HydroATLAS is a global compendium of hydro-environmental attributes for all sub-basins and river reaches worldwide, providing 56 hydro-environmental variables organised in 281 attributes at 15 arc-second (~500m) resolution. Developed as part of the HydroSHEDS initiative. Three components: BasinATLAS (sub-basin polygons with attributes), RiverATLAS (river reach lines with attributes), and LakeATLAS (lake polygons with attributes). Variable categories include: hydrology & hydrography (discharge, runoff, lake area), physiography (elevation, slope, terrain), climate (temperature, precipitation, aridity, seasonality), land cover & use (forest, cropland, urban, wetland), soils & geology (soil type, lithology, karst, permafrost), and anthropogenic influences (population, GDP, dam storage, water use). Open-access dataset published in Nature Scientific Data (Linke et al. 2019). Valuable for large-scale hydrological characterisation, transboundary analysis, and comparative basin studies across the Incomati system.