Blackwood River (Western Australia)

Blackwood River
Colour Patch area at mouth of Blackwood river and start of eastern section of estuary
Country	Australia
Basin features
Main source	Junction of Arthur River and Balgarup River 219 metres (719 ft)
River mouth	Hardy Inlet, Augusta sea level
Basin size	28,100 km2 (10,849 sq mi)
Physical characteristics
Length	300 kilometres (186 mi)
Discharge	Average rate: 29.8 m3/s (1,050 cu ft/s)

The Blackwood River is a major river and catchment in the South West of Western Australia.

The river begins at the junction of Arthur River and Balgarup River near Quelarup and travels in a south westerly direction through the town of Bridgetown then through Nannup until it discharges into the Southern Ocean at Hardy Inlet near the town of Augusta.

Hardy Inlet has a number of islands – namely Molloy Island and Thomas Island. The mouth of the river has attracted interest in its various points of opening and closing over the last 100 years, Duke Head at the west side being a benchmark location for the shifting mouth.

The river has 41 tributaries including Dinninup Brook, Balingup Brook, St John Brook, Boyup Brook, Tweed River, Ti Tree Gully, Christmas Creek and Tanjannerup Creek.

The river has a total catchment area of 28,100 square kilometres (10,849 sq mi) stretching from Kukerin in the east to Hardy Inlet in the west, and from Darkin in the north to Augusta in the south.

Several major towns are found within the catchment including Katanning, Narrogin, Bridgetown and Nannup.

The upper or larger catchment area of the river is in agricultural areas, while the middle catchment area passes through forest areas, and the lower portion of the river passes into mixed forest, agricultural and residential lands. The river emerges into Flinders Bay at Augusta.