Floodwaters continued to wreak havoc in the outback towns of Australia's Queensland state on Friday, as heavy rains following a prolonged drought swelled rivers to record high levels.

Officials at the Queensland town of St. George ordered the evacuation of homes and an aged-care centre as the town's 3,000 residents prepared for an onrush of water from the nearby Balonne and Maranoa rivers.

St. George, which lies about 500 kilometres west of Brisbane, is just the latest town in the dry deserts of Queensland state to be hit by flood waters, as record rainfall began falling in the region since the weekend.

The town of Birdsville, which lies some 1,100 km further inland than St. George, was among the first communities to be hit by record rainfall, with more than 168 millimetres falling on Sunday — about as much rain as falls annually, according to local official Scott Gander.

Heavy flooding spread to other communities in the state's southwest deserts, as formerly dry creeks and rivers filled and broke their banks.

Rains could return to some communities

The Queensland government has declared many of the areas under threat disaster areas, including the nearby communities of Charleville and Roma.

Australian meteorologists were also warning Friday that the storm responsible for the torrential rain was drifting east but could drift back west and strike the Charleville a second time.

Emergency sirens wailed for the second time in a week in Charleville on Thursday and business owners began to sandbag their stores.

Dozens of residents were expected to sleep at the local show grounds overnight, on higher ground.

With files from The Associated Press, Australian Broadcasting Corporation