Current Capabilities and Planned Enhancements of SUSTAIN

Efforts have been under way by the U.S. Environmental Protection Agency (EPA) since 2003 to develop a decision-support tool for placement of best management practices (BMPs) at strategic locations in urban watersheds. The tool is called the System for Urban Stormwater Treatment and Analysis INtegration (SUSTAIN). It is designed for use by watershed and stormwater practitioners to develop, evaluate, and select optimal BMP options for various watershed scales based on cost and effectiveness. SUSTAIN seamlessly integrates GIS analysis and visualization, watershed/BMP simulation, cost, and system optimization. It incorporates an innovative concept of developing a cost-effectiveness curve for watershed decision making. In addition, an equally innovative multi-tier concept was incorporated for performing staged optimizations from smaller watersheds to a larger watershed. SUSTAIN Version 1.0 was released in November, 2009 (http://www.epa.gov/ednn rmrl/models/sustain/index.html). EPA has committed additional funds to provide user support, showcase applications, and perform needed enhancements to better facilitate the setup and application of SUSTAIN while improving output accuracy and credibility. In addition to describing the current capabilities of SUSTAIN, this paper highlights the planned enhancement to the modeling processes of wetlands/swales/buffers and permeable pavements, BMP selection and placement algorithms, cost database, multiple-scale applications, and visualization.