flying debris. Photos and scattered reports document property damage (including damage to private utilities) occurring as a result of wind events, yet cumulative losses due to wind damage have been negligible. Table 4-52 High Winds and Downbursts Hazard Risk Summary County Geographic Extent Probability of Future Occurrence Potential Magnitude/ Severity Overall Significance Converse Significant Likely Negligible Medium Natrona Significant Likely Negligible Medium Niobrara Significant Likely Negligible Medium 4.2.10 Landslide/Rockfall/Debris Flow Hazard/Problem Description A landslide is a general term for a variety of mass movement processes that generate a downslope movement of soil, rock, and vegetation under gravitational influence. Landslides are a serious geologic hazard common to almost every state in the United States. It is estimated that nationally they cause up to $2 billion in damages and from 25 to 50 deaths annually. Some landslides move slowly and cause damage gradually, whereas others move so rapidly that they can destroy property and take lives suddenly and unexpectedly. Gravity is the force driving landslide movement. Factors that allow the force of gravity to overcome the resistance of earth material to landslide include: saturation by water, erosion or construction, alternate freezing or thawing, earthquake shaking, and volcanic eruptions. Landslides are typically associated with periods of heavy rainfall or rapid snow melt and tend to worsen the effects of flooding that often accompanies these events. In areas burned by forest and ---PAGE BREAK--- Region 2 4-113 Regional Hazard Mitigation Plan 2018 brush fires, a lower threshold of precipitation may initiate landslides. Generally, significant landslides follow periods of above-average precipitation over an extended period followed by several days of intense rainfall. It is on these days of intense rainfall that slides are most likely to occur. Areas that are generally prone to landslide hazards include existing old landslides; the bases of steep slopes; the bases of drainage channels; and developed hillsides where leach-field septic systems are used. Landslides are often a secondary hazard related to other natural disasters. Landslide triggering rainstorms often produce damaging floods. Earthquakes often induce landslides that can cause additional damage. Slope failures typically damage or destroy portions of roads and railroads, homes and public buildings, sewer and water lines, and other utility lines. Even small-scale landslides are expensive due to clean up costs that may include debris clearance from streets, drains, streams and reservoirs; new or renewed support for road and rail embankments and slopes; minor vehicle and building damage; personal injury; and livestock, timber, crop and fencing losses and damaged utility systems. The most common geologic hazard in Wyoming is landslides. According to the State Hazard Mitigation Plan, Wyoming has among the highest landslide densities in the country. There are many types of landslides that pose a risk to Wyoming. In order to properly describe landslide type, the Geologic Hazards Section developed a landslide classification modified from Varnes (1978) and Campbell (1985). As can be seen in Figure 4-49 , there are five basic types of landslides that occur in three types of material. Falls, topples, slides, lateral spreads, and flows can occur in bedrock, debris, or earth. While individual landslide types can occur in nature, most landslides are complex, or composed of combinations of basic types of landslides. ---PAGE BREAK--- Region 2 4-114 Regional Hazard Mitigation Plan 2018 Figure 4-49 Wyoming Landslide Classifications Rockfall A rockfall is the falling of a detached mass of rock from a cliff or down a very steep slope. Weathering and decomposition of geological materials produce conditions favorable to rockfalls. Rockfalls are caused by the loss of support from underneath through erosion or triggered by ice wedging, root growth, or ground shaking. Changes to an area or slope such as cutting and filling activities can also increase the risk of rockfall. Rocks in a rockfall can be of any dimension, from the size of baseballs to houses. Rockfall occurs most frequently in mountains or other steep areas ---PAGE BREAK--- Region 2 4-115 Regional Hazard Mitigation Plan 2018 during the early spring when there is abundant moisture and repeated freezing and thawing. Rockfalls are a serious geological hazard that can threaten human life, impact transportation corridors and communication systems and result in other property damage. The Spring season is considered the landslide and rockfall season in Wyoming, as the snow melts and saturates soils and temperatures begin to enter into freeze and thaw cycles. Rockfall and landslides are influenced by seasonal patterns, precipitation and temperature patterns. Earthquakes could trigger rockfalls and landslides as well. Debris Flow Debris flows, sometimes referred to as mudslides, mudflows, lahars, or debris avalanches, are common types of fast-moving landslides. They are a combination of fast moving water and a great volume of sediment and debris that surges down slope with tremendous force. Similar to a flash flood these flows generally occur during periods of intense rainfall or rapid snowmelt and may occur with little warning. They usually start on steep hillsides as shallow landslides that liquefy and accelerate to speeds that are typically about 10 miles per hour, but can exceed 35 miles per hour. Figure 4-50 describes identifying characteristics of debris flows. The consistency of debris flow ranges from watery mud to thick, rocky mud that can carry large items such as boulders, trees, and cars. Debris flows from many different sources can combine in channels, and their destructive power may be greatly increased. When the flows reach level ground, the debris spreads over a broad area, sometimes accumulating in thick deposits that can wreak havoc in developed areas. The National Flood Insurance Program covers mudflows but it does not cover landslides. ---PAGE BREAK--- Region 2 4-116 Regional Hazard Mitigation Plan 2018 Figure 4-50 Field Evidence of Debris Flow Geographical Area Affected The Wyoming Department of Transportation Geology Program has documented 248 landslide sites across the state that are impacting roads, including areas repaired, mitigation projects in process. Figure 4-51 below shows mapped landslides in the Region. Note the relatively high concentration of landslide deposits in Natrona County, particularly near the City of Casper. Natrona County is the second most populous county in the state, it is also the most vulnerable county in the Region to landslides. Natrona County Landslide Areas In Natrona County the primary areas of concern are landslide deposits near the north side of Casper Mountain where homes are located, along Hwy 220, and the Wolf Creek drainage. Unincorporated areas are also at risk of landslides and would be the most affected by the hazard in the county. The Towns of Mills and Bar Nunn are not affected by landslides based on available mapping. Converse County Landslide Areas Overall, landslide susceptibility is minimal across Converse County as the geologic conditions do not make the county susceptible to landslides. Results from GIS analysis indicate that there are no properties or critical infrastructure located in areas prone to landslides. The county is not completely immune to landslides, however; transportation networks are most exposed to landslide and debris flow incidents in the county. Transportation infrastructure that would likely be impacted by one of these incidents include the east-west portion of Interstate 25 that goes through Glenrock and Rolling Hills, Highway 18 that runs north through Lost Springs and the north-south portion of State Highway 59 that passes through Douglas and Bill. Although the overall vulnerability to ---PAGE BREAK--- Region 2 4-117 Regional Hazard Mitigation Plan 2018 populations is low, the loss of transportation networks could have an impact on the County’s overall infrastructure, including revenue and emergency response capabilities. The HMPC notes in the 2018 Converse County HMP Update that land subsidence especially in the City of Glenrock is more of a concern than landslides or debris flow. Mine and land subsidence hazards are profiled in more detail in Section 4.2.12 of this Plan. Niobrara County Landslide Areas There is one small landslide hazard area present in the southern portion of Niobrara County. Landslides on the Silver Springs Quadrangle have been examined by the Wyoming State Geological Survey and Niobrara County Emergency Management. Overall, there are no landslide areas that could have a significant effect on property, populations, or cultural and/or historic landmarks in the county. ---PAGE BREAK--- Region 2 4-118 Regional Hazard Mitigation Plan 2018 Figure 4-51 Region 2 Landslide Areas ---PAGE BREAK--- Region 2 4-119 Regional Hazard Mitigation Plan 2018 Past Occurrences Although limited information is available on previous occurrences of geologic hazards that have caused a particular high amount of damage or incurred some other cost or unique impact, landslides, debris flows, and rockfalls occur regularly in Wyoming and the Region. According to the 2016 Wyoming State Mitigation Plan, between 1960 and 2015 there have been two landslide events that have taken place in the Region; both occurred in Natrona County. The total property damage from those events was $100,500. In the 2017 Natrona County Hazard Mitigation Plan, the HMPC reported debris flows in spring of 2013 on the Sheepherder Hill burn scar after wildfires in the area. They also reported debris flows on Alcova Lake Shore Drive, and associated rockfall risk. Neither the State HMP nor the Converse County or Niobrara Counties noted significant landslide events taking place in the past. Frequency/Likelihood of Occurrence The probability of a landslide causing damage in the Region is difficult to determine because of the poor availability of historic data. Typically, there is a landslide/rockfall ‘season’ that coincides with increased freeze-thaw cycles and wetter weather in the spring and early summer. Heavy periods of precipitation or significant development could also have an effect on slope stability. However, given it is reasonable to assume that damaging events have between a 10 and 100% chance of occurrence in the next year or a recurrence interval of 10 years or less it can be assumed landslides, rockfalls or debris flows are likely to occur in the Region. Potential Magnitude There are three measures of future landslide impacts – historic dollar damages, estimated yearly damages, and building exposure values. There are not enough current data to estimate historic or yearly dollar damages. In general terms, landslides can threaten human life, impact transportation corridors and communication systems, and cause damage to property and other infrastructure. Actual losses can range from mere inconvenience to high maintenance costs where very slow or small-scale destructive slides are involved. The potential magnitude of landslides, rockfall and debris flows in the Region is limited, as events would typically be isolated in most counties. However, even a small isolated event has potential to close state or U.S. highways in the Region that can result in long detours for days or weeks. With the added cost of detours, and the potential for life safety impacts, some landslides could have greater costs. ---PAGE BREAK--- Region 2 4-120 Regional Hazard Mitigation Plan 2018 Vulnerability Assessment Population The overall vulnerability of population is low. The general population is not overly vulnerable to landslides, but rockfall can cause serious injury or death. There are areas prone to rockfall on Interstate 25, Highway 18, and State Highway 59. General Property During the 2018 development of this Regional Plan, a GIS analysis of exposure to landslide hazard areas was performed. The greatest risk to general property is in Natrona County as shown in Table 4-53, which summarizes landslide exposure in the county, based on an intersect of improved parcels with landslide hazard areas. Based on this analysis, there are 133 buildings and a total exposure of $61,442,113 located in the landslide hazard zones in Natrona County. Table 4-53 Landslide Exposure in Natrona County Jurisdiction Property Type Building Count Improved Value Est. Content Value Total Exposure Population City of Casper Commercial 1 $5,629,648 $5,629,648 $11,259,296 Residential 2 $541,281 $270,641 $811,922 5 Total 3 $6,170,929 $5,900,289 $12,071,218 5 Unincorporated Commercial 2 $110,197 $110,197 $220,394 Exempt 1 $0 $0 $0 Res Vacant Land 2 $0 $0 $0 Residential 125 $32,767,001 $16,383,501 $49,150,502 305 Sub Total 130 $32,877,198 $16,493,698 $49,370,896 288 Grand Total 133 $39,048,127 $22,393,986 $61,442,113 293 Source: Natrona County; WYDOT; WY Geospatial Hub; HSIP Freedom 2015; WGS Essential Infrastructure, Facilities, and Other Important Community Assets Transportation networks are the most exposed aspect of the Region to rockfall, landslide and debris flow incidents. Residents and visitors alike are impacted by landslides when roads are damaged by landslides. This includes Highways 487 and 220 near Casper in Natrona County and Interstate 25 cross through Glenrock and Rolling Hills, Highway 18 running north through Lost Springs, and State Highway 59 passing through Douglas and Bill in Converse County. The loss of transportation networks could potentially cause secondary damage to the overall Region’s infrastructure, including revenue, transportation availability, emergency response mechanisms and other essential capabilities by preventing the means of these resources from activating or moving between locations. ---PAGE BREAK--- Region 2 4-121 Regional Hazard Mitigation Plan 2018 Natrona County HMP identifies two critical facilities located in the unincorporated area of the County that are potentially at risk to landslides. Table 4-54 Critical Facilities at Risk to Landslides in Natrona County Landslide Type Jurisdiction Critical Facility Type Name Complex Slope Movement Unincorporated EPA FRS Location BROKEN WRENCH LLC Debris or Earth Flow Unincorporated EPA FRS Location KINDER ENTERPRISES INCORPORATED Future Development The severity of landslide problems is directly related to the extent of human activity in hazard areas. Human activities such as property development and road construction can also exacerbate the occurrence of landslides. Landslide areas tend to be picturesque and often within mountainous locations and therefore attract development. Development in landslide areas frequently consists of vacation homes and represents a potential risk for injury, loss of life and property. Summary Overall, landslides, rockfalls and debris flows range from low to high significance hazards in the region. Landslides have the potential for direct property impacts including residential structures but more likely infrastructure corridors including roads and highways, power line corridors, and gas lines. Table 4-55 Landslide Hazard Risk Summary County Geographic Extent Probability of Future Occurrence Potential Magnitude/ Severity Overall Significance Converse Limited Unlikely Limited Low Natrona Limited Occasional Limited Medium Niobrara Limited Unlikely Limited Low 4.2.11 Lightning Hazard/Problem Description Lightning is a danger across Wyoming. Lightning is a sudden electrical discharge released from the atmosphere that follows a course from cloud to ground, cloud to cloud, or cloud to surrounding air, with light illuminating its path. Lightning’s unpredictable nature causes it to be one of the most feared weather elements. ---PAGE BREAK--- Region 2 4-122 Regional Hazard Mitigation Plan 2018 Anyone that is caught in an exposed area during a thunderstorm could be at risk to a lightning strike. In Wyoming, outdoor enthusiasts venturing to high and exposed areas should be especially cautious because rapid thunderstorm development with associated lightning can place even the most experienced persons in jeopardy without warning. Lightning strikes can cause power outages. Lightning is also the leading cause of wildland fires in Wyoming, and is indirectly responsible for millions of dollars’ worth of fire damage. Geographical Area Affected All the region is susceptible to lightning impacts, particularly the higher elevation mountainous areas. Past Occurrences Vaisala’s National Lightning Detection Network (NLDN) recorded 347,035 cloud to ground lightning flashes in Wyoming in 2015; they also record an average of 279,632 cloud to ground lightning flashes per year between 2006 and 2015 for the state. This ranks Wyoming 39th nationally for flashes per square mile, averaging 2.9 cloud to ground lightning flashes per square mile, per year. Nationally, Wyoming ranks 36th in number of lightning fatalities, 33rd in injuries, and 40th in property damage from 1959 to 1994 according to the National Oceanic and Atmospheric Administration, National Severe Storms Laboratory (NOAA, NSSL). Wyoming is number one in the nation in lightning deaths per capita according to the National Weather Service in Salt Lake City. According to the NCEI, lightning has been responsible for 8 deaths, 75 injuries, over $1 million in property damage and $91,000 in crop damage in Wyoming between 1996 and 2015. The 2016 Wyoming State Hazard Mitigation Plan lists loss-causing lightning events from 1960- 2015, collected from SHELDUS and NCEI events databases. 