The goals of the Cheyenne River Watershed Phase I Total Maximum Daily Load (TMDL) assessment are to locate and document major areas of impairment using existing data and to determine the need and scope of additional sampling and analysis. The project process is a phased approach. In Phase I, analysis of existing data will be completed along with physical habitat and geomorphologic analysis at 50 sites. This information will be used to support initial guidance for Best Management Practices (BMP) implementation. The Phase I report will present recommendations for additional monitoring and modeling assessment to further refine the identification of nonpoint source pollution in the watershed and produce feasible restoration recommendations. Phase II will implement the Phase I assessment recommendations such as monitoring and modeling.
Specifically, Phase I will evaluate existing data for fecal coliform and total suspended solids (TSS) from the United States Geological Survey’s (USGS) and the South Dakota Department of Environment and Natural Resources’ (SD DENR) sampling and flow measurements. This project will result in summaries of historical data, water quality statistics, and physical habitat statistics. Products will include a hydrologic budget, as well as water quality budgets for parameters listed for impairments within the watershed, and will recommend a focused sampling plan and BMPs for implementation where possible.
To accomplish the Phase I goals for the Cheyenne River Watershed TMDL, the effort has been divided into five major objectives. These objectives are:
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Compile and Analyze Historical Flow Data
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Compile and Analyze Historical Water Quality Data
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Identify High Potential Sediment Load Contributors Outside the Riparian Zone
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Collect and Analyze Stream Assessments at 50 Selected Sites
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Information and Education Focused on Data Dissemination and the Creation of a Watershed Technical Working Group.