Spring Creek is a small perennial mountain stream located in Pennington and Custer Counties in the Black Hills of South Dakota. Spring Creek is a tributary of the Cheyenne River, which flows into the Missouri River. The drainage area of Spring Creek is approximately 425 square miles (1,100 square kilometers) at the confluence with the Cheyenne River.
Land use in the watershed is primarily silviculture, recreation, residential, and grazing. Some animal feeding areas are located in the watershed. Metamorphic slates and schists, along with granite rock, underlie a large portion of the basin and form the Central Crystalline Area of the Black Hills that covers the majority of the study area.
The average annual precipitation in the watershed is 20.8 inches; 80 percent usually falls in April through September. Tornadoes and severe thunderstorms strike occasionally. These storms are local and of short duration and occasionally produce heavy rainfall events. The average seasonal snow pack is 27.3 inches per year.
Total Maximum Daily Loads (TMDL)
Spring Creek was assigned the following beneficial uses: coldwater permanent fish life propagation (above Sheridan Lake), coldwater marginal fish life propagation (below Sheridan Lake), immersion recreation, limited contact recreation, fish and wildlife propagation, recreation and stock watering, and irrigation. The numeric TMDL target established for the beneficial uses for Spring Creek is based on the current daily maximum criteria for fecal coliform bacteria.
Water-quality criteria for the immersion recreation beneficial use requires that (1) no sample exceeds 400 colony-forming units (cfu)/100 milliliters (mL) and (2) during a 30-day period, the geometric mean of a minimum of five samples collected during separate 24-hour periods must not exceed 200 cfu/100 mL. This criteria is applicable from May 1 through September 30. The impaired (303(d) listed) segment, because of fecal coliform, of Spring Creek has a length of 31 miles and flows through Mitchell Lake, which has a surface area of 10 acres.
The project goal is to bring Spring Creek into compliance for fecal coliform/E. coli by implementing the recommended best management practices (BMPs) by 2021. The goal of this project segment, as set forth in the Spring Creek/Sheridan Lake TMDL study, is to:
- Implement several BMP pilot projects that will be used to demonstrate and promote the effectiveness of BMP implementation on water quality.
- Develop a 10-year Spring Creek Watershed Project Plan, Stormwater Management Plan, and Septic System Management Plan that will help prioritize BMP implementation and public outreach efforts.
- Conduct significant public education and outreach to stakeholders within the Spring Creek Watershed.
- Perform water-quality monitoring to aid in developing a baseline condition that will ensure that BMPs are effective and proper BMPs are being implemented.
The strategy of the Spring Creek Watershed Implementation Team is to progressively and efficiently implement BMPs within the Spring Creek Watershed to bring the creek back into compliance with its assigned beneficial uses. This project segment focuses heavily on planning and public outreach that will ensure the proper prioritization and adoption of BMPs. Baseline and event monitoring will be conducted to assess pre-implementation conditions and measure improvement.
The project strategy will be reviewed annually to measure overall success to determine adjustments and to obtain funding for the future project segments. Federal, state, and private funding will be used to fund BMPs. A final report will be produced for each 319 project segment completed. Additional projects and funding proposals will be submitted during the next 10 years to continue installing BMPs that reduce fecal coliform, temperature, and nutrients to meet the TMDLs.