Distributed storage modeling in Soap Creek for flood control and agricultural practices

In 1988, the counties of Appanoose, Davis, Monroe, and Wapello created the Soap Creek Watershed Board. This group put in place a plan to fund and construct 154 farm ponds in an effort to provide water for agriculture practices as well as provide flood protection for the residents inside the Soap Creek watershed. Through collaborative efforts and funding from federal, state, and local sources, to date 132 ponds have been constructed.

Currently there is no stream monitoring in place in the watershed to observe stream conditions. This leads to no stored data on the benefits of the projects in the basin and the reduced flood impacts. With funding from the Iowa Watershed Projects (IWP) through the IIHR - Hydroscience & Engineering lab, a lumped parameter surface water model was created to show the benefits of the constructed projects. Using detailed LiDAR data, a Hydrologic Engineering Center-Hydrologic Modeling System (HEC-HMS) model was created. This model used arcHydro and ARC-GeoHMS, tools in ARCgis. Detailed LiDAR, SURGGO soil data, and land cover data was used to create the model parameters. Several design and historical storms were modeled to quantify the benefits in peak flow reductions and in amounts of water stored behind the projects.