Evaluating Implementation of LID/BMP in Storm Water System using EPA SUSTAIN

This paper describes an application of the U.S. Environmental Protection Agency (EPA)'s System for Urban Stormwater Treatment and Analysis INtegration (SUSTAIN) model to identify potential flood, erosion, and water quality mitigation measures through the use of Low Impact Development (LID) and Best Management Practices (BMPs) in Fort Gordon, a U.S. Army Installation, in Georgia. Fort Gordon occupies approximately 56,000 acres and is located within an area commonly referred to as the Central Savannah River Area (CSRA). In an earlier study, EPA's Stormwater Management Model (SWMM), Version 5.0.009 was used to analyze the performance of Fort Gordon's storm sewer system under a range of flows to determine capacity issues. The results of this earlier study were used as baseline and were reproduced using SUSTAIN. This involved exporting SWMM input parameters into SUSTAIN and representing in detail Fort Gordon's storm sewer network within the SUSTAIN GIS framework. EPA SUSTAIN was then used to determine near optimal combination of LIDs and BMPs to cost-effectively address frequent flooding. The SUSTAIN model was also used to calculate the erosion and water quality benefit corresponding to the selected flood mitigation measures. A cost-effectiveness curve was derived to evaluate the potential cost corresponding to reducing peak discharge values.