Mass evacuations were under way in northern Australia on Sunday as record flooding that has cut off thousands of people threatened to engulf areas devastated by wild weather last year.
Authorities urged residents of St George, a town of 3,800 people in the state of Queensland, to leave their homes as rising floodwaters threatened to isolate the area, with time running out to shore up a levee.
"Significant rises upstream indicate possible above record levels by midday Monday with further rises possible," officials said in an emergency alert to the town.
"Residents are strongly encouraged to self-evacuate to areas not affected by flood waters via the Moonie Highway while that access is open and remains available."
St George has seen major flooding twice in the past two years, with the swollen Balonne River hitting a record 13.4 metres in March 2010.
The town was swamped again during last year's unprecedented flooding emergency, which claimed 35 lives across the state, wrecked vast tracts of farmland and inundated tens of thousands of homes.
Deputy Queensland police commissioner Ian Stewart said the situation in the region had "somewhat deteriorated" overnight with "very large spikes" in water levels south of Roma, where 200 homes flooded earlier this week.
"We are working on our contingencies to manage the evacuation of areas south of Roma and in particular St George," Stewart said.
"There are very large volumes of water in those systems getting to record levels."
Stewart said there was still time for residents to flee but forced evacuations were being "very seriously" considered to ensure resident safety.
The bureau of meteorology said St George was expected to reach the 2010 flood level by tomorrow morning and "continue rising, possibly above 14 metres on Tuesday and Wednesday."
Canberra dispatched eight military helicopters to the flood zone yesterday to help with search, evacuation and resupply efforts, as huge rains swept across two eastern states.