Take a birds-eye tour of the Victorian Desalination Plant, built to meet the growing needs of our city as we face ongoing challenges from population growth and climate change.



Victorian desalination plant

Why do we need a desalination plant?

The Victorian Desalination Plant plays a critical role in Melbourne's water future.

Announced as a project during the Millennium Drought when water storage levels were critically low (16.5% in our largest reservoir), the desalination plant can now deliver up to 150 billion litres of high-quality drinking water a year. 

That's one-third of Melbourne’s needs – or around 60,000 Olympic swimming pools.

Because it can only produce around one-third of Melbourne's annual demand, it needs to be used early and often to: 

  • build a buffer in our storages for a growing population, by regularly topping up our reservoirs
  • take pressure off our reservoirs during drier periods and droughts.

The Department of Environment of Land, Water and Planning manages the contract with the plant’s operator, AquaSure.



Why it helps secure our water supply

In March, Water Minister Lisa Neville ordered another 125 gigalitres (GL) for 2020-21. The water order commenced on July 1, with desalinated water continuing to contribute to our water storages. 

  • The water order is the same as the 2019-20 order.
  • This decision was underpinned by careful consideration of the following factors:
    • current water storage conditions
    • projected water demands
    • possible future climate conditions
    • the balance between managing security of supply and minimising customer impacts.

Without this order, our water storages would be around 11% lower. For more detail, read the technical analysis:


Arrival of desalination plant commissioning water, Greg Schelfhout
Melbourne Water staff at Cardinia Reservoir, where desalinated water enters our water supply network.

How desalination works

The desalination plant works by removing dissolved salts from seawater. It uses a reverse osmosis process to produce high quality drinking water that meets our strict quality requirements.

Did you know:

  • the plant’s power requirements are 100% offset by renewable energy
  • water quality is tested first at the desalination plant, and again at all delivery points 
  • like all our water, desalinated water meets the strict standards of the Australian Drinking Water Guidelines, Victorian Safe Drinking Water Act and World Health Organization guidelines
  • desalinated water from the plant in Wonthaggi travels to Berwick through an 84-kilometre, two-way pipeline — with pipeline offtakes enabling South Gippsland and Western Port to receive water from the plant, and from Melbourne, if needed
  • the water joins our supply network at Berwick and flows on to Cardinia Reservoir, where it mixes with water from our catchments  — so that water can then be transferred to Silvan Reservoir and on to most of Melbourne?

Watch this video for more information:

See how water moves around the system in this interactive map.


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Victorian Desalination Plant

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Find out how Melbourne’s water corporations are working hard with government and a range of other partners to secure our water supply. 

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Last updated:
27 July 2020