Green Myths of the Murray-Darling

Ten years ago, almost 40% of Australia’s agricultural production, worth $15 billion, came from the 14% of the continent that is the Murray-Darling Basin.  The productivity of the region owed a great deal to the 2%-or-so of its area that was irrigated.  But in recent years governments have reduced the availability of water for irrigation, leading to a decline in agricultural output. 

In broad terms the average – though highly variable – annual flow along the Murray-Darling river system is about 24,000 gigalitres.  About half of this until recently was used for irrigation, though only 7,000 gigalitres was “high security”, offering irrigators a reasonably certain availability.

The irrigation and the controls introduced tamed a river system that once periodically flooded a great deal of its basin — floods that were followed by a river reduced to a trickle as drought replaced torrential rainfall.  For most of us the thriving agricultural-based environment must surely be regarded as a great improvement on the area’s natural state.

However, this is not the view of the activist green lobby hostile to modern agriculture and its use of water.  Salinity and increasing the flow to the sea to prevent the mouth closing were the original causes around which the activists recruited broad support to mount their attack on farming.  Ironically, in seeking increased flows to the sea, environmental activists were striving to modify the natural state of the river. Barrages were built to keep out the sea and convert a brackish river mouth into one of fresh water.

With regard to salinity, in a series of reports in the early 1990s, groups like the ACF and WWF alleged that salt intrusion as a result of irrigation was doing irreparable damage to the Basin’s environment and future farm output.  The ambit claim was to reduce annual irrigation usage by some 7,000 gigalitres.  In 2001, an official government report claimed that salinity brought costs of $294 million, setting in train the present Basin Salinity Strategy under which 2,700 gigalitres of irrigation water is to be “returned to the environment”.

The reports on which these various claims were made presented no evidence of increased salinity.  Instead, the public was confronted with alarmist assertions and fabricated numbers forecasting a dire future. In fact, the record clearly shows salinity declining steadily from the 1970s.  Salinity in the region is caused by natural outcrops of salt — the Darling itself was originally named Salt River by the explorer Charles Sturt in 1829.  The salinity itself is readily reduced by engineering works and little is now heard about this as a rationalisation for curtailing irrigation.

Instead, without skipping a beat, those targeting irrigated agriculture morphed their case within the global climate-change scare.  The contention was that global warming would mean sharply reduced rainfall within the region and less would be available for irrigation.  Those claims appeared to be corroborated by the “Millennium Drought” which ran from 1997 to 2007.  The infamous Garnaut Report claimed that half the Basin’s agricultural production would be lost by 2050 as a result of global warming.

That drought having broken, it is now recognised as having been just another example of the normal, inconstant nature of the Australian climate.  There is no evidence of a long-term decline in rainfall across the Basin.  Meanwhile, we have policies in place that, on some estimates, have reduced the region’s output by 20 per cent.  The irrigators themselves have been compensated in the purchase price they received and the associated lift in the value of their on-going water rights.  But the program has had a devastating effect on once prosperous local communities, and this at a time when Australian agriculture is well placed to take advantage of increased export demand. Yesterday (January 30) came an announcement of partial closures of rice mills in the region, one outcome of this diversion of water from irrigation.

The Murray-Darling Basin Authority and its associated regulatory machinery, like other such bodies, once in place develops an inertia that, even when it has a negative value, makes it difficult to dismantle.  But at least we should make a start by stopping further purchases and expenditures in the Basin, and by starting to re-sell the water that has been purchased from irrigators.  The “high security” water the Commonwealth has bought would command some $4 billion if sold back to the farmers.

Such a start must be made or Garnaut will have been proven correct (but for the wrong reasons) when, in his eponymous report,  he claimed that global warming would mean the end of irrigated agriculture.  Unless we abandon the present strategy of constraining irrigation water supplies, the hysteria generated by claims of global warming risk will become a self-fulfilling prophecy.

Alan Moran is a Director of the Australian Environment Foundation and was the main author of its submission to the Senate Select Committee Murray-Darling Basin Plan