The city has already been badly hit, with many people being forced to flee.

More than 20 towns have already been cut off or flooded across an area larger than France and Germany, with more than 200,000 people affected.

Earlier, a woman swept from the road in her car has become the first victim of the widespread flooding, and at least two others are reported missing.

While waters are receding in some areas, in Rockhampton - a city of 77,000 - they have yet to reach their peak.

Floodwaters are expected to reach nine metres (30 feet) on Monday and peak at 9.4 metres on Wednesday, threatening as many as 4,000 homes.

Rockhampton's airport, a major regional hub, was closed to commercial traffic due to flooded runways, while many main roads and railways into the town had been cut off, and power supplies were disrupted.

The city could be isolated for up to 10 days, reports say.

"These waters are exceptionally fast, they're not to be trifled with and they're not to be taken lightly," said Alistair Dawson, Queensland's assistant police commissioner.

Meanwhile, the weather bureau has warned Queensland residents of another severe storm, which is forecast to bring "damaging winds, very heavy rainfall, flash flooding and large hailstones".