An 830-kilometre stretch of the Murray River, from where it mixes with the Darling River to the point it meets the sea, could soon be designated critically endangered by the federal government.
The same status could also be given to the massive Macquarie Marshes wetland, also known as Maliyanga Ngurra, in the Murray-Darling Basin in New South Wales.
But what does it mean to declare natural waterways such as a river and marsh critically endangered?
For scientists, the listings are a recognition of the depleted state of the environment. For others, it represents barriers to the function and development of the $30 billion agricultural industry that relies on the waterways.
‘Threatened’ listings aren’t just for animals
We often hear how individual plants or animal species facing the threat of extinction are recognised by the federal government as being vulnerable, endangered or critically endangered.
Those threat levels can also be assigned to certain unique or biologically important habitats under a key national environment law: the Environment Protection and Biodiversity Conservation Act.
The Macquarie Marshes is a massive wetland in western New South Wales. (Flickr: Margaret Donald, Macquarie Marshes, CC BY-NC-ND 2.0)
These habitats are known as threatened ecological communities, and often support or are intrinsically linked to a range of organisms.
The list of registered threatened ecological communities includes woodlands, forests, swamps, bogs, grasslands and caves.
Like an endangered animal, a threatened ecological community is a recognition that a particular habitat is in danger of being wiped out.
Sydney’s Cooks River is the only river currently on the national threatened ecological community register — but it could soon be joined by a much larger system.
Which parts of the river system could be listed?
Both Macquarie Marshes and lower Murray River, also known in South Australia by the Ngarrindjeri word Murrundi, were nominated for threatened ecological community consideration last year.
Environment Minister Tanya Plibersek and a group of scientists who advise the government, known as the Threatened Species Scientific Committee, deemed them a priority for assessment last October.
The committee has since tentatively indicated both waterways should be listed as critically endangered based on scientific evidence from hundreds of reports and consultation with more than 100 experts.
For the lower Murray, the draft listing area includes the river itself, flood plains either side of its banks, associated wetlands and lake and estuary systems at its mouth.
The assessment of the lower Murray says it is a “one-of-a-kind” river system nationally because of its complex features and high biodiversity.
Numerous species of fresh and saltwater fish, migratory and non-migratory birds, and flora are supported by the ecosystem.
And this lower section of river, which flows through western NSW and Victoria into South Australia, consists of six sub-regions.
The Macquarie Marshes, about 600km north-west of Sydney, drains into the Darling River and varies in size with flooding.
Sometimes it spans around 2,200 square km, but much of the area is used for grazing.
About 1,000 square km has been slated for the draft listing.
It provides a refuge for frogs, snakes and threatened birds, among other species.
How’s the health of the waterways?
University of NSW river ecologist Richard Kingsford has been involved in the nomination of both waterways. He said critically endangered listings would reflect the long-term degradation of the systems.
“I think that’s important for us to understand what we’re actually dealing with in terms of a problem,” he said.
The draft listing assessment for the lower Murray states river regulation, water over-extraction, flood plain clearing and the introduction of invasive species had severely impacted the system.
“These have compounded and intensified over the past 100 years and, over the past few decades, have been exacerbated by the current and increasing threats of climate change,” the draft listing assessment said.
The Millennium Drought was one of the worst drought periods on record in Australia post-European arrival. (ABC Riverland: Will Hunter)
The Millennium Drought, between 1996 and 2010, saw the lower Murray verge on environmental collapse with historically low flows.
Wetlands dried up. Fish that spend part of their life in salt and freshwater were cut off from important reproduction sites.
Despite large-scale flooding between 2020 and 2023, driven by three years of wet weather during La Niña cycles, the long-term environmental decline remains, according to the listing report.
University of NSW river ecologist Richard Kingsford. (ABC News: Carl Saville)
Professor Kingsford said water extraction meant less natural flooding of the Murray and Macquarie Marsh systems.
A separate government instrument, the 2012 Murray-Darling Basin Plan, has aimed to improve water flows and restore the waterways.
The plan did allow parts of systems to recover, Professor Kingsford said.
“But [I] would argue it still does not bring it back from critically endangered just because the extent of the damages has been so severe.”
The draft lower Murray listing report states the Basin Plan alone does not have the capacity to address the myriad of ecological challenges for the threatened ecological community as it is mainly concerned with water.
The Basin Plan has also faced difficulties in its implementation and the Productivity Commission found last year there had been little progress.
What would a listing mean?
It would help create enforceable protections for the parts of the river system not currently protected.
About 43 per cent of the proposed threatened ecological community area for the Murray and 20 per cent for the Macquarie Marshes are considered internationally significant wetlands, known as Ramsar sites, and are already protected nationally.
But recognising the rest of the systems has several legal ramifications for the river and marshes.
Unapproved destruction or damage to the sites would result in fines, and development applications within the threatened ecological community areas would require government assessment.
A list of conservation actions for the government to improve the sites’ environmental health would also be tied to the listings, although these are not enforceable.
We’ve been here before
This is the second time the two sites have been up for listing after they were recognised as threatened ecological communities for four months under a Labor government in 2013, before being reversed by a Liberal-National government.
The listings faced a strong backlash from the agricultural sector and the National Irrigators’ Council.
Council chief executive Zara Lowien said the organisation wasn’t aware of the potential relistings until being notified by the ABC.
With no press releases or wider announcements the listings were out for public consultation, she said it was disappointing the council would have little time to make a submission regarding the proposals.
Ms Lowien said there was still uncertainty around how much revised listings would affect towns and businesses, but what stakeholders did know was there would be additional regulation.
“This could mean that those projects have to go through a federal check and balance to get ahead for that new piece of infrastructure or for modifying existing infrastructure,” she said.
Ms Lowien added this could also mean delays to implementing sustainable diversion limit adjustment mechanism projects, part of the Basin Plan, which were supposed to improve access to environmental water flows.
She thought listings should be held off for a few years until information from a review of the basin plan and effectiveness of measures to improve environmental flows was analysed.
NSW Nationals Senator Perin Davey. (ABC News: Nick Haggarty)
Opposition water spokesperson Perin Davey, who lives near Deniliquin, did not think threatened ecological community listings for the lower Murray and Macquarie Marshes was the solution to basin management.
“I think we need to park this idea and get back to looking at river management, environmental water management and riparian landscape management,” she said.
“And look at the system holistically and work with communities in partnership to deliver on the environmental outcomes that we actually want to achieve.”
Getting the environmental and economic balance right for the heavily modified system, on which the nation’s agricultural sector relies, continues to be a difficult task.
But Professor Kingsford said it was still important to have a legislative and scientific process that looked at evidence of what the waterways faced.
“When it comes to discussions about water in these systems and the basin plan, it’s really important to have that sort of [threatened] status recognised,” he said.
