State Water says it has started pre-releasing water from the Riverina's two main storages ahead of predicted rain over the coming days.
A cold front will cross the Riverina today, and could result in falls of between 25 and 50 millimetres of rain.
As of yesterday, Burrinjuck Dam was at 99 per cent capacity and Blowering, 98 per cent.
State Water's Strategic Assets General Manager Dan Berry says there have been increased outflows at Burrinjuck since Sunday, but the Murrumbidgee should not exceed the minor flood level.
"Blowering we've been pre-releasing the maximum rates for the Tumut River since early July, so the Tumut River at Tumut has been running at channel capacity for six weeks now and probably will continue to the the end of the month to maintain airspace," he said.
State Water says its airspace policy in its Murrumbidgee River dams ensures water security for downstream irrigators.
Mr Berry says the variable policy works well.
"The studies that were done after the 1970s floods went through and looked at having a fixed airspace policy, so setting a 95, 90, 85 per cent level and running that all year round," he said.
"What they found was that had a significant impact on water security, if you consistently kept the storage down.
"Whereas the variable airspace policy, you try and get the best of both worlds.
"That policy has been around for a while and that policy suits very well the conditions we have now, where we're getting much better forecasts from the Bureau.
"So we can confidentially pull the storages down to lower levels now, than what they did when the policy was established.
"So the policy works very well with the weather forecasts we get these days."
The management of the storages has come under scrutiny following large scale floods in the rivers downstream in 2010 and in March this year.
© ABC 2012
17:01 EST Sydney's offshore Sea Surface Temperatures (SST's) have remained above 21 degrees for the last four days.