Science

Adapting to drought and flooding rains

Rivers are the nation's lifeblood. (Photo: Bob Beale, UNSW)
Wednesday, 18 July, 2012
Richard Kingsford *

Water defines our continent. Like crazy paving, our rivers carry it as they criss-cross the landscape, from the tops of catchments to their bottoms. It governed the distribution of our first people and their trade routes and controlled where settlers gravitated and country towns mushroomed. But these rivers never flow predictably – they boom and they bust. Australia has the most variable river systems in the world, with years between floods that can often come one after another.

We dodged an environmental bullet with the recent sequence of floods in the Murray-Darling Basin. They saved the Coorong and Lower Lakes from an ecological disaster brought on by the Millennium drought and over-allocation upstream. Creeping sulfuric acid and increasing salinity were rapidly changing this internationally renowned wetland forever. The most poignant expression of this problem was the fate of freshwater tortoises living in the lakes; the backs of their shells were colonised by marine worms and their cement cases as the salinity increased. This eventually weighed down the tortoises so much that they drowned, unable to come up for air. Primary school children vainly had working bees to chip the shells free of these worms. If the floods hadn’t arrived, Australia would undoubtedly have made the international shame list for wetland stewardship under the Ramsar Convention. We seemed to have quickly forgotten the drought, as floods wash away our memories.

Ironically the floods that saved the ecological health of the Murray-Darling are now its greatest political weakness. The proposed Murray-Darling Basin Plan, with its high ideals to restore the sustainability of this might river system, lies bruised and battered at the feet of the Environment Minister Tony Burke. Conservative governments in the big eastern states have abandoned any pretence of supporting ecological sustainability by arguing that even 2,750 gigalitres of additional environmental flow for the river represents too much of an impost on their irrigation communities. These same governments seem to have forgotten their other constituents, not only the floodplain graziers who rely on floods for their livelihoods but also their conservation responsibilities for wetlands and floodplains. Environmental water is critical for wetlands and floodplains in Victoria, NSW and Queensland.

"Rivers die from the mouth upwards"

NSW has not just gone home but also taken a few other people’s bats and balls from the game. In the last month, the State reduced its funding to the Murray-Darling Basin Authority by more than sixty %, promising more to come with a reduction to more than 70% next year. For more than a century the States have ceded responsibility for running the River Murray to the Australian Government through the River Murray Management Authority, the Murray-Darling Basin Commission and now the Murray-Darling Basin Authority. Unlike other Murray-Darling rivers within each State’s borders, cooperation made sense given the impossibility of separating Victorian from NSW water in the River Murray, which forms the border. The spat has nothing to do with the proposed Basin Plan. Sixty percent of the money withdrawn by the NSW Government was just to run the River Murray and the other 40% was to monitor its management. One of the first casualties is the Sustainable Rivers Audit, one of the only basin-wide monitoring programs, with even NSW State employees losing their role and funding. It would be no surprise to see other shareholder States and the Commonwealth arguing that NSW reduce its influence of management – perhaps irrigation water is better managed south of the border? 

The Murray-Darling Basin is no different to any of the world’s great river basins: development moves wealth upstream and costs downstream. Rivers die from the mouth upwards. South Australia battles on at the bottom of this river, arguing that the volume of environmental water in the proposed Murray-Darling Basin Plan will not deliver sustainability. It intends to argue its case before the High Court. The State is also paying for most of the externalities, assisted by the Commonwealth. The Millennium Drought and over-allocation delivered a water bill of more than $2billion dollars for dealing with acidification and environmental degradation of system. It also included having to reduce Adelaide’s reliance on the River Murray for more than half its water, through the building of a desalination plant. This water bill has taken more than a half century to arrive – a very real reminder that today’s river decisions can benefit or hurt the grandchildren of those who make them.

This land of droughts and flooding rains defines our water resources - past, present and future. The ying and yang of our capricious water environment has often been the political catalyst for governments to ‘flood-proof’ or ‘drought-proof’ the country by building dams. It is not just the building of dams that is so ecologically damaging for rivers but that the dams allow water to be regulated and diverted away from the river. An Upper House inquiry in NSW is currently calling for submissions into the adequacy of water storages or dams, explicitly considering any proposals to construct dams or increase their capacity.

". . . this problem can be partly solved by the use of nuclear explosives to create giant storage basins"

Most dams in NSW were built between the 1950s and 1970s, occupying many of the best available sites for capturing water. The 1971 manifesto of this development by the government agency in charge, the Water Conservation and Irrigation Commission, promoted the economic benefits of capturing water wasted in wetlands for productive use. In the preface, there is an admission: “Limitations on storage sites and the magnitude of occasional floods make it inevitable that a large proportion of the surface flow will continue to occur as unregulated discharge.” The following sentence captured the development sentiment of the time and possibly an active imagination. “It has been suggested that this problem can be partly solved by the use of nuclear explosives to create giant storage basins in the level areas where no conventional storage structures are possible.” It will be interesting to see what the Upper House comes up with this time.

It’s time to take stock of the lessons of history, particularly in the Murray-Darling Basin, as we plan for a future where our population is predicted to reach 35 million by 2050 and the world population rises well beyond its current seven billion. In the global market, our rivers are fair game. Virtual water is now the global currency for measuring how water moves through markets in the production of goods and services, particularly irrigated food and fibre, such as cotton. We export a substantial amount of virtual water. Like most natural resources, river water is cheap to develop and to appropriate, and is often highly subsidised by taxpayers through the building of dams and management of rivers. But the public picks up environmental costs not adequately dealt with by the market, often decades or more later – the so called externalities. Look at the $10billion bill for restoring the Murray-Darling.

