A group of scientists who campaign for water policy reform to protect critical environments have released a peer-reviewed report finding the $13b Murray-Darling Basin Plan has failed to improve the health of Australia’s biggest river system.
The Wentworth Group of Concerned Scientists’ report, titled Murky Waters Running Clearer, found the country’s largest and most important river system “continues to decline”.
The aim of the Murray-Darling Basin Plan (MDBP) is to keep enough water in the system to improve the environment, predominantly through water licence buybacks and upgrading infrastructure such as lining irrigation channels to reduce evaporation.
A lack of regular overbank flows led to these floodplains at Bottle Bend drying out, turning them saline. (ABC Rural: Nikolai Beilharz)
Water flows no better
Twelve authors with environment and water policy expertise from eight Australian universities produced the report which was published in Marine and Freshwater Science.
They looked at 27 indicators assessing the Indigenous, economic, and social impact of the Murray-Darling Basin Plan as well as compliance activity between 1980 and 2023.
The report found 74 per cent of indicators were not met after more than a decade of operation and pointed to pressure from flood plain harvesting in the Northern Basin, land-use change and global warming as possible causes.
Study co-author and director at the UNSW Sydney Centre for Ecosystem Science, Professor Richard Kingsford, said overall the findings were “pretty alarming”.
Water flows at 90 per cent of sites did not meet expectations, water bird populations were decreasing, and fish kills were increasing.
“We have been monitoring now for four decades,” Dr Kingsford said.
“We have had 60-70 per cent decline [in waterbird populations] over that time.”
During the mass fish kill events dead fish blanketed the Darling River for kilometres. (ABC News: Bill Ormonde)
Fish kill events at Menindee in 2019 and 2023 resulted in the loss of millions of native fish along the Darling river.
The report’s lead author, Matthew Colloff from the Australian National University, said there was cause for concern regarding future fish kill events.
“Our data seems to suggest that large fish kills are increasing in frequency,” Dr Colloff said.
Redgum forests on the flood plain in the SA Riverland were experiencing a build up of salt, NSW flood plain forests were not getting water in the Murrumbidgee region, and infrequent flood events in Victorian forests were driving severe hypoxic — or blackwater — events that kill fish and crayfish.
Water levels have dropped significantly in recent months at Clear Lake in Narran Lake Nature Reserve. (Supplied: Richard Kingsford, UNSW)
“We have taken so much water out of the system those floods aren’t as big as they used to be,” Dr Kingsford said.
Indigenous groups worst affected
The Wentworth Group said Indigenous communities, not irrigators, were suffering the most.
Dr Moggridge says engagement with Indigenous communities is “pretty poor”. (Supplied: Wentworth Group of Concerned Scientists)
Report co-author and Kamilaroi man, Brad Moggridge, said in a statement that Indigenous-owned water entitlements were “grossly inadequate”.
“Access to safe drinking water is not being met in many communities across the Murray-Darling Basin, including predominantly Indigenous communities like Wilcannia,” Professor Moggridge said.
The basin includes more than 30,000 wetlands and covers 46 Indigenous nations.
The report found there was a decline in Indigenous-owned water entitlements and no change in the level of flows to wetlands under their jurisdiction.
The report found there was a decline in Indigenous-owned water entitlements. (ABC News: Saskia Mabin)
Dr Kingsford said that research showed the engagement with Indigenous communities regarding the river was still “pretty poor”.
“We’ve seen that particularly in the 2018-2019 period when the Darling dried up to virtually nothing,” he said.
Irrigator impact disputed
While irrigation communities have argued they have been badly affected by the water buybacks, the Wentworth Group found water buybacks had not hurt irrigation communities economically.
Dr Colloff said they were expecting to find “pretty dismal figures” for irrigation communities, but found the opposite.
“Their profitability was increasing during the period of the highest level of buybacks,” Dr Colloff said.
The report looked at seven different economic indicators and found that five of them had improved since the Murray-Darling Basin Plan came into effect.
“What we found was that farmland prices had improved massively,” Dr Colloff said.
They increased by a mean value of 26 per cent per year between 2006–07 and 2022–23, according to the report figures.
The group analysed local government data and found that personal incomes in the basin region had also improved, apart from the drought years of 2017-20, as had the gross value of irrigated agricultural production.
Irrigators were taking less surface water but producing more food and farmer’s income remained steady, the report found.
“Cash income goes up and down with drought and wet years, but on the whole had increased quite dramatically,” Dr Coloff said.
The Barmah Millewa floodplain was part of a survey undertaken by the UNSW in November. (Supplied: Richard Kingsford, USNW)
But Kerang farmer Andrew Leahy, who is chairman of the Victorian Farmers Federation water council, said he totally refuted the Wentworth report’s findings that farmers were not worse off.
Mr Leahy said they had been impacted in a number of ways, including temporary water prices rising by $70 a megalitre and the local community suffering since the plan came into effect
“The local high school used to be 1,000 kids and now it is 200,” Mr Leahy said.
He said they had been forced to stop irrigation during the summer because of the cost and had to adapt their farm systems to suit the changes.
Overall, the Wentworth Group report also found a lack of monitoring and evaluation of the basin plan.
Recommendations in the report included looking at improved reporting frameworks and more publicly-available data that monitored the health of the river and the needs of basin communities.
A pelican frolicks on the Gayini wetlands on the Low Bidgee. (Supplied: The Nature Conservancy)
Climate impacts
La Trobe University Centre for Freshwater Ecosystems director Nick Bond said he was not surprised by the study’s findings and was sure many of the reported “trends” were credible.
“I’d add though that we also need to acknowledge that there are also changes occurring in the climate across the basin, which were not addressed in the initial Basin Plan, but which appear to reducing inflows and water availability,” Professor Bond said.
“This raises the question as to whether the health of rivers and wetlands would have declined even more without the Basin Plan?”
He said while it was a difficult question to answer, it was clear more needed to be done to protect aquatic ecosystems into the future, especially in some parts of the basin.
The Murray-Darling Basin Authority (MDBA) said it recognised the value of new science and evidence in building knowledge of the basin.
A spokesperson said the MDBA provided technical feedback on a previous draft of the report in June 2024.
“When this research is published we will take time to review its content,” the statement said.
“The MDBA is currently undertaking the Basin Plan Evaluation, which is due for release in mid-2025, and will be a critical input to the 2026 Basin Plan Review.”
