The Tide Must Turn

21 October 2019
The Tide Must Turn - Featured image

Topher Field is a filmmaker and self-described optimist and libertarian. His videos on the Murray-Darling have been viewed more than 300,000 times.

Water has become the most fought- over commodity on the Australian continent today and while it may not be a literal war, it has a very real body count numbering in the hundreds so far and growing every week. The waters of the Murray Darling Basin are subject to the Murray Darling Basin Authority (MDBA) and their Basin Plan. The Authority was created by the Water Act of 2007, a flawed piece of reactionary legislation rammed through at the height of the Millennium Drought.

At the time 2006 had set a new record low for water inflows into the Basin, at least since European records began, and there were warnings the Murray and Darling river systems were ‘dying’. Politicians were given to believe that the Australian bush, which has been dealing with a cycle of droughts and floods since time immemorial, was now somehow in grave danger and it was up to them to fix it. In truth, the big dry was neither unprecedented nor any more harmful than what the Australian bush had endured and recovered from countless times before.

By many metrics, the rivers actually were better off than they would have been without human intervention. Our dams and weirs ensured continued flows down the Murray even during the worst of the drought, and in the process provided habitat for birds and animals that would simply not have been able to survive the drought prior to human intervention on the rivers. We have historic photographs proving the Murray River ran practically dry, with no more than a trickle left in the bottom. The Mighty Murray became narrow enough for a grown man to simply step across. That is what the Murray would have looked like in 2006–’07 were it not for our dams and weirs, so there’s no question human intervention is a net positive for the rivers and their surrounding habitats. But in 2006, one key area was unquestionably worse off than it had ever been before: the Lower Lakes in South Australia. Prior to human intervention these ‘Lower Lakes’ had been an estuary with a mix of fresh and sea water for the previous 7,000 years. But in the 1940s, the estuary was cut off from the ocean by the construction of barrages and turned into freshwater lakes, now dependent on unreliable fresh water inflows from the Murray River to maintain their health and their water level.

From 1950 to 2000 rainfall in the Basin was above the 1900-1950 average, and as a result there was enough fresh water to maintain the Lower Lakes, but this is the ‘land of droughts and flooding rains’ and by 2006/7 the Millennium meant the low flows from the Murray River (despite being higher than they would have been without our dams and weirs) meant that the artificially fresh Lower Lakes were faced with an existential crisis.

Not enough water was flowing in to replace the 850,000,000,000 litres (more than 1.5 Sydney Harbours) of water evaporating every year, and Lake Alexandrina dropped to half a metre below sea level! Politicians were confronted with a serious environmental crisis. Acid sulphate soils were now being exposed to sunlight and there was a very real risk of the lower lakes being turned into a toxic wasteland if the water level was not recovered, urgently!

This crisis in the Lower Lakes was entirely man-made. Prior to the barrages being built water lost to evaporation was replaced by ocean water flowing in, so the water level stayed steady and these soils were not exposed— even during droughts. So what solution did our esteemed political class propose? Would they restore the health of the lower lakes by opening them up to the ocean once again, returning them to their natural state? Of course not. The solution proposed by then Federal Water Minister Turnbull, supported by all subsequent Prime Ministers and Water Ministers, was to create the Murray Darling Basin Authority and task it with removing 2,750GL (2,750,000,000,000 litres, or 5.5 x Sydney Harbour) of water from productive use in the Murray Darling Basin, and returning it ‘to the environment’—a euphemism for letting it flow out to sea via the lower lakes.

This represented a more than 40 per cent reduction in water availability, compared to 2009/10 water use. Instead of maintaining the health of the lower lakes using ocean water at no loss to anyone, the lower lakes would be kept fresh by using 40 per cent of the water our farmers used to grow the food we eat. Brilliant. The impact of this plan on our irrigators has been devastating. Water prices have soared far above the break-even point for most irrigators,
creating a spate of bankruptcies, suicides and gutting rural communities.

