| Blackwood River | |
|---|---|
Colour Patch area at mouth of Blackwood river and start of eastern section of estuary |
|
| Origin | Junction of Arthur River and Balgarup River |
| Mouth | Hardy Inlet, Augusta |
| Basin countries | Australia |
| Length | 300 kilometres (186 mi)[1] |
| Source elevation | 219 metres (719 ft) [2] |
| Mouth elevation | sea level |
| Avg. discharge | 29.8 m³/s [3] |
| Basin area | 28,100 square kilometres (10,849 sq mi) [4] |
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.
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 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.
It was first discovered by a European in 1827 by Captain (later Admiral Sir) James Stirling and named in honour of Henry Blackwood, under whom Stirling had served as a youth from April 1808 to April 1810.
Historically it was of considerable importance in the early days of the Swan River Colony, and more recently of importance in the ecology of the Augusta-Margaret River region due to conflicts in land use policy. The upper catchment contains Toolibin Lake, a nature reserve and Ramsar site.
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.