Journal of the Department of Agriculture, Western Australia, Series 4


Dense tree plantings covering at least 30 per cent of cleared land can lower groundwater levels by two metres or more in 10 years from the time of planting. This sizeable drop can be expected at sites receiving 700 to 800 mm of rain a year. Research by the Water Authority of Western Australia shows the most promising strategy when using trees is to put dense plantings on the discharge zone and on lower to midslopes. This strategy is successful where groundwaters contain less than 30,000 milligrams per litre total soluble salts (TSS).

This article discusses research in the 450 to 800 mm rainfall zone by the Water Authority, the Department of Agriculture, the Department of Conservation and Land Management (CALM) and CSIRO.