Wentworth Group calls for 726GL more water for Murray Darling Basin rivers

Wentworth Group scientists have called for an additional 726GL of water to be added to the Murray Darling Basin target, in addition to the Albanese Government’s 450GL promise.

The Wentworth Group’s call to boost the basin’s environmental flows by 3856GL has angered irrigators, but all agree on the need to end cold-water pollution from large dams.

The Wentworth Group of Concerned Scientists has released an environmental manifesto in the lead-up to the federal election that advocates raising the Murray Darling Basin Plan water target by 726 gigalitres.

Basin communities already face the Albanese Government wading into the water market to strip 450GL out of the irrigation sector to boost environmental flows.

But in their recently released Blueprint to Repair Australia’s Landscapes, the Wentworth Group called for another 726GL to be added to the basin target, on top of the 450GL.

“The Guide to the Basin Plan showed that a minimum of 3856 GL/y of water must be recovered from consumptive uses if the Murray-Darling Basin is to reach an environmentally sustainable level of surface water extraction with high uncertainty,” the group’s blueprint states.

“Given the current Basin Plan target is 3130GL, a further 726GL of water needs to be recovered in a once-off adjustment via the buyback of water entitlements and/or the deployment of more water-efficient infrastructure to reach this target.”

National Irrigators’ Council chair Jeremy Morton said: “These guys are going back to the guide, which was burned in the streets for good reason.

“The scale of that sort of recovery would take irrigation back to a cottage industry.”

But while irrigators disagreed on the quantum of water recovery, Mr Morton said they shared the Wentworth Group’s call to action on complimentary measures – such as removing barriers to flow connectivity and fish migration, plus cold water pollution from large dams.

For almost 30 years researchers have called for action on the release of cold water from the depths of the basin’s big dams, which forms icy plumes that can stretch for more than 250km, freezing out native fish.

Both the NIC and Wentworth Group have backed that call, given the cost of modifying dam outlets pales in comparison to the more than $13 billion spent on the plan – most of which has been on water recovery.

The Wentworth Group’s blueprint states cold-water pollution is “widely considered a major driver of deteriorating river health” and estimates the average cost of modifying dam outlets at $8.5 million.

Fisheries researchers have previously identified 24 dams in Victoria’s share of the basin that cause severe cold-water pollution, nine in NSW and about eight in the ACT and Queensland.

“At the end of the day we all want great environmental outcomes across the basin,” Mr Morton said. “Why wouldn’t you?”