USACE CWMS - Des Moines River Watershed

The Corps Water Management System (CWMS) includes four interrelated models to assist with water management for the basin:

- GeoHMS (Geospatial Hydrologic Modeling Extension)
- ResSIM (Reservoir System Simulation)
- RAS (River Analysis System)
- FIA (Flood Impact Analysis)

The Des Moines River basin is the largest basin in the state of Iowa, covering approximately 14,800 square miles. The headwaters originate at Lake Shetek located in Murray County, MN, however the river is only gauged up to Windom, MN. Spanning the entire state from North to South, the basin generally flows in a southeasterly direction and drains to the Mississippi River, with the outlet located just downstream of the city of Keokuk Iowa. The basin is roughly 360 miles long and has an average width of 55 miles. The Des Moines River has a very sinuous channel with low banks and a small slope. During times of heavy rains, the valleys in the basin can be subjected to serious flooding as was seen in the 1993 flood of record. The primary land use in the basin is agriculture. The largest urbanized areas in the watershed (population over 10,000), include Des Moines, Ottumwa, Fort Dodge, and Boone. There are also several other small towns located along the banks of the Des Moines River and spread
throughout the basin.

There are two reservoirs constructed and operated by the US Army Corps of Engineers in the watershed: Saylorville Lake and Lake Red Rock. Both dams are located on the main stem of the Des Moines River and are operated in tandem by the Rock Island District. The purpose of the reservoirs is to provide flood damage reduction, to create recreational opportunities, to augment water supply, to enhance water quality, to augment flows for the lower Des Moines River, and to provide fish and wildlife conservation. There are no Locks located along the Des Moines River as there is not sufficient width or depth for a navigation channel.