THOUSANDS of Australians were forced to abandon their homes yesterday as a record deluge swept through areas still reeling from last year's devastating floods, claiming its first life.

Police ordered the 3,800 residents of the town of St George, in northern Queensland state, to evacuate as rising floodwaters raced towards record heights, threatening to cut the one remaining exit road.

In the town of Roma, further north, a woman whose car was swept from a flooded roadway became the disaster's first official victim, with searchers finding her body two days after she went missing. "Residents of St George are required to evacuate by road before the Moonie Highway is cut by floodwaters, which is expected to occur sometime in the early part of Sunday evening," police said in a mandatory evacuation order.

"Air evacuation to Brisbane is being organised to ensure evacuations can proceed after the Moonie Highway closes."

Police doorknocked every home in town to deliver the order and are permitted to use reasonable force if people refuse to leave, with mayor Donna Stewart warning resident safety could no longer be guaranteed.

"It's pretty panicky here," said St George resident Angela Doran.

"I think everyone just wants to get out now."

The swollen Balonne River, flooding for the third time in less than two years, was expected to peak at 15 metres (50 feet) on Tuesday night, far exceeding the previous record of 13.4 metres set in March 2010.

"This is a very serious situation and I urge people to cooperate," said Queensland Premier Anna Bligh.

Prime Minister Julia Gillard dispatched a military transport plane to airlift patients from the town's hospital to the coast, and the local nursing home was also being emptied.

Eight defence helicopters are already helping search and rescue efforts in the flood zone, winching people to safety and dropping food, bedding, medical supplies and other essentials such as generators.

St George has seen major flooding twice in the past two years, once in March 2010 and again last year during Queensland's flooding disaster, which claimed 35 lives and swamped vast tracts of farmland and tens of thousands of homes.

Deputy Queensland police commissioner Ian Stewart said the situation in the region had "deteriorated" overnight with "very large spikes" in water levels south of Roma, where 200 homes flooded earlier this week.AFP