Water Minister Peter Walsh on Wednesday announced the government would not order water from the Wonthaggi plant in 2013-14, saying that with Melbourne's dams almost 74 per cent full - about 10 per cent higher than this time last year - it was unnecessary.

But Fairfax Media understands the supply contract with plant owner AquaSure requires the government to make ''non-binding'' forecasts for the following two financial years.
It is understood the government has told Aquasure that, at this stage, it does not intend to order water for 2014-15 or 2015-16. The forecasts are not set in stone and can be reassessed before formal notification of orders is given each year before April 1.

The desalination plant was built under the former Brumby Labor government and will cost taxpayers between $19 billion and $24 billion to 2040, depending on how much water is ordered. It can produce up to 150 gigalitres of drinking water a year.

In 2013-14, the plant will cost Victorian taxpayers $649 million even without water ordered.