Desalination now Perth’s main water supply

The Water Corporation is using Perth’s dams to stockpile groundwater and desalinated water from the Kwinana plant, in addition to groundwater and the usual rain run-off.

In the last financial year, dam water accounted for just 7 per cent of total water supply, with desalinated water contributing 47 per cent and groundwater 46 per cent.

“While Perth no longer relies on stream flow into dams as a secure source of water, we still need to be mindful of our water use,” a Water Corporation spokeswoman said.

She said more than 40 per cent of household water was used in the garden and urged people to be mindful of their water use.

As of October 5, Serpentine Dam was at 26.2 per cent capacity.

Overall, Perth’s drinking water dams are at 32.5 per cent capacity, which is 12 per cent more than this time last year.

The Water Corporation spokeswoman said Perth’s drinking water dams had received 34.1 billion litres of stream flow, compared to 11.3 billion litres at the same time last year.

“Although this may seem like a lot of water, to put it into perspective, we supply more than 290 billion litres of drinking water a year to more than two million people connected to the Integrated Water Supply Scheme (IWSS) in Perth, the Goldfields and Agricultural Region and some parts of the South-West.”

Last year, stream flows were the lowest on record.

Inflows to dams this year were still well below the post-1975 annual average of 189 billion litres.