| Oldfield River | |
|---|---|
| Mouth | Oldfield Estuary |
| Basin countries | Australia |
| Length | 95 kilometres (59 mi) |
| Source elevation | 329 metres (1,079 ft)[1] |
| Avg. discharge | 6,900 ML/year |
| Basin area | 2479 km2 [2] |
The Oldfield River is an ephemeral river in the Goldfields-Esperance region of Western Australia that rises 95 kilometres (59 mi) inland from the South Coast at the edge of the Yilgarn plateau. The river starts at 300 metres (984 ft) above sea level then flows in a south easterly direction crossing the South Coast Highway near Munglinup.
The river gently undulates through sandstone forming gentle valleys with many granite outcrops, the river then carves deeper valleys through the siltstone before entering the coastal plain. The river is then joined by its tributary, the Munglinup River, before flowing into the Oldfield estuary which discharges into the Southern Ocean.
The only other tributary of the Oldfield River is Coujinup Creek.
The river is regarded as saline[3] with high nutrient levels, moderate sedimentation, moderate fringing vegetation and has a low flood risk.