Water Quality

The US Army Corps of Engineers is currently working with other agencies and organizations to establish a long term cooperative water quality monitoring program for Rathbun Lake. The cooperative program will focus on monitoring water quality in the Rathbun Lake and its 549 square mile watershed. That area stretches from Rathbun Dam to Chariton to Humeston to Corydon and back to the dam and covers about 1% of the State of Iowa.

Rathbun Lake is a major recreational facility in Southern Iowa and serves boaters, swimmers, fishermen and many other water based sports. Rathbun Lake is also a water supply for Rathbun Regional Water Association, which serves individuals and cities in parts of seventeen counties in Southern Iowa and Northern Missouri.Organizations involved in this water quality monitoring program include the US Army Corps of Engineers, the US Geological Survey, the Natural Resources and Conservation Service, Iowa Department of Natural Resources, Rathbun Regional Water Association, Iowa State University, University of Iowa Hygienics Lab, Chariton Valley RC&D, and the Rathbun Land and Water Alliance. Testing will be conducted on ten creeks above Rathbun Lake, the North and South Forks of the Chariton River, three lake sampling sites and the Chariton River below Rathbun Dam. The program will include testing for agricultural herbicides, nutrients, sediment. In lake sampling will include top and bottom sampling and profile information.The Corps of Engineers has been performing water quality testing since the Rathbun Lake was built in 1969. Other agencies have various responsibilities to also conduct water testing at the lake. This cooperative program will allow all of the participating agencies to gather their needed information and reduce individual costs to each agency.

The monitoring program will help identify isolated areas in Rathbun Lake’s upstream drainage basin that may be contributing to sedimentation in the lake. Once these areas are identified corrective measures can be evaluated and applied where practical and acceptable.