Navigate home logo
Perth's increasing population requires water planning for the future. Climate change has affected Perth's rainfall, so we can’t rely on this water source. 

In the 1960s, Perth recorded rainfall run-off (streamflow) into dams of 420GL per year. Dams supplied 88% of the city’s water needs. Today, Perth has 70GL of streamflow, so dams provide just over 10% of our drinking water. Groundwater and desalination plants have made up the difference.


Groundwater supplies

The large Leederville and Yarragadee aquifers cover much of the Perth metropolitan area. Abstraction bores into these aquifers supply our groundwater. With reduced rainfall, Perth’s aquifers aren’t being replenished like they once were. To help recharge this precious groundwater resource, we inject the aquifers with purified recycled water. 

This process is called groundwater replenishment and involves treating recycled wastewater to produce purified water, beyond drinking water standards. 

Pioneers in groundwater replenishment scheme

We were the first in Australia to use groundwater replenishment. The scheme started operating in 2017 at the Beenyup Advanced Water Recycling Plant. Since then, stage one has injected more than 54 billion litres of recycled water back into the ground. That’s as much as 54 Optus Stadiums filled with water recharging Perth’s deep aquifers.   

For more information about our pioneering groundwater replenishment scheme, take the virtual tour:

Read a transcript of this video

Due to the success of the first stage, we have now expanded our recharge capacity. We have the capacity to inject up to 28 billion litres each year back into the ground. The purified recycled water is cleaner than the water already in the aquifers. We test the recycled water before and after recharging it into the ground. 

Testing treated wastewater

Water Corporation worker testing treated wastewater

The recycled water stays in the aquifers for many years before we draw it out again. But when we finally do, we treat it again before the water enters our Integrated Water Supply Scheme. This provides drinking water to more than two million Western Australians.