The latest edition of the EPA's Storm Water Management Model (SWMM) software includes several improvements. The revisions to the software—designed to help plan, analyze, and design urban stormwater drainage and sewer systems—include an enhanced interface, more intuitive modeling, and improved computational speed. The program is open source, and its numerical engine can be integrated easily into third-party interfaces.
SWMM is a rainfall runoff computer model that simulates single-event or continuous stormwater runoff quantity and quality primarily for urban areas. The tool, used in sewer and stormwater studies across the globe, has played a significant role in combined and sanitary sewer overflow abatement programs and in National Pollutant Discharge Elimination System permitting.
The runoff component simulates the operation of drainage areas that receive rainfall and generate runoff that may include pollutants. The routing component simulates the transport of runoff through a system of pipes, channels, storage/treatment devices, pumps, and regulators. In addition, the software tracks runoff generated within each drainage area, flow rate, flow depth, and quality of water in each pipe and channel during a simulation period comprised of multiple time steps.
To obtain the free SWMM program, including tutorials, visit www.epa.gov/ednnrmrl/swmm.