Yahoo News 24 Nov 08;
SYDNEY (AFP) – A new report revealed on Monday the devastating effect of settlement, irrigation and Australia's long-running drought on one of the country's biggest rivers.
The assessment of the Murray-Darling Basin -- known as the "food basket" of Australia because of its high level of farming -- found that water flowing to the mouth of the Murray River had dropped from more than 12,000 gigalitres a year 200 years ago to below 5,000 gigalitres.
"Integrating the flow impacts down through the connected rivers of the basin shows that total flow at the Murray mouth has been reduced by 61 percent; the river now ceases to flow through the mouth 40 percent of the time," it said.
The Commonwealth Scientific and Industrial Research Organisation report found that the basin, which covers more than one-seventh of mainland Australia, has been subjected to extensive clearing of native vegetation.
Water flows along the basin's three rivers -- the Darling, the Murray and the Murrumbidgee -- had been impacted by the construction of dams and the diversion of water for irrigation, stock and domestic uses, it said.
The report's lead author Tom Hatton said flows to the Murray's mouth could be down by 80 percent by 2030 unless changes were made.
The report found that while the impact of climate change was uncertain, water availability across the entire basin was more likely to decline than to increase over the next two decades.
The Murray-Darling Basin generates more than 40 percent of the gross value of Australian agricultural production and uses 60 percent of all irrigation water in the country.
