Melbourne will never again go above stage 3 water restrictions, with Premier John Brumby promising that yesterday's decision to relax the curbs was ''sustainable in all circumstances''.
Melbourne will revert to stage 3 restrictions next month after three years on stage 3a, meaning more water can be used on home gardens, public gardens and sports fields.
In a boost for the environment, the government also vowed to increase water flows in stressed rivers such as the Yarra and Thomson, and will boost water supplies to struggling farmers in Werribee and Bacchus Marsh.
The move follows years of planning to reduce restrictions before this year's state election, and Mr Brumby indicated that restrictions could be further eased before the November poll.
''If we got an average [rainfall] year, we might be in a position to look at them again,'' he said.
No date was given, but Mr Brumby said the level of restrictions would be reviewed about the end of winter.
In a bullish statement, he said the government had opted for modest changes to the restrictions because it wanted to ''make sure that there are no circumstances in which we would ever, ever have to go back to stage 3a or stage 4''.
''The easing of restrictions we are announcing today are sustainable in all circumstances, in all conditions, into the longer term.''
While the start of flows in the north-south pipeline, water conservation and improved rainfall were credited with boosting dams so that restrictions could be eased, a huge factor has been a series of controversial flow restrictions on the Yarra and Thomson rivers.
About 108 billion litres more than usual was extracted from the rivers over the past 2½ years, meaning a sixth of all water in Melbourne's dams today is due to the flow restrictions.
Water Minister Tim Holding conceded yesterday's promise to return 7 billion litres to the Yarra and 3 billion to the Thomson was less than was originally owed to the rivers but was still a good boost.
Environment Victoria chief executive Kelly O'Shanassy said the move was better than nothing but less than conservationists had hoped for.
''It's going to help our rivers get sick less quickly,'' she said.