Dryland salinity has an economic and environmental impact within the southern Australian agricultural zone. The role of trees in ameliorating these impacts has been researched across a number of catchments in Western Australia, including the Collie River catchment. The research has demonstrated the benefits of integrating deep-rooted perennial plants into farming systems.
The Collie River recovery catchment upstream from the Wellington Reservoir is the largest impounded surface water resource in the south-west of Western Australia. Progressive land clearing for agriculture has resulted in salinity levels increasing from around 280 milligrams per litre (mg/L) in 1945 up to the current level of 950 mg/L. High levels of salinity restrict the uses and value of this water. Currently water in the Collie River can only be used for irrigated pastures, however if it is improved it could be available for horticultural use. The State Government is evaluating strategies where it can improve the use of this water under its Water for Food program.