Floyd River Drainage Mitigation

Engineering students developed design solutions to mitigate the threat of pooling behind the Floyd River levee and reduce flood insurance rates for the Leeds neighborhood in Sioux City, IA. These designs included recommendations for detention basins, pumping stations, and green alternatives.

The Leeds neighborhood within the city of Sioux City, IA has experienced many significant flood events, due to its proximity to the Floyd River. To alleviate the possibility of flooding, the US Army Corps of Engineers channelized the Floyd River and installed levees and floodgates to protect the neighborhood. However, recent improvements to the FEMA floodplain maps have classified many properties in the Leeds neighborhood as a high-risk flood area, even though they are protected by the levee. These levee-protected properties are classified as high-risk because pooling behind the levee can occur during local rainfall events that coincide with flood conditions on the Floyd River. During high discharges or flooding conditions, the levees and floodgates protect the neighborhood, but don’t allow stormwater to enter the channel, causing pooling scenarios during local rainfall events.