A simplified stormwater management model has been developed to provide an inexpensive, flexible tool for planning and preliminary sizing of stormwater facilities. The model was developed to be part of a methodology for use in the management of stormwater that utilizes both simple computer programs and hand computations. The model consists of three uncomplicated but interrelated programs that can be used singularly or together. Capabilities of the model, in addition to quantity and quality analyses for stormwater flows, include dry-weather flow, hourly simulation, overflow event analysis, pollutant removals due to sedimentation in storage, and lateral inflows. Postprocessor programs can also provide histogram plots of flow and quality and analyses of receiving water coliform limitation violation days for several coliform standards.