You are here:
SWMM 5 - A Case Study of Model Re-Development
Citation:
Rossman, L. SWMM 5 - A Case Study of Model Re-Development. Presented at ECI Conference, Boulder, CO, September 24 - 26, 2012.
Impact/Purpose:
To inform the stormwater modeling community.
Description:
By the turn of the 21st century the U.S. Environmental Protection Agency’s (EPA) Storm Water Management Model (SWMM) already had a 30-year history of extensive use throughout the world for analyzing complex hydrologic, hydraulic, and water quality problems related to urban drainage. However the program itself had not kept pace with advances in either stormwater modeling or software engineering. It had become an unmanageable patchwork of poorly documented Fortran code that still relied on an outdated input file structure and command line interface. In order to breathe new life into SWMM, in 2002 EPA entered into a Cooperative Research and Development Agreement with the engineering firm CDM-Smith to re-develop SWMM from the ground up. The goals of this project were to re-write SWMM’s computational engine using an object-based approach, provide SWMM with a modern graphical user interface, improve key computational aspects of the program, and provide a complete set of documentation. The result of this effort, SWMM 5, was released to the public in 2005. Running under Windows, SWMM 5 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. These include color-coded drainage area and conveyance system maps, time series graphs and tables, profile plots, and statistical frequency analyses. Aside from its graphical user interface, SWMM 5 offers many other enhancements over the previous version. These include: • replacement of multiple program modules with a single, object-based representation of the drainage system under study • no preset limits on the number of components that can be modeled • improved speed and numerical stability in flow and pollutant routing • well structured and commented source code written in ANSI-standard C • easy integration of SWMM 5’s numerical engine into third-party user interfaces