Groundwater replenishment

With fresh water thinking, we are replenishing groundwater. This innovative process involves treating wastewater to drinking water standards and recharging it into existing groundwater supplies. The water is then stored and removed some time later for further treatment, ready to supply our drinking water system.

Perth's Groundwater Replenishment Scheme

The successful completion of the Groundwater Replenishment Trial at the end of 2012 showed conclusively that it is a highly viable option to boost drinking water supplies in Western Australia.

In August 2013, the State Government announced that groundwater replenishment would become the next new climate resilient water source for Perth.

On 22 October 2014, the Minister for Water Mia Davies turned the first sod with Water Corporation CEO Sue Murphy to mark the start of construction for Australia’s first full-scale groundwater replenishment scheme.

 Find out more about construction of the Groundwater Replenishment Scheme

As WA continues to experience a drying climate and an increasing population, demands on our water supplies are greater than ever. Groundwater replenishment will help Perth by:

  • reducing our dependence on rainfall as a source of water
  • ensuring ‘climate resilience’ by recycling water on a large scale
  • potentially providing up to 20% of Perth’s drinking water supplies by 2060 (if expanded to our other major wastewater treatment plants.

From 2009 to 2012, we trialed groundwater replenishment under local conditions at our Advanced Water Recycling Plant in Craigie to determine if it could be used as a sustainable option to boost drinking water supplies in the future.

At the end of 2012, the Groundwater Replenishment Trial had successfully achieved its three objectives to:

  1. Prove technical feasibility
  2. Establish a framework for policy and regulation
  3. Ensure sufficient community engagement and acceptance

The trial also allowed us to gain knowledge about the effect groundwater replenishment has on the groundwater environment.  

At the end of the trial, more than 62,300 water quality samples had been taken (throughout the treatment process and at the point of recharge), all of which met stringent health and environmental guidelines.

We also engaged the community through tours of the visitor centre, social media, community festivals and online forums.

Community support remained consistent throughout the trial with the final telephone survey in October 2012 showing community support for a full-scale scheme at 76 per cent.

At the end of the trial, together with the regulators – Department of Health, Department of Water, and Department Environment and Conservation (now Department of Environmental Regulation) – we prepared an assessment of the trial for the state government’s consideration. In July 2013, the state government endorsed the report and plans to proceed with a full-scale scheme.

For the trial, before wastewater reached the advanced water recycling plant, it had already undergone rigorous treatment at the Beenyup Wastewater Treatment Plant.  

This treatment removed chemicals and micro-organisms such as bacteria, nutrients, detergents, oils, pesticides and heavy metals.

At the plant, it underwent further treatment processes that included ultra filtration, reverse osmosis and ultraviolet disinfection. This removed chemicals and micro-organisms to meet Australian guidelines for drinking water.


Up to September 2014, 3.896 billion litres of recycled water had been recharged into groundwater supplies at the Groundwater Replenishment Trial site.

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

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

For more information view the latest Water Quality Report.

How does it work?

Watch our video which explains how this innovative process works (or skip this video):

Read a transcript of this video (new window)

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Find out about the progress of Perth's Groundwater Replenishment Scheme project here.

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