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

The desalination plant plays a critical role in our 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.

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.

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

Helping to secure our water supply


For the 2019-20 financial year, the Minister for Water ordered 125 billion litres (GL) of water from the Desalination Plant. This is the largest order that has been made to date.

The most recent order will help secure our water supply by boosting water storage levels, following five years of decline and a summer of particularly low rainfall.

Regular orders will:

  • 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.


How desalination works

  • Desalinated water from the plant in Wonthaggi travels to Berwick through an 84-kilometre, two-way pipeline. If needed, pipeline offtakes enable South Gippsland and Western Port to receive water from the plant — and from Melbourne.
  • At Berwick, the water joins our supply network and flows on to Cardinia Reservoir, where it mixes with water from our catchments.
  • The water can then be transferred to Silvan Reservoir and on to most of Melbourne.

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

How much is ordered?

Each year, we collaborate with Melbourne’s water retail companies to provide advice on ordering desalinated water to the Department of Environment, Land, Water and Planning. We consider a number of factors, including:

  • how much water will be needed throughout the year
  • how much rain is expected
  • current levels in our water storages
  • cost to consumers.

The Minister for Water makes the final decision on the desalination order to be delivered the following year.

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How the water sector is taking action


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

How the water sector is taking action

Last updated:
13 January 2020