Floodwater in southern New South Wales is being called unusually slow-moving and unpredictable by those living on the riverbanks.
The state currently has 67 active flood warnings in place. In the state's south, the Murrumbidgee River is experiencing significant flooding.
Engineer Bryan Short has studied flood movements in the Riverina region for 50 years and works with local councils in flood management.
He said compared with major flooding in 2012, the current flood peaks moving down the Murrumbidgee River were taking longer to reach communities and longer to leave.
"With regards to this flow going on and on and on for a fair while the main problem is that it's been such a wet year," he said.
Mr Short said the swollen river systems did not have time to recover between releases from inland dams.
He said river levels were only able to drop a small amount before the next outflow from dams begins, leading to "extended periods of flow in the river".
"That's what's keeping it high for the past month or so."
Water NSW said predicted rainfall this week would be the third major inflow into inland the dams in a fortnight.
Narrandera, on the Murrumbidgee River, waited days for a flood peak that finally arrived on Wednesday night.
Narrandera mayor Neville Kschenka said water levels were lower than the devastating 2012 flood but more difficult to forecast.
"2012 was a much higher flood — substantially higher — but it seems to have come down in my memory in a wave and then passed through and went further downstream," Mr Kschenka said.
"This time it seems to come sporadically."
Darlington Point is downstream of Narrandera, and Murrumbidgee mayor Ruth McRae said the SES was working with the community to ensure people were well informed.
"These unexpected rain events are concerning because of the irregularity and the amounts that are falling so quickly," she said.
Differing view
Farmer Christine Ferguson has lived on a mixed-farming property on Murrumbidgee River, downstream of Gundagai, for 45 years.
She said the farm flooded every decade or so.
The most recent floods this month and in August reached nine metres, which caused moderate flooding and required cattle and sheep to be moved.
"The water receded quite quickly, but the problem will be if we get more rain this coming week," Ms Ferguson said.
"The water in the ground is so saturated so the water might stay there a little longer."
Once flooding stops, Ms Ferguson said it would take weeks to repair fencing and clean the pastures of debris.
She estimated the damage bill would be more than $60,000.
Ms Ferguson said she would not describe the recent flooding as different, apart from the heights.
"It didn't do the amount of damage that was done 10 years ago, so I think it's what I'd call a milder river flow, but of course it always does damage.
"I think they're managing the river pretty well in that you have these rain events and it's a whole new scenario."
Mr Short said the slow-moving system could prove more disastrous for farmers in Western NSW than other floods.
He said flooding on flat terrain west of Wagga Wagga was unlikely to drain for weeks, if not months.
"If water doesn't stop coming those crops will be a bit of a disaster," he said.
