The Department of Water and Environmental Regulation (DWER) has developed draft plans aimed at rebalancing Perth and Mandurah’s groundwater resources.
In a statement, the Department said the resources were at risk from the impacts of climate change and increasing use.
It said the draft plans included a new Gnangara groundwater allocation and a proposal to align garden bore sprinkler rosters with the scheme sprinkler roster which, combined, would save 70GL of water per year.
The DWER said the Gnangara groundwater system supplied up to 40 per cent of Perth’s drinking water, as well as water for industry and horticulture, garden bores, parks and other green spaces north of the Swan River.
“It also supports significant environmental values, including wetlands, caves and bushland, with lowered water levels now evident through the visible drying of wetlands such as Loch McNess and the loss of the unique Yanchep cave ecosystems,” it said.
“Over half of the 30 sites used to gauge the health of Gnangara’s groundwater-dependent ecosystems are now breaching minimum water levels.”
The Department said the draft plans proposed reductions in water entitlements for most licensed groundwater users to be limited to just 10 per cent.
“A 27 per cent reduction to groundwater taken by the Water Corporation for Perth’s drinking water is also proposed,” it said.
“The proposed changes would come into effect from July 2028.
“In addition, a proposal to align the domestic garden bore sprinkler roster with the two-days-per-week sprinkler roster for scheme water users in Perth and Mandurah from 1 September 2022 is now open for public comment.”
Minister for Water, Dave Kelly said because of climate change, Perth and Mandurah’s precious groundwater supply was literally disappearing beneath people’s feet.
“By everyone making small changes to how we use groundwater, we can deliver environmental benefits, provide industry with clarity and certainty, and protect this precious resource for future generations,” Mr Kelly said.
Minister for Climate Action, Amber Jade Sanderson said sustainable use of groundwater was critical to help protect wetlands, lakes and bushland from the impacts of climate change.
“The Gnangara groundwater allocation plan and the proposed garden bore roster changes are two important steps we can take to help make Perth a more climate-resilient city,” Ms Sanderson said.
Public comment on the draft plan and proposed changes to the sprinkler roster is open until 28 February 2022 and further information can be accessed at this PS News link.