Desalination

The Victorian Desalination Plant is the only source of water that doesn’t need rain, which makes it a valuable asset for meeting our water needs — now and into the future.

Key facts:

  • The desalination project was announced in 2007 during the Millennium Drought, when water storage levels were critically low: down to 16.5% in our largest reservoir.
  • The plant can deliver up to 150 billion litres of high-quality drinking water a year — one-third of Melbourne’s needs.
  • The Department of Environment of Land, Water and Planning manages the contract with the plant’s operator, AquaSure, on behalf of Victoria.

Why desalination?

We need a resilient water supply system to cope with Melbourne’s growing population and the extremes of a changing and variable climate.

During droughts we can no longer rely solely on water restrictions, and governments across Australia are looking to other sources to meet our needs. This includes:

  • stormwater
  • recycled water
  • making the most of our water supply system, including desalination

The Victorian Desalination Plant helps guarantee a reliable, sustainable water supply by:

  • taking pressure off our reservoirs during droughts
  • building a buffer in our storages for future droughts, by regularly topping up our reservoirs

How water enters the supply system

  1. 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.
  2. At Berwick, the water joins our supply network and flows on to Cardinia Reservoir, where it mixes with water from our catchments.
  3. The water can then be transferred to Silvan Reservoir and on to most of Melbourne.

Water quality is tested at the plant and at all delivery points before it enters our system. Like all our water, it meets the strict standards of the:

  • Australian Drinking Water Guidelines
  • Victorian Safe Drinking Water Act
  • World Health Organization guidelines

To see how water moves around our system, view our interactive water supply map.

Water orders

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:

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

On 19 March 2017, the Minister for Water announced a minimum annual order of 15 billion litres for the next three years, starting in 2017/18.

This is at no extra charge to consumers, and supports water security, better plant management and steadier prices.

Current advice

The 2017–18 desalinated water order advice is for:

  • no extra water above the minimum annual water order
  • non-binding forecasts of 50 billion litres (including the minimum orders) for 2018–19 and 2019–20
Last updated:
25 October 2017