Title: Study Report Analyses on Lower Bad River Basin of South Dakota

The Study of Lower Bad River-River Basin which was completed in March of 1994 and the Upper Bad River-River Basin Study was finished in October of 1998. The first phase of the project was mainly designed to find out the sources of sediment of bad river basin. The second phase analyzed that implementation of conservation best Management Practices (BMP’S) promoted with cost-share and incentive programs to the cooperators in the target watershed. Both studies indicate that sediment occurs from several sources of erosion, which include cropland, gullies, stream banks, rangeland, and the Badlands area. The cropland erosion is severe but most of the eroded soil is trapped and remains in the uplands. Runoff from this cropland increases when the residual cover is low and does have a significant effect on the gully and stream bank erosion in the lower portions of the watershed. In addition, it demonstrated that significant sediment reduction was achieved without jeopardizing the economic stability of the landowners. Thus, rate of Landowner participation in the Plum Creek Watershed was approximately 90%, and 95% lands under BMP’s (USDA, 1994). Besides that, phase II and phase III of water quality project was mainly designed and developed to implement and evaluate sediment control on highly erodible croplands and fragile clay rangelands in the lower watershed (USDA, 1998).

Oahe Dam is located about six miles upstream from the mouth of the Bad River. Since high water releases from Oahe Dam, The increased water elevation is causing flooding and high water tables in parts of both towns. Whenever large discharges of water are released from the dam, the flooding and related problems are increasing. During the winter months when ice cover occurs on Lake Sharpe, These problems have been especially troublesome. The ice builds up, causing reduced flows downstream and raising the water level in the upper portion of Lake Sharpe. This results in the need for reduced discharge from Oahe Dam to alleviate the flooding and related high water problems.

When the Bad River is running and discharging large sediment loads during the
summer months, immersion recreation is severely impaired .The Bad River provides some limited warm water fishing, stock water and irrigation along the main channel and major tributaries. The sediment in the Bad River runoff negatively affects these uses during periods of high flow. Sediment has a negative effect on fishing and recreation use of Lake Sharpe. Sediment also affects the access to Lake Sharpe in the Pierre - Ft. Pierre area. Dredging has to be performed about every four years Island to provide access for boats to the main channel of Lake Sharpe. The sediment accumulation (sediment built up at a given point since Lake Sharpe was created) below the mouth of the Bad River is creating a higher water elevation in the Pierre-Fort Pierre portion of Lake Sharpe.

List of References
United States Department of Agriculture, Soil Conservation Service, 1994. Lower Bad River-River Basin Study Final Report
United States Department of Agriculture, Natural Resources Conservation Service, 1998. Upper Bad River-River Basin Study Project #5005