Hawkesbury River

Hawkesbury River (Deerubbun)
Semi–mature tide dominated, drowned valley estuary
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
Country	Australia
State	New South Wales
Region	Greater Metropolitan Sydney
Tributaries
- left	Colo River, Webbs Creek, Macdonald River, Mangrove Creek, Popran Creek, Mooney Mooney Creek
- right	Cattai Creek, South Creek, Berowra Creek
Primary source	Nepean River
- location	north of Penrith
Secondary 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; 151.30000Coordinates: 33°33′53.9994″S 151°18′0″E / 33.564999833°S 151.30000°E / -33.564999833; 151.30000
Length	120 km (75 mi)
Depth	13.8 m (45 ft)
Volume	1,541,412 m3 (54,434,451 cu ft)
Basin	21,624.1 km2 (8,349 sq mi)
Area	114.5 km2 (44 sq mi)
Discharge
- average	95 m3/s (3,355 cu ft/s)
- max	15,000 m3/s (529,720 cu ft/s)
- min	0 m3/s (0 cu ft/s)
Islands	Milson Island, Peat Island, Spectacle Island, Long Island, and Dangar Island
Website: NSW Environment and Heritage webpage

The Hawkesbury River, is a semi–mature tide dominated drowned valley estuary located to the west and north of Sydney, New South Wales, Australia. The Hawkesbury River and its associated main tributary, the Nepean River, virtually encircle the metropolitan region of Sydney.

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 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, that together with the Hawkesbury River flow into the Tasman Sea at 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 the Darkinjung, Darug, Eora, and Kuringgai Aboriginal peoples. They used the river as a source of food and a place for trade.

The headwaters of the Hawkesbury River, the Avon River, the Cataract River, and the Cordeaux River, rise only a few miles from the sea, about 80 kilometres (50 mi) south of Sydney. These streams start on the inland-facing slopes of the plateau which forms the escarpment behind Wollongong. Flowing north-west, away from the sea, these streams combine to form the Nepean River, and flow north past the towns of Camden and Penrith. Near Penrith, the Warragamba River emerges from its canyon through the Blue Mountains and joins the Nepean. The Warragamba, formed by the joining of the Wollondilly River, the Nattai River, the Kowmung River and Coxs River drains a broad region of New South Wales on the eastern side of the Great Dividing Range. The other principal component of the upper Hawkesbury river system, the Grose River, rises in the area of Mount Victoria in the Blue Mountains.