This study presents an integration of hydrologic methods from the Hydrologic Engineering Center’s Hydrologic Modeling System (HEC-HMS) with the hydraulic component of the Environmental Protection Agency’s Storm Water Management Model (EPA SWMM). The integration was implemented using Python scripting within PCSWMM, and the process involves several key steps, including the creation and parameterization of a subbasin polygon layer, the export of HEC-HMS model input files, and the organization of time series data from the HEC-DSS output file. The SWMM model is then run using either the inflows interface file or the SWMM 5.2 API to update model nodal lateral inflow based on HEC-HMS output time series, followed by post-processing.
Each of these development steps is discussed in detail, and a demo is presented to demonstrate the use of the developed tools. Case studies are also conducted to compare SWMM model runtimes using the inflows interface file versus EPA SWMM API, providing valuable insights for future researchers and practitioners.
Overall, this study highlights the potential of integrating hydrologic and hydraulic modeling techniques. The development process outlined in the study provides a useful framework for others interested in implementing similar integration.
Click here to watch recorded presentation on YouTube.