8 June 2010

Population, making a living, and the limits of the murray darling basin

I grew up in Broken Hill, which is dependent on the Darling River.  I remember hearing stories of such widespread flooding of the river that the paddle-steamers on their way up to Bourke got lost because the captains were unable to determine where the main channel was.

I spent 15 years in the South Australian parliament.  By their very nature MPs have to be generalists, but I was a generalist with a passion for the environment.  As a member of the Natural Resources Committee I moved that the committee investigate a reference on how upstream irrigation practices were impacting on the River Murray in South Australia.  This resulted in the committee visiting sites in Victoria, New South Wales and Queensland.

The Murray-Darling Basin or MDB, (sometimes known as the Murray-Darling-Goulburn Basin) is made up of 23 rivers in 4 states and 1 territory, and covers one-seventh of the continent.  Two million people live in the basin and another 1.4m living outside the basin are directly dependent on it, in particular South Australia.

The waters of that system are severely over-allocated, although farmers argue that it is not over-allocation but over-use that is the problem.  Whichever term one uses, between 1983-84 and 1996-97 extraction of water in the MDB grew by 65%.

Amazingly, when the MDB water is already over-allocated, Melbourne is about to become dependent on it too!  And why?  Because of increased demands for water there, which in turn relates to increasing population numbers.  The farmers in the Goulburn River valley are totally against the diversion of water to Melbourne, but for a Labor Government the votes are in Melbourne, so that’s where the water will go.

Of the rain that falls in the Murray Darling Basin, 94% evaporates, 2% is absorbed into the ground, and only 4% is runoff.  The annual flow through the MDB is less than a day’s flow of the Amazon.

There are 150 locks, dams and weirs in the system, which has turned the river effectively into a series of pools and lakes.  Add to this the outflow of 38 sewage treatment plants along the banks and 4000 tonnes of animal waste from feedlots and piggeries, and it comes as no surprise that algal blooms break out in summer.  Sometimes one hears arguments about whether Australians would be prepared to drink treated effluent, and I usually retort that South Australians already do.

South Australia has a legal entitlement to a minimum flow of 1850 Gl p.a., and this is probably the only thing that forces some flow within the system – SA gets 7% of the total flow.  When you consider that 3.4m people live in communities directly dependent on the MDB, that 7% is a piddling amount.

In addition to the problem of over-allocation we have drought plus climate change.  We made the mistake of thinking that the rain and floods we had in the 50s would always be like that.

Irrigation uses 95% of all the water taken from the MDB – this in turn produces 40% of Australia’s agricultural produce which is worth somewhere between $9 and 15 billion p.a., so it’s not an easy thing to just shut down these activities even when we know damage is being done.

Currently the basin is only 27% full, which says much about the diversion of water to irrigation.  Even more telling is that, despite all the flooding in the St George area earlier this year, the storages in the Condamine-Ballone catchment are still only at 48% capacity.

Water demand from the MDB has increased five-fold over the past 100 years.  When irrigation first began in the basin 100 years ago the population of Australia was 3.5 million, so obviously the population increase has something to do with that increased demand on the river.

In recent times, governments have become unwilling to build large dams & reservoirs, which is not surprising given that elections have been won and lost on them.

In the early 1970s, South Australians chose between a Labor Government offering a dam at Chowilla (a redgum floodplain in the South Australia Riverland) or a Liberal Opposition advocating construction of the Dartmouth Dam (upstream of the Hume Weir).  The Liberals and the Dartmouth Dam fortunately won.  I say fortunately because Chowilla is a hot, dry and flat area, which would have had massive evaporation and salinity problems.   The Dartmouth Dam was a far better option in terms of topography and climate. 

By putting money into the construction of that dam, South Australia was consequently guaranteed an annual flow of River Murray water.  But despite that, the Murray Mouth closed over in 1981 due to low flows – the first time in recorded history.  Dredges were brought in to re-open it again, and removed after completion.

However, due to continuing low flows, dredging had to recommence in 2002 to keep the mouth open, and it has had to continue since then.  This should be seen as a national problem, not a South Australian one.  Water had been flowing freely to the sea at that location for 8000 years.   And the cost of dredging and pumping of the sand is $4.1m p.a.

Under these circumstances it’s a no-brainer therefore that South Australia ought not to be increasing its population, but the SA government is intent on doing just that.

In Victoria, Bendigo, Ballarat and Ararat are planned growth centres, but no plans are being made for the water they will need.  Tony Burke, Australia’s new Population  Minister, would have us believe that our population problems can be solved merely by shifting people from one part of the country to another.

We need to ask whether irrigation is sustainable.  Around Mildura, historically the home of irrigation in Australia, farmers are now deserting the industry in droves.  Something is seriously wrong.


