Residents in Queensland's North and South Burnett regions are watching creeks and rivers rise, with about 100 people isolated after heavy rain.
More then 30 residents spent last night in evacuation centres in Kingaroy and Murgon as a precaution.
South Burnett Mayor Wayne Kratzman says if the catchments keep filling there will be flooding.
"Stuart River overnight has risen substantially downstream at Proston and that rise is a bit of a worry," he said.
"Of course, Lake Boondooma is full to the brim."
He says more rain would be devastating.
"Normally after a flood event you wake up to blue skies, but that's certainly not the case in the South Burnett this morning," he said.
"We are concerned about any further rain which will cause huge problems."
In the North Burnett, Three Moon Creek is still rising and the road to Biloela is closed.
North Burnett Mayor Don Waugh says authorities are trying to get milk trucks to about 12 isolated dairy farms in the Monto area.
"What we are looking at doing this morning is getting access to the milk farms there so we can get a pick-up," he said.
Several residents in low-lying areas around Monto were evacuated from their homes late yesterday.
Heavy rain in catchment areas in the Bunya Mountains caused some concern for residents in low-lying areas, but authorities say Gordonbrook Dam has dropped half-a-metre overnight.
More than 20 roads remain cut at Kingaroy, Murgon, Cherbourg and Nanango.
Meanwhile, residents in low-lying parts of Maryborough will be asked to evacuate their homes this morning as a precaution.
Access to the Granville Bridge at Kent Street was cut last night and the Lamington Bridge is also blocked.
The Mary River is expected to peak early at around seven metres tomorrow morning.
© ABC 2013
15:24 EST The weather bureau has implemented a new system of forecasting the seasonal outlook called Predictive Ocean Atmosphere Model for Australia, or POAMA.