Volume 2 Hazard Inventory (R)
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2018 HENNEPIN COUNTY MULTI-JURISDICTIONAL HAZARD MITIGATION PLAN Volume 2 Hazard Inventory (R) 01 February 2018 1 2018 Hennepin County Multi-Jurisdictional Hazard Mitigation Plan Volume 2- Hazard Inventory THIS PAGE WAS INTENTIONALLY LEFT BLANK 2 Hennepin County Multi-Jurisdictional Hazard Mitigation Plan Volume 2- Hazard Inventory TABLE OF CONTENTS- VOLUME 2 TABLE OF CONTENTS ........................................................................................................................ 3 SECTION 1: HAZARD CATEGORIES AND INCLUSIONS ...................................................................... 5 1.1. RISK ASSESSMENT PROCESS ........................................................................................................... 5 1.2. FEMA RISK ASSESSMENT TOOL LIMITATIONS ............................................................................... 5 1.3. JUSTIFICATION OF HAZARD INCLUSION ......................................................................................... 6 SECTION 2: DISASTER DECLARATION HISTORY AND RECENT TRENDS............................................. 11 2.1. DISASTER DECLARATION HISTORY ................................................................................................ 11 SECTION 3: CLIMATE ADAPTATION CONSIDERATIONS ................................................................... 13 3.1. CLIMATE ADAPTATION .................................................................................................................. 13 3.2. HENNEPIN WEST MESONET .......................................................................................................... 13 SECTION 4: COMPREHENSIVE NATURAL HAZARD ASSESSMENT PROFILES ..................................... 15 4.1. GEOLOGICAL HAZARDS ................................................................................................................. 15 4.1.1. LANDSLIDES ......................................................................................................................... 15 4.1.2. SINK HOLES .......................................................................................................................... 21 4.1.3. SOIL FROST ........................................................................................................................... 27 4.1.4. VOLCANIC ASH..................................................................................................................... 35 4.2. HYDROLOGICAL HAZARDS ............................................................................................................ 39 4.2.1. FLOODING, URBAN ............................................................................................................. 39 4.2.2. FLOODING, RIVER ................................................................................................................ 45 4.3. METEOROLOGICAL HAZARDS ....................................................................................................... 51 4.3.1. CLIMATE CHANGE ............................................................................................................... 51 4.3.2. TORNADO ............................................................................................................................ 71 4.3.3. WINDS, EXTREME STRAIGHT-LINE ..................................................................................... 83 4.3.4. HAIL ...................................................................................................................................... 95 4.3.5. LIGHTNING ......................................................................................................................... 109 4.3.6. RAINFALL,EXTREME .......................................................................................................... 117 4.3.7. HEAT, EXTREME ................................................................................................................. 133 3 Hennepin County Multi-Jurisdictional Hazard Mitigation Plan Volume 2- Hazard Inventory 4.3.8. DROUGHT .......................................................................................................................... 145 4.3.9. DUST STORM ..................................................................................................................... 155 4.3.10. COLD, EXTREME .............................................................................................................. 161 4.3.11. WINTER STORM, BLIZZARD/EXTREME SNOWFALL ....................................................... 171 4.3.12. WINDS, NON-CONVECTIVE HIGH ................................................................................... 187 4.3.13. ICE STORM ....................................................................................................................... 207 SECTION 5: HUMAN CAUSED TECHNICAL/INDUSTRIAL HAZARD ASSESSMENT ............................ 217 TO BE PREPARED AT A FUTURE DATE SECTION 6: HUMAN CAUSED ADVERSARIAL HAZARD ASSESSMENT............................................. 217 TO BE PREPARED AT A FUTURE DATE SECTION 7: MASS EVACUEE AND IMMIGRATION MOVEMENT ..................................................... 217 TO BE PREPARED AT A FUTURE DATE SECTION 8: VULNERABILITY ASSESSMENT .................................................................................... 219 8.1. HAZARD RANKING MAPS ............................................................................................................ 219 SECTION 9: CULTURAL RESOURCE INVENTORY ............................................................................. 241 9.1. INVENTORIES................................................................................................................................ 241 9.2. MINNESOTA NATIONAL HISTORIC LANDMARKS ....................................................................... 241 9.3. HENNEPIN COUNTY HISTORIC LANDMARK MAP ...................................................................... 250 SECTION 10: CRITICAL INFRASTRUCTURE KEY RESOURCES (CIKR)**REDACTED** ........................ 257 4 Hennepin County Multi-Jurisdictional Hazard Mitigation Plan Volume 2- Hazard Inventory SECTION 1 HAZARD CATEGORIES AND INCLUSIONS 1.1. Risk Assessment Process Risk from natural hazards is a combination of hazard and vulnerability. The risk assessment process measures the potential loss to a community, including loss of life, personal injury, property damage and economic injury resulting from a hazard event. The risk assessment process allows a community to better understand their potential risk and associated vulnerability to natural, intentional human-caused and unintentional human-caused hazards. This information provides the framework for a community to develop and prioritize mitigation strategies and plans to help reduce both the risk and vulnerability from future hazard events. This section describes the hazards that may impact Hennepin County and assesses their associated risk. Hazards that may affect Hennepin County are identified and defined in terms of their range of magnitude, spectrum of consequences, potential for cascading effects, geographic scope of hazard, historical occurrences and likelihood of future occurrences. The following hazard assessment information should be considered as new information and not an update from the 2010 plan. The Planning Team reviewed hazards from the previous plan and have identified hazards that need to be added. Several hazards from the 2010 plan were eliminated, TABLE 1.1A lists those removed with justification: TABLE 1.1A 2010 Eliminated Hazard Justification for Elimination Dams Although several dams exist across Hennepin County, none pose a significant threat to populations or property. Earthquakes This assessment will be a part of the future natural hazard build out. Hazardous Materials This assessment will be a part of the future plan un-intentional human-caused hazard build out. Radiological This assessment will be a part of the future plan un-intentional human-caused hazard build out. Terrorism This assessment will be a part of the future plan intentional human- caused hazard build out. Transportation This assessment will be a part of the future plan un-intentional human-caused hazard build out. In addition, a thorough geospatial risk analysis was conducted using locally available parcel data and building values. Further, maps were provided where hazard boundaries and data existed. These improvements help to provide a more accurate assessment of risk in the county to develop mitigation actions. 1.2. FEMA Risk Assessment Tool Limitations In 1997, FEMA developed the standardized Hazards U.S., or HAZUS model to estimate losses caused by earthquakes and identify areas that face the highest risk and potential for loss. HAZUS was later expanded 5 Hennepin County Multi-Jurisdictional Hazard Mitigation Plan Volume 2- Hazard Inventory into a multi-hazard methodology, HAZUS-MH, with new models for estimating potential losses from wind (hurricanes) and flood (riverine and coastal) hazards. HAZUS-MH is a Geographic Information System (GIS) based software program used to support risk assessments, mitigation planning, and emergency planning and response. It provides a wide range of inventory data, such as demographics, building stock, critical facility, transportation and utility lifeline, and multiple models to estimate potential losses from natural disasters. The program maps and displays hazard data and the results of damage and economic loss estimates for building