The Murray-Darling Basin - what I learned.

With the current outcry in every news and social feed I look at, I’m almost certain everyone is aware of the catastrophic Fish Kill at Menindee Lakes. Instead of my usual headline and maybe first paragraph read, I dedicated some time to learn about the current state of the Murray-Darling Basin, with a focus on the Darling River and Menindee Lakes.

I’ll frame it up with a couple of key points;

• The Murray-Darling Basin is the largest and most complex river system in Australia
• It runs from Queensland, through New South Wales and the ACT, to Victoria and South Australia, spanning 77,000kms of rivers
• More than 2.6 Million Australians (close to 10% of our population) call the Murray-Darling Basin home, with over 3 Million people having access to fresh, clean drinking water from the Basin
• The basin is the ‘food bowl’ of the nation; the agriculture industry is worth $24B annually
• Farming runs through all regions with approximately 9,200 irrigated agriculture businesses across the Basin
• The Basin’s tourism industry is worth $8B annually
• There are approximately 30,000 wetlands across the Basin, with 16 being classed as internationally significant
• The Basin is a diverse habitat for 120 waterbird species and 46 native fish species
• The Basin has been home to more than 40 Aboriginal nations for thousands of years (the oldest human remain 
• Australia oldest human remains, including Mungo Man, dated to approximately 42,000 years were found at Lake Mungo which is part of the basin.

The Darling River

The Darling officially starts about 50kms east of Bourke and ends when she joins the Murray River on the border of Victoria and New South Wales at Wentworth, NSW. Unfortunately, the Darling has been in poor health for some time, attributed to overuse (consumption), pollution from pesticide runoff (Agriculture), and prolonged drought.

• It has been recorded that the flow is quite irregular with the river drying up 45 times between 1885 and 1960.
• In 2008 the Federal government purchased Toorale Station in Northern New South Wales returning 11 gigalitres (11 Billion litres / 11,000,000,000L) of environmental flows into the Darling per annum
• It has been estimated that the Darling is ‘missing’ approximately 300 gigalitres (300 Billion Litres) of water to be healthy
• The somewhat controversial Cubbie Station uses a 460 megalitres (460 Million Litres) at full capacity (Cubbie station is the most substantial irrigated property in the southern hemisphere producing cotton - at full capacity (water dependent) they can grow approximately 49500 acres (200km2) per annum, on current restrictions they are growing about 490 acres, Cubbie is now an internationally owned property spanning approximately 240,000 acres)

Menindee Lakes

110 km south-east of Broken Hill, the Menindee Lakes was a series of shallow natural ephemeral (lasting for a very short time) lakes along the Darling River which have been developed into water storage. When full they hold approximately 1.731 trillion litres of water (which can be surcharged above this level within certain constraints to a total volume of 2.05 trillion litres)

• - In the 1950s and 1960s, the NSW Government built a series of weirs, levees and canals to capture and retain floodwaters, and regulate the release of water downstream
• The lakes themselves are very shallow and are in a hot, windy, and dry areas which means that evaporation is very high.
• It is estimated that on aver about 400 gigalitres of water is evaporated each year from the lakes.

The Fish Kill(s)

In your news feed, the current fish kill at Menindee Lakes is claimed to kill upward of 1,000,000 fish - the immediate cause was a dramatic change in temperatures that killed much of the blue-green algal bloom. The dying algae worsened already low levels of dissolved oxygen in the water, pushing the fish beyond their tolerance levels.

Fish kills like this are somewhat familiar, just not at the scale of the current kill at Menindee.

Biggest Challenges

It is widely agreed, and sometimes denied, that the downstream issues come from the mismanagement of water upstream, including;

• the diversion of rainfall (people have changed the course of the natural water collection flows and diverted the natural flow of water into dams for irrigation purposed)
• over-pumping; in particular drawing water from the basin during periods of the embargo, drawing non-metered water and manipulating meters to draw more water
• run off of pollutants such as pesticides into the waterways

What’s been done? 

Frankly, not enough. 

Successive governments have well been aware of the declining health of the Murray-Darling Basin for decades, to date there have been commitments of over $13B to assist. This has been used to buy-back water ‘rights’, buy-back land, provide grants to irrigators to improve and modernise their irrigation infrastructure, re-population fish stocks, etc.

The Water Act (2007) has as its principal objects:

1) 3d(i) to ensure the return to environmentally sustainable levels of extraction for water resources that are over-allocated or overused; and

2) 3d(ii) to protect, restore and provide for the ecological values and ecosystem services of the Murray-Darling Basin

A Basin Plan enacted in November 2012 with its key objective to achieve Sustainable Diversions Limits by reducing surface water diversions by an equivalent to, on average, 2,750 GL per year by 1 July 2019 while noting that CSIRO concluded that increases in actual Murray-Darling Basin stream flows of 3,000 GL per year would be INSUFFICIENT to meet South Australia’s environmental water requirements.

There is currently a pipeline under construction to draw water from the Murray River and pump it to the Menindee Lakes - this doesn't solve the upstream problems (although Cotton Australia claims this is the solution the region needs).

The Four Corners Report helped to expose the overuse and mismanagement of the Darling which has led to the NSW Government to investigate and prosecuted property owners.

There are many lobbies for a federal enquiry. However, it is felt that this will delay action.

One of the most significant challenges is that each state is tasked with enforcing appropriate use of the system, there is nobody that can enforce, force, or penalise a state for not playing by the rules.

What’s the key? 

It is widely agreed that we need to improve the flow of water back into the system and reduce contamination to get the Murray-Darling basin back to an acceptable level of health.

That means we need to take less, divert less, manage better (all apexes of our waterways inclusive of weirs, dams, levees etc.), reduce run-offs. 

A Few Thoughts

It’s appropriate for all of us to ask why/how this happened, and if existing practices, infrastructure and agriculture played a part. We need to be asking those who we elect the hard questions.

It is effortless to draw to the conclusion that if we stop/restrict the irrigators then the system will fix itself- that’s not going to happen any time soon as too many people rely on the Basin for food and water - plus, despite best intentions, no politician will go hard against their donors/constituents wishes at the end of the day, generally speaking, Australian Politicians, along with those that own the businesses that draw water have a short-term focus as opposed to the long-term health of our ecosystem and country.

Let’s get creative with alternate solutions… 

To support the works being done to reduce surface water diversions, reduce allocation, reduce overuse, and reduce run-off. So here’s a potential part to the overall solution from me;

Across Australia over the past ten years, we have invested heavily in desalination plants - many of which are now running as ‘hot standby’ which means they are not producing water to put into the drinking water - the majority of plants were planned and operational inside three years.

• The Gold Coast Desalination plant which is currently running as hot standby is capable of producing 133 million litres a day, that’s just over a week to make 1 Gigalitre(GL) (1GL = 1 billion litres)
• The Sydney Desalination plant which is also currently on hot standby (they call it Care and Maintenance Mode) is capable of 250 million litres a day, that’s 1 GL every four days
• The Victorian Desalination Plant which was immediately put into standby mode on completion incapable of producing 410 million litres a day, under 2.5 days to produced 1 GL. It has been reported that the government incurs an ongoing cost of $608million a year - even though it's on ‘standby mode.’

In one week these three desalination plants could produce approximately 5.5 GL, or around 286 GL annually.

This is only a fraction of what needs to be done, but if we can inject more water at critical points, this will give us the chance to improve flow while creating infrastructure works that could be leveraged in times of future drought.