26 incidents are recorded for the counties in Region 2, resulting in a total of 3 injuries, 3 deaths, and a total of $748,849 in property and crop damage; these incidents are listed in Table 4-56. Table 4-56 Region 2 Lightning History 1960– 2015 County Number of Events Injuries Fatalities Property Damage Crop Damage Total Damage Converse 9 0 3 $ 347,339 $ 5,000 $ 352,339 Natrona 13 3 0 $ 362,771 $ 0 $ 362,771 Niobrara 4 0 0 $ 30,739 $ 3,000 $ 33,739 Total 26 3 3 $ 740,849 $ 8,000 $ 748,849 Source: 2016 Wyoming State Hazard Mitigation Plan All three lightning fatalities since 1960 occurred in Converse County. On July 24, 1973, a 17-year- old boy and the horse he was riding were killed by lightning on a ranch just north of Douglas. The following month, on August 27, 1973, lightning struck a tree which a man was leaning against, ---PAGE BREAK--- Region 2 4-123 Regional Hazard Mitigation Plan 2018 killing him instantly. And on July 7, 1976, a cowboy was killed by lightning (circumstances unknown). There have been no recorded fatalities from lightning in Region 2 since 1976. Frequency/Likelihood of Occurrence Nationwide, lightning strikes are routinely monitored by Vaisala, Inc. with accuracies to within a 0.625-mile (1 kilometer) resolution. The Wyoming annual lightning strike frequency is depicted in Figure 4-52 for the period of 2005 through 2014. Clearly the eastern plains have more than three times the cloud to ground lightning strikes as the western half of the state. Region 2’s flash density varies considerably, ranging from 0.75 to 6 flashes per square mile per year in much of Natrona County, to 3 to 12 flashes per square mile per year in Niobrara Counties. Despite annual variation, the locations of maximum and minimum strikes do not change much from year to year. A warming climate may also affect the frequency of lighting; in 2014 researchers at the University of Berkeley conducted a study that found that for every one-degree Celsius rise in the average global temperature, there will be a 12% increase in the amount of lightning strikes. (Source: Science Magazine, http://www.sciencemag.org/content/346/6211/851.abstract;) Figure 4-52 Average annual lightning flash density (flashes/sq. mi./year) 2005-2014 over Wyoming. Source: Illustration courtesy of Vaisala Inc. U.S. statistics show that one in 345,000 lightning flashes results in a death and one in 114,000 results in an injury nationwide. According to meteorologists at Vaisala, Inc., the odds for an American being hit by lightning sometime in the course of an 80-year lifespan is about 1 in 3,000. Any persons caught in the open without cover during a lightning storm are vulnerable to strikes. ---PAGE BREAK--- Region 2 4-124 Regional Hazard Mitigation Plan 2018 Although lightning strikes occur with high frequency throughout Region 2, Table 4-56 shows that strikes resulting in injuries or reportable damage are somewhat less-common. Based on this data, the chance of a loss or injury-causing lightning strike in any given year ranges from around 7% in Niobrara County, to 16% in Converse County, to 23% in Natrona County. Note that while Niobrara County has the highest number of lightning strikes, it has the lowest number of strikes that cause damage or injuries. Potential Magnitude Lightning can cause deaths, injuries, and property damage, including damage to buildings, communications systems, power lines, and electrical systems. It also causes forest, brush and structural fires. Damage from lightning occurs in four ways: • Electrocution, severe electrical shock, and burns of humans and animals • Vaporization of materials in the path of the strike • Fire caused by the high temperatures associated with lightning • Power surges that can damage electrical and electronic equipment When people are struck by lightning, the result is deep burns at the point of contact (usually on the head, neck and shoulders). Approximately 70% of lightning survivors experience residual effects such as vision and hearing loss or issues. These effects may develop slowly and only become apparent much later. Death occurs in 20% of lightning strike victims. Lightning strikes cause intense but localized damage. In contrast to other hazards, lightning does not cause widespread disruptions with the community. Structural fires, localized damage to buildings, damage to electronics and electrical appliances, and electrical power and communications outages are typical consequences of a lightning strike. Additionally, indirect fatalities may result via electrocution when a person steps from a vehicle into standing water that was previously “charged” by a live power-line that was knocked loose by a lightning strike. The indirect social and economic impacts of lightning damage are typically associated with the loss of electrical power. Since society relies heavily on electric power, any disruption in the supply, even for a short time period, can have significant consequences. Wildfires can also be an indirect result of a lightning strike. Past events in Region 2 indicate that the potential magnitude of lightning events will likely be limited—isolated deaths and/or injuries may occur; major or long-term property damage that threatens structural stability due to structural damage or fires; and/or interruption of essential facilities and services for 24-72 hours due to structural damage or utility outages. ---PAGE BREAK--- Region 2 4-125 Regional Hazard Mitigation Plan 2018 Vulnerability Assessment Population Anyone who is outside during a thunderstorm is at risk of being struck by lightning. Aspects of the population who rely on constant, uninterrupted electrical supplies may have a greater, indirect vulnerability to lightning. As a group, the elderly or disabled, especially those with home health care services relying on rely heavily on an uninterrupted source of electricity. Resident populations in nursing homes, Community Based Residential Facilities, or other special needs housing may also be vulnerable if electrical outages are prolonged. If they do not have a back-up power source, rural residents and agricultural operations reliant on electricity for heating, cooling, and water supplies are also especially vulnerable to power outages. According to the Vaisala Group and National Lightning Detection Network, Wyoming ranked 37th among the 50 U.S. states, Puerto Rico, and Washington D.C. for overall lightning deaths between 1959 and 2009. This would suggest that lightning is not a major hazard for Wyoming. However, the state had the second highest per capita fatality rate within that same time period at 1.27 deaths per million people. Nationwide, 85% of lightning victims are children and young men ages 10-35 engaged in outdoor recreation or work. Outdoor recreation is a major economic contributor to Region 2. People may often find themselves outside and need to be especially watchful of the weather during the summer months when afternoon thunderstorms are more common. General Property According to the event details collected in the NCEI database, the majority of reported damages from lightning are fires to private structures, damage to chimneys or steeples, or small grass fires. Property is more vulnerable to lightning than population because of the exposure ratios. Buildings remain exposed. Mitigation techniques such as choice of building materials or landscaping help reduce the vulnerability of these properties, but there is not data available to segment these properties out of the overall vulnerability assessment. Essential Infrastructure, Facilities, and Other Important Community Assets Some essential infrastructures and facilities can be impacted by lightning. Emergency responders, hospitals, government services, schools, and other important community assets are not more vulnerable to lightning than the general vulnerabilities established for property and population. Some aspects of infrastructure are constructed of materials and/or located in places that increase their vulnerability to lightning. Sometimes, communications and infrastructure are interrupted by lightning strikes. These events raise the vulnerability of the essential functions by delaying response times, hindering interagency communication efforts, or endangering or damaging communication networks. ---PAGE BREAK--- Region 2 4-126 Regional Hazard Mitigation Plan 2018 Natural, Historic and Cultural Resources There are no indications that cultural or historic resources are more vulnerable to lightning than as previously accounted for as general structures. Natural resources may be vulnerable to indirect impacts of lightning, such as wild fires caused by lightning strikes. The presence of large areas of water, or of wide, open spaces in natural habitats may increase the danger of lightning strikes to trees, people, or structures, but these vulnerabilities are not directly related to natural resources. Campgrounds are areas where lightning strikes have more dangerous impacts, so populations utilizing the campgrounds may have a higher vulnerability. Finally, lightning can also have many cascading impacts, including power failure and ignition of wildfires. Future Development Any development built above ground will be susceptible to lightning strikes. Buildings should be built with grounding when possible to prevent the ignition of structure fires. Summary Lightning is an annual occurrence in Region 2, although strikes with recorded damage or injuries are much rarer. Anything that can conduct electricity and is exposed is vulnerable to lightning strikes and their effects. Future impacts from lightning are difficult to determine because of the erratic nature of storms, though it is reasonable to assume that impacts to people, infrastructure and the natural environment will continue into the foreseeable future. Table 4-57 Lightning Hazard Risk Summary County Geographic Extent Probability of Future Occurrence Potential Magnitude/ Severity Overall Significance Converse Significant Occasional Limited Low Natrona Significant Likely Limited Medium Niobrara Significant Likely Limited Medium 4.2.12 Mine and Land Subsidence Hazard/Problem Description Underground coal mining began in Wyoming during the 1860s. Many of the early coal mines were not designed and constructed well. Many were also shallow, and often had minimal ground support in the form of mine timbers. As a result, the underground pillars can fail. If enough pillars fail, the caprock in the mine will collapse. The effect of the collapse reaches the surface in some cases. If that happens, a subsidence pit, a sinkhole, or a trough forms. Mine subsidence is hence generally ---PAGE BREAK--- Region 2 4-127 Regional Hazard Mitigation Plan 2018 defined as the movement of the ground surface as a result of readjustments of the overburden, due to collapse or failure of the underground mine or land workings. Not all subsidence from mining is due to poor design, however. Most underground mines eventually have roof failures due to lack of maintenance and continuous loading of the unsupported rock layers overhead. In some cases, the pillars were pulled as mining retreated from an area. In other cases where fires occurred in the mines, the result is a loss of strength in the pillars and caprock. Geographical Area Affected A map showing documented subsidence in Wyoming is provided in Figure 4-53. Figure 4-54 shows abandoned mine sites that are likely to suffer from subsidence issues. Gray dots and polygons from the immediate figure below represent mined-out areas with subsidence; Region 2 is highlighted with a green rectangle. Figure 4-53 Mine Subsidence in Wyoming Solid gray polygons represent mined-out areas where subsidence occurs. Region 2 falls within the green rectangle. Source: 2016 Wyoming Multi-Hazard Mitigation Plan ---PAGE BREAK--- Region 2 4-128 Regional Hazard Mitigation Plan 2018 Figure 4-54 Abandoned Mine Sites with Subsidence-Prone Underground Workings Region 2 falls within the green rectangle. Source: 2016 Wyoming Multi-Hazard Mitigation Plan While the geographical extent of the hazard is limited, there are several abandoned mine sites with subsidence-prone underground workings in Converse County, especially in the southern areas bordering Albany and Platte Counties. Natrona also has a fair amount of these mine sites, spread throughout the county. Niobrara has the least number of mines, with most located towards the southern tip of the county, near the edge with Goshen County. Past Occurrences The 2016 Wyoming Hazard Mitigation Plan addresses mine subsidence, given it does occur occasionally throughout the state. Over the past several years, the Wyoming Abandoned Mine Lands (AML) Program at the Wyoming Department of Environmental Quality (DEQ) has funded a few large subsidence mitigation projects annually. This is in addition to a large number of traditional mine reclamation projects on both coal and non-coal mine sites, along with smaller projects aimed at protecting individual homeowners. Recent mine and land subsidence mitigation projects have focused on protecting critical infrastructure. ---PAGE BREAK--- Region 2 4-129 Regional Hazard Mitigation Plan 2018 Glenrock in Converse County, has been noted to be especially vulnerable to subsidence, and an HMPC member indicated that over 60% of the Town could be impacted. Though federal reclamation programs have been instituted, the mines surrounding the Glenrock community are subsiding and additionally prone to flooding. Neither Natrona or Niobrara Counties have reported major mine/land subsidence issues in recent times, however. Figure 4-55 displays the number of mined-out areas and mine subsidence events throughout the Region (enclosed within the green rectangle). Though all counties in the Region show some mine subsidence occurrences, the events may have taken place many years back and not reflect present- day risk potential. Figure 4-55 Mined-out Areas and Mine Subsidence Cases in Wyoming Source: 2016 Wyoming Multi-Hazard Mitigation Plan Frequency/Likelihood of Occurrence Although many areas of the state have already implemented mitigation projects designed to reduce or remove the impacts from underground mining and subsidence, subsidence may still occur in some areas. This hazard is rated occasional (between a 1% and 10% probability of occurrence in ---PAGE BREAK--- Region 2 4-130 Regional Hazard Mitigation Plan 2018 the next year). The potential for future damage from this hazard could additionally be reduced by mass adoption of a recent state effort, which created an assistance program for mine subsidence threats: the Wyoming Mine Subsidence Insurance Program. This program can help everyday citizens protect their home and business investments, given the insurance is affordable and addresses this specific hazard. Potential Magnitude Many mines in the Region have already been identified and mitigation work undertaken in the past, to remove the threat posed to the surrounding area; many identified mines that remain unmitigated pose little to no threat to infrastructure or property in the surrounding area. Any identified or unidentified mines located under or around buildings, roads, pipelines, or other critical infrastructure can pose higher risk to the surrounding area, including collapse, flooding, and unsettling of the ground. These risks vary by mine and area, though, but overall the potential magnitude/severity of this hazard to the Region is negligible. Vulnerability Assessment There has been property and infrastructure damage associated with mine subsidence in Wyoming communities before. The dollar amounts of the damage are not readily available. Underground coal fires can also occur in abandoned mines. The dollar impact attributed to these types of events is difficult to predict. An indirect measure of the impacts is the existing cost of mitigating the hazards. The AML Program has spent $303.4 million through 2013, mitigating the effects of mine subsidence alone, as part of the abandoned mine reclamation program. If any of the above mines are found to be un-reclaimed and appear to pose a hazard to the public, the Abandoned Mine Lands Program at the Wyoming Department of Environmental Quality should be contacted (Wyoming Hazard Mitigation Plan 2016). While hundreds of mine subsidence events have taken place across the Region in