NSW yesterday opened the inlet to lakes Menindee and Cawndilla in a move certain to fill the storage above the 640-gigalitre threshold for Murray Darling Basin Authority control.

Murray Bridge engineering consultant Rob Frazer welcomed the move, saying the flows into the Menindee Lakes would be too much for the 1700-gigalitre system to hold.

“It will have an impact down here, depending on how they (NSW) use it (upstream of Menindee),” he said.

“If they don’t pinch it there should be enough to fill the entire system.”

Mr Frazer said the timing was right to fill Lake Menindee as it could help minimise losses to flood plains and, coming at the end of summer, losses to evaporation.

“There’s enough to shoot some down the Darling in a controlled manner so we don’t have the losses to flooding,” he said.

He said recent flooding around the Murrumbidgee River and upper Murray was also likely to boost South Australia’s supply.

South Australian opposition River Murray spokesperson Adrian Pederick said reaching the 640GL threshold would be positive but the Government had not done enough to guarantee significant flows to South Australia.

“The (South Australian) Government have always said we can’t make it rain, well now it has rained and we’re not securing the water,” he said.

Mr Pederick said he understood NSW and Queensland were trying to secure as much water as possible while South Australia had failed to stake its claim.

A spokesperson for the South Australian Government said Premier Rann was continuing to negotiate with Queensland Premier Anna Bligh and NSW Premier Kristina Keneally to secure more water for the State.

NSW water commissioner David Harriss said filling lakes Menindee and Cawndilla would minimise flooding on private properties but could not say how much water was expected.