Low-cost, simple changes could improve the declining health of Australia's long-mismanaged Murray-Darling Basin, leading researchers say.
As town tap water quality declines and the politics of water buybacks rage, a dozen environment and water experts on Monday released a damning assessment of the health of the basin that's home to 2.3 million Australians.
The researchers found widespread failures to meet economic, environmental, social, Indigenous and compliance targets.
The failures resulted in lower-than-expected river flows at 90 per cent of sites measured, poor use of environmental flows and declining abundance of waterbirds.
Town tap water quality is declining along the Murray-Darling river system, researchers say. (Mick Tsikas/AAP PHOTOS)
"Despite $13 billion committed to water reforms, trends of most indicators (74 per cent) show no improvement or are worsening," the researchers conclude.
One of the authors said the assessment of the Indigenous and social indicators was alarming.
"We found Indigenous-owned water entitlements to be grossly inadequate, furthering the disempowerment of Indigenous peoples in the management of water on country and contributing to negative effects on their health and wellbeing," Professor Bradley Moggridge, a Kamilaroi man, said on Monday.
The assessment comes after a 12-year, multi-government plan to restore sustainability in the complex river system failed, forcing its extension to December 2027.
The federal government at the same time lifted a cap on water buybacks, in which farmers are paid to reduce their water take to boost environmental flows.
That policy has faced fierce opposition from some farmers, regional communities and states including NSW, which says prior federal intervention has skewed the market.
But Prof Moggridge and his co-authors found irrigation communities were not experiencing the severe or even moderate economic hardship claimed and attributed to the basin plan.
That was based on an analysis of personal income and income disparity in basin districts in the first nine years of the plan.
Indigenous-owned water entitlements are grossly inadequate, researcher Bradley Moggridge says. (Peter Veness/AAP PHOTOS)
The social impact of poor river health was however felt in towns reliant on the system for domestic water supply.
The number of water restrictions and drinking-water quality incidents increased across 10 years, particularly during periods of flood and drought.
Lower Darling water was frequently below minimum safety standards due to low river flows and blue-green algae blooms, the paper found.
The researchers proposed several solutions including some form of rigorous, transparent, accountable system for monitoring, evaluating and reporting on the basin's health.
Low-cost options included centralising data on threats to water quality, water law breaches, mass fish kills and town water security and supply.
A more ambitious target for restoration of wetland ecosystem functions and biodiversity that went beyond "just add water" was also needed.
The paper, led by a member of the Wentworth Group of Concerned Scientists, was published in the journal Marine and Freshwater Research.