the last decades, vulnerability to the hazard is generally low due to minimal or no damages incurred by the jurisdictions or the individual populations. However, this risk should be further investigated when siting future development, especially in the Glenrock (Converse County) area, where occurrences have been known to take place several times before. Future Development Mine subsidence occurs throughout the Region in both populated and unpopulated areas. Development in locations where mine subsidence occurs certainly have the potential to impact individual homes or neighborhoods. While it is believed that all mined out areas in Wyoming have been mapped, it is unknown if all locations of potential subsidence have been located appropriately. The uncertainty regarding the locations of more potential subsidence areas means there is the possibility that development may occur in a subsidence-prone location without the knowledge of contractors or developers. Given this fact, there is no way to determine with certainty ---PAGE BREAK--- Region 2 4-131 Regional Hazard Mitigation Plan 2018 the likelihood that development will occur in a subsidence-prone location. Therefore, putting a risk factor to this hazard, as it relates to development within Wyoming’s borders, is rather complicated. Businesses seeking to lay pipelines, electrical transmission lines, develop a well site, or build another type of business structure in an area subject to subsidence hazards are typically referred to the AML during the environmental review process. This contact helps ensure new, developing infrastructure can be routed around problem areas, or if more efficient and possible, the area can be mitigated for subsidence hazards before structures or individuals are exposed to the hazard. Overall, the risk of mine subsidence across Region 2 is low. Summary Table 4-58 Mine and Land Subsidence Hazard Risk Summary County Geographic Extent Probability of Future Occurrence Potential Magnitude/ Severity Overall Significance Converse Significant Occasional Negligible Low Natrona Limited Occasional Negligible Low Niobrara Limited Unlikely Negligible Low 4.2.13 Severe Winter Weather Hazard/Problem Description The National Weather Service defines a storm as “any disturbed state of the atmosphere, especially affecting the Earth’s surface, and strongly implying destructive and otherwise unpleasant weather.” Winter storms occur during the winter months and produce snow, ice, freezing rain, sleet, and/or cold temperatures. Winter storms are an annual occurrence in climates where precipitation may freeze and are not always considered a disaster or hazard. Disasters occur when the severe storms impact the operations of the affected community by damaging property, stalling the delivery of critical services, or causing injuries or deaths among the population. Winter storm watches and warnings may be helpful for determining the difference between a seasonal winter storm and a severe winter storm. Warnings are issued if the storm is producing or suspected of producing heavy snow or significant ice accumulations. Watches are usually issued 24 to 36 hours in advance for storms capable of producing those conditions, though criteria may vary between locations. Winter Weather Advisories are issued when a low-pressure system produces a combination of winter weather that presents a hazard but does not meet warning criteria. (Source: National Weather Association Online Glossary, http://www.weather.gov/glossary/) ---PAGE BREAK--- Region 2 4-132 Regional Hazard Mitigation Plan 2018 Heavy snow can immobilize the counties in Region 2, isolating communities, stranding commuters, stopping the flow of supplies, and disrupting emergency and medical services. Accumulations of snow can collapse roofs and knock down trees and power lines. In rural areas, homes and farms may be isolated for days, and unprotected livestock may be lost. The cost of snow removal, damage repair, and business losses can have a tremendous impact on cities and towns. Heavy accumulations of ice can bring down trees, electrical wires, telephone poles and lines, and communication towers. Communications and power can be disrupted for days until damages are repaired. Even small accumulations of ice may cause extreme hazards to motorists and pedestrians. Some winter storms are accompanied by strong winds, creating blizzard conditions with blinding wind-driven snow, severe drifting, and dangerous wind chills. Strong winds with these intense storms and cold fronts can knock down trees, utility poles, and power lines. Blowing snow can reduce visibilities to only a few feet in areas where there are no trees or buildings. Serious vehicle accidents can result with injuries and deaths. Winter storms in the counties of the Region, including strong winds and blizzard conditions, may cause localized power and phone outages, closures of streets, highways, schools, businesses, and non-essential government operations, and increase the likelihood of winter-weather related injury or death. People may be stranded in vehicles or other locations not suited to sheltering operations or isolated from essential services. A winter storm can escalate, creating life threatening situations when emergency response is limited by severe winter conditions. Other issues associated with severe winter storms include the threat of physical overexertion that may lead to heart attacks or strokes. Snow removal costs can pose significant budget impacts, as can repairing the associated damages caused by downed power lines, trees, structural damages, etc. Heavy snowfall during winter can also lead to flooding or landslides during the spring if the area snowpack melts too quickly. Extreme cold often accompanies a winter storm, or is left in its wake. It is most likely to occur in the winter months of December, January, and February. Prolonged exposure to the cold can cause frostbite or hypothermia and can become life-threatening. Infants and the elderly are most susceptible. Pipes may freeze and burst in homes or buildings that are poorly insulated or without heat. Extreme cold can disrupt or impair communications facilities. Extreme cold temperatures can destroy crops and cause utility outages, leaving people without water or power until the utility companies are able to restore service. What constitutes extremely cold temperatures varies across different areas of the United States, based on normal climate temperatures for the time of year. In Wyoming, cold temperatures are normal during the winter. When temperatures drop at least 20 degrees below normal winter lows, the cold is considered extreme and begins to impact the daily operations of the county. Extreme cold/wind chill impacts plants, animals and water supplies. ---PAGE BREAK--- Region 2 4-133 Regional Hazard Mitigation Plan 2018 The effects of extremely cold temperatures are amplified by strong to high winds that can accompany winter storms. Wind-chill measures how wind and cold feel on exposed skin and is not a direct measurement of temperature. As wind increases, heat is carried away from the body faster, driving down the body temperature, which in turn causes the constriction of blood vessels, and increases the likelihood of severe injury or death to exposed persons. Animals are also affected by wind-chill however cars, buildings, and other objects are not. In 2001, the NWS implemented an updated Wind-Chill Temperature index. This index was developed to describe the relative discomfort/danger resulting from the combination of wind and temperature. Wind chill is based on the rate of heat loss from exposed skin caused by wind and cold. As the wind increases, it draws heat from the body, driving down skin temperature and eventually the internal body temperature. Figure 4-56 National Weather Service Wind-Chill Chart Source: National Weather Service Geographical Area Affected Winter storms are a yearly feature of the Wyoming climate and may occur anywhere in the state. Generally, severe winter storms and extreme cold events are considered regional, which implies the storms impact multiple counties simultaneously, often for extended time periods. It is possible for the geographic extent of the hazard to vary significantly within a single county - a regional storm may directly impact only a small portion of the planning area while still extending over a ---PAGE BREAK--- Region 2 4-134 Regional Hazard Mitigation Plan 2018 large portion of the surrounding area. However, even in these instances, while the percent of the planning area directly affected ranges from less than 10% to 100% depending on the specific circumstances, if any portion of the planning area is impacted by the storm then the entire planning area suffers indirect impacts. Therefore, they are considered to have an extensive geographic impact rating. Past Occurrences NCEI data on winter storms and extreme cold events in Region 2 extends from January 1996 through December 2017; during that period, the counties in Region 2 experienced 244 winter weather incidents, including blizzards, extreme cold, heavy snow, ice storms, winter storms and winter weather. There has been only 1 recorded injury and no recorded fatalities associated with these incidents; the single reported injury was a firefighter who was struck by a sliding car. Total reported property damages in the Region amounted to $3,019,000, with no reported crop damage. $3,000,000 of this property damage occurred in a single storm on October 3, 2013. From NCEI records: “Natrona County was hardest hit with over a foot of snow in most parts of the County, including 16.2 inches at the Casper Airport and up to 22 inches in the foothill areas of Casper Mountain. The heavy, wet snow fell on trees that still had full foliage and caused branches and in some cases whole trees to fall. Many of these landed on power lines and caused widespread power outages. Around 14,000 customers were without power at the peak of the storm. Several warming shelters were established along the I-25 corridor to help those without heat. The heavy snow also brought many road closures to central Wyoming. In Casper, snowfall of 16.2 inches was the tenth highest storm total since records began in 1937 and held a liquid water content of 2.14 inches. The highest snowfall amounts fell in the higher elevations with over two feet of snow recorded in the higher elevations of the Wind River, Bighorn, and Absaroka ranges, as well as Casper Mountain. The highest amount was at the Reno Hill SNOTEL where 34 inches of snow was recorded.” Table 4-59 Winter Weather Events Summary 1996-2017 County Winter Storms Ice Storms Extreme Cold Injuries/ Fatalities Property Damage Crop Damage Total Damage Converse 48 0 8 0 / 0 $0 $0 $0 Natrona 159 0 1 1 / 0 $3,019,000 $0 $3,019,000 Niobrara 27 1 1 0 / 0 $0 $0 $0 Source: NCEI. The “Winter Storm” column includes events labelled as blizzards, heavy snow, winter storm or winter weather. The most significant blizzard in Wyoming’s history occurred from January 2, 1949 to February 20, 1949. Snowfall in parts of eastern and southeastern Wyoming measured up to 30 inches, with drifts 20 to 30 feet high. Seventeen people perished, along with 55,000 head of cattle and over 105,000 sheep. Total economic loss was more than $9 million dollars. In 2009 dollars, the loss would be over $81 million. The most extreme cold event on record in Wyoming occurred in March 1975, when zero-degree temperatures combined with 40-50 mph winds caused livestock losses worth $12,312,872 ---PAGE BREAK--- Region 2 4-135 Regional Hazard Mitigation Plan 2018 (adjusted to 2016). Another cold wave in December 1983 brought low temperatures between - 20°F and -40°F, resulting in $6,650,688 in damages, primarily from freezing water pipes. In late January 1996, record low temperatures were recorded for many areas, with 38 below zero recorded in Worland on the morning of January 31st. Low temperatures in the western Bighorn Mountains dropped to between ten below zero and 45 below zero during this time across the State of Wyoming. On the 1st, strong winds lowered wind chill temperatures to as low as 60 below zero in some locations. Some young livestock were frozen. The cold also froze many pipes and caused some water lines to break or leak. A number of schools and events were cancelled across the state during this time. About forty residences were without natural gas in the Big Horn Basin on the 3rd due to the cold causing a valve malfunction. Many accidents occurred on the 1st due to poor visibility. One person froze to death just north of Buffalo, WY early on the 2nd after walking for help after his car broke down. On December 30th, 2014, northerly flow following the passage of an Arctic cold front brought brutally cold temperatures and dangerous wind chills to much of western and central Wyoming. The Daniel cooperative observer recorded a low temperature of -48F on the morning of Wednesday, December 31st. In addition, many locations across Fremont, Hot Springs, Lincoln, Sweetwater and Washakie counties saw temperatures of -30F to -35F. Wind chill temperatures of -30F were common. The following table shows regional temperature profiles based on data from the Western Regional Climate Center for sensor locations in each county. The record low for the Region is -43°F in Douglas in 1919. Table 4-60 Region 2 Temperature Summaries County Station Winter1 Average Minimum Temperature Summer1 Average Maximum Temperature Highest Recorded Maximum Temperature Lowest Recorded Minimum Temperature # Days >90qF/ Year # Days <32qF/ Year Converse Douglas 13° F 83.7° F 106° F 7/25/1931 -43° F 12/09/1919 26 180 Natrona Casper WSO AP 14.8° F 84.1° F 104° F 7/12/1954 -41° F 12/21/1990 30 180 Niobrara Lusk 2 12.7° F 82.4° F 105° F 7/27/1931 -38° F 1/14/1972 25 190 Source: Western Regional Climate Center, www.wrcc.dri.edu/ 1Winter: December, January, February; Summer: June, July, August Frequency/Likelihood of Occurrence Winter storms and extreme cold are an annual occurrence in Wyoming, often occurring multiple times each winter, and affecting entire regions in their size and scope. Since 1996, the Region has averaged around 10 days with a recorded severe winter weather incident per year. ---PAGE BREAK--- Region 2 4-136 Regional Hazard Mitigation Plan 2018 It is important to note that the lack of specific historical accounts on extreme cold temperatures does not necessarily indicate a low frequency of occurrence. Residents of Wyoming are used to cold weather, and may be less likely to report events that might be considered extreme in other areas. Potential Magnitude The damages caused by severe winter storms, blizzards and extreme cold vary and are dependent on several factors: the duration of the storm; the geographic extent; the time of year; meteorological factors such as wind, moisture content of the snow, ground and air temperatures; and the advance warning of the storm. Impacts from the storm dictate the magnitude of the event, emphasizing that the amount snow may not always directly correlate to how bad the storm is. Damaged power lines and dangerous or impassable roadways may forestall the delivery of critical services such as medical and emergency assistance, the delivery of food supplies and medications, or even the provision of basic utilities such as heat and running water. When events happen with a long warning time, it is possible to pre-mitigate the effects of insufficient supply levels or to pre- test emergency generators, which may prevent some of the previously described impacts from occurring. Unanticipated storms increase the number of people stranded, both in cars and at public locations, which may increase the number of injuries and deaths attributed to the event (often caused by exposure) and place uneven and unanticipated strains on public sheltering capacities. The weight of the snow, driven by the water content of the fall, increases the potential for damages caused to structures and trees. Lighter snow caused by extreme cold increases the damages caused to livestock, agriculture and landscaping due to freezing conditions. Winter storms which go through periods of thaw and freeze prolong dangerous icy conditions, increasing the likelihood of frozen and damaged water pipes, impassable or dangerous roadways, damaged communication lines, or more extensive damages to infrastructure and structures caused by seeping water freezing under roofs, porches, patios, inside sidings, or causing damage to vehicles. Extreme cold can also impact livestock and even crops if the event occurs during certain times of the year. Winter storms usually cover a significant part of the state, and as such are easier to describe regionally than on a county by county basis. Vulnerability Assessment Population The threat to public safety is typically the greatest concern during severe winter storms. While virtually all aspects of the population are vulnerable to severe winter weather, there are