Surface drainage catchment polygons from the National Geochemical Survey of Australia; shown for Western Australia and parts of South Australia and the Northern Territory.

These catchments were derived from a national scale 9 second (approximately 250 m) resolution digital elevation model (DEM) as part of the National Geochemical Survey of Australia. Catchments were extracted from an unpublished, interim version of a nested catchment framework with an optimal catchment area of 5000 km2, sourced from Geoscience Australia. Catchments shown in 'Hydrology – catchments DWER extended' were roughly used to determine extent included into South Australia and the Northern Territory.