The Busselton Coast catchment is 3057 km2 and consists of many short river and creek systems primarily confined to the coastal plain between Bunbury and Augusta. The larger river systems – the Capel, Ludlow, Abba and Sabina – have headwaters in the Darling and Whicher ranges.
Rainfall varies between 800 and 1100 mm annually, with the highest rainfall occurring in the south-western corner.
The natural drainage has been highly modified to drain low-lying areas of the Swan Coastal Plain for agriculture, primarily dairy farming. Five of the river systems have been diverted from the Vasse-Wonnerup estuary to discharge directly to the ocean. A number of creeks along the Leeuwin-Naturalist Ridge, discharging to Geographe Bay, contain near-intact fringing vegetation.