The Preston River is a river in the South West region of

Western Australia Western Australia (WA) is the westernmost state of Australia. It is bounded by the Indian Ocean to the north and west, the Southern Ocean to the south, the Northern Territory to the north-east, and South Australia to the south-east. Western Aust ...

. The river has a total length of and rises near Goonac siding then flows in a north-westerly direction until discharging into the Leschenault Estuary. The headwaters are inland within the

Darling Range The Darling Scarp (), also referred to as the Darling Range or Darling Ranges, is a low escarpment running north–south to the east of the Swan Coastal Plain and Perth, Western Australia. The escarpment extends generally north of Bindoon, West ...

and run across the Blackwood Plateau and the

Swan Coastal Plain The Swan Coastal Plain in Western Australia is the geographic feature which contains the Swan River as it travels west to the Indian Ocean. The coastal plain continues well beyond the boundaries of the Swan River and its tributaries, as a geol ...

. The majority of the river catchment has been cleared for agriculture although some remnant forest vegetation exists at the headwaters. The towns of Donnybrook and Boyanup are on the shores of the Preston River. The major

tributaries A tributary, or an ''affluent'', is a stream or river that flows into a larger stream ('' main stem'' or ''"parent"''), river, or a lake. A tributary does not flow directly into a sea or ocean. Tributaries, and the main stem river into which the ...

of the river include the Ferguson River and Joshua Creek. Minor tributaries include Thomson Brook, Crooked Brook, Charley Creek, Waterfall Gully, Mininup Brook, Millbrook and Gavin Guly. The Glen Mervyn

Dam A dam is a barrier that stops or restricts the flow of surface water or underground streams. Reservoirs created by dams not only suppress floods but also provide water for activities such as irrigation, human consumption, industrial use, aqua ...

is along the Preston River. The river basin is monitored routinely as a result of

eutrophication Eutrophication is a general term describing a process in which nutrients accumulate in a body of water, resulting in an increased growth of organisms that may deplete the oxygen in the water; ie. the process of too many plants growing on the s ...

problems within the Leschenault Inlet. The water quality is fresh in many places and generally low in nutrients although some areas are slightly enriched with

nitrogen Nitrogen is a chemical element; it has Symbol (chemistry), symbol N and atomic number 7. Nitrogen is a Nonmetal (chemistry), nonmetal and the lightest member of pnictogen, group 15 of the periodic table, often called the Pnictogen, pnictogens. ...

. The river is named after , an officer in the

Royal Navy The Royal Navy (RN) is the naval warfare force of the United Kingdom. It is a component of His Majesty's Naval Service, and its officers hold their commissions from the King of the United Kingdom, King. Although warships were used by Kingdom ...

, who settled in the

Swan River Colony The Swan River Colony, also known as the Swan River Settlement, or just ''Swan River'', was a British colony established in 1829 on the Swan River, in Western Australia. This initial settlement place on the Swan River was soon named Perth, an ...

after arriving on in 1829.

References

{{Rivers of Western Australia Rivers of the South West region Swan Coastal Plain