GRASS GIS
Open Source
Four decades of geospatial engineering — r.watershed and the most battle-tested hydrology modules in GIS.
Arc Hydro
ActiveEsri's free hydrology framework for ArcGIS Pro — terrain preprocessing and the data model behind many agency workflows.
by Esri
- Pricing
- Free
- License
- Proprietary (free add-on)
- Commercial use
- Permitted
- Ecosystem
- ArcGIS Pro, Python (arcpy)
- Platform
- Windows
About Arc Hydro
Arc Hydro is Esri's water-resources framework: a data model plus a large toolbox for terrain preprocessing, watershed and stream delineation, characterisation and map-to-model handoffs, developed with the water community over two decades. Many US agency workflows (and datasets) are structured around Arc Hydro conventions.
The tools are free but require ArcGIS Pro, which defines its audience: if your organisation is Esri-native, Arc Hydro is the mature, supported path for GIS hydrology; if not, the open QGIS/WhiteboxTools stack covers equivalent ground without the platform dependency.
Where it fits in the workflow
TerrainCatchmentRainfallRunoffRoutingHydraulicsMappingReporting
Alternatives to Arc Hydro
Ranked by the topics, categories and workflow stages they share with Arc Hydro.
HydroSHEDS
Free
The global hydrography reference — basins, river networks, lakes and hydro-environmental attributes, free.
SAGA GIS
Open Source
The geomorphometry powerhouse — hundreds of terrain and hydrology modules behind a free desktop GIS.
WhiteboxTools
Open SourceVerified
500+ fast geospatial analysis tools with the best DEM hydrology toolkit in open source.
TauDEM
Open Source
Utah State's parallel terrain-analysis suite — D-infinity flow modelling and objective stream-network extraction.
QGIS
Open SourceVerified
The free, open-source GIS that has become the default spatial platform for water engineers worldwide.