segments of the population that are more vulnerable to the potential indirect impacts of a severe winter storm than others, particularly the loss of electrical power. As a group, the elderly or disabled, especially those with home health care services that rely heavily on an uninterrupted source of electricity. Resident populations in nursing homes or other special needs housing may also be vulnerable if electrical outages are prolonged. If they do not have a back-up power source, rural residents and ---PAGE BREAK--- Region 2 4-137 Regional Hazard Mitigation Plan 2018 agricultural operations reliant on electricity for heating and water supplies are also especially vulnerable to power outages. Extreme cold/wind chill pose the greatest danger to outdoor laborers, such as highway crews, police and fire personnel, and construction. The elderly, children, people in poor physical health, and the homeless are also vulnerable to exposure. Overall, the population has a medium exposure to severe cold. Severe winter weather also increases the vulnerability of the commuting population. While there is no way to quantify which of these accidents occur during severe winter storms versus regular winter storms, the numbers indicate that winter driving conditions raise the vulnerability of the commuting population. General Property Property vulnerabilities to severe weather include damage caused by high winds, ice, or snow pack and subsequently melting snow. Vehicles may be damaged by the same factors, or temporarily un- useable due to the driving conditions created by severe winter weather. Contents of homes, storage units, warehouses and storefronts may be damaged if the structures are compromised or fail due to the weather, or during potential flooding caused by melting snow. Very wet snow packs down densely and is very heavy. This may create strains on structures, causing partial or entire collapses of walls, roofs, or windows. This is impacted both by architecture and construction material, and should be assessed on a building-by-building basis. These records are probably tracked via insurance or other private vendors. Crops, livestock and other agricultural operations are also highly vulnerable to severe winter storms. Extreme cold/wind chill presents a minimal risk to the structures of Region 2. Property damage occurs occasionally when water pipes freeze and break. Homes without adequate insulation or heating may put owners at a higher risk for damages or cold-related injury. In cases of periods of prolonged cold, water pipes may freeze and burst in poorly insulated or unheated buildings. Vehicles may not start or stall once started due to the cold temperatures and the risks of carbon monoxide poisoning or structure fires increases as individuals attempt to warm cars in garages and use space heaters. Stalled vehicles, or those that fail to start, may result in minor economic loss if individuals are unable to commute between work, school, and home. Driving conditions may deteriorate if extreme cold/wind chill prolongs icy road conditions, which will impact commutes and emergency response times as well. Landscaping and agricultural products may be damaged or destroyed by unseasonable occurrences of extreme cold/wind chill, causing plants to freeze and die; this may increase the indirect vulnerabilities to severe cold by causing greater economic costs and losses for the year. The overall vulnerability of general property is low. Essential Infrastructure, Facilities, and Other Important Community Assets The physical structures which comprise essential infrastructure are as vulnerable as those outlined in the General Property subsection of this profile. Severe winter weather may also disrupt the ---PAGE BREAK--- Region 2 4-138 Regional Hazard Mitigation Plan 2018 availability of services from essential infrastructure, including utility delivery (gas, electric and water), telephone service, emergency response personnel capabilities, road plowing, and childcare availability. Severe winter storms may even halt the operation of an area for periods of time, making the vulnerability of the counties even higher. Like general property, extreme cold/wind chill events have a limited impact on the physical property of essential infrastructures and facilities. Communications lines such as fiber optic cables can freeze. There may be incidents of delayed emergency response due to stalled vehicles, delays in dispatching due to frozen communications lines, or an increased volume in calls. Hospitals may see an increase in cold-related injuries directly or injuries associated as secondary effects of the cold (traffic accidents, broken bones or severe cuts due to slips, etc.) and a prolonged extreme cold/wind chill event may impact hospital personnel capabilities. Personnel working in the cold, such as firefighters, EMTs, police officers and construction workers, have a higher vulnerability due to exposure times, and response capabilities may be hindered. Human services programs that care for at-risk individuals and families may be stressed, but usually can still adequately provide services through the duration of the extreme cold/wind chill event. Unusually high volumes of individuals seeking shelter or food may overwhelm some facilities if the event is prolonged. There may be an increased number of displaced individuals or families due to flooding caused by ruptured pipes, which may strain local aid organizations such as the Red Cross. Older venues or historical properties suffer the same vulnerabilities associated with private and general properties that are older, with the added vulnerability of damaging historic and often irreplaceable property in the process. If the event is extremely extended and impacts multiple other counties and states, which in turn impacts the availability of mutual assistance, the risk factors may increase. The overall vulnerability of essential infrastructure and community assets is medium. As mentioned previously, ice or heavy accumulations of snow, particularly with blowing and drifting, can temporarily impact the roadway system. These accumulations also require vast amounts of overtime for county highway and local streets departments to remove snow and melt ice. Ice storms or high winds in winter storms can cause extensive loss of overhead utility lines due to buildup either on the lines or on adjacent trees that either collapse due to the weight or blow down onto the utility lines. Services such as telephone, electricity, and cable TV are frequently affected by winter storms. The overall vulnerability of essential infrastructure is medium. Natural, Historic and Cultural Resources Natural resources may be damaged by the severe winter weather, including broken trees and death of unsheltered wildlife. Unseasonable storms may damage or kill plant and wildlife, which may impact natural food chains until the next growing season. Historical areas may be more vulnerable to severe winter storms due to construction and age of structures. Cultural resources generally experience the same vulnerabilities outlined in General Property, in addition to lost revenue impacts due to transportation impacts. The overall vulnerability of these resources is medium. ---PAGE BREAK--- Region 2 4-139 Regional Hazard Mitigation Plan 2018 Future Development Where building codes are applicable, future residential or commercial buildings built to code should be able to withstand snow loads from severe winter storms. Future power outages or delays in power delivery to future developments may be mitigated by construction considerations such as buried power lines. Future development will also require future considerations for snow removal capacity including equipment, personnel, and logistical support. Adequate planning will help establish the cost-effective balance. Due to the relative prevalence of cold incidents across the Region, it is common practice to build infrastructure with the appropriate safeguards to protect it from extreme cold incidents. This practice will continue as infrastructure is built to face the realities of living in Wyoming. Public education efforts may help minimize the risks to future populations by increasing knowledge of appropriate mitigation behaviors, clothing, sheltering capacities, and decision making regarding snow totals, icy roads, driving conditions, and outdoor activities (all of which are contributors to decreased public safety during severe winter storms). New establishments or increased populations who are particularly vulnerable to severe winter storms (such as those with health concerns or those who live in communities that may be isolated for extended periods of time due to the hazard) should be encouraged to maintain at least a 72-hour self-sufficiency as recommended by FEMA. Encouraging contingency planning for businesses may help alleviate future economic losses caused by such hazards while simultaneously limiting the population exposed to the hazards during commuting or commerce-driven activities. Summary Residents of the Region are generally well-adapted to severe winters and cold temperatures. Nevertheless, Severe Winter Storms are generally a high significance hazard in the Region due to the widespread nature, severity, and potential impacts to life and property. Table 4-61 Winter Weather Hazard Risk Summary County Geographic Extent Probability of Future Occurrence Potential Magnitude/ Severity Overall Significance Converse Significant Highly Likely Limited High Natrona Significant Highly Likely Limited High Niobrara Significant Highly Likely Limited High ---PAGE BREAK--- Region 2 4-140 Regional Hazard Mitigation Plan 2018 4.2.14 Tornado Hazard/Problem Description A tornado is a swirling column of air extending from a thunderstorm to the ground. Maximum winds in tornadoes are often confined to extremely small areas, and vary tremendously over very short distances, even within the funnel itself. Tornadoes can have wind speeds from 40 mph to over 300 mph, the majority displaying wind speeds of 112 mph or less. Erratic and unpredictable, they can move forward at up to 70 miles per hour, pause, slow down and change directions. Most have a narrow path, less than 100 yards wide and a couple of miles long. However, damage paths from major tornadoes can be more than a mile wide and 50 miles long. Based on national statistics for 1970 – 1980, for every person killed by a tornado, 25 people were injured and 1,000 people received some sort of emergency care. Tales of complete destruction of one house next to a structure that is totally unscathed are well documented. Within a building, flying debris or missiles are generally stopped by interior walls. However, if a building has no partitions or has any glass, brick or other debris blown into the interior, the tornado winds can be life threatening. In order to examine tornado activity and the potential impact on the Region and its residents, it is important to understand how tornadoes are rated. Rating a Tornado In 1971, Dr. T. Theodore Fujita of the University of Chicago devised a six-category scale to classify U.S. tornadoes into intensity categories, F0 through F5. These categories are based upon the estimated maximum winds occurring within the funnel. The Fujita Tornado Scale (or the "F Scale") became the definitive scale for estimating wind speeds within tornadoes based upon the damage done to buildings and structures. It is used extensively by the National Weather Service in investigating tornadoes, and by engineers in correlating damage to building structures and techniques with different wind speeds caused by tornadoes. Table 4-62 Fujita Scale Description F-Scale Number Intensity Phrase Wind Speed Type of Damage Done F0 Gale tornado 40-72 mph Some damage to chimneys; breaks branches off trees; pushes over shallow-rooted trees; damages signboards. F1 Moderate tornado 73-112 mph The lower limit is the beginning of hurricane wind speed; peels surface off roofs; mobile homes pushed off foundations or overturned; moving autos pushed off the roads; attached garages may be destroyed. F2 Significant tornado 113-157 mph Considerable damage. Roofs torn off frame houses; mobile homes demolished; boxcars pushed over; large trees snapped or uprooted; light object missiles generated. ---PAGE BREAK--- Region 2 4-141 Regional Hazard Mitigation Plan 2018 F-Scale Number Intensity Phrase Wind Speed Type of Damage Done F3 Severe tornado 158-206 mph Roof and some walls torn off well-constructed houses; trains overturned; most trees in forest uprooted F4 Devastatin g tornado 207-260 mph Well-constructed houses leveled; structures with weak foundations blown off some distance; cars thrown and large missiles generated. F5 Incredible tornado 261-318 mph Strong frame houses lifted off foundations and carried considerable distances to disintegrate; automobile sized missiles fly through the air in excess of 100 meters; trees debarked; steel reinforced concrete structures badly damaged. Source: NOAA Changes to Tornado Rating Scale Devastating tornadoes in Jarrell, Texas on May 1997 and Moore/Oklahoma City on May 1999 demonstrated to that the wind estimates in the original F-scale may be too high. From 2000 to 2004, the Wind Science and Engineering Research Center at Texas Tech University, in cooperation with numerous expert meteorologists, civil engineers and the National Weather Service (NWS), developed an Enhanced Fujita Scale, or EF-scale. In addition to improving the ranking process, it was essential to the development team that the new EF-scale support and be consistent with the original F-scale. The EF-scale documentation includes additional enhanced descriptions of damage to multiple types of structures and vegetation with photographs, a PC-based expert system, and enhanced training materials. In February 2007, the Enhanced Fujita scale replaced the original Fujita scale in all tornado damage surveys in the United States. The following table compares the estimated winds in the original F- scale with the operational EF-scale that is currently in use by the NWS. Table 4-63 The Enhanced Fujita Tornado Scale Fujita Scale Operational EF-Scale F Number Fastest Fastest 1/4 – mile (mph) 3 Second Gust (mph) EF Number 3 Second Gust (mph) 0 40-72 45-78 0 65-85 1 73-112 79-117 1 86-110 2 113-157 118-161 2 111-135 3 158-207 162-209 3 136-165 4 208-260 210-261 4 166-200 5 261-318 262-317 5 Over 200 Source: NOAA ---PAGE BREAK--- Region 2 4-142 Regional Hazard Mitigation Plan 2018 Geographical Areas Affected The entire area of the Region is susceptible to tornadoes. While some areas may have seen more tornadoes than others, this is more of a statistical anomaly than a causal result. Figure 4-57 Region 2 Tornadoes ---PAGE BREAK--- Region 2 4-143 Regional Hazard Mitigation Plan 2018 Past Occurrences Tornado statistics, especially prior to the 1970s, must be viewed as incomplete since many twisters occurred without being witnessed. Wyoming's open rangelands experience little if any damage from these storms, so many go unreported. Many documented tornadoes occurring in the counties in Region 2 are given low ratings on the Fujita Scale (F0s and F1s) simply because these tornadoes are often formed over open land and result in little or no damage. Since 1950, there have been 101 tornadoes between the three counties of Region 2, as documented by the National Climatic Data Center. These tornadoes resulted in 18 injuries, no fatalities, and $2,640,600 in total recorded property damage in the Region. Table 4-64 Tornado History by County, Region 2 (1950-2016) County Total Incidents Magnitude Damage- Causing Incidents Fatalities Injuries Property Damage Converse 34 0-2 8 0 5 $205,150 Natrona 33 0-2 12 0 8 $655,300 Niobrara 34 0-2 17 0 5 $1,780,150 Total 101 0-2 37 0 18 $2,640,600 Source: NOAA NCEI data allows for examination and statistical analysis of tornadoes occurring in the Region. The majority of the historical tornadoes in the Region were rated F0 or EF0; the most powerful tornado recorded across the counties in Region 2 was rated as an EF2. ---PAGE BREAK--- Region 2 4-144 Regional Hazard Mitigation Plan 2018 Table 4-65 History of Damage-Causing Tornadoes, Region 2 (1950-2016) County Date Magnitude Fatalities Injuries Property Damage Crop Damage Niobrara 1982-06-05 2 0 3 $500,000 $0 Niobrara 1984-06-13 2 0 1 $500,000 $0 Niobrara 1978-07-28 2 0 0 $500,000 $0 Natrona 1987-06-18 2 0 0 $500,000 $0 Natrona 1962-06-11 2 0 4 $50,000 $0 Converse 1982-06-05 1 0 3 $50,000 $0 Niobrara 1960-05-24 1 0 1 $50,000 $0 Converse 1965-06-14 1 0 1 $50,000 $0 Natrona 1978-07-20 2 0 1 $50,000 $0 Converse 1982-06-05 2 0 1 $50,000 $0 Natrona 1962-06-15 1 0 0 $50,000 $0 Niobrara 1962-07-17 1 0 0 $50,000 $0 Niobrara 1976-04-12 1 0 0 $50,000 $0 Niobrara 1979-08-01 0 0 0 $50,000 $0 Converse 1984-06-13 1 0 0 $50,000 $0 Niobrara 1984-06-13 1 0 0 $50,000 $0 Niobrara 1953-06-11 1 0 0 $5,000 $0 Niobrara 1960-06-26 1 0 0 $5,000 $0 Niobrara 1977-05-09 1 0 0 $5,000 $0 Niobrara 1983-06-20 0 0 0 $5,000 $0 Converse 1984-06-13 0 0 0 $5,000 $0 Niobrara 1985-07-26 0 0 0 $5,000 $0 Niobrara 1985-07-26 0 0 0 $5,000 $0 Natrona 1988-07-07 1 0 0 $5,000 $0 Niobrara 1950-06-07 1 0 0 $50 $0 Niobrara 1952-05-08 1 0 0 $50 $0 Converse 1955-07-25 0 0 0 $50 $0 Natrona 1962-06-12 1 0 0 $50 $0 Natrona 1968-09-02 0 0 0 $50 $0 Natrona 1969-05-15 0 0 0 $50 $0 Natrona 1974-08-09 1 0 0 $50 $0 Natrona 1975-05-08 1 0 0 $50 $0 Converse 1977-06-20 1 0 0 $50 $0 Converse 1982-06-05 0 0 0 $50 $0 Natrona 1982-06-05 0 0 0 $50 $0 Niobrara 1983-06-20 1 0 0 $50 $0 Natrona 1971-05-29 2 0 3 $0 $0 TOTALS 0 18 $2,640,600 $0 Source: NOAA ---PAGE BREAK--- Region 2 4-145 Regional Hazard Mitigation Plan 2018 Figure 4-58 was created by Western Water Assessment based on their analysis of NCEI data; shows the number of tornado events in Wyoming per county from 1950-2017. Figure 4-58 Tornado Events in Wyoming, 1950-2017 ---PAGE BREAK--- Region 2 4-146 Regional Hazard Mitigation Plan 2018 Figure 4-59 EF-Scale Tornadoes by Rating – Region 2 Source: NOAA The data also allows for the development of profiles on historical time periods of tornadoes. Figure 4-60 and Figure 4-61 give historical perspective on the time of year and time of day that tornadoes in the region have occurred. Figure 4-60 Region 2 Historical Tornadoes by Month: 1950-2016 Source: NOAA Historically, tornadoes occur in the spring/summer months between April and September, with the highest number of tornadoes occurring in June. EF2 9% EF1 21% EF0 70% 0 5 10 15 20 25 30 35 40 45 50 APR MAY JUN JUL AUG SEP ---PAGE BREAK--- Region 2 4-147 Regional Hazard Mitigation Plan 2018 Figure 4-61 Historical Tornadoes by Time of Day: 1950-2016 Source: NOAA Historical tornadoes in Region 2 occurred mainly between 10am and midnight, with prime hours being 3:00 pm to 9:00 pm. Most tornadoes recorded in the Region cause no recorded injuries, no recorded fatalities, and little to no damage to property - $5,000 range). Of the 101 tornadoes that have been recorded by NOAA in Region 2 from 1950 to 2016, 37 (37%) have caused recorded property damage or injuries, and none have caused recorded crop damage. Frequency/Likelihood of Occurrence There were 101 tornadoes in the Region recorded between 1950 and 2016; of those, 37 resulted in damage or injuries. Each of the three counties in Region 2 experience a tornado roughly every two years. The frequency of damaging tornadoes varies from one every 8.4 years in Converse County, to one every 5.6 years in Natrona County, to one every 3.9 years in Niobrara. On average, Region 2 experienced 1.5 recorded tornadoes per year, and experienced a damaging tornado every 1.8 years; this trend will likely continue into the future. Potential Magnitude The National Weather Service considers tornadoes to be among nature’s most violent storms. The most violent tornadoes are capable of tremendous destruction with wind speeds of 250 mph or more. Tornadic winds can cause people and autos to become airborne, can tear homes to shreds, and can turn broken glass and other debris into lethal missiles. Even weaker tornados can cause major damage. The wind zone map shown below indicates the potential magnitude of wind speeds. Most of Region 2 is located in Zone II, which can expect winds up to 160 mph. 0 5 10 15 20 25 30 10am11am12pm 1pm 2pm 3pm 4pm 5pm 6pm 7pm 8pm 9pm 10pm11pm12am 1am 2am ---PAGE BREAK--- Region 2 4-148 Regional Hazard Mitigation Plan 2018 Figure 4-62 Wind Zones in the United States Source: FEMA According to NCEI records, the storm of record for Region 2 occurred on June 5, 1982, when a severe thunderstorm complex spawned five tornadoes across all three counties in the planning area. All told, the five tornadoes destroyed two mobile homes and a barn, and damaged several other structures as well as several cars, and injuring seven individuals; total property damage was over $300,000. Though the strength of a tornado often dictates the impacts, it is important to remember that the location (rural or urban) of a tornado is just as important when assessing these risks, and that location is a random factor. Vulnerability Assessment Because of its rural composition, people or property within the county have not been historically impacted during past tornado incidents. While the F-Scale ratings of historical tornadoes in the counties in the Region are low, those ratings are partially based on recorded damage; recorded damage may have been much more substantial if these tornadic events had impacted one of the many communities in the Region, rather than timber, outlying range, and farm acreage. Tornadoes occur at random throughout the Region; all structures, critical facilities, essential services, and populations are considered vulnerable. ---PAGE BREAK--- Region 2 4-149 Regional Hazard Mitigation Plan 2018 Future Development Any future development that is exposed and above ground will be vulnerable to a direct or indirect hit by a tornado. Generally, most areas in the Region lack building codes. In areas where building codes are not in place and enforced, buildings may not be built to withstand tornado-force winds. Summary Historically, the impacts to the counties and the Region from tornadoes has been low; however, depending on a tornado’s size, intensity and path, it can cause severe impacts to people, property and infrastructure. Table 4-66 Tornado Hazard Risk Summary County Geographic Extent Probability of Future Occurrence Potential Magnitude/ Severity Overall Significance Converse Significant Occasional Limited Medium Natrona Significant Occasional Limited Medium Niobrara Significant Occasional Limited Medium 4.2.15 Wildland Fire Hazard/Problem Description Wildland Fire is defined as a highly destructive fire or any instance of uncontrolled burning in grasslands, brush or woodlands. Wildfire has encroached into urban interface situations as more people move closer to forest settings. As defined by the National Interagency Fire Center (NIFC), a “wildland fire” is any non-structure fire, other than prescribed fire, that occurs in the wildland. The term “wildland/urban interface” or WUI is widely used within the wildland fire management community to describe any area where man-made buildings are constructed close to or within a boundary of natural terrain and fuel, where high potential for wildland fires exists. “Aspect” refers to the direction in which a slope faces. “Fuel” consists of combustible material, including vegetation, such as grass, leaves, ground litter, plants, shrubs, and trees that feed a fire. Wildfires can occur at any time of the year, but are most likely to occur during the spring, summer or fall. Thunderstorms that contain lightning frequently start wildfires, but they can also be caused by humans. Wyoming’s semi-arid climate and rural character make the state vulnerable to catastrophic wildland fires, which comprise more than 50% of all fires in Wyoming. As the population and the wildland/urban interface in Wyoming increases, the risk of wildland fire becomes more significant. The past 100 years of wildland fire suppression has led to heavy vegetation growth and thus has greatly increased the potential fuel-load for a wildfire to burn. As the wildland/urban interface has grown into these densely packed forests, the potential for catastrophic wildland fires has increased as well. Fires have historically played a natural role on ---PAGE BREAK--- Region 2 4-150 Regional Hazard Mitigation Plan 2018 western landscapes. For example, some species of trees occupy sites following fire until replaced by more shade-tolerant species. In some cases regeneration of vegetation can be enhanced by fire. Fires may have positive or negative effects, or both, depending upon the resources at risk in the fire area. Geographical Area Affected Certain areas of the counties in Region 2, because of their semi-arid climate and availability of fuel, are vulnerable to catastrophic wildland fires. Historically, over 50% of all wildfires in Wyoming involve wildland areas. A major portion of the Region is susceptible to wildfires, with the exception of areas above the tree line. According to the methodology for characterizing spatial extent, a significant portion of the planning area is affected by wildfires. The wildland and wildland-urban interface areas are of most concern and are shown in Figure 4-63, based on the Wildland Urban Interface Hazard Assessment. This assessment was produced by a joint venture of the Wyoming State Forestry Division, USFS, BLM, NPS, and other interested parties. This Geographic Information System (GIS)-based mapping effort builds on the Front Range Redzone Project in Colorado. The Assessment seeks to map fire hazard incorporating population density against slope, aspect, and fuel conditions. With the mapping analysis evaluating areas of varying wildfire vulnerability, the final output results in a Risk, Hazard, and Value (RHV) map displaying areas of concern (called Redzones) for catastrophic wildland fires. According to the Redzones analysis, the following areas seem to be at highest risk, based on wildfire-prone vulnerable characteristics: • Converse County has characteristics that indicate that a Catastrophic Fire is possible, especially surrounding the Towns of Rolling Hills and Glenrock • The southern tip of Converse, along the boundary with Albany County, could also experience wildland fires • Parts of Natrona County towards the southeast, including Casper, Mills, Bar Nunn, and Evansville • All areas in or near forest lands, such as near the Medicine Bow-Routt National Forest and Thunder Basin National Grassland ---PAGE BREAK--- Region 2 4-151 Regional Hazard Mitigation Plan 2018 Figure 4-63 Region 2 Wildland Fire Redzones ---PAGE BREAK--- Region 2 4-152 Regional Hazard Mitigation Plan 2018 Past Occurrences The Federal Wildland Occurrence Database was used to analyze fire history in Region 2. The database, maintained by the USGS and other agencies, includes perimeter and point GIS layers for fires on public lands throughout the United States. The data includes fires dating back to 1980. The National Park Service, Bureau of Land Management, and U.S. Forest Service reports include fires of 10 acres and greater. The database is limited to fires on federal lands. Some fires may be missing altogether or have missing or incorrect attribute data. Some fire information may be lacking because historical records were lost or damaged, fires were too small for the minimum cutoffs, documentation was inadequate, or fire perimeters have not yet been incorporated into the database. Also, agencies are at different stages of participation. For these reasons, the data should be used cautiously for statistical or analytical purposes. The following figure shows wildfires that have affected the area based on the Federal Wildland Occurrence Database. Some of the largest recorded fires occurred in central Converse County, southeast Natrona, edge between northeast Natrona and northwest Converse, southern top of Converse County (on the boundary with Albany County), and northwest Niobrara. Some of the more significant fires are discussed by county in the following section. ---PAGE BREAK--- Region 2 4-153 Regional Hazard Mitigation Plan 2018 Figure 4-64 Region 2 Wildland Fire Occurrences 1980-2016 ---PAGE BREAK--- Region 2 4-154 Regional Hazard Mitigation Plan 2018 Converse County Converse County has had 29 recorded fires of over 1,000 acres in size since 1980; a portion of the wildfires occurred in heavily vegetated area such as the Medicine Bow Routt National Forest and the Thunder Basin National Grasslands. The largest fire in the county (Boner) took place in 2006, and was deemed as a natural-sourcing wildfire that burned almost 54,000 acres. 2006 was the year with the most fires in the database, with six large scale events recorded. Orpha, which happened in 2010, burned 25,093 acres and is the second largest single wildfire in the county since 1980; it was human-caused. In total there have been 212,920 acres affected by wildfires in the County. The table below describes Converse County wildfires that burned 1,000 or more acres between 1980 and 2016, sorted by size. Table 4-67 Wildfires over 1,000 acres in Converse County: 1980-2016 Fire Name Acres Burned Cause Year Boner 53,930 Natural 2006 Orpha 25,093 Human 2010 Hensel 14,855 Natural 2002 Twenty Mile 11,083 Natural 2006 11,042 Natural 2000 Thompson 10,464 2011 Antelope 10,000 Human 1999 Walker 10,000 Human 1999 Henry’s 9,500 Natural 1996 Willow Creek 9,239 2010 Little boxelder 5,882 Natural 2012 Carson 5,670 Human 2011 Douglas 5,199 2000 Russells Camp 4,905 Natural 2012 Bixby 3,030 Human 2005 Converse 3 2,955 2011 Walker Creek 2,764 2006 Harshman 2,128 Natural 2000 Cheyenne River 2,000 Natural 2006 Converse 8 1,964 2011 Ugly 1,827 Natural 2000 Olmstead D 1,520 Natural 1996 Elk Mountain 1,322 2006 Converse 7 1,184 2011 Ross #1 1,160 Natural 1996 Lance Creek 1,116 Natural 2006 Sand Creek 1,044 Natural 2012 Lake Creek 1,034 Natural 2003 Wagonhound 1,010 Human 2015 Source: Federal Wildland Occurrence Data. A double dash symbol means the cause of the fire is not available in the database. ---PAGE BREAK--- Region 2 4-155 Regional Hazard Mitigation Plan 2018 Natrona County Historically, most significant fires in Natrona County have occurred in the southeastern parts, south of Casper. Natrona has had a total of 21 fires of over 1,000 acres in size since 1980, with 122,146 burned acres (see Table 4-68). The largest fire in the county occurred in 2006, burning 16,503 acres. It was the Sawmill fire. The second most damaging fire, Sheepherder Hill, burned 15,556 acres. While 13 wildfires were natural-caused, 7 were caused by human actions and one records its cause as both human/natural- derived. The table below describes Natrona County wildfires that burned 1,000 or more acres between 1980 and 2016. Table 4-68 Wildfires over 1,000 acres in Natrona County: 1980-2016 Fire Name Acres Cause Year Sherwood 2,000 Natural 1980 Goat Mtn 6,661 Natural 1985 Mudsprings 2,266 Human 1991 1,667 Natural 1995 Geary D. 2 14,700 Natural 1996 Cole Creek 9,290 Human 1996 Lawn Creek 1,033 Human 1998 Henderson 8,390 Natural 2000 Deadhorse 5,900 Natural 2000 33 Mile 2,514 Natural 2000 Hemmingway 1,069 Natural 2000 Casper Creek 1,354 Natural 2001 Sage Hen 1,271 Natural 2005 Sawmill 16,503 Natural 2006 Jackson Canyon 11,765 Natural 2006 Poison Spider 3,166 Natural 2006 Geary Dome 2,879 Human 2010 205 Fire 2,573 Human 2011 Arapahoe 2,073 Human 2011 Sheepherder Hill 15,556 Human/Natural 2012 Station AKA Cole 9,516 Human 2015 Source: Federal Wildland Occurrence Data. Niobrara County Large fires in Niobrara have taken place in the northwest and southeast of the county, but smaller ones have burned through the northeast (near the Cheyenne River), about 4 miles northwest of Manville, and sporadically throughout. The most damaging fire in Niobrara occurred in 2002, burning 5,025 acres (Tollman Fire). Three additional fires of over 1,000 acres took place in the county, however: one in 2007 and two in 2011. A total of 10,523 acres have been affected by these four major wildfires in Niobrara. Table 4-69 below summarizes these large wildfire occurrences. ---PAGE BREAK--- Region 2 4-156 Regional Hazard Mitigation Plan 2018 Table 4-69 Wildfires over 1,000 acres in Niobrara County: 1980-2016 Fire Name Cause Year Total Acres Burned Tollman Natural 2002 5,025 Smith 2011 2,201 77 Hill 2007 1,751 Cheyenne River 2011 1,546 Source: Federal Wildland Occurrence Data. Frequency/Likelihood of Occurrence Wildfires are likely to occur in the Region each year. It is important to note that the risk of wildfires occurring may increase during times of drought, especially prolonged droughts such as the statewide Wyoming drought which began around 2000 and did not end until 2004. Potential Magnitude The counties’ individual risk to wildfire ranges from significant to critical, given around 25% to 75% of property could be severely damaged during an event, and facilities and services likely to become unavailable between 1 and 7 days. In addition, wildfire can have significant economic impacts as they often coincide with the busy tourist season in the summer months. These natural hazards coupled with the predictions by the Redzone fire assessments discussed previously (including a careful study of the historical prevalence of wildfires throughout the five counties), makes the overall potential for magnitude of wildfires significant. More specific consequences based on parcel analysis are discussed by county in the next section, Vulnerability Assessment. It is important to note that, while only a small number of built environments infrastructure in the towns and cities) might be affected from wildfires, agricultural lands and other amenities valuable to the Region can still be greatly damaged, in turn affecting other aspects and sectors of the economy in the Region. Vulnerability Assessment GIS tools are designed to collect, store, analyze, manipulate, and display/represent spatial data. In the case of a Wildland Urban Interface Hazard Assessment, wildfire hazard vulnerability is determined by comparing values such as slope, aspect, vegetation, and housing density, which then produce datasets such as the Redzone layer incorporated for this Plan’s fire analyses. The following is from the Wyoming Wildland Urban Interface Hazard Assessment Methodology—a report written by the Wyoming State Forestry Division: “The Wildland Urban Interface Hazard Assessment uses three main layers to determine fire danger—Risk, Hazard, and Values. The following lists include the data used to create each of the three layers. 