Evaluation of flood management practices in the Cedar River Watershed

In response to increasing flood risk due to more frequent and intense rainfall events in the Cedar River Watershed, this study evaluates strategies to mitigate peak streamflow during flood events. Three methods were assessed: converting row-crop agriculture to native tall-grass prairie to enhance soil infiltration, implementing cover crops to increase soil water retention, and utilizing distributed ponds for runoff storage and delayed release. Results from 3 scenarios for each method that differ in the amount of the method used show that converting agricultural land to native prairie reduced peak streamflow by 12% to 48%, while cover crop implementation resulted in reductions of 6% to 30%, and distributed ponds decreased peak flow by 0.6% to 9%. These findings demonstrate that native tall-grass prairie restoration is the most effective strategy for reducing peak streamflow in the Cedar River Watershed. However, the cost of each method and loss of agricultural productivity must also be considered. Keeping this in mind, the use of cover crops is likely the most effective method at providing a viable solution for peak streamflow reduction in the region.