MARION COUNTY HAZARD MITIGATION PLAN July 13, 2016 Table of Contents INTRODUCTION AND PLANNING PROCESS ................................................................................................... 3 Purpose ......................................................................................................................................................... 3 Background and Scope .................................................................................................................................. 3 Plan Organization .......................................................................................................................................... 6 Planning Process ........................................................................................................................................... 7 Goals and Objectives ..................................................................................................................................... 8 Multi-Jurisdictional Participation .................................................................................................................. 9 Coordination with Other Departments and Agencies ................................................................................ 13 Public Involvement ..................................................................................................................................... 15 RISK ASSESSMENT ....................................................................................................................................... 16 Animal/Crop/Plant Disease ......................................................................................................................... 41 Dam Failure ................................................................................................................................................. 46 Drought ....................................................................................................................................................... 51 Earthquake .................................................................................................................................................. 58 Expansive Soils ............................................................................................................................................ 61 Extreme Heat .............................................................................................................................................. 63 Flash Flood .................................................................................................................................................. 70 Grass or Wildland Fire ................................................................................................................................. 75 Hazardous Materials ................................................................................................................................... 78 Human Disease ........................................................................................................................................... 84 Infrastructure Failure .................................................................................................................................. 87 Landslide ..................................................................................................................................................... 89 Levee Failure ............................................................................................................................................... 91 River Flooding ............................................................................................................................................. 93 Severe Winter Storm & Extreme Cold ...................................................................................................... 114 Sinkholes ................................................................................................................................................... 124 Thunderstorms & Lightning/Hail .............................................................................................................. 127 Tornado ..................................................................................................................................................... 138 Transportation Incidents ........................................................................................................................... 144 Windstorm ................................................................................................................................................ 148 Hazard Analysis Summary ......................................................................................................................... 154 1 | P a g e July 13, 2016 MARION COUNTY HAZARD MITIGATION PLAN 2 | P a g e MARION COUNTY HAZARD MITIGATION PLAN July 13, 2016 INTRODUCTION AND PLANNING PROCESS Purpose Marion County and the participating cities, fire departments, colleges, and school districts prepared this Multi-Jurisdictional Hazard Mitigation Plan (HMP) to guide hazard mitigation planning to better protect the people and property of the County from the effects of natural hazard events. For the County, this plan serves as the plan update to their Local Hazard Mitigation Plan that was developed and approved by the Federal Emergency Management Agency (FEMA) in 2012. This plan will identify specific vulnerabilities and mitigation projects for the planning area, which has not changed since the 2012 HMP. This plan demonstrates the communities’ commitments to reducing risks from hazards and serves as a tool to help decision makers direct mitigation activities and resources. This plan was also developed to make Marion County and the participating jurisdictions eligible for certain federal grant programs; specifically, the FEMA Hazard Mitigation Assistance (HMA) grants such as the Hazard Mitigation Grant Program, Pre- Disaster Mitigation Program, and Flood Mitigation Assistance Program. Background and Scope Each year in the United States, natural 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 natural 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. On average, each dollar spent on mitigation saves society an average of $4 in avoided future losses in addition to saving lives and preventing injuries (National Institute of Building Science Multi-Hazard Mitigation Council 2005). 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 determined, prioritized, and implemented. This plan documents the hazard mitigation planning process undertaken by the Planning Team. It identifies relevant hazards and vulnerabilities in the planning area and sets forth a mitigation strategy to decrease vulnerability and increase resiliency and sustainability in Marion County. In 2012, Marion County commissioned their Council of Governments (COG) to write the 2012 HMP. Much of the information within this plan has been updated since the 2012 plan, but the old plan will be used for reference purposes. The Marion County Multi-Jurisdictional Hazard Mitigation Plan is a multi-jurisdictional plan that geographically covers the participating jurisdictions within Marion County’s boundaries (hereinafter referred to as the planning area). The following jurisdictions officially participated in the planning process: 3 | P a g e July 13, 2016 MARION COUNTY HAZARD MITIGATION PLAN 1. Marion County (unincorporated population/demo data) 2. Bussey 3. Hamilton 4. Harvey 5. Knoxville 6. Marysville 7. Melcher-Dallas 8. Pella 9. Pleasantville 10. Swan The following school district, colleges, hospitals or fire departments participated in the planning process: 11. Knoxville Community School District 12. Melcher-Dallas Community School District 13. Pella Community School District 14. Pella Christian Schools 15. Pleasantville Community School District 16. Twin Cedars Community School District 17. Central College 18. Knoxville Hospital 19. Pella Regional Health Center The following figure displays the location of Marion County in relation to the state of Iowa. Figure 1: Location of Marion County The following figure displays the location of the incorporated communities in relation to Marion County. 4 | P a g e MARION COUNTY HAZARD MITIGATION PLAN July 13, 2016 Figure 2: Location of Incorporated Communities 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