The Avon River is a river in Western Australia. A

tributary 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 they ...

of the Swan River, the Avon flows from source to mouth, with a catchment area of .

Avon catchment area

Lake Yealering in the

Shire of Wickepin The Shire of Wickepin is a local government area in the Wheatbelt region of Western Australia, east of Narrogin and about southeast of the state capital, Perth. The Shire covers an area of , and its seat of government is the town of Wickepi ...

is the point of origin for the upper Avon River, and the catchment size above the confluence with the Salt River at Yenyening Lakes is . The basin covers much of the Western Australian wheatbelt and extends beyond that in some areas near almost-always-dry Lake Moore in the northeast, water is received regularly from only the extreme western edge of the basin. Indeed, until an abnormally wet year in 1963 it was not realised that the northeastern part of the basin beyond

Wongan Hills Wongan Hills is a range of low flat-topped hills in the Avon Wheatbelt bioregion of Western Australia. It is located at , in the Shire of Wongan–Ballidu. History The range was first recorded in 1836 by Surveyor General of Western Australia Jo ...

ever drained water into the river. Under present climatic conditions, it is almost impossible to produce runoff from anywhere outside the extreme west of the basin because the amount of rain required to fall before runoff would begin is as high or higher than the mean annual rainfall. The river has three main sub-catchments: catchments for the Mortlock, Yilgarn, and Lockhart rivers. The river flows past

County Peak County Peak, also known as Mt Quajabin or Quajabin Peak, is located in the western zone of the Wheatbelt region of Western Australia, about 120 km south-east of Perth. ''Quajabin'' is this mountain's Noongar Aboriginal name, which predate ...

, creating a picturesque view from the top.

Course and features

Thirty creeks and rivers flow into the Avon; some of the larger tributaries include the

Dale River The Dale River is a perennial river located in the Wheatbelt (Western Australia), Wheatbelt region of Western Australia. Rising on the eastern slopes of the Darling Scarp, the river flow generally east by north, joined by six major tributaries ...

, Brockman River,

Mortlock River The Mortlock River is a perennial river in the Wheatbelt region of Western Australia. Course and features The headwaters of the river rise near Belmunging then flow in a northerly direction, crossed by the Goldfields Road and continuing in a ...

and the

Mackie River The Mackie River is a river in the Wheatbelt region of Western Australia. The river is ephemeral and flows following winter and spring rains. The water discharged is saline. The river rises east of Corriging Hill and flows in a north wester ...

. Most of these watercourses are

ephemeral Ephemerality (from the Greek word , meaning 'lasting only one day') is the concept of things being transitory, existing only briefly. Academically, the term ephemeral constitutionally describes a diverse assortment of things and experiences, fr ...

and only flow after rain in winter and spring. Some permanent pools exist along the course of the river including Burlong Pool, Robins Pool, Long Pool, Cobblers Pool and Jimperding Pool. The Avon River Valley is the third and final route for the Eastern Railway line through the

Darling Scarp 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, to ...

between Midland and Northam, having been constructed in the 1960s. It is the site of an annual

whitewater Whitewater forms in the context of rapids, in particular, when a river's Stream gradient, gradient changes enough to generate so much turbulence that air is trapped within the water. This forms an unstable current that foam, froths, making t ...

boating event, the

Avon Descent The Avon Descent is an annual, two-day, white water event along the Avon and Swan Rivers in Western Australia. It includes both paddle craft (kayaks, surf skis) and small motor boats, and runs from Northam to the Perth suburb of Bayswater. I ...

Soils

Due to the extraordinary age of the

soil Soil, also commonly referred to as earth, is a mixture of organic matter, minerals, gases, water, and organisms that together support the life of plants and soil organisms. Some scientific definitions distinguish dirt from ''soil'' by re ...

s in the basin (which is on the extremely ancient Yilgarn craton), the rooting density of native flora is very high and its average specific discharge is probably the lowest of any basin of comparable size in the world. The extreme age of the soils also means that, at least after clearing for agriculture, almost all rivers in the basin have salinities above 0.3% (one-tenth that of the oceans and eight times that necessary to qualify as "fresh" water) and some much more than that. Passing through some of the oldest settled European agricultural areas in Western Australia, the catchment area has extensive

soil salinity Soil salinity is the salt (chemistry), salt content in the soil; the process of increasing the salt content is known as salinization (also called salination in American and British English spelling differences, American English). Salts occur nat ...

issues, which have attracted governmental programmes to alleviate the loss of agricultural lands. Catchment groups that oversee projects in the tributary parts of the river have had considerable support and funding from commercial and non-governmental sources as well.

References

External links

* http://www.wheatbeltnrm.org.au/ – formerly the ''Avon Catchment Council'' – known now as the ''Wheatbelt Natural Resource Management Inc.'' {{Authority control Swan River (Western Australia)

Avon catchment area

Course and features

Soils

See also

References

Further reading

External links