Warren River (Western Australia) facts for kids
Quick facts for kids Warren River |
|
|---|---|
| Country | Australia |
| Physical characteristics | |
| Main source | Tone State Forest 140 metres (459 ft) |
| River mouth | Southern Ocean sea level |
| Length | 137 kilometres (85 mi) |
| Basin features | |
| Basin size | 4,350 km2 (1,680 sq mi) |
The Warren River is an important river in the South West part of Western Australia. Its catchment area includes the towns of Manjimup and Pemberton.
The river got its name from Governor James Stirling. He likely named it after Admiral Sir John Borlase Warren. Stirling had served under Admiral Warren in North America in 1813.
A Look Back in Time
In 1831, a naval officer named Lieutenant William Preston RN discovered the river. He was on a boat trip to map the coast from Albany to Fremantle. His boat, the Success, and later the Sulphur, was unfortunately wrecked near Green Point.
Because of the wreck, Preston and his crew had to walk all the way from Albany to Fremantle. This was the first time anyone had made that journey by land along the coast. Interestingly, Lieutenant Preston was also Governor Stirling's brother-in-law.
The first person to settle along the Warren River was Edward Reveley Brockman. In 1862, he built a home called Warren House and started a farm right on the river's banks.
The River's Journey
The Warren River starts in the Tone State Forest. This is about 30 kilometres (19 mi) south-east of Manjimup. It begins where the Tone and Perup Rivers meet at a place called Murtinup.
From there, the river flows for 137 kilometres (85 mi) towards the south-west. It crosses the South Western Highway. The river then travels through the Warren State Forest, the Greater Hawke and D'Entrecasteaux National Parks, and the Dombakup Nature Reserve. Finally, it empties into the Southern Ocean near Coolyarbup.
The Warren River is a medium-sized river. It starts in areas with medium rainfall, among marri and wandoo trees. As it flows, it passes through jarrah and marri forests. Closer to the coast, it goes through areas with high rainfall and karri trees.
It is the second largest river in the Busselton-Walpole area when you look at how much water flows through it. Other smaller rivers and streams that flow into the Warren River are called tributaries. These include the Perup, Yerraminnup, Wilgarup, and Tone rivers. Quinninup, Lefroy, and Dombakup brooks also join the Warren.
How Salty is the Water?
Before people started clearing land for farming, the Warren River's water was quite fresh. Its salt level was about 120–350 mg/L. Water with less than 500 mg/L of salt is considered fresh.
Around 1925, some areas like the Wilgarup, Dombakup, and Lefroy sub-catchments were cleared for farming. Then, in the 1950s and 1960s, a lot more land was cleared. This caused the river's saltiness to increase a lot. The water was no longer considered fresh.
Because people were worried about the rising salt levels, the Warren catchment was declared a "clearing control catchment" in 1978. This meant that clearing land in this area was now controlled. After this, a lot of new trees were planted, especially in the Perup and Tone River areas. These two areas contribute a lot of salt to the Warren River.
Today, the salt levels seem to be leveling off. About 35% of the total land in the catchment has been cleared. The lower part of the Warren River, near where it meets the ocean, is a bit salty. Its average saltiness was 990 mg/l between 1993 and 2002. However, Dombakup Brook is still considered fresh, with less than 440 mg/l of salt.
