About

The United States Environmental Protection Agency (EPA) Storm Water Management Model (SWMM) is a popular, open source, hydrology and 1D modelling system. First developed in the late 60s and early 1970s by the University of Florida, Metcalf & Eddy, and CDM, the application has had many major upgrades over the decades to its current version. SWMM is used worldwide and has been embedded in many different modelling platforms using its flexible API.

EPA SWMM develops a graphical user interface (GUI), though people tend to develop these model inputs within a separate GIS system before manually transferring the information to the SWMM GUI. The TUFLOW plugin in QGIS, is a freely available plug-in that enables efficient creation and editing of SWMM data in a GIS GeoPackage format. The plugin includes functions to:

1. Create an empty GIS GeoPackage file with designated SWMM tables (Conduits, Junctions, etc).
2. Edit and visualize the SWMM network and input data.
3. Review network integrity. Checks include bulk identification of unreasonable changes in area, adverse slopes, and insufficient cover.
4. One-click data conversion, either from a SWMM project file (inp) to a GIS GeoPackage representation, or the reverse, GIS GeoPackage to a SWMM project file (inp).

The TUFLOW plugin tools can also be used to prepare a model to run using TUFLOW-SWMM, linking the 2D TUFLOW solver to the 1D SWMM solver for a complete integrated catchment model.