HEC-HMS

HEC‑HMS (Hydrologic Engineering Center – Hydrologic Modeling System) is a hydrologic modelling application developed by the U.S. Army Corps of Engineers. It is used to simulate precipitation‑runoff processes in watersheds and drainage systems, supporting applications such as flood forecasting, water‑resource analysis, urban drainage studies, and reservoir design. The software includes tools for modelling infiltration, runoff, streamflow routing, evaporation, snowmelt, and other hydrologic processes within a watershed.

For help installing and getting started, see the HEC-HMS User Manual.

Mac users: note the developer’s additional instructions for running the app as it it not digitally signed.

Note: When downloading, choose the current stable version rather than a beta pre-release version.