All Posts (522)

EPA releases improved Storm Water Management Model

CINCINNATI, OH, April 26, 2005 -- Civil and environmental engineers now have an improved software tool, the Storm Water Management Model (SWMM), to help plan, analyze, and design urban storm water drainage and sewer systems. This latest revision to SWMM includes several improvements not available in previous editions. These include a modern graphical user interface, a more intuitive modeling approach, and improved computational speed. SWMM continues to be open source and its numerical engine can easily be integrated into third-party interfaces.

SWMM is a dynamic rainfall runoff computer model that simulates single event or continuous storm water runoff quantity and quality primarily for urban areas. The tool has been used in thousands of sewer and storm water studies throughout the world and has historically played a significant role in combined and sanitary sewer overflow (CSO/SSO) abatement programs and in National Pollutant Discharge Elimination System (NPDES) permitting.

The runoff component of SWMM simulates the operation of drainage areas that receive rainfall and generate runoff that may include pollutants. The routing component of SWMM simulates the transport of runoff through a system of pipes, channels, storage/treatment devices, pumps, and regulators. SWMM tracks the quantity and quality of runoff generated within each drainage area as well as the flow rate, flow depth, and quality of water in each pipe and channel during a simulation period comprised of multiple time steps.

Running in a Windows-based format, SWMM provides an integrated environment for editing study area input data, running hydrologic, hydraulic and water quality simulations, and viewing the results in a variety of formats. This approach allows analysts to study and compare design alternatives much more efficiently than could be done using earlier versions of the program.

"This newest upgrade is another example of EPA's commitment to maintain a leadership role to the storm water management community by providing open source computing tools like SWMM," said James A. Goodrich, Ph.D., Acting Director of EPA's National Risk Management Research Laboratory (NRMRL) Water Supply and Water Resources Division in Cincinnati, Ohio. This latest version of SWMM is a joint development effort with CDM Inc., a global consulting, engineering, construction, and operations company. CDM worked with EPA on this project under a Cooperative Research and Development Agreement.

The free SWMM program, including tutorials, is available on EPA's Wet Weather Flow Research web page at and can be accessed 24-hours a day.

The EPA relies on quality science as the basis for sound policy and decision-making. The agency's laboratories and research centers, as well as research grantees, are building the scientific foundation needed to support the agency's mission to safeguard human health and the environment.
Read more…