The great Murray-Darling swindle



A million dead fish, floating on putrid green water. Images of this ecological catastrophe on the Darling River over summer shocked the nation. Was it the result of drought? Blue-green algae poisoning? Excessive summer temperatures and climate change? Too much water taken upstream for irrigation? Mismanagement by the authorities?

Some of the fish found dead near Broken HillAfter several months and at least four published reports, we know the answers. It's time to state plainly what has been going on, and who is to blame.

For the immediate crisis of the fish deaths, we can look at the Interim Report to the Australian Government, released 20 February. There were three large-scale fish kills, all in the Menindee region of the Darling River. This is the point in south-west New South Wales where the river reaches the Menindee Lakes. It's hot and dry, averaging about 250mm of rain a year.

During two periods in 2012 and 2016, it rained enough to fill the lakes. When full, these lakes become important nurseries for native fish. If a lot of water is flowing through the river, the fish can travel both upstream and downstream. Flowing water also circulates oxygen within the water column and helps to reduce algal blooms.

After 2016, there were no further inflows of water to the lakes. Some water was released downstream for the environment, but the largest flows (peaking at 6200 megalitres a day) were for the River Murray, to meet commitments at the South Australian border and for the irrigation season. To get there, the water passed over a nearby pool called 'Weir 32', which is much smaller than the lake. Fish and algae went with the flow, but as the water level dropped they became trapped in the weir pool.

The dry conditions continued. Rainfall for the northern Basin in 2018 was about half the long-term average. Most of the Murray-Darling had its hottest December-January period on record. The highest temperature in Menindee was 48.8 degrees, three days before the third mass fish death.

When it gets this hot and the river isn't flowing much, the water column splits. There's a layer of hotter water at the top, and cooler water at the bottom. The temperature difference means the layers can't mix. This keeps most of the oxygen in the shallow and warmer surface, while the much larger and deeper bottom layer becomes deprived of oxygen. The fish would have been pushed into the shallow surface waters, which were also covered in algal blooms.


"The biggest swindle isn't irrigators taking advantage of loopholes, but how the whole system has been rigged in their favour — possibly illegally."


Then the cool change arrived, and the water temperature plummeted. Winds stirred the waters, mixing the two layers. Suddenly the amount of oxygen in the shallow surface layer wasn't enough for the total volume, and the die-off of algae also sucked up more oxygen. The fish had nothing to breathe and nowhere to escape. They suffocated in their millions.

That's the immediate reason for the deaths, but for the ultimate cause we have to look at a different report from the Australian Academy of Science. For all the technical explanations, it's actually pretty simple. '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.' And prevention is simple too. To reduce the risk of algal blooms and splitting of the water column, we need more water flowing down the river.

So why isn't there enough water in the Darling? The answer is 'excessive diversions upstream'. In other words, it's big irrigators in NSW and Queensland taking too much water for their own purposes. One particular concern is unregulated 'floodplain harvesting'. Agribusinesses have built channels, levees and huge storage dams to capture water flowing on the floodplains and use it to irrigate thirsty crops like cotton, but this isn't properly monitored or reported.

However the biggest swindle isn't irrigators taking advantage of loopholes, but how the whole system has been rigged in their favour — possibly illegally. This argument is set out in the South Australian Royal Commissioner's scathing assessment of the Murray-Darling Basin Plan, released late January.

The whole point of Australia's Water Act 2007 and the subsequent Murray-Darling Basin Plan, writes the commissioner, is to restore the degraded environment. In fact, the Commonwealth's key legal justification for muscling in on the states' business is our international treaty obligations on wetlands and biodiversity. The act requires setting an environmentally sustainable level of water that can be taken from the river, based on the best available science.

Instead, the Murray-Darling Basin Authority has consistently dismissed independent scientific recommendations and based its water targets on politics. The environment is supposed to be primary, but the MDBA has adopted a 'triple bottom line' approach that includes social and economic factors. And their target has failed to take into account the hotter and drier conditions expected under climate change.

