Avon River (Western Australia) - Catchment Area

Catchment Area

Lake Yealering in the Shire of Wickepin is the point of origin for the upper Avon river, and the catchment size above the confluence with the Salt River at Yenyenning Lake is 91 500 km2.

The basin covers much of West 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 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.