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Storm Water Management Model (SWMM) is a dynamic rainfall-runoff water quality simulation model.

It can be used for single event or long-term (continuous) simulation of runoff quantity and quality from primarily urban areas. The runoff component operates on a collection of sub-catchment areas that receive precipitation and generate runoff and pollutant loads. The routing portion transports this runoff through a system of pipes, channels, storage/treatment devices, pumps, and regulators. SWMM tracks the quantity and quality of runoff generated within each sub-catchment, and the flow rate, flow depth, and quality of water in each pipe and channel during a simulation period, typically at the hourly or sub-hourly time step. SWMM 5 has been extended to model the hydrologic performance of specific types of low impact development (LID) controls.

Intended User: Model is designed to be handled by professionals with a watershed modeling background.

Geographic focus: Model is designed to simulate any watershed, provided the user selects or enters the appropriate input information.

Scale: Lot scale to watershed

Developer: EPA. Contact Michelle Simon at 513-569-7469

  • How are source contributions estimated?
  • How is pollutant load removal estimated?
  • What does the user need to input?
  • What can the user expect as outputs?
  • Considerations
  • Additional Features