The Carbunup River is located in the South West corner of Western Australia. The mouth of the Carbunup River is approximately 20 kilometres (12 mi) west of Busselton where the river flows into Geographe Bay. The Carbunup River is 36 kilometres (22 mi) in length and flows North from its headwaters in the Treeton State Forest/Whicher Range in the Shire of Augusta-Margaret River. The nearest water courses are Mary Brook to the West and Buayanyup River to the East, both of these rivers travel in a parallel direction to the Carbunup River. The catchment area is 170 square kilometres (65.6 sq mi) of which 55% is cleared. The Carbunup River is located in the Leeuwin-Naturaliste area where it crosses two physiographic regions, the 15 km wide Swan Coastal Plain and the gently undulating Blackwood Plateau.