Thousands of people in the NSW central west may be forced to evacuate as inland rivers across the state rise, fuelled by days of torrential rain.
Of prime concern to authorities is the Lachlan River, with more than 8000 people in the town of Forbes in the path of the floodwaters, which are rising upstream.
The Bureau of Meteorology has predicted major flooding on Tuesday, with the river to on Wednesday morning peak at level similar to or higher than the September 2016 floods.
Moderate flooding is occurring at Cowra, where the waters have peaked, while downstream Nanami is experience major flooding, with waters to peak in the next 24 hours.
The river level is higher than the September 2016 flood peak but lower than that of August 1990.
It's too early to tell how high the floodwaters will reach in Forbes, the BOM says, but the State Emergency Service has warned locals in up to 800 homes to prepare to leave before they hit the town.
SES Superintendent Greg Swindle says volunteers and the community are well prepared.
"The community in Forbes are resilient. They've been preparing for this," he said.
Downstream from Forbes, major flooding is also expected at Cottons Weir and Jemalong from Monday.
The affected communities have been lucky to have time on their side, BOM hydrologist Justin Robinson said.
"One fortunate thing about the floods in western NSW is that they're a slow moving, evolving event," he said.
"Hopefully that we'll be able to provide them adequate warning and leave time for them to prepare ahead of the floods actually arriving and impacting their personal properties and communities."
St Andrews Church in Forbes has been set up as an evacuation centre as residents are urged to be on high alert for an SES evacuation text message.
Volunteers in the area have been kept busy already, with more than 100 calls for help, mostly for sandbagging and leaking roofs.
But across the state, since the downpour started last week, the SES has responded to 1500 calls for help, after high winds combined with rain caused widespread havoc, particularly in Sydney's Hills district, the Blue Mountains and the regional city of Wagga Wagga.
Moderate flooding is also occurring along the Belubula River. Levels peaked at Canowindra on Sunday afternoon and are now falling.
Flood levels along the Macintyre River are also easing following minor to moderate flood peaks on Sunday afternoon in the Boggabilla and Goondiwindi area.
Meanwhile minor flooding is occurring along the Snowy River at McKillops Bridge and Basin Creek, extending downstream to Orbost.
Minor flooding is still expected along the Macquarie River at Warren Town and the Paroo River at Willara Crossing, but is also possible along the Namoi River at Bugilbone and Goangra.
While most of the wet weather has eased, BOM meteorologist Agata Imielska said it marked only on the begging of a soggy summer for much of the state.
"Most of NSW and the central west region that we're talking about has already received its (average) November rainfall - for some of those locations, even two to three times what you would get in November," she said.
"Catchments are wet, dams are full. This is exactly what we've been talking about for this season, with the elevated flood risk.
"It is a really important time to really be keeping very close eye on any flood warnings."