The government provided two Blackhawk helicopters to help evacuate all 300 residents from the town of Theodore, one of the worst affected by the floods. The Theodore River remained at high levels Wednesday, with only police and essential services personnel staying in the town, the Queensland government said.

Queensland Emergency Services Minister Neil Roberts said Theodore was one of about 20 communities that had to be evacuated because of the floods.

Major flooding is now heading toward two cities - Rockhampton, a city of 50,000 on the coast, and the central city of Emerald, with 15,000 residents, he said.

Forecasters have said the weather will clear over the next 48 hours, Roberts said, but the heavy rain the area has had so far means water has built up in river catchment areas.

"It does take a day to three days, in some instances, for that water to come down in some of the cities that are under threat, so we're over the worst of the rain, but some of the worst flooding is still yet to come," he said.

The Bureau of Meteorology said flood warnings remained in place for many areas of Australia, with major and moderate flooding still occurring throughout much of Queensland's southern half.

Thirty-one of Queensland's 73 communities are now receiving government disaster assistance, Prime Minister Julia Gillard's office announced.

Acting Attorney General Brendan O'Connor said the government would continue to monitor the situation in disaster-declared areas across Australia and work with state authorities to provide more assistance.