But even this 2,750GL isn’t enough, with Federal Water Minister David Littleproud announcing in July his intention to proceed with a further 450GL of water to be sent down the rivers ‘for the environment’. To say that the mood in irrigating communities is one of ‘despair’ is an understatement.

As I said in a video in 2011, where I warned of the devastation to come if the then water minister Tony Burke followed through on the proposed Murray Darling Basin Plan: “Our farmers have survived droughts, floods, and locusts, but now they’re faced with a new threat: Bureaucrats… Death by bureaucrat? It’s a nasty way to go.” At the time it was a funny throwaway line. In the eight years since, it’s become painfully and literally true. And all for the sake of some artificial freshwater lakes at the end of the Murray River.

The MDBA claim they do far more than just look after the Lower Lakes. Even if that were true, and it’s debatable, they cannot get away from the fact they exist principally for the sake of the lower lakes. It’s written into legislation they are tasked with maintaining:

  • Barrage flows of at least 2000 GL year (4 x Sydney Harbours!)
  • Water levels in the lower lakes to be above sea-level and at 0.4 AHD (Australian height datum), 95 per cent of the time
  • The Murray River mouth [actually the heads of the Alexandrina Estuary] to be open 90 per cent of the time to an average depth of 1m (Murray Darling Basin Authority, 2014, pp. 23, 24).

There’s no question the MDBA were created for the sake of the ‘Lower Lakes’ and tasked with taking water from farmers for the purpose of keeping the Lower Lakes in this highly unnatural freshwater state. It’s important to note the South Australian Government somewhat unbelievably insists the Lower Lakes have always been fresh, and so they must be kept that way. There is no doubt the South Australian Government is wrong! The ample scientific and historical evidence that Lake Alexandrina was estuarine includes the diaries of early explorers, oral history from indigenous tribes, and a hugely profitable fleet of Mulloway fishing boats stationed at Milang who protested against the building of the barrages in the 1930s on the basis they would destroy the Mulloway breeding grounds and their livelihoods in the process.
Barrages (in red) constructed in the 1930s cut Lake Alexandrina off from the ocean.

The only scientific paper to conclude the Lower Lakes have historically been fresh is a 2009 report titled An environmental history of the Lower Lakes and the Coorong. This paper was authored by three of the five authors of a previous peer-reviewed paper published in 2007 which concluded the opposite: the lakes had been historically estuarine. No real explanation is given why these authors reversed their position, no new evidence from the Lower Lakes is introduced. The 2009 report was not submitted for peer-review, while the 2007 report passed peer review.

The reports that have been peer-reviewed, including most notably Prof Peter Gell’s 2019 peer-reviewed report published by the CSIRO, are all in agreement with the other historical evidence: the lower lakes were estuarine prior to the barrages being constructed in the 1940s, and had been so since long before European arrival. However the MDBA, the South Australian Government, and the Federal Government all seem unwilling to accept the facts and are sacrificing the survival of irrigators upstream in order to maintain these artificial lakes downstream.

As of the time of this writing, the Murray Darling Basin Plan continues unabated, water prices remain sky high, more irrigators file for bankruptcy or worse every week, and the cold war over water continues. No meaningful political action has been taken, and nothing is likely to be done in the foreseeable future. We made a mistake in the 1930s when we decided to build barrages on Lake Alexandrina. Eighty years later, the time has come to admit we got it wrong. They must be upgraded as per the plan put forward by investigative journalist and Goolwa resident Ken Jury, titled A Better Way for the MDB. At its core, this is a plan to upgrade the barrages from their 1940s design to a modern design that is able to open and close much faster. This enables us to use the rise and fall of the tides to pump water around the lakes, scour the ‘Mouth of the Murray’ and achieve all the MDBAs objectives without wasting fresh water.

It is possible to use ocean water to maintain the health of the lower lakes while protecting their amenity for the people who live there. We can fix this mistake, and we must. We’ve lost too many irrigators in the Murray Darling Basin already. How many more will we lose before our politicians act?

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