This dataset is the Western Australian component of a national Drainage Divisions and Basins dataset overseen by the Australian Water Resources Council. It is part of a hierarchical order of 4 datasets ranging from Subcatchments through Catchments and Basins to Divisions. The Subcatchments, Catchments and Basins are hierarchically ordered subsets of the Divisions dataset.

Catchment boundaries have been defined for more than 3400 key sites on streams throughout Western Australia. The Subcatchments dataset contains polygons derived from all the defined boundaries, while the Catchment, basin and division polygons are based on subsets of the same boundaries.

This dataset was formally known as Hydrographic Catchments - Subcatchments (DOW-015)