Carbon County 2015 Hazard Mitigation Plan Update TABLE OF CONTENTS 1. INTRODUCTION ............................................................................................................... 1 2. COMMUNITY PROFILE ..................................................................................................... 4 3. PLANNING PROCESS .................................................................................................... 17 4. RISK ASSESSMENT ...................................................................................................... 26 4.2.1. Table of Presidential Disaster Declarations .................................................................................. 27 4.2.2. Summary of Hazards ....................................................................................................................... 28 4.3.1. Drought ............................................................................................................................................. 32 4.3.1.1. Location and Extent .................................................................................................................. 32 4.3.1.2. Range of Magnitude .................................................................................................................. 35 4.3.1.3. Past Occurrence ....................................................................................................................... 37 4.3.1.4. Future Occurrence .................................................................................................................... 38 4.3.1.5. Vulnerability Assessment .......................................................................................................... 38 4.3.2. Flood, Flash Flood, Ice Jam ............................................................................................................ 43 4.3.2.1. Location and Extent .................................................................................................................. 43 4.3.2.2. Range of Magnitude .................................................................................................................. 47 4.3.2.3. Past Occurrence ....................................................................................................................... 51 4.3.2.4. Future Occurrence .................................................................................................................... 57 4.3.2.5. Vulnerability Assessment .......................................................................................................... 58 4.3.3. Hailstorm .......................................................................................................................................... 61 4.3.3.1. Location and Extent .................................................................................................................. 61 ii Carbon County 2015 Hazard Mitigation Plan Update 4.3.3.2. Range of Magnitude .................................................................................................................. 61 4.3.3.3. Past Occurrence ....................................................................................................................... 62 4.3.3.4. Future Occurrence .................................................................................................................... 65 4.3.3.5. Vulnerability Assessment .......................................................................................................... 65 4.3.4. Hurricane, Tropical Storm, Nor’easter ........................................................................................... 65 4.3.4.1. Location and Extent .................................................................................................................. 65 4.3.4.2. Range of Magnitude .................................................................................................................. 67 4.3.4.3. Past Occurrence ....................................................................................................................... 69 4.3.4.4. Future Occurrence .................................................................................................................... 72 4.3.4.5. Vulnerability Assessment .......................................................................................................... 74 4.3.5. Landslide .......................................................................................................................................... 74 4.3.5.1. Location and Extent .................................................................................................................. 74 4.3.5.2. Range of Magnitude .................................................................................................................. 78 4.3.5.3. Past Occurrence ....................................................................................................................... 78 4.3.5.4. Future Occurrence .................................................................................................................... 78 4.3.5.5. Vulnerability Assessment .......................................................................................................... 78 4.3.6. Radon Exposure .............................................................................................................................. 81 4.3.6.1. Location and Extent .................................................................................................................. 81 4.3.6.2. Range of Magnitude .................................................................................................................. 86 4.3.6.3. Past Occurrence ....................................................................................................................... 87 4.3.6.4. Future Occurrence .................................................................................................................... 88 4.3.6.5. Vulnerability Assessment .......................................................................................................... 88 4.3.7. Wildfire .............................................................................................................................................. 89 4.3.7.1. Location and Extent .................................................................................................................. 89 4.3.7.2. Range of Magnitude .................................................................................................................. 92 4.3.7.3. Past Occurrence ....................................................................................................................... 92 4.3.7.4. Future Occurrence .................................................................................................................. 101 4.3.7.5. Vulnerability Assessment ........................................................................................................ 101 4.3.8. Winter Storm .................................................................................................................................. 106 4.3.8.1. Location and Extent ................................................................................................................ 106 4.3.8.2. Range of Magnitude ................................................................................................................ 107 4.3.8.3. Past Occurrence ..................................................................................................................... 110 4.3.8.4. Future Occurrence .................................................................................................................. 110 4.3.8.5. Vulnerability Assessment ........................................................................................................ 111 4.3.9. Building and Structure Collapse .................................................................................................. 112 4.3.9.1. Location and Extent ................................................................................................................ 112 4.3.9.2. Range of Magnitude ................................................................................................................ 114 4.3.9.3. Past Occurrence ..................................................................................................................... 114 4.3.9.4. Future Occurrence .................................................................................................................. 114 4.3.9.5. Vulnerability Assessment ........................................................................................................ 114 4.3.10. Dam Failure .................................................................................................................................... 116 4.3.10.1. Location and Extent ................................................................................................................ 116 4.3.10.2. Range of Magnitude ................................................................................................................ 117 4.3.10.3. Past Occurrence ..................................................................................................................... 117 4.3.10.4. Future Occurrence .................................................................................................................