At least 3200 gigalitres of water must be returned to the Murray to ensure its long-term health, according to new scientific modelling revealed yesterday.
The figure is an extra 450GL proposed by the Murray-Darling Basin Authority (MDBA) draft plan.
The new modelling, which was requested by the NSW, Victoria, Queensland, ACT and South Australia State Environment Ministers in June, outlines what would happen if key constraints were relaxed in the water catchment system.
Federal Water Minister Tony Burke said the new model could deliver better environmental benefits for the ailing Murray-Darling river system.
“We’ve never had information like this on the table before,” Mr Burke told media in Canberra yesterday.
“If we’re ever going to get the sort of co-operation that the Murray-Darling Basin desperately needs, the next few weeks is when it’s going to happen.”
Victorian Water Minister Peter Walsh said he did not support the plan.
“The 3200GL modelling shows only marginal improvement of environmental outcomes for a significant socio-economic cost that is far too great for communities,” Mr Walsh said.
“Transmitting 3200GL of environmental water would cause substantial and sustained flooding of towns and private land, which is totally unacceptable to Victoria.”
Mr Burke said some questions still remained unanswered about the impact it could have on upstream communities.
But he said the modelling represented a “massive shift” in the debate about how the Murray-Darling system could be rejuvenated, and the potential benefits could not be ignored.
“If you can achieve the same environmental outcomes with less water, that can’t be anything but an improvement in the situation for communities,” Mr Burke said.