Effects of rainfall decline to date

Rainfall in the south-west of Western Australia is now around 16 per cent below the long-term average. Less rainfall results in less water flowing into rivers and aquifers and to date there has been up to a 50% reduction in average run-off into rivers and streams, and up to a 30 per cent reduction in recharge of aquifers depending on the location.

Research shows this drying trend is set to continue, but whether it will be only slightly drier or much drier isn’t certain.

The changes in precipitation will have important impact on how society will have to make decisions on how water is used

Data Source

  • Department of Water (2015). Securing water resources for the South West. Perth, Western Australia.
  • Storer T, White G, O’Neill K, Rennie B, Heald D, Christie E, Galvin L & Braimbridge M. (2016b). Chapman Brook condition summary: Review of river condition to inform evaluation of the Whicher Area Surface Water Allocation Plan.  Unpublished report by Water Science Branch for Water Allocation Planning Branch, Department of Water, Perth.