Murray-Darling Basin Authority Faces Class Action Over Alleged Water Mismanagement

A major class action against the Murray-Darling Basin Authority (MDBA) has opened in the New South Wales Supreme Court, with irrigators accusing the agency of mismanaging water and breaching its own operational guidelines.

The eight-week hearing, which began on Monday, will test claims that the MDBA failed in its duty of care to irrigators, reducing water availability for agriculture and causing widespread financial losses. The case has been brought on behalf of 28,000 irrigators across the central Murray region of southern NSW and the Goulburn Murray region in northern Victoria.

At the centre of the dispute is "overbank" flooding at the Barmah Choke - a narrow stretch of the Murray River between Tocumwal and Deniliquin - during the 2017/18 and 2018/19 water years. Plaintiffs allege the MDBA deliberately pushed river flows beyond the choke's capacity by opening regulators to flood the Barmah Millewa redgum forest, allowing the water to eventually rejoin the river downstream.

In his opening address, barrister Tony Bannon SC, representing the irrigators, described the approach as a "blunt and inefficient instrument" and claimed it went against the MDBA's own procedures.

"It was not reasonable, not reasonably required and contrary to their own operating parameters, guidelines and assessments at the time," he told the court.

The irrigators argue the practice reduced their water allocations, inflated temporary water prices, and left some unable to fulfil supply contracts - with estimated losses of around $1.5 billion over the two years.

The MDBA has denied the allegations in court documents, and its legal team has yet to deliver opening arguments.

Around a dozen irrigators attended the Sydney court hearing in person. Southern Riverina Irrigators chief executive Sophie Baldwin said it was a relief to see the matter finally proceed after being lodged in 2019.

"It's not about money - it's about managing our water resources better and protecting the staple food production for our country," she said.

Moulamein farmer Darcy Hare said the outcome could be crucial for the future of water use in the Basin.

"It's imperative to make sure something like this doesn't happen ever again," he said.

NSW Murray MP Helen Dalton added the case could have significant implications for national water policy.

"The MDBA has been unaccountable and lacking transparency for too long. If the federal government won't hold them to account, then the courts will now."