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Discover more about this innovative process and the role it's playing in reducing our dependence on rainfall, recycling and replenishing groundwater for generations to come.

What is groundwater replenishment?

It's an innovative concept where treated wastewater is purified to drinking water standards at an advanced water recycling plant (AWRP) and then pumped (recharged) underground. This purified recycled water is stored in deep groundwater aquifers, which provide additional natural filtration of the water until we need it. It doesn't rely on rainfall and has the potential to recycle large volumes of water.  

Currently, groundwater replenishment makes up 5% of our Integrated Water Supply Scheme

How does it work?

Watch our video about what happens at an advanced water recycling plant.


Read a transcript of this video

A first for Australia

We were the first utility in Australia, and among the first in the world, to replenish our groundwater supplies this way. Our groundwater replenishment scheme is located in Craigie, in Perth's northern suburbs. The first stage started recharging purified recycled water to Perth's deep aquifers in 2017. By 2022, the second stage of the groundwater replenishment scheme was completed. This expansion doubled the treatment capacity of AWRP from 14 billion litres to 28 billion litres of water per year. Actual treatment rates depend on the amount of wastewater available.  

The purified water can be recharged into deep, confined aquifers in Craigie, Wanneroo and Neerabup.


In 2012, we completed a successful three-year groundwater replenishment trial at our Advanced Water Recycling Plant in Craigie. 

The trial achieved its objectives to:

  1. Prove technical feasibility of groundwater replenishment. 
  2. Establish a framework for policy and regulation to meet Department of Health and Australian Drinking Water Guidelines.
  3. Ensure sufficient community engagement and acceptance, gaining support from Perth residents, business and government.

The trial was overseen by our regulators, the Department of Health and Department of Water and Environmental Regulation and they continue to regulate the full scale scheme.

Before wastewater reaches the Advanced Water Recycling Plant, it has already undergone rigorous treatment at the Beenyup Wastewater Treatment Plant.

At the Advanced Water Recycling Plant, it undergoes further advanced treatment processes that included ultrafiltration, reverse osmosis and ultraviolet disinfection. This removes chemicals and micro-organisms to meet Australian guidelines for drinking water.

Image of wastewater treatment process

There are several water quality checkpoints (known as critical control points) throughout the treatment process to ensure each stage of the plant is working at an optimum levels.

If water does not meet the required standard when it reaches a check point, it triggers an alert for action to be taken. For example, we may divert the water to waste or temporarily shut down the plant.

Groundwater replenishment stage 2

Scheme expansion

The Groundwater Replenishment Scheme was expanded with the completion of Stage 2 in August 2022.