Avon River The Avon River in Western Australia winds approximately 240km, starting
at a river in Wickepin in the State's Great Southern agricultural region to Walyunga National Park in Upper
Swan (Avon Valley). The river joins Wooroloo Brook in the National Park to eventually flow into the Swan River . The Avon River accounts for approximately 60% of the Swan River's flow. The Avon
River has a mean annual flow of 320 million cubic metres. The river experiences a multitude of changes as it
flows towards the Swan River. From the flat, deep waters at Northam to the shallow, twisting rapids at Bells Falls. The river flows through the towns of
Brookton, Beverley , York, Northam and Toodyay .
It is believed that the Avon River was once a freshwater river that flowed
in the opposite direction and emptied into the Yenyenning Lakes near Brookton. The Avon River's main
environmental threat is siltation. The siltation problem began in the 1960's with extensive clearing of
natural vegetation for farming purposes. Topsoil washed into the river causing silt to build up. During the
same time bulldozers were used to clear islands in the river. The islands were thought to have been the main
reason for flooding in the area. It was thought that by removing the islands it would increase the flow of the
river and alleviate the blockages. Unfortunately the decision resulted in larger siltation problems. The Avon
River is the only breeding ground of the white swan in Australia. Northam has an extensive white swan breeding program. The river is also
the location of the Avon Descent an annual whitewater boating event.
Other main rivers in Western Australia are the Ord River, Blackwood River , Swan River and the Murchison River.