Natural floods bring enormous environmental benefits but also poorly understood economic gains. Mostly our news coverage screams disaster, neglecting the long-accumulating and essential positive effects of flooding in rivers and for rural communities. For example, the fourth year of flooding in a row in the rivers of Lake Eyre gives a lie to its labelling by some early explorers as the dead heart of the continent. The Lake and its feeder rivers are brimming with life, disgorging their life-giving water onto vibrant floodplains, providing homes to countless organisms and delivering ecosystem services as lush grazing to grow organic beef for niche markets around the world. Money is also pouring into the outback towns of Innamincka and Birdsville, as tourists flock to see Lake Eyre and its rivers with water. In the tropics, rivers predictably tumble down steep escarpments during each year’s wet season to flood expansive floodplains such as those in Kakadu and the Daly River before pouring into the ocean. Northern Territory tourism thrives on floods, whether for spectacular waterbird concentrations in Kakadu, monster saltwater crocodiles or rich barramundi fishing. 

". . . Prime Minister Gillard promoted Australia's opportunity to become the food bowl of Asia"

Australia’s tropical rivers hold 60% of the continent’s freshwater, often labelled as wasted. Unsurprisingly, they have become Australia’s next great frontier for river development. The Howard Government established the Northern Australia Land and Water Taskforce, chaired by Senator Bill Heffernan, to ostensibly identify irrigation opportunities on Australia’s tropical rivers. The political push has continued with injection of millions of dollars by the Federal and Queensland governments into an irrigation precinct on the Flinders and Gilbert Rivers which flow into the Gulf of Carpentaria, in northern Queensland.

Irrigation is well established on the Ord River and early developments are under way on the Daly River. Speaking at the Global Foundation summit in May this year, Prime Minister Gillard promoted Australia’s opportunity to become the food bowl of Asia; development in northern Australia would undoubtedly underpin this goal. There is little discussion of potential long-term ecological or financial costs.

The salutary lesson about history is that it often repeats itself. The last major river to be developed in the Murray-Darling Basin was the Condamine-Balonne river system, for which the Sydney Harbour-sized dams of Cubbie Station have been demonised. The Queensland Government of the mid-1990s argued that it should be allowed to develop its rivers as the southern states of NSW, Victoria and South Australia did. It refused to sign the mid-1990s cap on diversions from Murray-Darling Basin rivers. Within government circles, Queensland promised that State-sanctioned water development of the Condamine-Balonne would be sustainable, unlike other rivers of the Murray-Darling.

"It is not easy to lose a river in a mere 10 years, but this was achieved . . ."

A similar argument was running in the international community on Brazil’s right to cut down its Amazonian forests as rich European countries and the United States had done in centuries before. Like reformed smokers, these countries pointed out the inevitable environmental costs of such a policy; the southern States tried the same tack to educate Queensland but to no avail. It is not easy to lose a river in a mere 10 years, but this was achieved with expansive development of irrigation infrastructure. It will inevitably mean the demise, over the next century, of much of the million hectares or more of floodplain downstream in Queensland and NSW on the Condamine-Balonne river system. You can’t unscramble such eggs.

We will alter many of our pristine tropical rivers if irrigated agriculture in the region is to form the centrepiece of Australia’s drive to be the food bowl of Asia. Much of the world’s food and fibre is grown using water from rivers for irrigation. We will inevitably repeat many of the mistakes of the Murray-Darling Basin. Tropical Australia is one of the world’s last wildernesses, dissected by 65 rivers, each with more than 40 native fish species and few invasive species. Contrast this with the Murray-Darling Basin where about 30 native fish species are overrun by European carp - the rabbit of our waterways. Contrary to popular opinion, the waters from our rivers are not wasted in wetlands or out at sea. They supply water to floodplains, estuaries and marine ecosystems, including underpinning a tropical prawn fishery valued in the hundreds of millions of dollars each year.  

There is a poorly understood rear-guard action across the country to stop development of Australia’s rivers. This action is not led by so called latte-drinking and chardonnay-quaffing greens of inner Sydney and Melbourne, but by the graziers and indigenous people of the outback. The result is a growing list of rivers with no-irrigation development signs from the tops to their bottoms and governments are generally falling into line. Many of these people watched in despair at the fate of the might Murray-Darling Basin rivers, firming in their commitment to protect their river environments and the ecosystem services they derive from them. There is widespread recognition that we need better models to protect our freshwater ecosystems around the world, which have lost as much as 40 % of its freshwater biodiversity since the 1970s. Protecting rivers from the building of dams, contamination by mining and urbanisation remain the primary ways of maintaining sustainability.   

Australia should be leading the world in water management but we have a long way to go. Even though we live in the world’s driest inhabited continents, we are profligate with our water use. In 2010, we had the highest per-capita level of water use of anywhere in the world, exceeding two million litres a year. Our cities will continue to grow as will our demand for fresh water. Development of our tropical rivers will push our per capita use of water higher. The choices are stark: we either build more dams or learn to be clever and reduce demand for water and improve storage of run-off in cities. The latter will be a path to sustainability and the former will just increase our water footprint. Sustainability will inevitably maintain our unique continent’s reputation as a land of flooding rains and droughts. It’s high time we learned to adapt to that, rather than failing time and time again to try to make it adapt to us.

 

​Professor Richard Kingsford is Director of the Australian Rivers and Wetlands Centre and Professor of Environmental Science in the UNSW School of Biological, Earth and Environmental Sciences. This is an edited text of the Eric Rolls Memorial Lecture, which he was invited to give last night at the National Library of Australia, in Canberra.