1) Risk – Probability of Ignition a. Lightning Strike density ---PAGE BREAK--- Region 2 4-157 Regional Hazard Mitigation Plan 2018 b. Road density c. Historic fire density 2) Hazard – Vegetative and topological features affecting intensity and rate of spread a. Slope b. Aspect c. Fuels – Interpreted from GAP Vegetation information. 3) Values – Natural or man-made components of the ecosystem on which a value can be placed a. Housing Density – Life and property 4) Non-flammable areas Mask – a mask was created to aid in the analysis for areas that will not carry fire such as water and rock areas. These areas show in the final assessment as a zero value for hazard.” The statewide Wildland Urban Interface Hazard Assessment and its resultant outputs serve two primary purposes: assisting in prioritizing and planning mitigation projects, and creating a communications tool to which agencies can relate common information and data. With the mapping analysis evaluating areas of varying wildfire vulnerability, the final output will result in a Risk, Hazard, and Value (RHV) map displaying areas of concern (called Redzones) for catastrophic wildland fires. To estimate vulnerability from wildfire hazards, a common approach is to determine the value of structures and buildings/parcels that are located within Redzones. Wildland fire building exposure values are the values of buildings that can be potentially damaged by wildland fire in an area. For this Plan, a vulnerability assessment based on the Redzone fire hazard zones and parcel data was conducted, to determine potential losses to property and assets in each community (broken up by attributes such as property type, estimated content values, and total exposure to wildfire hazards). In addition, the population affected under this Redzone fire hazard analysis was also estimated, based on average household sizes for each county. The potential number of people who would be at risk of wildfire are summarized for each of the county exposure tables (Table 4-70 through Table 4-72). An explanation of the population exposure to the hazard follows the section below. General Property Exposure The total exposure value for Region 2 totals $1,066,987,604, according to the Redzone analysis. The tables below summarize the counties’ wildfire exposure by jurisdiction. Converse County According to the Redzone and parcel data analysis, Converse County’s potential exposure was determined to be $143,511,121 ---PAGE BREAK--- Region 2 4-158 Regional Hazard Mitigation Plan 2018 Table 4-70 Converse County Property Exposure based on the Redzone Fire Hazard Jurisdiction Property Type Parcel Count Improved Value Est. Content Value Total Exposure Population Douglas Commercial 1 $1,169,266 $1,169,266 $2,338,532 Exempt 1 $374,388 $374,388 $748,776 Total 2 $1,543,654 $1,543,654 $3,087,308 Glenrock Industrial 1 $594,938 $892,407 $1,487,345 Residential 65 $9,049,914 $4,524,957 $13,574,871 160.55 Total 66 $9,644,852 $5,417,364 $15,062,216 161 Rolling Hills Commercial 1 $11,204 $11,204 $22,408 Residential 146 $26,025,440 $13,012,720 $39,038,160 360.62 Total 147 $26,036,644 $13,023,924 $39,060,568 361 Unincorporated Agricultural 38 $8,084,185 $8,084,185 $16,168,371 Commercial 11 $2,737,195 $2,737,195 $5,474,390 Exempt 2 $1,286,071 $1,286,071 $2,572,141 Residential 287 $41,390,752 $20,695,376 $62,086,128 708.89 Total 338 $53,498,203 $32,802,827 $86,301,030 709 GRAND TOTAL 553 $90,723,352 $52,787,769 $143,511,121 1,230 Natrona County Natrona County’s losses were calculated in Table 4-71. ---PAGE BREAK--- Region 2 4-159 Regional Hazard Mitigation Plan 2018 Table 4-71 Natrona County Property Exposure based on the Redzone Fire Hazard Jurisdiction Property Type Building Count Improved Value Est. Content Value Total Exposure Population Bar Nunn Com Vacant Land 1 $0 $0 $0 Commercial 1 $140,946 $140,946 $281,892 Industrial 1 $722,100 $1,083,150 $1,805,250 Res Vacant Land 31 $0 $0 $0 Residential 488 $89,692,660 $44,846,330 $134,538,990 1,191 Total 522 $90,555,706 $46,070,426 $136,626,132 1,191 Casper Commercial 3 $6,696,169 $6,696,169 $13,392,338 Exempt 11 $0 $0 $0 Industrial 1 $1,522,792 $2,284,188 $3,806,980 Multi-Use 1 $122,248 $122,248 $244,496 Res Vacant Land 2 $0 $0 $0 Residential 1,238 $234,695,278 $117,347,639 $352,042,917 3,021 Total 1,256 $243,036,487 $126,450,244 $369,486,731 3,021 Edgerton Commercial 12 $1,216,719 $1,216,719 $2,433,438 Residential 26 $772,204 $386,102 $1,158,306 63 Total 38 $1,988,923 $1,602,821 $3,591,744 63 Unincorporated Agricultural 2 $0 $0 $0 Com Vacant Land 1 $0 $0 $0 Commercial 143 $8,204,804 $8,204,804 $16,409,608 Exempt 38 $0 $0 $0 Industrial 3 $791,863 $1,187,795 $1,979,658 Multi-Use 7 $849,714 $849,714 $1,699,428 Res Vacant Land 86 $0 $0 $0 Residential 1,981 $270,064,587 $135,032,294 $405,096,881 4,834 Vacant Land 3 $226,986 $226,986 $453,972 Total 2,264 $280,137,954 $145,501,592 $425,639,546 4,834 GRAND TOTAL 4,080 $615,719,070 $319,625,083 $935,344,153 9,109 Niobrara County According to the Redzone and parcel data analysis, Niobrara County’s losses were determined to amount to the values specified in Table 4-72. Table 4-72 Niobrara County Property Exposure based on the Redzone Fire Hazard Jurisdiction Property Type Parcel Count Improved Value Est. Content Value Total Exposure Population Unincorporated Agricultural 8 $1,275,543 $1,275,543 $2,551,086 Commercial 1 $8,720 $8,720 $17,440 Duplex 1 $154,929 $77,465 $232,394 2 Industrial 1 $488,474 $732,711 $1,221,185 Residential 5 $1,036,026 $518,013 $1,554,039 11 Total 16 $2,963,692 $2,612,452 $5,576,144 13 GRAND TOTAL 16 $2,963,692 $2,612,452 $5,576,144 13 ---PAGE BREAK--- Region 2 4-160 Regional Hazard Mitigation Plan 2018 Any flammable materials are vulnerable during a wildfire, including structures and personal property. The vulnerability of general property increases as the distance of the property to wildfire- prone areas decreases, and is particularly high for structures located in the WUI. These structures receive an even higher level of vulnerability if the properties surrounding them are not properly mitigated for fire. Appropriate mitigation techniques include using non-flammable materials such as concrete for construction, leaving appropriate spaces between buildings and vegetation areas filled with non-flammable materials (such as decorative rock or stone), and clearing of underbrush and trees. Population Exposure The most exposed populations, as recorded in the three tables above, are those living in the wildland-urban interface (WUI) zones, where residential properties are directly intruding into traditional wildland areas. The exposure of the population in these zones increases with the exposure of the corresponding general property. Other exposed (at-risk) population groups include children, the elderly, or those with breathing conditions who may be particularly affected by high levels of smoke. Population at-risk estimates were calculated by taking the number of populated property units parcels) falling within the Redzone fire hazard layer, and multiplying that number by the average household size for each county, based on the Census Bureau’s estimates. The average household factor was 2.54 for Converse, 2.44 for Natrona, and 2.24 for Niobrara. It is important to note that many of these structures may include seasonal homes that could be vacant, although the likelihood of them being occupied during fire season is higher. The summary of all the parcels/populated property units, their values, estimated content, total exposure to the hazard, and finally exposed (vulnerable) populations is provided in Table 4-73 below. Table 4-73 Region 2 Property and Population Exposure based on the Redzone Fire Hazard Analysis County Parcel Count Improved Value Est. Content Value Total Exposure Population Converse 553 $90,723,352 $52,787,769 $143,511,121 1,230 Natrona 4,080 $615,719,070 $319,625,083 $935,344,153 9,109 Niobrara 16 $2,963,692 $2,612,452 $5,576,144 13 Total 4,649 $709,406,114 $375,025,303 $1,084,431,418 10,352 Critical Infrastructure, Facilities, and Other Important Community Assets To assess critical facilities at risk in the planning area, the inventory of critical and essential facilities and infrastructure was analyzed. Spatial analysis was carried out to determine which facilities would be damaged from wildfires, based again on the Redzone fire hazard layer. Table 4-74 and Table 4-75 provide a summary of the critical facilities within the Redzone hazard zones, by county and jurisdiction. Note that Niobrara County does not have any critical facilities falling within Redzone areas, and as such only tables of Converse and Natrona Counties are provided. ---PAGE BREAK--- Region 2 4-161 Regional Hazard Mitigation Plan 2018 Table 4-74 Converse County Critical Facility Exposure within the Redzone Jurisdiction Facility Type Facility Count Rolling Hills Electric Substations 4 EPA FRS Power Plants 2 Fire Stations 2 Microwave Service Towers 4 Power Plants 2 Unincorporated Microwave Service Towers 2 TOTAL 16 Table 4-75 Natrona County Critical Facility Exposure within the Redzone Jurisdiction Facility Type Facility Count Casper Day Care Facilities 1 Edgerton Cellular Towers 1 Unincorporated AM Transmission Towers 1 BRS & EBS Transmitters 3 Cellular Towers 1 EMS Stations 1 Fire Stations 1 FM Transmission Towers 9 Microwave Service Stations 23 Paging Transmission Towers 2 Power Plants 1 TV Analog Station Transmitters 4 TV Digital Transmitters 4 TOTAL 52 Facilities in the Region such as those summarized in the tables above may be exposed directly or indirectly to wildfire. Direct exposures are similar to those of General Property, and vulnerabilities increase as the infrastructure or facilities and capabilities move into the WUI zones. Communication infrastructure and lines passing through susceptible areas such as forests are more exposed than those located in cities and more urbanized areas. The indirect vulnerability of response capabilities increases seasonally and with the number of occurrences. Though the populations making up the response capability systems are not directly exposed to all fire events, the response of some of the personnel to an event lessens the capabilities overall for responses to other emergency situations. If there is a large increase in the number of simultaneous wildland fires, even small ones, the response capability of the Region could easily be compromised. ---PAGE BREAK--- Region 2 4-162 Regional Hazard Mitigation Plan 2018 Overall, there are a total of 68 critical facilities found in Region 2. While Niobrara did not contain any of these facilities within the Redzone areas, Converse has 16 facilities and Natrona 52 (primarily microwave service towers). Table 4-76 Summary of Region 2 Critical Facilities within the Redzone, by County County Facility Type Facility Count Converse Electric Substations 4 EPA FRS Power Plants 2 Fire Stations 2 Microwave Service Towers 6 Power Plants 2 Natrona Day Care Facilities 1 Cellular Towers 2 AM Transmission Towers 1 BRS & EBS Transmitters 3 EMS Stations 1 Fire Stations 1 FM Transmission Towers 9 Microwave Service Towers 23 Paging Transmission Towers 2 Power Plants 1 TV Analog Station Transmitters 4 TV Digital Transmitters 4 GRAND TOTAL 68 Natural, Historic and Cultural Resources A portion of the Region (particularly Converse County) includes National Forest and Grassland, which contains many natural and cultural resources potentially at risk. Wildfires in open spaces and forests may also have a regional impact on summer tourism and other economic sectors. Wildfire can have negative impacts where significant areas of sagebrush are burned within crucial mule deer winter range and sage-grouse breeding and winter habitats, for example. Nevertheless, natural resources and spaces can actually benefit from wildland fire, to encourage a healthy ecological redevelopment of areas impacted by pests or other such deterrents to the environment’s native species growth. Historic and cultural resources exhibit a vulnerability rating similar to those in general property. However, vulnerability ratings increase the closer into the WUI a particular property is, and the less mitigated the landscaping surrounding the property is. In addition, older buildings may be exempt from internal fire mitigation such as sprinklers and fire suppression technology, which may increase the vulnerability of the resource. The way in which the building or property was constructed based on weakened or less reliable materials) can also play a part when it comes to vulnerability to fire. Examples of units of exempt nature may include historic buildings in downtown and tourist areas, such as museums or restaurants, especially those constructed with ---PAGE BREAK--- Region 2 4-163 Regional Hazard Mitigation Plan 2018 wooden materials that can burn rapidly or have their structural grounds significantly damaged during a wildfire. Future Development The wildland/urban interface (WUI) is a very popular building location, as shown by national and statewide trends. More and more homes are being built in the interface. Overall, Wyoming has less developed WUI than most western states. Throughout Wyoming there remains potential for future home construction in undeveloped, forested private lands adjacent to fire-prone public lands. Building homes in these high-risk areas would put lives and property in the path of wildfires. Regulating growth in these areas will be a delicate balance between protecting private property rights and promoting public safety. Should the region begin to experience this type of WUI growth, local government may wish to consider: regulation of subdivision entrance/exit roads and bridges for the safety of property owners and fire personnel; reviewing building plans pertaining to land on slopes greater than 25% (in consideration of access for fire protection of structures); and reviewing water supply requirements set forth to include ponds, access by fire apparatuses, pumps, and backup generators. Such standards serve to protect residents and property, as well as enable emergency services personnel and government/public resources during a wildfire. Summary Wildfires occur within the region on a frequent, almost annual basis. Based on GIS analysis of the Redzone and property values, the Region has over $1 billion in building/parcel value potentially at risk to wildland fires (as summarized on Table 4-77, under the Total Exposure column). Though it is not likely that the areas at risk will simultaneously face a destructive event, this figure provides the upper end of what could be affected and is currently exposed. Overall, wildfire is a high significance hazard to the entire Region 2, based on the reported analyses as well as input from the HMPC. County ratings are noted in the table below for each county. Table 4-77 Wildfire Hazard Risk Summary County Geographic Extent Probability of Future Occurrence Potential Magnitude/ Severity Overall Significance Converse Significant Highly Likely Critical High Natrona Significant Likely Critical High Niobrara Medium Likely Significant High ---PAGE BREAK--- Region 2 5.1 Regional Hazard Mitigation Plan 2018 CHAPTER 5 MITIGATION STRATEGY Requirement §201.6(c)(3): [The plan shall include] a mitigation strategy that provides the jurisdiction’s blueprint for reducing the potential losses identified in the risk assessment, based on existing authorities, policies, programs and resources, and its ability to expand on and improve these existing tools. 