The Donnelly River catchment t is 1727 km2 and lies around 230 km south of Perth.
It is made of the Donnelly River and the major tributary Barlee Brook, and the smaller tributaries of the Beedelup, Carey, Fly, Manjimup and Record brooks.
The Donnelly and Warren rivers are used for agriculture water supply. There are more than 480 on-stream dams distributed across the Warren–Donnelly catchments. These dams are refilled by streamflow which varies significantly from year to year. The department began work on the Warren–Donnelly surface water allocation plan in 2008 after a study indicated that some rivers may be fully allocated or over-allocated. This highlighted that individual licence assessments were no longer enough to manage water use effectively at a subarea level and allocation limits needed to be introduced. For more information click here