HEC-HMS
FreeVerified
The US Army Corps standard for rainfall-runoff modelling — event and continuous simulation, free to use.
WBNM
StableThe Watershed Bounded Network Model — free Australian runoff-routing hydrology for flood estimation.
- Pricing
- Free
- License
- Freeware
- Commercial use
- Permitted
- Ecosystem
- Standalone
- Platform
- Windows
About WBNM
WBNM (Watershed Bounded Network Model) is one of Australia's established runoff-routing flood models, in the same family as RORB and URBS: subareas bounded by watershed divides, nonlinear storage routing, and ensemble design-event simulation in the Australian Rainfall & Runoff tradition. Originating with Michael Boyd's work in the 1970s and long maintained with Ted Rigby and collaborators, it has decades of calibration literature behind it.
Unlike its commercial siblings it is free to download and use, which has kept it popular with councils and smaller consultancies. It pairs naturally with ARR 2019 Data Hub inputs, and the open pyromb library can now build its catchment files straight from GIS.
Where it fits in the workflow
TerrainCatchmentRainfallRunoffRoutingHydraulicsMappingReporting
Alternatives to WBNM
Ranked by the topics, categories and workflow stages they share with WBNM.
Visual OTTHYMO
Commercial
Hydrologic modeling software for urban and rural stormwater management, master drainage planning, and pond design.
Delta Hydro Studio
FreemiumVerified
Browser-based hydrology and hydraulics calculators for practising engineers — no install, report-ready output.
Wflow.jl
Open Source
Deltares' distributed hydrological model in Julia — gridded rainfall-runoff with kinematic-wave routing.
hms-commander
Open Source
Python automation for HEC-HMS — batch and parallel runs, design storms, and DSS handoff to HEC-RAS.
pyromb
Open Source
Build RORB, WBNM and URBS model files straight from GIS shapefiles — with companion QGIS plugins.