Integrated water supply scheme

The Integrated Water Supply Scheme (IWSS) is the largest scheme we manage. The IWSS delivers 301 billion litres of water each year to over 2 million people. The distribution network is wide with people living in Perth, the Goldfields, the Agricultural region and part of the South West. 

The IWSS is made up for the following water sources:

• Desalinated seawater
• Groundwater
• Dams
• Groundwater replenishment

In future, more water will come from seawater desalination, secure groundwater sources and groundwater replenishment. There will be less reliance on our dams. 

A new desalination plant is being built in Alkimos.  The Alkimos Seawater Desalination Plant (ASDP) will be able to supply 100 billion litres a year of clean, safe drinking water at full capacity. The first stage will be operational in 2028. 

Stage 2 of the Groundwater Replenishment Scheme was completed in 2022. The second stage doubles the capacity of the Beenyup plant. Up to 28 billion litres of treated wastewater can be recharged into groundwater supplies each year.

Learn more about Perth’s water supply with our interactive tool.

We have developed a long-term plan to ensure our future generations have a secure water supply. Learn more about our goals for 2050.