Members of the Murray-Darling Basin Knowledge Alliance explain why the original Basin plan was flawed and the proposed new plan will also fail to protect and restore the rivers of Murray-Darling Basin.

The Murray-Darling Basin is Australia’s breadbasket and home to threatened ecological communities and species. For many years there has been a contest between different Basin stakeholders as to how its limited water will be allocated: how much for production and how much for the environment.

The Basin Plan, developed and implemented by Australia’s Murray-Darling Basin Authority (MDBA), attempts to navigate this contested allocation problem. The first Basin Plan was enacted in 2012 and is now under review.

The plan for the next ten years is increasingly looking like a disaster in the making. The claim by the MDBA that only small changes to the 2012 plan are needed to deliver an environmentally sustainable and economically productive Murray-Darling Basin don’t add up. Its proposals will continue to cause widespread and severe ecological destruction, while negatively affecting many communities.

The 2012 Basin Plan, still in force in 2026, was supposed to achieve an environmentally sustainable level of take. Despite substantial volumes of water being recovered for the environment from buybacks of water rights from willing sellers, there are at least four key failings with the current Basin Plan.

First, the sustainable diversion limits (SDLs) for surface and groundwater extractions were originally set at trillions of litres more than a ‘low environmental risk’ outcome proposed by the MDBA in 2010. Too much water is still being taken from the Basin, with water diversions for irrigation accounting for more than half of the inflows during drought years.

Second, several billion taxpayer dollars were spent on subsidies and grants for on- and off-farm irrigation infrastructure. These expenditures have had the perverse effect of reducing the essential return flows to stream rivers and aquifers. This is because a proportion of the water extracted for irrigation is not consumed.

Third, much time, effort and public money have been spent getting water down the rivers, without it reaching much of the biodiversity hotspots of the Basin’s wetlands.

Fourth, despite most of the funding being paid for by the federal government, state governments have delayed meeting their obligations and, in some cases, deliberately obstructed implementation of the 2012 Basin Plan.

In 2026, the bottom line is that we have a 2012 Basin Plan still in force but which has not delivered on the key objects of the Commonwealth Water Act 2007 namely:

– the return to environmentally sustainable levels of extraction for water resources that are over allocated or overused; and – to protect, restore and provide for the ecological values and ecosystem services of the Murray–Darling Basin.

A ‘State of the Basin’ analysis identified that 18 out of 20 environmental, Indigenous, social and compliance indicators have not been achieved. The health of the Baaka (Lower Darling River) is in severe decline, while other rivers are also in poor health.

Ecological decline is evident at the Murray mouth and Coorong and in the catastrophic fish kills and mussel deaths on and alongside the Baaka at Menindee. These massive fish kills occurred in the drought of 2017–2019, and again in 2023, when there was no drought. According to the Australian Academy of Science (2019):

The root cause of the fish kills is that there is not enough water in the Darling system to avoid catastrophic decline of condition through dry periods.

The decline in the northern basin is largely due to uncontrolled floodplain harvesting in the NSW northern basin where off-river storages increased from 557 billion litres in 1993–94 to 1.393 trillion litres in 2019–20, a 2.5-fold increase in 26 years, when there was supposed to be a cap in place. Despite these huge increases in water storage and extractions, in 2018 the Australian Parliament allowed for an additional 70 billion litres per year of much needed environmental water to be extracted from the northern basin than was planned for in the 2012 plan. Yet, a recent assessment of farm storages and irrigation channels in cotton-producing catchments found an annual loss to evaporation of 1.2 trillion litres. Much of this evaporated surface water would have flowed to rivers and floodplains. None is accounted for when setting sustainable diversion limits.

The MDBA’s 2026 discussion paper canvassed options for the next 10 years of the Basin Plan, due for implementation 1 July 2027. But it did not include most of the relevant scientific literature required for transparent and evidence-based decision making. Further, it posited that only 10 per cent of groundwater and surface water sustainable diversion limit areas were, possibly, not environmentally sustainable. It also claimed that irrigation communities have already ‘given’ enough water and are suffering because of it. This is notsupported by the economic evidence and ignores the fact that all sales of water rights were from willing sellers, all of whom were fully compensated.

In June 2026, the Authority published its What we heard report based on some 2,500 submissions. This report suggests to us that the MDBA will:

• leave the sustainable diversion limits in the 2012 Basin Plan more or less unchanged, with some possible ‘tweaks’ in a small number of catchments
• continue to unlawfully ignore climate change science, as was found in the 2019 Murray-Darling Basin Royal Commission.

How can this be justified? The MDBA claims the ‘heavy lifting’ for the next Basin Plan will be delivered by ‘Complementary Measures’ (e.g. fish ladders and infrastructure to improve floodplain connectivity) and ‘Relaxation of Constraints’ (e.g. stream flow corridors, raising the height of roads to allow for greater flooding). There is no evidence that this will work at the basin scale in the next decade. The Inspector-General of Water Compliance Northern Basin Toolkit Inquiry Report has pointed out that two state governments failed to deliver on more than $160 million in water infrastructure measures to improve river health in the northern basin – eight years after they were first promised.

Current (and future) levels of water extractions in the Basin are not sustainable. Increases in average global surface temperatures are accelerating and this is directly attributable to increased greenhouse gas concentrations in the atmosphere. Australia will shortly experience increased warming with predictions of a strong to very strong El Niño event, coupled with the highest ever recorded global sea surface temperatures in June 2026. In the Basin, higher temperatures are already driving greater evaporation rates, increased variability (magnitude and timing) in rainfall and reduced stream flows.

As a nation, we must build the next Basin Plan using the best available scientific knowledge and socio-economic analysis (bio-physical, Indigenous, social sciences), as required by the Water Act 2007. Yet, of the hundreds of research publications about what is, and what is not, working about the current Basin Plan, at least 86 per cent have never been cited by the MDBA. Ignoring the evidence is contrary to the MDBA’s mission to be “steadfast stewards of the Basin”.

The MDBA is proposing to extract too much water in an increasingly hotter climate in a Basin already suffering from large-scale ecological declines. Australians need to push back against what the MDBA has proposed, for the sake of our rivers, communities, environment, and our future.

Republished from Global Water Forum

The views expressed in this article may or may not reflect those of Pearls and Irritations.