More than 14,000 properties are without power due to heavy rains from Tropical Cyclone Jasper.
More than 300 people were rescued in the northeastern state of Queensland overnight, with military helicopters deployed to assist areas cut off by the floods, officials said on Monday.
Cairns, a popular tourist destination that serves as a gateway to the Great Barrier Reef, has been almost completely cut off by floodwaters amid fears the town’s 160,000 residents will soon not have access to clean drinking water.
Local officials said the town had received about 600mm of rain over 40 hours through early Monday morning, more than three times the December average.
All flights into and out of Cairns Airport, where plans have been partially submerged by floodwaters, were cancelled or postponed on Monday.
More than 14,000 properties across the region are without power, according to authorities.
In Wujal Wujal, a rural community in the Cape York region, nine people, including a seven-year-old boy, sought shelter on the roof of a hospital.
Crocodiles have been spotted swimming in floodwaters in several rural areas, including Wujal Wujal and Ingham.
The flooding follows heavy rains and strong winds brought on by Tropical Cyclone Jasper, which made landfall in Australia last week.
Queensland state Premier Steven Miles said the flooding was the worst natural disaster he had ever seen in the state.
“The problem is rain won’t stop and until it eases up, we can’t get aerial support into remote places,” Miles told the Australian Broadcasting Corporation.
Queensland Treasurer Cameron Dick has warned that the disaster will have a “billion-dollar impact” on the state.
Weather officials have forecast more rain on Monday as Jasper is expected to linger over the region.
Prime Minister Anthony Albanese said that the Australian military had been put on standby for rescue and relief efforts.