Formed through the confluence of the Coxs River and two minor tributaries, Warragamba River rises within Lake Burragorang and is the river on which Warragamba Dam is established, creating a large reservoir with total capacity of 2,031 gigalitres (7.17×1010 cu ft),[3] that forms a major part of the water supply to greater metropolitan Sydney.

The river descends 96 metres (315 ft), the majority of which is over the dam spillway, and then flows north into the Nepean River, north of the village of Warragamba, a course of approximately 18 kilometres (11 mi).

[2] Prior to the creation of Lake Burragorang, the Warragamba River would have been formed by the confluences of the Coxs, Nattai, and Wollondilly rivers in the Burragorang Valley.

It was this configuration which allowed a relatively short but high dam wall in the gorge to impound a large quantity of water.

[1][4] The area surrounding Warragamba River is managed by Sydney Catchment Authority under the Sydney Water Catchment Management Act, 1998 (NSW) that defines special zones and places restrictions and controls on land use, development and access[5] in order to safeguard potable water.