Water Corporation of Western Australia - Perth's Groundwater Replenishment
Perth, Western Australia, Australia · 2017 · Water Corporation of Western Australia.
Operationally, the combination of demand management, desalination and groundwater replenishment has enabled the city to keep its water supply reliable even during record-breaking droughts. Socially, it pioneered the "water-literacy" model, where the utility openly invited the public to a visitor center to see the process, turning a potentially "contentious" project into a point of civic pride. It serves as a proven model for any water-stressed city with access to underground aquifers.
Highlight
Turning purified recycled water into a long-term underground water bank for Perth’s climate-resilient water supply.
Extended description
Context: Perth faces a significant water supply challenge due to population growth and declining rainfall, streamflow and groundwater recharge. Traditional groundwater extraction was depleting aquifers and threatening local ecosystems.
How it works: Treated wastewater from the Beenyup Water Resource Recovery Facility undergoes advanced purification at the Advanced Water Recycling Plant. The treatment process uses ultrafiltration, reverse osmosis and ultraviolet disinfection to produce purified recycled water that meets or exceeds the Australian Drinking Water Guidelines.
Operational logic: The purified water is recharged into deep, confined Leederville and Yarragadee aquifers through dedicated recharge bores. It is stored underground for years before being recovered from separate abstraction bores and treated again before entering Perth’s drinking-water system. This creates a form of long-term underground storage while replenishing groundwater resources.
Systemic implications: The scheme changes the role of wastewater from a waste stream to a strategic water resource. Rather than depending solely on rainfall, dams and groundwater extraction, Perth can recycle water, store it underground and recover it when required. Groundwater replenishment therefore forms part of a diversified, climate-independent water-supply strategy alongside desalination, water conservation and other sources.
The scheme was developed in stages following a three-year trial completed in 2012. Stage 1 began recharging in 2017, while the Stage 2 expansion doubled the scheme’s capacity to 28 billion litres per year and was commissioned in 2022.
Demonstrated metrics
Capacity: Licensed to recharge up to 28 billion litres (28 GL) of purified recycled water per year, following the 2022 expansion (approx. 8% of Perth’s total supply).
Cumulative recharge: More than 100 billion litres had been recharged into Perth’s aquifers by March 2025.
Annual recharge: 16.3 billion litres were recharged during FY2023–24.
Treatment: Advanced purification using ultrafiltration, reverse osmosis and UV disinfection, producing water meeting or exceeding Australian Drinking Water Guidelines.
Storage: Purified recycled water is stored in deep, confined aquifers for years before recovery and further treatment for drinking-water supply.
Scale-up: Stage 2, commissioned in 2022, doubled capacity from 14 to 28 GL/year and included a second recycling plant, recharge infrastructure and a 13-km transfer pipeline.
Real impact
The GWRS has added a climate-independent water source to Perth’s diversified water-supply system, allowing treated wastewater to become a strategic resource rather than a waste stream. By 2025, more than 100 billion litres of purified recycled water had been recharged into deep aquifers, providing additional groundwater storage while reducing reliance on rainfall-dependent sources.
The scheme also demonstrates how advanced wastewater treatment can be integrated with groundwater management at metropolitan scale. Purified recycled water is stored underground for later recovery and further treatment before entering the drinking-water network, linking water recycling, aquifer replenishment and potable supply in one system. Its expansion to 28 GL/year has made groundwater replenishment a significant component of Perth’s long-term climate-resilient water strategy.
Implementation location & date
Perth, Western Australia; Trial (2010–2012), Stage 1 operational (2017), Stage 2 operational (2022).
Similar cases elsewhere
Orange County GWRS (California, USA)
Sources
https://www.watercorporation.com.au/Our-water/Groundwater/Groundwater-replenishment