| Cordeaux | |
| Subdivision Type1: | Country |
| Subdivision Name1: | Australia |
| Subdivision Type2: | State |
| Subdivision Name2: | New South Wales |
| Subdivision Type3: | Region |
| Subdivision Name3: | Sydney Basin (IBRA), Southern Highlands, Macarthur |
| Subdivision Type5: | Municipalities |
| Subdivision Name5: | Wollongong, Wollondilly |
| Length: | 32km (20miles) |
| Source1: | Illawarra escarpment |
| Source1 Location: | below Mount Keira |
| Source1 Elevation: | 315m (1,033feet) |
| Mouth: | confluence with the Nepean River |
| Mouth Location: | near Wilton |
| Mouth Elevation: | 147m (482feet) |
| River System: | Hawkesbury-Nepean catchment |
| Tributaries Left: | Avon River (Wollongong) |
| Custom Label: | Reservoir |
| Custom Data: | Lake Cordeaux |
| Extra: | [1] |
The Cordeaux River, a perennial river of the Hawkesbury-Nepean catchment, is located in the Southern Highlands and Macarthur regions of New South Wales, Australia.
The Cordeaux River rises on the western slopes of the Illawarra escarpment, below Mount Keira within the Wollongong local government area and flows generally north and northwest, joined by the Avon River, before reaching its confluence with the Nepean River, south of Wilton. The river descends [1] over its 37km (23miles) course.
The river is impounded by Lake Cordeaux, one of four reservoirs within the Upper Nepean Scheme that supplies potable water for greater metropolitan Sydney. Located near Ryans Crossing, approximately south-west of Sydney,[2] construction of the dam wall on the Cordeaux River commenced in 1918 and was completed in 1926.
The "address locality" of Cordeaux is defined as a suburb of the City of Wollongong, "lying beside the Cordeaux River between Lake Cordeaux and Upper Cordeaux No 1 Dam".[3] At the, it had no population.