5.1 Mitigation Strategy: Overview This section describes the mitigation strategy process and mitigation action plan for the Region 2 Hazard Mitigation Plan. It describes how the participating jurisdictions in the Region meet the following requirements from the 10-step planning process: • Planning Step 6: Set Goals • Planning Step 7: Review Possible Activities • Planning Step 8: Draft an Action Plan The results of the planning process, the risk assessment, the goal setting, the identification of mitigation actions and the work of each county’s HMPC led to this mitigation strategy and action plan. Section 5.2 identifies the goals of this plan; Section 5.4 describes the mitigation action plan. 5.2 Goals and Objectives Requirement §201.6(c)(3)(i): [The hazard mitigation strategy shall include a] description of mitigation goals to reduce or avoid long-term vulnerabilities to the identified hazards. Up to this point in the planning process, each county’s HMPC has organized resources, assessed hazards and risks, and documented mitigation capabilities. The resulting goals and mitigation actions were developed and updated based on these tasks. During the 2018 development of this plan, a meeting was held with each county HMPC designed to achieve a collaborative mitigation strategy as described further throughout this section. During the planning workshops held in 2018, the counties reviewed the results of the hazard identification, vulnerability assessment, capability assessment and the goals from previous county- level hazard mitigation plans as well as the State of Wyoming Mitigation Plan (2016). The analysis of the risk assessment identified areas where improvements could be made and provided the framework for the counties to review planning goals (in some instances objectives) to base the development of new or updated mitigation strategies for the counties in the Region. Goals were defined for the purpose of this mitigation plan as broad-based public policy statements that: ---PAGE BREAK--- Region 2 5.2 Regional Hazard Mitigation Plan 2018 • Represent basic desires of the community; • Encompass all aspects of community, public and private; • Are nonspecific, in that they refer to the quality (not the quantity) of the outcome; • Are future-oriented, in that they are achievable in the future; and • Are time-independent, in that they are not scheduled events. Goals are stated without regard to implementation; cost, schedule, and means of implementation are not considered. Goals are defined before considering how to accomplish them to not be dependent on the means of achievement. Goal statements form the basis for objectives (where applicable) and actions that will be used to achieve the goals. When used, objectives are more specific and measurable than goals, and are used to define strategies to attain goals. They are sometimes developed in mitigation planning as an intermediate step between goals and mitigation actions or projects. The update and validation of goals for each county in the region was initiated through a facilitated discussion at each county planning workshop held in 2018. The HMPC members were provided a PowerPoint presentation that explained goals, objectives and actions and provided examples of each. Existing goals and related plan goals were noted in the PowerPoint, including the State of Wyoming Mitigation Plan. This review was to ensure that the Regional Plan’s mitigation goals were aligned and integrated with existing plans and policies. Based on the risk assessment update, each county identified, updated, or developed specific goals which provide the direction for reducing future hazard-related losses within the counties and regional planning area. During the planning process for the 2018 Regional Plan, all three counties determined the existing number and intent of goals and objectives continue to be appropriate and no revisions or additions were necessary. The updated goals and objectives (where applicable) for each county in the Region are noted below. Converse County Converse County reviewed and validated the following goals during the planning process. Goal 1: Strengthen public infrastructure. Goal 2: Improve local mitigation capabilities. Goal 3: Reduce economic losses due to hazard events. Goal 4: Reduce local costs of response and recovery. ---PAGE BREAK--- Region 2 5.3 Regional Hazard Mitigation Plan 2018 Natrona County Natrona County reviewed and validated the following goals and objectives during the planning process. Goal 1: Continue to implement actions to mitigate the effect of hazards through education, ordinances and resolutions, and proper project analysis, to enhance life safety and reduce property losses. Objective 1.1: The County and jurisdictions will participate in activities and support mitigation projects that enhance the protection of citizens from hazards. Objective 1.2: The County and jurisdictions will create public awareness campaigns to educate citizens of the possible hazards associated with all hazards that affect the planning area. Goal 2: Continue coordination among all entities of Natrona County to assess all hazards and take various actions to reduce or eliminate the risk factors of those hazards. Objective 2.1: The County and jurisdictions will participate and support projects that ensure emergency services are properly equipped and trained to provide the level of service the community deserves. Objective 2.2: Continue multi-jurisdictional collaboration on hazard mitigation projects to the benefit of all jurisdictions. Goal 3: Reduce the economic impact on the local economy caused by the effects of hazards in the communities. Objective 3.1: Communities working together shall develop policies for hazard prone areas that either limit development or provide additional mitigation measures within those areas. Niobrara County Niobrara County reviewed and validated the following goals during the planning process. Goal 1: Mitigate natural hazards to reduce potential injury and loss of life, and property damage in the Town of Lusk. Goal 2: Mitigate natural hazards to reduce potential injury and loss of life, and property damage in the Town of Manville. Goal 3: Mitigate natural hazards to reduce potential injury and loss of life, and property damage in the Town of Van Tassell. ---PAGE BREAK--- Region 2 5.4 Regional Hazard Mitigation Plan 2018 Goal 4: Mitigate natural hazards to reduce potential injury and loss of life, and property damage in Niobrara County. 5.3 Identification and Analysis of Mitigation Actions Requirement §201.6(c)(3)(ii): [The mitigation strategy shall include a] section that identifies and analyzes a comprehensive range of specific mitigation actions and projects being considered to reduce the effects of each hazard, with particular emphasis on new and existing buildings and infrastructure. The next step in the mitigation strategy is to identify and analyze a comprehensive range of specific mitigation actions and projects to reduce the effects of each hazard on new and existing buildings and infrastructure. During the 2018 Regional Plan development, each county Hazard Mitigation Planning Committee (HMPC) analyzed viable mitigation options by hazard that supported the identified goals. The were provided with the following list of categories of mitigation actions, which originate from the Community Rating System: • Plan and Regulations (Prevention): Administrative or regulatory actions or processes that influence the way land and buildings are developed and built. • Property protection: Actions that involve the modification of existing buildings or structures to protect them from a hazard or remove them from the hazard area. • Structural and infrastructure projects: Actions that involve the construction of structures to reduce the impact of a hazard. • Natural resource protection: Actions that, in addition to minimizing hazard losses, also preserve or restore the functions of natural systems. • Public information/education and awareness: Actions to inform and educate citizens, elected officials, and property owners about the hazards and potential ways to mitigate them. • Emergency services: Actions that protect people and property during and immediately after a disaster or hazard event. To identify and select mitigation actions to support the mitigation goals, each hazard identified and profiled in Chapter 4 was evaluated at the planning workshop. At the county workshops a handout was provided showing existing mitigation actions identified in its previous plan, as well as examples of potential mitigation action alternatives for each of the above categories and for each of the identified hazards. Another reference document titled “Mitigation Ideas” developed by FEMA was also made available. This document lists the common alternatives for mitigation by hazard. The counties were asked to consider both future and existing buildings in considering possible mitigation actions. A facilitated discussion then took place to examine and analyze the options. Appendix A includes each county specific handout given at the planning workshops. The mitigation strategy is based on existing local authorities, policies, programs, and resources, as well as the ability to expand on and improve these existing tools. As part of the Regional Plan development the county planning teams reviewed existing capabilities for reducing long-term ---PAGE BREAK--- Region 2 5.5 Regional Hazard Mitigation Plan 2018 vulnerability to hazards. Those capabilities are noted by jurisdiction in the county annexes and can be assessed to identify gaps to be addressed and to enhance through new mitigation actions. For instance, gaps in design or enforcement of existing regulations can be addressed through additional personnel or a change in procedure or policy. Based upon the capability assessment and key issues identified in the risk assessment, the counties came to consensus on proposed mitigation actions for each hazard for their jurisdictions. Certain hazards’ impacts were best reduced through multi-hazard actions. A lead for each new action was identified to provide additional details on the project in order to be captured in the plan. Final action strategies are discussed in Section 5.4 and detailed within the respective annexes. 5.3.1 Prioritization Process Once the mitigation actions were identified, the county planning teams discussed FEMA’s recommended prioritization criteria, STAPLEE, to assist in deciding why one recommended action might be more important, more effective, or more likely to be implemented than another. STAPLEE is an acronym for the following: • Social: Does the measure treat people fairly? different groups, different generations) • Technical: Is the action technically feasible? Does it solve the problem? • Administrative: Are there adequate staffing, funding, and other capabilities to implement the project? • Political: Who are the stakeholders? Will there be adequate political and public support for the project? • Legal: Does the jurisdiction have the legal authority to implement the action? Is it legal? • Economic: Is the action cost-beneficial? Is there funding available? Will the action contribute to the local economy? • Environmental: Does the action comply with environmental regulations? Will there be negative environmental consequences from the action? Other criteria used to assist in evaluating the priority of a mitigation action included: • Does the action address hazards or areas with the highest risk? • Does the action protect lives? • Does the action protect infrastructure, community assets or critical facilities? • Does the action meet multiple objectives? During the planning workshops, the counties used the above criteria to determine which of the new identified actions were most likely to be implemented and effective. The results of the evaluation process produced prioritized mitigation actions for implementation within the planning area, or evaluated existing actions already laid out in county hazard mitigation plans. ---PAGE BREAK--- Region 2 5.6 Regional Hazard Mitigation Plan 2018 Each mitigation action developed for this plan contains a brief description of the proposed project and it’s benefits, the entity with primary responsibility for implementation, a cost estimate, a priority level and a schedule for implementation. Development of these project details further informed the determination of a high, medium, or low priority for each. During the plan update some of the mitigation actions were identified to be carried forward from the Converse, Natrona, and Niobrara Counties’ existing hazard mitigation plans. More information on the priority levels on these actions were revisited and, in some cases, modified to reflect current priorities based on the STAPLEE principles. 5.4 Mitigation Action Plan Requirement §201.6(c)(3)(iii): [The mitigation strategy section shall include] an action plan describing how the actions identified in section (c)(3)(ii) will be prioritized, implemented, and administered by the local jurisdiction. Prioritization shall include a special emphasis on the extent to which benefits are maximized according to a cost benefit review of the proposed projects and their associated costs. This section outlines the development of the mitigation action plan. The action plan consists of the specific projects, or actions designed to meet the identified goals within the plan. Over time the implementation of these projects will be tracked as a measure of demonstrated progress on meeting the plan's goals. 5.4.1 Progress on Previous Mitigation Actions The mitigation actions in Converse, Natrona, and Niobrara Counties’ previous hazard mitigation plans provided the basis for the updates of mitigation action strategies. As part of the update process these three counties reviewed the previously identified actions to assess progress on implementation. These reviews were completed through a discussion during the planning workshop to capture information on each action, including if the action was completed or to be deferred to future planning efforts. Actions that were not completed were discussed for continued relevance and were either continued in the plan or in some cases recommended for deletion. The counties and participating jurisdictions have been successful in implementing actions identified in their respective plans’ Mitigation Strategy, thus, working steadily towards meeting each plan’s goals. Progress on mitigation actions previously identified in these planning mechanisms are detailed in the mitigation action strategy in the county annexes. These action plans were also shared amongst the regional plan participants to showcase progress and stimulate ideas amongst the respective county planning committees. Reasons that some actions have not been completed include low priority, lack of funding, or lack of administrative resources. Refer to the county annexes for more details on the progress of implementation. ---PAGE BREAK--- Region 2 5.7 Regional Hazard Mitigation Plan 2018 5.4.2 New Mitigation Actions One of the takeaways from the public survey was that the public is interested in being provided information on hazards that pose a risk to where they live. In response to this, each county revisited their action strategy to ensure this concern was adequately addressed in existing actions, adding a new mitigation measure when needed. Mitigation actions for each county can be found in their respective annexes. 5.4.3 Continued Compliance with NFIP Given the significance of the flood hazard in the planning area and as required by the DMA, an emphasis will be placed on continued compliance with the National Flood Insurance Program (NFIP). Counties and jurisdictions that participate in the NFIP will continue to make every effort to remain in good standing with the program. The table below summarizes the NFIP mapping and participation status for applicable jurisdictions in the Region. Table 5.1 NFIP Participation Status Summary Jurisdiction Effective Map Status Date Joined Comments Converse County City of Douglas 10/17/78 10/17/78 Participating Town of Glenrock 11/15/85 11/15/85 Participating Town of Lost Springs n/a n/a Not participating - never mapped Town of Rolling Hills 8/08/08 Not participating Converse County 4/5/88 4/5/88 Participating Natrona County City of Casper 09/15/77 09/15/77 Participating Town of Bar Nunn n/a n/a Not participating – never mapped City of Edgerton n/a n/a Not participating – never mapped Town of Evansville 07/17/78 07/17/78 Participating Town of Midwest n/a n/a Not participating – never mapped Town of Mills 12/01/86 12/01/86 Participating Natrona County 08/15/78 08/15/78 Participating Niobrara County Town of Manville n/a n/a Not participating – never mapped Town of Lusk 03/18/86 03/18/86 Participating Town of Van Tassell n/a n/a Not participating – never mapped Niobrara County n/a n/a Not participating – never mapped Unincorporated Niobrara County is not mapped and does not participate in the NFIP, resulting in residents unable to purchase flood insurance. In June 2015, the county was impacted by a flood event that according to the HMPC cost the county $3 million. As a result of this regional planning ---PAGE BREAK--- Region 2 5.8 Regional Hazard Mitigation Plan 2018 process, the county determined to keep the existing mitigation action of encouraging property owners to purchase flood insurance. Continued compliance with the NFIP includes continuing to adopt floodplain maps when updated and implementing, maintaining and updating floodplain ordinances. Actions related to continued compliance include: • Continued designation of a local floodplain manager whose responsibilities include reviewing floodplain development permits to ensure compliance with the local floodplain management ordinances and rules; • Suggest changes to improve enforcement of and compliance with regulations and programs; • Participate in Flood Insurance Rate Map updates by adopting new maps or amendments to maps; • Utilize Digital Flood Insurance Rate maps in conjunction with GIS to improve floodplain management, such as improved risk assessment and tracking of floodplain permits; • Promote and disperse information on the benefits of flood insurance. Also to be considered are flood mitigation actions contained in this Regional Plan that support the ongoing efforts by participating counties to minimize the risk and vulnerability of the community to the flood hazard and to enhance their overall floodplain management program. 