Water Corporation has announced that Perth’s water flows have been the lowest on record since 1911.
Water Corporation spokesperson, Clare Lugar, said runoff into Perth’s dams had been virtually non-existent since the start of winter.
“Perth’s dams have received a total of 2.3 billion litres* of inflow – this is the lowest ever inflow for May, June and July since records began in 1911,” she said.
“We are often asked if the dams are full after a few days of rain and we remind people that in our drying climate our catchments must be completely soaked before they produce any decent runoff,” Ms Lugar said.
Ms Lugar said it had been so long since people growing up in Perth had experienced ‘average’ winter rainfall that just a few days of rain felt like a really wet winter.
“Around ten years ago Water Corporation started planning for the possibility we could no longer rely on rainfall for Perth’s water supply.”
She said this meant surface water collected by dams only accounted for 18 per cent of our drinking water in 2013-14. Groundwater supplied 43 per cent and water from two desalination plants supplied 39 per cent.
While we have developed new climate-independent water sources, Ms Lugar said it was important for Western Australians to continue to save water.
“By changing the way we live the average per person water use is now 60,000 litres a year less than it was in 2001 and the Winter Sprinkler Ban alone saves about 4.5 billion litres of water a year,” she said.
*In order to provide an accurate historical comparison inflow from Stirling, Wokalup and Samson Brook Dams are not included in this data as these dams only came online in 2001. Inflow is therefore modelled on Perth dams pre-2001.
- Water Corporation’s largest scheme, the Integrated Water Supply Scheme (IWSS), delivers nearly 300 billion litres of water annually to more than 2 million customers.
- The dams which supply Perth and the Integrated Water Supply Scheme are at 27.7 per cent capacity (as of 5/8/2015), which is 3.6 per cent less than last year.
- So far this winter, Perth has received about 398mm of rain, with below average monthly rainfall in May, June and July.
- See Water Corporation’s Dry July summary for more information.