A South Australian academic has supported further water buybacks, as the best way of overcoming what he says are the shortcomings of current Murray Darling Basin management.
University of South Australia Head of School: Commerce, Professor Lin Crase, says those shortcomings could turn catastrophic, if hotter, drier weather patterns escalated over coming years.
"The system is already vulnerable in numerous places and will be sorely tested with climate change," Prof Crase said.
"A 10 per cent reduction in rain equates to a 30pc reduction in stream flow, so if the system is already weakened by poor water management, it is unlikely to do well in the future."
Current Murray Darling Basin policy was built around spending public money to buy more efficient irrigation equipment for farmers, in the belief that if less water was 'wasted' in maintaining crops, more water would be left in the river system.
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Prof Crase said even without questioning whether it was being implemented fairly or effectively, research strongly suggested the policy was built on a false premise.
He said international studies demonstrated that somewhat counterintuitively, improving irrigation efficiency actually reduced water flow in a river system.
"Throughout the world, whenever schemes have been designed to make irrigation more technically efficient, the river systems dry up," he said.
"This happens because when you water a crop and supposedly 'waste' some water, that water doesn't just disappear, it actually flows back into the river system."
The alternative was to stop investing public money in irrigation infrastructure
Instead, those funds should be used to pay farmers not to irrigate, leaving the water in the river system, known as water buyback.
There are currently caps on how much water the government could buy back from irrigators.
But Prof Crase said there was substantial evidence to support recent calls for those caps to be lifted, and that doing so would benefit both the environment and MDB communities.
"Our research shows the farmers who have sold their water in the past are generally better off
"In the initial buybacks the vast majority of people were still staying on the land, they were just using the money to re-gear their businesses and set up differently, so they are less dependent on irrigation," Prof Crase said.
In the initial buybacks the vast majority of people were still staying on the land, they were just using the money to re-gear their businesses and set up differently, so they are less dependent on irrigation.
"When you drive through the Basin, you will see some communities doing well, and this is not at all related to where the subsidies on irrigation infrastructure are being spent.
"Most infrastructure projects benefit individuals, not the community at large - and the system-wide impacts on the river are a real problem.
"Buying water back off irrigators delivers environmental benefits at roughly half the cost of irrigation schemes, and the money invested goes into helping communities adapt to a different future."