Desalination is a secure water source that doesn’t depend on the rain. Find out about our two desalination plants and how they contribute to Perth's water supply.
As WA continues to experience a drying climate, it is important that we pursue sustainable and more climate resilient water sources.
How does desalination work?
Seawater desalination is the removal of salt and impurities from seawater to produce fresh water. Our desalination plants use a reverse osmosis process. Seawater is pumped into the desalination plant from the ocean and passes through pre-treatment filtration to remove majority most of the large and small particles.
The filtered seawater is then forced under pressure through special membranes whereby the osmosis process that normally occurs in nature is reversed. The pores in the membranes are so tiny that salt, bacteria, viruses and other impurities are separated from the seawater. In essence that act like microscopic strainers. About half of the water that enters the plant from the sea becomes fresh drinking water. The salt and other impurities removed from the sea water is then returned to the ocean via diffusers, which ensures it mixes quickly and prevents impacted the marine environment.
The desalinated water is then subject to further treatment to meet drinking water standards before it reaches our customers.
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Our desalination plants
Water Corporation operate two seawater desalination plants: the Perth Seawater Desalination Plant in Kwinana and the Southern Seawater Desalination Plant in Binningup.
Our long term planning includes a potential two additional seawater desalination plants, to the north and south of Perth to secure Perth’s water supply for the future.