The target of 3200 gigalitres of water to be recovered for the environment was a political compromise, and it's been further compromised since. Myths and lies about the economic impact of returning more water to the river have spooked communities in the Basin. Bowing to this backlash, the government has capped 'water buybacks', which are the most efficient and socially just way of restoring our river to health. Instead, millions of dollars has been wasted on efforts to make irrigation more efficient, without evidence that the water saved will actually benefit the environment.

Even the water that has been recovered may not have flowed where it was intended. A study by the Wentworth Group of Concerned Scientists found that 'there has actually been no improvement or even a decline in water flows since the implementation of the Basin Plan'. Dams and weirs are impeding the flow of water and it's hard to 'shepherd' this water through the system. Most scandalous of all, under NSW water-sharing rules 'water that should have been left in the rivers, for environmental purposes, can be extracted' by irrigators.

The result? If a similar situation occurs that led to the recent fish kills, we won't have enough water flow to do much about it. The best we can do is localised techno-fixes like using mechanical aerators to increase oxygen levels in the water.

Even less encouraging is that key solutions to deliver more water involve repealing recent compromises of the Basin Plan, such as the cap on buybacks. That's the right thing to do for the environment, but it could just lead to another cycle of fighting. It's starting to look a lot like the politics of climate change, with back-and-forth policy that achieves very little.

With such polarised perspectives, who is right? For me, the voice to trust is that of South Australia because it is the major downstream state. When you think about it, the future is downstream of the present: our children will inherit the consequences of any decisions we make today. In this sense we all live downstream, and so it is the best viewpoint for long-term planning of the river system.

I believe we should implement the recommendations of the South Australian Royal Commission — even at the risk of starting another fight between the Basin states — because it's better than the current trajectory: the long, slow death of our greatest river system.



Greg Foyster headshotGreg Foyster is a Melbourne writer and the author of the book Changing Gears.

Topic tags: Greg Foyster, climate change, Murray-Darling Basin



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Existing comments

Apart from the scientific analysis around how the fish died, the article confirms basically what I and many believed. Too much fiddling with too little water, and too much water taking and (likely political) rigging of the water taking upstream(Qld/NSW border and northern NSW) by big agribusiness with multiple dams with huge water capacities on their properties. Yes, all downstream as in your analysis, particularly in future, will pay and suffer for these ignominious behaviours. Our children and theirs.
celeste showyin | 03 March 2019

Greg, with the recent catastrophic floods in North Qld and millions of litres of flood water pouring out to sea from The Ross, Burdekin and Palmer/Mitchell systems (the latter two much bigger volumes than the Murray) I agree we need an integrated plan. Why couldn't, in fact why shouldn't a channel be built to capture the flood waters from the north along the Mitchell Highway to link up to the Darling System approximately 2100 km further south. Or a series of links. Such a link could alleviate cattle losses in extreme weather events as well. Surely that in theory could alleviate the problems of the Murray Darling. And why couldn't a user pay system be legislated on all irrigators in all 3 states? So that excessive flood plain harvesting to the detriment of the down stream environment is curtailed? With the intention that the big cotton producers don't hog too much water? Adopt an integrated engineering and legislative outcome that is much fairer to all sectors? Surely the engineering couldn't be that difficult.
Francis Armstrong | 03 March 2019

