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Anoka County 2019 Multi-Jurisdictional All Hazards Mitigation Plan 92 plain. The Anoka County Flood Vulnerability Report located in Appendix A pages 5-19 review the historical information available regarding flooding in Anoka County and includes several case studies on the probable losses due to future flood events in Anoka County. The report also reviews infrastructure that is located in and around the 100-year flood plain and may be affected due to 100-year flood event. In reviewing the information on the infrastructure, facilities, and their physical location related to the flood plain from the maps provided by Anoka County GIS, the property may be in or next to a flood plain and property is marked as being in the flood plain. Many pieces of the infrastructure and structures were completed to meet current building codes and comply with the National Flood Insurance requirements and elevated above the 100-year flood plain level. As part of the Anoka County Mitigation Plan, jurisdictions will continue to review mitigation options to reduce the impact of flooding on infrastructure and structures that do not comply with the National Flood Insurance requirements and / or are at risk for loss from flooding. Flooding tends to occur in Anoka County during anomalous years of prolonged, regional rainfall (such as an El-Nino year) and excessive snowfall and is typified by increased humidity and high spring/summer temperatures. Flash flooding is a critical natural hazard caused by too much rain falling and/or snowmelt in a short time, often a result of thunderstorms or the remnants of a tropical storm. Several factors contribute to flash flooding: rainfall intensity and duration, topography, soil conditions, and ground cover. Most flash flooding is caused by slow-moving thunderstorms, repeatedly moving over the same area, or by multiple storm cells colliding. Flash flooding can occur within a few minutes of excessive rainfall or from a quick release from a dam or levee failure. Thunderstorms produce flash flooding, often far from the actual storm, and water may rise at night when natural warnings may not be noticed. Anoka County and participating jurisdictions have experienced flood events 37 times since 1965 resulting in one fatality and five injuries. A total of $203,714,028 in structure damage has been logged along with $481,287 in content damage. A detailed list of flood events is provided in Appendix A. In 1997, City of Anoka, which is located along the lower Rum River and Mississippi River was impacted to the extent that residents were evacuated, city streets closed, and septic and drain fields failed. Clean up was extensive in removing sandbags and debris. For Ramsey, Fridley and Anoka the likelihood of occurrence is moderate, but the impact is considered high.