CANBERRA (Reuters) - Drought in Australia's main food growing region of the Murray-Darling river system has worsened, with water inflows over the past two years at an all-time low, the government's top water official said on Tuesday.
The drought will hit irrigated crops such as 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.
The rainfall is sufficient to support hopes for a strong wheat harvest, but not enough to replenish ground water, which troubles those farmers who grow fruit rather than grain.
The record drought, which has gripped much of the country for close to a decade, was the worst in 117 years of record-keeping, with 80 percent of eucalyptus trees already dead or stressed in the region as large as France and Germany combined.
"It seems to me from what we've seen to date, there's no indication that it's going to end in the immediate future," said Wendy Craik, chief executive of the Murray-Darling Basin Commission which controls water use and flows in the rivers.
Average rainfall allowed many wheat farmers to plant crops in July, but had not reversed seven years of inflows at their lowest level since 1900, with a dry spring likely ahead, said Neil Plummer, the Acting Head of the National Climate Centre.
"What we really need to make some inroads in the situation is a big wet, and what our weather models aren't showing is a strong likelihood of a big wet over the next few months," Plummer told reporters in Canberra.
The July rains kept alive hopes of a good wheat harvest, with Australia forecast to recover from the last two drought years to boost the national 2008/09 wheat harvest to around 23.7 million tons, according to the official Australian Bureau of Agricultural and Resource Economics (ABARE).
Last year's crop was just 13.0 million tons and a farm forecaster this week said September would be a "make or break" month for crops sown this winter.
The Murray-Darling accounts for 41 percent of Australia's agriculture and provides A$21 billion ($17.8 billion) worth of farm exports to Asia and the Middle East. Around 70 percent of irrigated agriculture comes from the basin.
The drought has already wiped more than A$20 billion from the $1 trillion economy since 2002.
Craik said August rainfall was below average and inflows to dams and rivers during the month was only 275 gigaliters (GL), less than a fifth of the long-term average of 1,550 GL.
Dam storages, relied upon by food bowl irrigators heading into the spring and fierce Australian summer, were only 20 percent of capacity.
"The outlook for the Murray system remains very serious. Critical human needs can now be met through to next winter, but water availability for irrigation remains very low," Craik said.
Slowly warming temperatures, she said, were exacerbating the long dry, with climate scientists warning that every rise of 1.0C reducing river inflows by 15 percent in what was already the world's driest inhabited continent.
"Even with average rainfall, you won't get average inflows and the catchment dries out significantly. When it does rain in winter, we don't get the run-off that we used to," Craik said.
Plummer said the only bright spots on the climate horizon were benign neutral conditions in the Pacific and Indian oceans, which both strongly influenced Australia's weather patterns.
"That doesn't necessarily mean there will be average or above average rainfall," he said.
Reporting by Rob Taylor; Editing by Clarence Fernandez