In the wake of mass fish kills in the Menindee Lakes in January and scorching criticism of its stewardship of the Murray-Darling Basin, the Murray-Darling Basin Authority has announced that it will upgrade its scientific work on climate change and the river system.

The authority’s chief executive, Phillip Glyde, has invited the scientific community to collaborate on its work on climate change.

“The overwhelming scientific consensus is that climate change is currently affecting the Basin so more work is needed to inform future management strategies,” Glyde said.

“The MDBA’s discussion paper kicks off the next phase of work to better understand the likely impacts of climate change on the Basin in the future and to identify where the information gaps are.”

But the MDBA has strongly rejected the findings of the South Australian Royal Commission into the Murray Darling which accused it of gross maladministration of the plan. It said the royal commission effectively proposed abandoning the basin plan and starting again.

“The MDBA considers this would be a reckless act – setting back progress towards a healthy and sustainable Basin, and causing substantial uncertainty for Basin communities,” Glyde said.

“While many people support the concept of a Basin Plan, there is often sharp disagreement up and down the rivers, and across different stakeholder groups, about the most appropriate settings,” he said.

The MDBA’s role was to apply the best available science, feedback from the community and expert judgement to administer the plan and propose amendments.

On Monday a group of eminent scientists convened by the Academy of Science released a report saying that the fish kills at Menindee, which killed up to one million fish, were due to the low flows, caused by over-extraction upstream and exacerbated by the drought.

“Our review of the fish kills found there isn’t enough water in the Darling system to avoid catastrophic outcomes,” they warned.

The scientists pointed to serious deficiencies in governance and management, which have eroded the intent of the Water Act 2007 and the framework of the Murray-Darling Basin Plan.

One of the main criticisms of the basin plan by the royal commission and by scientists has been that the MDBA’s models use historical data to assess the variability of flows in the river, but do not take account of how climate change may be permanently altering rainfall and flows in the river system.

The models and the whole basin plan was based on work done in 2009 and it did not include any mechanism for taking account of climate change. It is due to be reviewed in 2026, but scientists say there is an urgent need to update the plan and the models that inform it, in light of what is actually happening to the river.

The Wentworth Group of Concerned Scientists released a report last week, which studied the actual flows at two sites along the river – Wilcannia and Chowilla. It found that actual flows were much lower than those predicted to occur as a result of the plan being implemented.

The MDBA says that’s because the plan is partway through but in the case of the floodplains at Chowilla, none of the targets for environmental inundations needed to keep river red gums alive had been reached.

Glyde said the basin plan was drafted “as an adaptive plan with climate change in mind” though almost every decision to amend the plan has been about reducing environmental water targets in favour of irrigators.

Glyde acknowledged that the information about climate change, particularly in the northern basin, had advanced.

“We now know more. Rainfall patterns are changing and these changes will increase pressure on the health of the basin’s environment, its communities and its economy,” he said.