The Victorian Desalination Plant is the only source of water that isn't dependent on rainfall, 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?

With the ongoing impacts of a growing population, a changing and variable climate and Melbourne being one of the fastest growing cities in the developed world, this presents major challenges for our most precious of resources – water. 

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

Building more dams is not a feasible solution because in the long run there will be less rain to fill them. 

Whilst good water saving behaviours have continued following the Millennium Drought, it is not sustainable to rely solely on water restrictions.

Melbourne Water along with other governments bodies across Australia are looking to other sources to meet our current and future water needs.

These include:

  • 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:

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

Regular desalinated water orders from the Victorian Desalination Plant can help increase the buffer in our water storages and help secure our water for our future. 

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.

Integrating the Victorian Desalination Project

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

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

Current advice

The Minister for Water has ordered 125 billion litres (GL) of water from the Desalination Plant for the 2019/20 financial year. This water will help restore our storage levels following five years of decline and a summer of particularly low rainfall. Full water storages are Melbourne’s buffer against severe drought and are essential to ongoing water security


Last updated:
18 March 2019