Arc Hydro
Free
Esri's free hydrology framework for ArcGIS Pro — terrain preprocessing and the data model behind many agency workflows.
Global Watersheds
ActiveClick anywhere on earth, get the upstream watershed in seconds — free delineation in the browser.
- Pricing
- Free
- License
- —
- Commercial use
- Check licence
- Ecosystem
- Browser
- Platform
- Web
About Global Watersheds
Global Watersheds (mghydro.com) delineates the upstream catchment and downstream flow path from any point on earth, in the browser, in about a second — built on the MERIT-Hydro global hydrography dataset. Results export as shapefile, GeoJSON or KML, and a free API serves programmatic requests.
Accuracy inherits MERIT-Hydro's ~90 m resolution, so it is a screening and communication tool, not a design deliverable — but for "how big is the catchment above this bridge" moments, teaching, and proposal figures, nothing is faster. A genuinely useful free service by Matthew Heberger.
Where it fits in the workflow
TerrainCatchmentRainfallRunoffRoutingHydraulicsMappingReporting
Alternatives to Global Watersheds
Ranked by the topics, categories and workflow stages they share with Global Watersheds.
GRASS GIS
Open Source
Four decades of geospatial engineering — r.watershed and the most battle-tested hydrology modules in GIS.
HydroSHEDS
Free
The global hydrography reference — basins, river networks, lakes and hydro-environmental attributes, free.
QSWAT+
Open Source
The QGIS interface for SWAT+ — delineate, discretise and build a watershed model without leaving the GIS.
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.