The Murray-Darling River Basin in southeast Australia is suffering its worst drought on record. The crisis has forced Australians to change how they use water.
 | Umberumberka Reservoir, New South Wales, AustraliaStarved of water from the drought-stricken Murray-Darling river system, reservoirs in southeast Australia are at their lowest levels ever (Photo: Murray-Darling Basin Commission) |
The bleached bones of an emu lie on cracked earth, just steps from a pond of muddy water. But this is not a desert in the Australian outback; it's what's left of the Umberumberka reservoir in New South Wales, Australia's most populous state. The scene is proof of the country's worst ever drought.
Umberumberka's water usually comes from the Murray-Darling river system that winds through Victoria, New South Wales, South Australia, and southern Queensland. Three and a half million Australians depend on the river basin, which is also the breadbasket of the country, producing everything from wheat to wine grapes.
But the basin is in crisis. The last two years have seen the lowest inflows into the Murray River since records began 116 years ago. Declining rainfall and rising temperatures are to blame. In order to survive, communities in the basin are adapting.
Water Rations
The Murray-Darling has suffered droughts before. The authorities responded by building dams, weirs, and other water storage facilities, culminating in the massive Snowy Mountains Scheme in the 1950s and 1960s that diverted water from east to west. But without rain, these facilities, like Umberumberka, are now running dry.
"We can't expect the river system to recover to where it was 50 to 60 years ago," says Ray Najar, general manager of the Murray-Darling Association. "We have got to plan on a system with much less water."
To that end, Australia's state governments have agreed water-sharing arrangements, and water is now rationed between government and private-sector users in a system of allocations ranked from ‘high-security' drinking water to ‘low security' water for cotton farming.
People don't have individual water rations, but there are restrictions on watering lawns and filling swimming pools. More households are using shower water and dishwater in the garden, and installing efficient showerheads, taps, and rainwater tanks. So, while people's lifestyles have not changed radically, they have adapted their water use.
Efficient farming
Farmers use about three quarters of the Murray-Darling's water. Now farmers' rations have been slashed. They can, however, save unused allocations for the following year. Farmers can also trade their water.
This has transformed dairy farmer Steve Mills' business. To grow one ton of feed, he needs one megaliter of water. Now, for the price of one megaliter, he can buy three tons of feed. "We will not return to irrigating perennial pastures," he writes in a report for the Australian Bureau of Agricultural and Resource Economics.
 | Picture Gallery (click on the image to start)See examples of how we can adapt to a changing climate |
Strict rationing has also forced cotton and rice growers to retrench. This year saw the smallest rice crop ever, closed mills, and lost jobs. By contrast, this year's grape crop is estimated to be near record levels. Yet vineyards have never had less water. How have they done it?
"A high degree of adaptation," says Wendy Craik, chief executive of the Murray-Darling Basin Commission, which manages the basin's water. "They have replaced some vines with more drought-tolerant ones. They have not grown grapes on less valuable vines. They have used more drip irrigation."
The most advanced farmers drip irrigate while measuring "soil tension" to judge when to irrigate. Ray Najar says that instead of using ten megaliters to grow one hectare of grapes, some vineyards now use only four.
Despite these advances, many question the sustainability of farming in the Murray-Darling Basin. Not all farmers use water efficiently. The federal government therefore plans to buy back three billion Australian dollars of water rights from farmers, in some cases from whole farming communities. Some politicians want compulsory buybacks, but Najar thinks small farmers will leave anyway because they cannot afford to adapt. If one in four farmers quit, that would be "about right," he says.
Management and manipulation
The Murray-Darling Basin Commission battles its mortal enemy - evaporation - by stopping river water flowing into low-lying, hot wetlands. Wendy Craik says that over two years, these measures have saved 35 to 50 gigaliters, enough water to supply Canberra for more than a year. The Commission also holds water behind dams in mountain areas.
"It is about being more flexible," Craik explains. "In winter there is less irrigation, so we slow the river. If we are expecting rain, we empty weirs so we can catch new water."
The Commission is not all-powerful, however. People hoard water, and in some areas, there is more private storage than public. "Everyone is grabbing their bit, and because it is in shallow storage in farmers' backyards, it evaporates quickly," says Ray Najar. "We need a massive rethink about private on-farm storage."
Najar supports another radical response: climate manipulation. For four years, Snowy Hydro Ltd., which runs the Snowy Mountains Scheme, has been firing silver iodide into the clouds above the Australian Alps to see if it increases snow and rainfall. Although the trial is incomplete, Najar says that "cloud seeding" can increase precipitation. "It is not necessarily an increase in total rainfall but an increase in the intensity," he says. "Whereas a light shower soaks into the ground, a heavy shower increases runoff into rivers."
An even more ambitious solution would be to bring water from monsoon-fed northern Australia to the southeast, via a pipeline perhaps. As water becomes scarcer and its price rises, this could become an attractive option. But not realistic, says Wendy Craik, because it would be too expensive. Najar agrees: "It is better to lead people to the water rather than taking water to the people."
Australians will need some persuading to abandon the relatively benign climate and prosperity of the southeast for the less-developed, tropical north. Indeed, the federal government is investigating ways to offer land rights in the north to migrants from the south. But if the Murray-Darling drought continues, they may have little choice but to take up the offer.
editor: James Tulloch
publishing date: September 02, 2008
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