Greg, I have read the Report complied by the Academy of Science .I completely agree with their conclusions . I grew up in the MIA town of Griffith in the 1950's and 60's when rainfall was much above average .There was no concern about climate change or droughts. However much has changed since then. The Darling River was not brought into irrigation until the 1960's , when thirsty crops like cotton were grown in northwest New South Wales and southern Queensland by big, mostly American owned agribusinesses . Unlike the Murray/Murrumbidgee systems, which head in the relatively reliable, wetter Snowy Mountains, the Darling Basin is a dry, unreliable rainfall area. The practice of flood plain harvesting and huge shallow storages off river in Northern New South Wales and Southern Queensland is absolutely dumb to say the least, since massive amounts of water are lost to evaporation. Growing cotton and other thirty crops in a arid area is equally idiotic. Simply put , there is not enough water in the system to support such practices without irreparable damage to the environment Whether the locals like it, or not, these unsustainable practices are going to cease. For most of the period of white settlement in the region, people have understood that intensive irrigation along the Darling was unsustainable due to irregular flows. Sadly, vested interests and lack of political intestinal fortitude will see the Darling River doomed to ecological disaster, unless ordinary voters voice their anger at the upcoming elections.
Gavin O'Brien | 03 March 2019

Absolutely disgusted at this article about the Murray Darling debacle. As I sit at Deniliquin in border NSW, the red gums are dying because of the water that they are trying to force through the Barmah Choke. Water was only supposed to flow through there in flood time- not all the time. Meanwhile the rice mill has closed with 100 jobs gone, Wakool is a ghost town, farmers here have zero allocation unlees they buy from the South Australian government price gouging at $500 a meg - even though these same farmers have water assets worth over $400000 hard bought and unaccessable! Meanwhile South Australia is filling their lakes for sporting activities, and giving their farmers 100% of allocations rather than zero! I am so disapointed at Eureka Street for running this sort of misinformation while our environment, people and small towns are being destroyed.
Cathy Cleary | 03 March 2019

This article is about legacy, birthright and entitlement. I quote Kate Jennings from her essay "Home Truths: Revisiting Wake in Fright": The plot of "Wake in Fright" is as old as an outcropping west of Menindee. As old as Virgil: The way downward is easy from Avernus./Black Dis's door stands open night and day./But to retrace your steps to heaven's air,/There is the trouble, there is the toil.
Pam | 04 March 2019

Why is anyone surprised with this pathetic government and when will we learn that without our environment there will be nothing for us or our kids!
TigerBren | 04 March 2019

Great piece Greg - it really is incumbent on all of us to put the acid on vested interests to pay for their externalities (and expect we all may have to pay a bit more as a result). The defense by the cotton industry is that theirs is the most productive use of limited water resources. I'm not able to determine whether this is true, given their harvesting, as you have noted, of unregulated flows, but that is less the point: all water harvested should bear the full cost of taking it, including environmental costs.
Mike Westerman | 04 March 2019

something has to be done about Government policies.
maryellen flynn | 04 March 2019

Greg. It seems that the northern basin is a convenient whipping boy for bloggers and the media. Obviously you cannot have a northern basin irrigation industry without extraction of river flows, and that balance will always be under review. But to say South Australia does not have some responsibility is not just. The latest draining of Menindee Lakes was mainly for South Australia's benefit. I did not recall that state volunteering for water to be held in Menindee. Secondly, the barrages at the end of the Murray are artificial and hold a lot of fresh water. Can the same scientists who always criticize the northern basin, give a scientific reason (apart from stopping salt incursion)that justifies the in-pounding of such a large volume of freshwater at the end of the system. My point is that the whole system needs to be evaluated, and by signaling out just one region will not solve any problems. Regions just get there angst going and nothing is resolved.
Robert Harpham | 04 March 2019

Thanks all for the comments. Robert, I have never heard a justification for that either so will do further research! Cathy, this article is based on assessing the four most recent reports, including from the Australian Academy of Sciences, which I trust as an independent and credible source. But it deals with the Basin as a whole system and of course there might be lots of localised issues as you describe where you live in NSW. Nevertheless, taking the broad view, the science is very clear that water is overextracted and more flows are needed to ensure the health of the river long term, and to reduce the risk of repeated large scale fish kills such as what happened at Menindee.
Greg Foyster | 06 March 2019

that was very helpful
Alexa | 11 September 2019


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