5.4.4 Mitigation Action Plan The action plan presents the recommendations developed by the county planning teams, outlining how each county and the Region can reduce the risk and vulnerability of people, property, infrastructure, and natural and cultural resources to future disaster losses. The mitigation actions developed by the counties are detailed in the county annexes. These details include the action description, hazard(s) mitigated, lead and partner agencies responsible for initiating implementation, costs, and timeline. Many of the action items included in this plan are a collaborative effort among local, state and federal agencies and stakeholders in the planning area. Further, it should be clarified that the actions included in this mitigation strategy are subject to further review and refinement; alternatives analyses; and reprioritization due to funding availability and/or other criteria. The counties are not obligated by this document to implement any or all of these projects. Rather, this mitigation strategy represents the desires of the community to mitigate the risks and vulnerabilities from identified hazards. The counties also realize that new needs and priorities may arise as a result of a disaster or other circumstances and reserve the right to support new actions, as necessary, as long as they conform to their overall goals as listed in this plan. Where feasible, it is recommended that mitigation be integrated and implemented through existing planning mechanisms. Specific related mechanisms are noted in the county annexes. Chapter 6 ---PAGE BREAK--- Region 2 5.9 Regional Hazard Mitigation Plan 2018 also discusses incorporating the plan into existing planning mechanisms, and how each county will address continued public involvement. ---PAGE BREAK--- Wyoming Region 2 6.1 Regional Hazard Mitigation Plan 2018 CHAPTER 6 PLAN ADOPTION, IMPLEMENTATION AND MAINTENANCE Requirement §201.6(c)(4): [The plan maintenance process shall include a] section describing the method and schedule of monitoring, evaluating, and updating the mitigation plan within a five-year cycle. Requirement §201.6(c)(5): [The local hazard mitigation plan shall include] documentation that the plan has been formally approved by the governing body of the jurisdiction requesting approval of the plan City Council, county commissioner, Tribal Council). Implementation and maintenance of the plan is critical to the overall success of hazard mitigation planning. This is Planning Step 10 of the 10-step planning process. This chapter provides an overview of the overall strategy for plan implementation and maintenance and outlines the method and schedule for monitoring, updating, and evaluating the regional plan. The chapter also discusses incorporating the plan into existing planning mechanisms and how to address continued public involvement. 6.1 Formal Adoption The purpose of formally adopting this plan is to secure buy-in from participating jurisdictions, raise awareness of the plan, and formalize the plan’s implementation. The adoption of this plan completes Planning Step 9 of the 10-step planning process: Adopt the Plan. The governing board for each participating jurisdiction has adopted this local hazard mitigation plan by passing a resolution. A copy of the generic resolution and the executed copies are included in Appendix B, Plan Adoption. This plan will be updated and re-adopted every five years in concurrence with the required DMA local and tribal plan update requirements. 6.2 Implementation Once adopted, the plan faces the truest test of its worth: continued implementation. While this plan contains many actions, each county and jurisdiction will need to decide which action(s) to undertake or continue. Two factors will help with making that decision: the priority assigned the actions in the planning process and funding availability. Low or no-cost actions most easily demonstrate progress toward successful plan implementation. Mitigation is most successful when it is incorporated into the day-to-day functions and priorities of government and development. Implementation will be accomplished by adhering to the schedules identified for each action and through constant, pervasive, and energetic efforts to network and highlight the benefits to the counties, communities and stakeholders. This effort is achieved through the routine actions of monitoring meeting agendas for hazard mitigation related ---PAGE BREAK--- Wyoming Region 2 6.2 Regional Hazard Mitigation Plan 2018 initiatives, coordinating on the topic at meetings, and promoting a safe, sustainable community. Additional mitigation strategies could include consistent and ongoing enforcement of existing policies and vigilant review of programs for coordination and multi-objective opportunities. Simultaneous to these efforts, it is important to maintain a constant monitoring of funding opportunities that can be leveraged to implement some of the more costly recommended actions. This will include creating and maintaining a bank of ideas on how to meet local match or participation requirements. When funding does become available, the Region and its counties will be in a position to capitalize on the opportunity. Funding opportunities to be monitored include special pre- and post-disaster funds, state and federal earmarked funds, benefit assessments, and other grant programs, including those that can serve or support multi-objective applications. 6.2.1 Role of Hazard Mitigation Planning Committee in Implementation and Maintenance With adoption of this plan, the Region, its counties, and its municipalities will be responsible for the plan implementation and maintenance. Each county, led by their Emergency Management Coordinators, will reconvene their HMPC for plan implementation and maintenance. This HMPC will be the same committee (in form and function, if not actual individuals) that developed this HMP and will also be responsible for the next formal update to the plan in five years. The county-level will: • Act as a forum for hazard mitigation issues; • Disseminate hazard mitigation ideas and activities to all participants; • Pursue the implementation of high-priority, low/no-cost recommended actions; • Ensure hazard mitigation remains a consideration for community decision makers; • Maintain a vigilant monitoring of multi-objective cost-share opportunities to help the community implement the plan’s recommended actions for which no current funding exists; • Monitor and assist in implementation and update of this plan; • Report on plan progress and recommended changes to county and municipal officials; and • Inform and solicit input from the public. Each HMPC will not have any powers over respective county staff; it will be purely an advisory body. The primary duty is to see the plan successfully carried out and to report to the county commissioners, municipal boards, and the public on the status of plan implementation and mitigation opportunities. Other duties include reviewing and promoting mitigation proposals, considering stakeholder concerns about hazard mitigation, passing concerns on to appropriate entities, and posting relevant information on county websites (and others as appropriate). ---PAGE BREAK--- Wyoming Region 2 6.3 Regional Hazard Mitigation Plan 2018 6.3 Plan Maintenance Plan maintenance implies an ongoing effort to monitor and evaluate plan implementation and to update the plan as progress, roadblocks, or changing circumstances are recognized. The regulation at 44 CFR§201.6(d)(3) requires that a local jurisdiction must review and revise its plan to reflect changes in development, progress in local mitigation efforts, and changes in priorities, and resubmit it for approval within five years in order to continue to be eligible for mitigation project grant funding. 6.3.1 Maintenance Schedule The Emergency Management Coordinators are responsible for initiating plan reviews and consulting with the heads of participating departments in their own counties. In order to monitor progress and update the mitigation strategies identified in the action plan, each county and their standing HMPC will conduct an annual review of this plan and/or following a hazard event. An annual mitigation action progress report will be prepared by the Emergency Management Coordinators based on the HMPC input and kept on file to assist with for future updates. The annual review will be conducted by re-convening each HMPC in November of each year. This plan will be updated, approved and adopted within a five-year cycle as per Requirement §201.6(c)(4)(i) of the Disaster Mitigation Act of 2000 unless disaster or other circumstances changing regulations) require a change to this schedule. The Region and its counties will inquire with WOHS and FEMA for funds to assist with the update. It is recommended to begin seeking funds in 2020 as most applicable grants have multiple years to expend the funds. Funding sources may include the Emergency Management Performance Grants, Pre-Disaster Mitigation, Hazard Mitigation Grant Program (if a presidential disaster has been declared), and Flood Mitigation Assistance grant funds. The next plan update should be completed and reapproved by WOHS and FEMA Region VIII within five years of the FEMA final approval date. The planning process to prepare the update should begin no later than 12 months prior to that date. 6.3.2 Maintenance Evaluation Process Evaluation of progress can be achieved by monitoring changes in vulnerabilities identified in the plan. Changes in vulnerability can be identified by noting: • Decreased vulnerability as a result of implementing recommended actions; • Increased vulnerability as a result of new or altered hazards • Increased vulnerability as a result of new development. Updates to this plan will: • Consider changes in vulnerability due to action implementation; • Document success stories where mitigation efforts have proven effective; ---PAGE BREAK--- Wyoming Region 2 6.4 Regional Hazard Mitigation Plan 2018 • Document areas where mitigation actions were not effective; • Document any new hazards that may arise or were previously overlooked; • Incorporate new data or studies on hazards and risks; • Incorporate new capabilities or changes in capabilities; • Incorporate growth and development-related changes to infrastructure inventories; and • Incorporate new action recommendations or changes in action prioritization. To best evaluate any changes in vulnerability as a result of plan implementation, each county and municipality will adhere to the following process: • A representative from the responsible office identified in each mitigation measure will be responsible for tracking and reporting on an annual basis to the department lead on action status and provide input on whether the action, as implemented, meets the defined objectives and is likely to be successful in reducing vulnerabilities. • If the action does not meet identified objectives, the lead will determine what additional measures may be implemented, and an assigned individual will be responsible for defining action scope, implementing the action, monitoring success of the action, and making any required modifications to the plan. Changes will be made to the plan to accommodate for actions that were not successful or were not considered feasible after a review of their consistency with established criteria, time frame, community priorities, and/or funding resources. Actions that were not ranked high but were identified as potential mitigation activities will be reviewed as well during the monitoring and update of this plan to determine feasibility of future implementation. Updating of the plan will be by written changes and submissions, as each HMPC deems appropriate and necessary, and as approved by the respective participating agencies. In keeping with the five-year update process, the HMPC will convene public meetings to solicit public input on the plan and its routine maintenance and the final product will be adopted by the governing council of each participating jurisdiction. 6.3.3 Incorporation into Existing Planning Mechanisms Another important implementation mechanism that is highly effective and low-cost is incorporation of the hazard mitigation plan recommendations and their underlying principles into other county plans and mechanisms. Where possible, plan participants will use existing plans and/or programs to implement hazard mitigation actions. As described in each county annex capability assessment, the counties already implement policies and programs to reduce losses to life and property from hazards. This plan builds upon the momentum developed through previous and related planning efforts and mitigation programs and recommends implementing actions, where possible, through these other program mechanisms. Where applicable, these existing mechanisms could include: • County or community comprehensive plans ---PAGE BREAK--- Wyoming Region 2 6.5 Regional Hazard Mitigation Plan 2018 • County or community land development codes • County or community emergency operations plans • Threat and Hazard Identification and Risk Assessments (THIRA) • Community Wildfire Protection Plans (CWPP) • Transportation plans • Capital improvement plans and budgets • Recovery planning efforts • Watershed planning efforts • Wildfire planning efforts on adjacent public lands • Master planning efforts • River corridor planning efforts • Other plans, regulations, and practices with a mitigation aspect The county annexes note, where applicable, how the previous versions of the hazard mitigation plan have been incorporated into existing planning mechanisms in the past five years. Each annex notes specific opportunities to integrate the mitigation plan into other mechanisms in the future. HMPC members involved in these other planning mechanisms will be responsible for integrating the findings and recommendations of this plan with these other plans, programs, etc., as appropriate. As described in Section 6.2 Implementation, incorporation into existing planning mechanisms will be done through the process of: • Monitoring other planning/program agendas; • Attending other planning/program meetings; • Participating in other planning processes; • Ensuring that the related planning process cross-references the hazard mitigation plan, where appropriate, and • Monitoring community budget meetings for other community or tribal program opportunities. The successful implementation of this mitigation strategy will require constant and vigilant review of existing plans and programs for coordination and multi-objective opportunities that promote a safe, sustainable community. Efforts should continuously be made to monitor the progress of mitigation actions implemented through these other planning mechanisms and, where appropriate, their priority actions should be incorporated into updates of this hazard mitigation plan. 6.3.4 Continued Public Involvement Continued public involvement is imperative to the overall success of the plan’s implementation. The update process provides an opportunity to solicit participation from new and existing stakeholders and to publicize success stories from the plan implementation and seek additional public comment. The plan maintenance and update process will include continued public and ---PAGE BREAK--- Wyoming Region 2 6.6 Regional Hazard Mitigation Plan 2018 stakeholder involvement and input through attendance at designated committee meetings, web postings, press releases to local media, and through public hearings. When each HMPC reconvenes for the update, they will coordinate with all stakeholders participating in the planning process – including those that joined the committee since the planning process began – to update and revise the plan. Public notice will be posted and public participation will be invited, at a minimum, through available website postings and press releases to the local media outlets, primarily newspapers, or through public surveys. As part of this effort, at least one public meeting will be held, or alternately a public survey, and public comments will be solicited on the plan update draft.