Forty years ago the Condamine/Ballone system was not used for irrigation – rather it was an area used for grazing. Land use in upper NSW has gone through a similar transition.

Should we intervene in the landuse activities being undertaken?  Should we have a say in what crops are grown?  The irrigators say that cotton is a crop that always sells and from that they can get four times the value of other crops.

I regularly check on the web for river levels in the Darling, and the impact of irrigation can be easily seen. At Bourke, in upper NSW, where cotton has been a principal crop, on 12th April the river level was 9.02m.  Five days later it was 6.72 metres.  Clearly it was not from evaporation as the water temperature was only 23 degrees.

Another of the problems that emerges from this sudden removal of water is riverbank slumping: the banks cannot dry out when water is removed so quickly, which can lead to collapse and high sedimentation loads downstream.

There is a certain level of greed that motivates.  Farmers at Goondiwindi  complained to my committee that they have had to forego $20m in production so that Broken Hill could have a guaranteed supply of water.  I wondered if they thought the people of Broken Hill should be left to die of thirst.

When we export the irrigated products that come from the MDB, such as cotton or wine, we are effectively exporting the water use to grow those products. 

Managed Investment Schemes (MIS’s) introduced by the Howard Government resulted in more plantation forestry so that more woodchips could be sent overseas for people in other countries to wipe their backsides. In Victoria alone MISs were responsible for an uptake of an extra 500-600 Gl p.a.


More grape vines were planted in South Australia, and now we have a glut with farmers unable to sell them, and Australia faces the real possibility of another government-subsidised vine-pull.


Salinity is another of the problems created by irrigation.  Geologically, the Australian coastline was once up around the River Murray, so the land is underlain with salt which is brought to the surface by irrigation.  Every minute 2.5 tonnes of salt cross the border into SA via the River Murray.


Eleven salt interception or disposal schemes have been constructed in SA, and another four are on the way.  Who pays for this construction? The taxpayer pays millions of dollars – in order to allow irrigators to continue to trash the environment.


The environment is the biggest loser in the exploitation and trashing of this river system. All river red gums adjoining the River Murray in SA are stressed, and those 200 m back are dying.


At the bottom of that system is the Coorong, which is a Ramsar-listed wetland.  The lower half of it is now five times the salinity of sea-water and is effectively dead.


Lake Alexandrina is now a metre below sea-level, and as of last Wednesday, direct seeding of the receding shoreline is occurring as way of stopping soil acidification.  It will cost $10m over 2 years – another taxpayer cross-subsidy to the irrigation industry.


So what are solutions?  Praying for rain is one solution that has been advocated, but there is little future in that one.


Then there’s water trading.  It does make sense to put a price on water, but is water just a commodity?  NSW farmers selling to SA farmers who are willing to pay higher prices are seen as traitors in their region.  Water traders deal with amounts of money similar to real estate agents, but they are not even licensed.


Desalination plants are another so-called solution to reduce our dependence on the MDB, but they are hugely expensive and energy intensive.  They emit greenhouse  gases when part of the reason we have a problem with water shortages is because of climate change caused by greenhouse gas emissions.


In South Australia a desalination plant will come on line at the end of the year, and while the government is using carbon offsets to justify those emissions, they are not using green energy.  That plant will be discharging hyper-saline water into the St Vincent Gulf, which is effectively a closed system.  Another one is planned in Spencer Gulf, which is also a closed system, with water taking 12 months to circulate and move back out to sea.


The COAG agreement signed In March 2008 will eventually have an impact, but in its early stages it is little more than a plan to have a plan; existing entitlements stay in place for 10 years.  For instance, Victoria has a cap on trading of water, such that only 4% of traded water is allowed to go out of Victoria.  South Australia has lodged a High Court challenge on this.


Professor Mike Young of the Wentworth Group says we should start at the bottom of the river and work up, by guaranteeing a 200 Ml flow through the mouth each year, then making all the adjustments upstream to make that happen.  We must forget state boundaries – the aim must be the health of the river.


The irrigation of wine grapes could be dealt a blow if we moved from a tax based on the price of the wine to an excise on the alcohol.  Wine writer, Philip White, says that this would see the cost of a $14 bladder pack rise to $31, and possibly help address the problem of alcohol abuse in the Northern Territory.


But there is one solution that is not being addressed and that is to stabilise and reduce our population.


Maude Barlow, when she spoke to Australian audiences last year, concluded with comments from US environmentalist Ernest Callenbach’s four laws of ecology: “All things are interconnected.  Everything goes somewhere.  There is no such thing as a free lunch.  Nature bats last.”#


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