Perth turns to groundwater replenishment as step to drought-proof the city
A Water Corporation plan to double the amount of recycled water being pumped into underground aquifers is the latest effort to help secure the city’s future water supplies.
This move brings the total amount of recycled water being pumped into the Gnangara Mound every year to 28GL, which doubles the current capacity of the Perth groundwater replenishment scheme.
The groundwater recharge is part of Water Corporation’s long-term plan to secure water supplies in the face of a variable climate, said Water Corporation spokeswoman Clare Lugar.
She said this proposal fits well with the organisation’s three-pronged approach to water security: encouraging people to use less water, increasing water recycling and developing new sources of water.
“Groundwater replenishment ticks two of these boxes: increasing water recycling and developing a new source,” she said.
The proposal would see Water Corporation build a 12.8km pipeline between a proposed recycled water plant in Beenyup and two different aquifer points, where it will be pumped into Leederville and Yarragadee aquifers.
The Beenyup plant would process and treat approximately 14GL of wastewater per year to pump into the aquifers. The same amount of water would be extracted from those aquifers each year and treated again to be used as drinking water.
“It is a climate-independent source of water, and the new plant at Beenyup will have the capacity to supply the same amount of water used by 100,000 homes each year,” Lugar said.
When approving the project, an Environmental Protection Authority (EPA) report stated that without an intervention, the city will have a 70GL supply gap each year for the next decade.
The goal is to make Perth’s water supply climate independent by 2022, and by 2060, one-fifth of Perth’s water supply is expected to be replenished groundwater.
Construction on the project is set to begin in July.