Visual OTTHYMO
Commercial
Hydrologic modeling software for urban and rural stormwater management, master drainage planning, and pond design.
HEC-HMS
DHS VerifiedActiveThe US Army Corps standard for rainfall-runoff modelling — event and continuous simulation, free to use.
by US Army Corps of Engineers (HEC)
- Pricing
- Free
- License
- US Government (public domain)
- Commercial use
- Permitted
- Ecosystem
- Standalone, Jython scripting
- Platform
- Windows, Linux
About HEC-HMS
HEC-HMS (Hydrologic Modeling System) from the US Army Corps of Engineers' Hydrologic Engineering Center is the default rainfall-runoff model for design hydrology in much of the world. It covers event and continuous simulation with a deep menu of methods: SCS Curve Number, Green-Ampt and Deficit-Constant losses; Clark, Snyder and SCS unit hydrographs; Muskingum and Muskingum-Cunge routing; frequency and hypothetical design storms; snowmelt; and erosion/sediment options.
Recent versions added GIS tooling that used to require HEC-GeoHMS — terrain preprocessing, subbasin delineation and grid-based modelling now live inside the program. Because it is free, documented to an exceptional standard, and accepted by virtually every reviewing agency, HEC-HMS is usually the safest choice for a defensible design hydrograph.
Where it fits in the workflow
TerrainCatchmentRainfallRunoffRoutingHydraulicsMappingReporting
Appears in collections
- The Free Drainage Engineer's Toolkit
Zero-budget, reviewer-accepted tools for everyday stormwater and drainage design.
Alternatives to HEC-HMS
Ranked by the topics, categories and workflow stages they share with HEC-HMS.
Delta Hydro Studio
FreemiumVerified
Browser-based hydrology and hydraulics calculators for practising engineers — no install, report-ready output.
WBNM
Free
The Watershed Bounded Network Model — free Australian runoff-routing hydrology for flood estimation.
hms-commander
Open Source
Python automation for HEC-HMS — batch and parallel runs, design storms, and DSS handoff to HEC-RAS.
WinTR-55
Gov-Public
NRCS's official implementation of TR-55 small-watershed hydrology: peaks, hydrographs and storage.
SWAT+
Open Source
The USDA watershed model for land use, sediment and nutrients — continuous simulation at catchment scale.