Back to Online Database


WinSLAMM (Source Loading and Management Model for Windows) is an urban stormwater model designed to evaluate runoff volume and pollutant loading at scales ranging from individual lots to whole communities.

It simulates pollutant loadings from specific source areas (e.g., roofs, sidewalks, paved and unpaved parking areas, playgrounds, landscaped areas) in various land use settings (e.g., residential, commercial, industrial) and evaluates pollutant and runoff removal from individual or multiple stormwater BMPs. Stormwater BMPs considered include distributed and regional-scale structural BMPs (e.g., hydrodynamic devices, wet detention ponds, filter strips, porous pavement) and nonstructural BMPs such as street sweeping and catch basin cleaning. WinSLAMM is capable of modeling specific BMP implementation scenarios and does not have planning or prioritization functionality. The model is capable of evaluating an extensive list of stormwater BMPs to determine their effectiveness, as well as the capital and maintenance costs of the BMPs. The model is included with default values that characterize a number of parameters including rainfall-runoff relationships, runoff quality, and particle size distributions for six broad regions of the United States. Site-specific or regionally relevant data should be used in place of these regional inputs when and where available. Required input from the user includes source area and land use size and BMP properties (e.g., structural BMP dimensions, street cleaning frequencies). WinSLAMM is intended

Intended User: for use by any public user.

Geographic focus: WinSLAMM can be employed to evaluate any area in the United States. Customized regional or site-specific parameter files can be loaded as inputs, if desired.

Scale: Lot scale to watershed

Developer: PV & Associates. Contact Doug Joachim at

  • 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