Water Quality Enhanced by Sustainable Watershed Evaluation and Planning Process at the Metropolitan Sewer District of Greater Cincinnati

Local governments and utilities across the nation are starting to address the needs for implementing more sustainable stormwater and watershed management strategies. These needs are driven by the necessity to reduce stormwater contributions to combined sewer overflows (CSO), water quality and designated use issues, total maximum daily load (TMDL) requirements, numeric nutrient criteria, and flood risk reductions. The U.S. Environmental Protection Agency (USEPA) has recognized the value of more “green” stormwater management approaches and has encouraged CSO programs, municipal separate storm sewer system (MS4) National Pollutant Discharge Elimination System (NPDES) permittees, and wastewater NPDES permittees to more actively implement sustainable programs including green infrastructure (GI) and low impact development (LID). In 2006, the Metropolitan Sewer District of Greater Cincinnati developed the Wet Weather Improvement Program (WWIP) to address these issues and the federal consent orders. The program was later re-branded as Project Groundwork and has been modified (in 2010) to include the evaluation of green infrastructure to address wet-weather discharges. The Sustainable Watershed Evaluation Planning Process (SWEPP) was developed to facilitate a balanced evaluation of sustainable and green alternatives, in combination with traditional gray alternatives, to meet the overall goals for wet-weather improvements on a watershed basis.This paper discusses the Sustainable Watershed Evaluation Planning Process (SWEPP) for the Upper South Branch Mill Creek Study Area.