Hawkesbury River

Hawkesbury-Nepean River
Aerial photograph showing the mouth of the Hawkesbury River as it flows into Broken Bay and out into the Tasman Sea, as seen looking across Sydney's Northern Beaches
Native name	Dyarubbin (Dharuk)
Location
Country	Australia
State	New South Wales
Region	Greater Metropolitan Sydney
Physical characteristics
Source	Nepean River
• location	north of Penrith
2nd source	Grose River
Mouth	Broken Bay
• location	west of Lion Island
• coordinates	33°33′53.9994″S 151°18′0″E / 33.564999833°S 151.30000°E / -33.564999833; 151.30000
Length	120 km (75 mi)
Basin size	21,624.1 km2 (8,349.1 sq mi)
Discharge
• location	Near mouth
• average	150.2 m3/s (4,740 GL/a)[1] 95 m3/s (3,400 cu ft/s)
• minimum	0 m3/s (0 cu ft/s)
• maximum	15,000 m3/s (530,000 cu ft/s)
Basin features
Tributaries
• left	Colo River, Webbs Creek, Macdonald River, Mangrove Creek, Popran Creek, Mooney Mooney Creek
• right	Cattai Creek, South Creek, Berowra Creek
Islands	Milson Island, Peat Island, Spectacle Island, Long Island, and Dangar Island

The Hawkesbury River, or Hawkesbury-Nepean River (Dharug: Dyarubbin)^[2] a river located northwest of Sydney, New South Wales, Australia. The Hawkesbury River and its associated main tributary, the Nepean River, almost encircle the metropolitan region of Sydney. Between Wisemans Ferry and the Pacific Ocean marks the boundary of Greater Metropolitan Sydney in the south and the Central Coast region to the north.

The Hawkesbury River has its origin at the confluence of the Nepean River and the Grose River, to the north of Penrith and travels for approximately 120 kilometres (75 mi) in a north–easterly and then a south–easterly direction to its mouth at Broken Bay, about 15 kilometres (9.3 mi) from the Tasman Sea. The Hawkesbury River is the main tributary of Broken Bay. Secondary tributaries include Brisbane Water and Pittwater, which, together with the Hawkesbury River, flow into Broken Bay and thence into the Tasman Sea north of Barrenjoey Head.

The total catchment area of the river is approximately 21,624 square kilometres (8,349 sq mi) and the area is generally administered by the Hawkesbury–Nepean Catchment Management Authority.

The land adjacent to the Hawkesbury River was occupied by Aboriginal peoples: the Darkinjung, Darug, Eora, and Kuringgai. They used the river as a source of food and a place for trade.^[3] In the languages of the traditional custodians the river is Deerubben or Dyarubbin.^[4][5][6]

In March 2021, the river level rose, and many areas were flooded as part of the March 2021 Australian floods.^[7]