As speculation grows that consecutive years of dry conditions could be a permanent climate "step change", Murray-Darling Basin Authority chief Rob Freeman has expressed confidence that wetter times will return.

Speaking at a water summit in Melbourne yesterday, Mr Freeman took aim at doomsday climate predictions that have followed the driest three-year period on record for the Murray-Darling Basin.

"Some commentators say this is the new future, I think that is an extreme position and probably a position that's not helpful to take," he said.

Mr Freeman acknowledged that average inflows to the river system might be lower than in the past, but he was adamant they would be higher than those measured since 2006.

"We are always going to have droughts and floods, but to suggest the future is this, I think is misrepresenting the situation … while it's nice to have a burning platform on which to implement reforms, we've also got to be very honest," he said.

The view echoes that of the Victorian Government, particularly in relation to the amount of water that can be saved in irrigation upgrades such as the Foodbowl Modernisation Project.

The Brumby Government has kept faith in its water recovery targets for the project, despite the fact rainfall must increase in northern Victoria for them to be achieved.

Mr Freeman declined to comment on the possible purchase of Queensland's Cubbie Station, which holds large water entitlements in the north of the Murray-Darling Basin. But he said it was important to have a scientific understanding of the benefits such a buyback could be bring before a purchase is made.

State governments continued to jostle over who should pick up the bill for Cubbie, if the cotton farm is to be purchased in the interest of river health.

Queensland's Natural Resources Minister, Stephen Robertson, told The Age that NSW and the Commonwealth should be at the forefront of any purchase "as the return of Cubbie water would benefit lakes and floodplains in NSW".

NSW Premier Nathan Rees said the state had already done its "fair share" of work to restore river health, and the Cubbie purchase was a "matter for the Commonwealth".

The Commonwealth has identified the attachment of Cubbie's water entitlements to the land as an impediment to Cubbie being bought in the name of river health.