HydroSHEDS is the standard global hydrological framework for any GIS analysis that involves water flow. Developed by WWF and USGS, it takes raw SRTM elevation data and processes it into a hydrologically consistent system: conditioned DEMs where water actually flows downhill, river centerlines with upstream-downstream connectivity, nested watershed boundaries from continental basins down to small catchments, and lake polygons — all globally consistent and topologically linked.
Without this kind of conditioning, raw elevation data produces unrealistic flow paths that break at flat areas, sinks, and noise artifacts. HydroSHEDS removes those problems, giving you a foundation for watershed delineation, flood routing, pollution transport modeling, and water resource assessment anywhere on Earth.
What elevates HydroSHEDS beyond basic hydrology layers is HydroATLAS, which pre-computes 56 environmental attributes — discharge, runoff, temperature, precipitation, land cover, soils, topography — for every river reach and watershed in the system. This means you can query and filter rivers or basins by environmental characteristics without manually overlaying and intersecting separate datasets.
For GIS analysts, this dramatically accelerates workflows like hydropower site identification (filter by discharge and gradient), freshwater biodiversity assessment (select basins by land cover and climate), or water risk screening (rank catchments by upstream land use). The hierarchical nesting of HydroBASINS also makes it straightforward to aggregate analysis at any spatial scale — from a single sub-catchment up to an entire continental drainage system.
