A Pilot Project Using GIS to Map Undocumented Levees in Minnesota
Local, state, and federal managers tasked with forecasting flood peaks, predicting the extent of flood inundation, mitigating the risk associated with flooding or levee failure, or responding during flood emergencies require detailed knowledge about levee locations and characteristics. Although some levees are accredited in FEMA's Flood Insurance Rate Maps and supporting studies and/or included in the USACE National Levee Database, many undocumented, unaccredited, and often unmaintained levees exist, which complicates flood forecasting, risk management, and emergency response.
The Minnesota Silver Jackets team supported an interagency effort that assessed two methods of using remote sensing with high-resolution LIDAR topographic data to identify undocumented levees. The methods drew on the topographic characteristics of accredited and any known unaccredited levees to develop search criteria and test methodologies for identifying existing, intentional levee structures near rivers as well as other levee-like structures that may or may not be acting as water barriers. U.S. Geological Survey (USGS) and USACE were the lead technical agencies with LIDAR data provided by the Minnesota Department of Natural Resources and local assessment completed by the cities of Delano and Springfield, MN. The published results of this pilot project are available for federal, state, and local communities so that they may apply these methodologies and identify potentially undocumented levees in other areas. Knowing the existence and location of levees especially in developed areas will greatly assist risk communications and emergency responders.
Emergency Action Plan Guidebook and Templates
The Minnesota Silver Jackets Team, in association with the North Dakota Silver Jackets Team, FEMA, MN Homeland Security and Emergency Management, USACE EM, and the USACE Levee Safety CoP, developed this guide for small to medium sized communities and tribes as a way to develop and document the information they would need to have a safe and effective flood emergency response. Many communities rely on county and state all-hazard plans, but have not complied the critical information for their location-specific conditions. This is also an opportunity to record the institutional knowledge of those residents and public officials who have experienced local flood events. The St. Paul District, through Silver Jackets support, has been able to conduct local and regional workshops on how to develop these community level flood emergency action plans. All of the documents and fillable forms for the guidebook can be found at the following link: Guidebook (pdf, 4.6 MB).