By Rob Taylor
Despite good autumn rains, June inflows into the river basin were the lowest in more than a century on record and climate experts are tipping a 60-70 percent chance of below average rain in the next decade, with the year ahead likely to be a "shocker".
The drought will hit irrigated crops like rice, grapes and horticulture the hardest, but would have less impact on output of wheat, which depends largely on rainfall during specific periods and is on track to double after two years of shrunken crops.
"Regrettably, the drought is getting worse," said Wendy Craik, chief executive of the government's overseeing Murray-Darling Basin Commission, revealing June inflows were only 95 gigalitres against a long-term average of 680gl.
"If the sort of climatic regime we've had in the past couple of years becomes a feature of the future, it's pretty clear we don't have the volume of water available that we've had in the past. Clearly the basin is not going to be the same," Craik said.
After good early rains, which briefly eased Australia's worst dry spell in 100 years, dry weather has set in again in the past three months, plunging more rural areas back into drought.
The Murray-Darling, an area the size of France and Germany, produces 41 percent of Australia's agriculture and provides A$21 billion ($20 billion) worth of farm exports to Asia and the Middle East. Some 70 percent of all irrigated agriculture comes from the sprawling region.
Wheat is grown throughout areas surrounding the basin and the brief wet spell prompted many growers to "bet the farm" on a good season, hoping another brief break in the long dry will come at the right time for a bumper harvest.
Although the June dry spell forced analysts to revise down their initial forecasts for a near-record crop, current expectations for a harvest of about 23 million tonnes would be well up from 10-13 million tonnes over the past two years.
Neil Plummer, Senior Climatologist at Australia's National Climate Centre, said rains barely dented the drought, or the one-in-two chance of a dry year ahead. As well, long-term trends now pointed to 6-7 years of below average rain each decade.
"Autumn can only be described as an absolute shocker in terms of climate conditions for the basin," Plummer said.
Craik said while the basin was expected to have enough water for critical needs in the coming year, many irrigators would face zero or near-zero water allocations and environmental river flows would be slashed to a bare minimum.
The warming outlook for what is already the world's driest inhabited continent would also force hard decisions on river use, with the water needed to save threatened lakes more than the total extracted last year by basin irrigators, she said.
The government's top climate adviser, economist Ross Garnaut, last week said the Murray-Darling could be devastated by climate change without global action, with irrigated agriculture slashed by 92 percent.
The current drought has already wiped more than A$20 billion from the economy since 2002.
But Craik said growers were proving surprisingly resilient, pointing to barely changed grape harvests last year, which dropped from 1.9 to 1.8 mln tonnes as farmers introduced more water-efficient cropping systems.
"Farmers can be incredibly adaptable," she said.
(Additional reporting by Michael Byrnes; Editing by Jonathan Leff)