Three people have died and hundreds of homes are under water on Monday after heavy rain brought flooding to parts of the Australian state of Queensland.
Bundaberg is expecting its worst floods ever - a mass evacuation is under way in part of the city, but hundreds of people are feared stranded.
In the state capital Brisbane, nearly 5000 homes and properties are at risk, while more than 200,00 people are without power throughout the state.
The rain was brought by tropical cyclone Oswald, which is now affecting the northern part of New South Wales where more than 2000 people have been isolated, a number of roads have been closed and 6000 homes are without power.
Bundaberg Mayor Mal Foreman said the floods would be "far worse" than those of 2011, which left 35 people dead across Queensland, with Bundaberg among the areas affected, the BBC reports.
The Burnett River in Bundaberg is at record levels and has broken its banks on Monday.
Authorities have told residents of North Bundaberg to evacuate immediately. Police Superintendent Rowan Bond said there was "an imminent danger of people being killed and drowned".
At least 1200 properties have flooded and State Premier Campbell Newman said up to 1500 people may still be stranded.
Mr Newman said 14 helicopters were at work plucking people from rooftops on Monday, but that more were being brought in. He urged stranded people to group together and ensure less mobile people were not left behind.
Residents of the Lockyer Valley, the scene of deadly flash floods in 2011, have also been told to evacuate as creeks and rivers rise.
The town of Gympie has been cut off and dozens of businesses are underwater, the ABC reports, while hundreds of homes are threatened in Ipswich, where the Bremer River is expected to peak later in the day.
The flooding has claimed three lives to date. Police said the body of an elderly man who went to check on a yacht north of Bundaberg had been recovered on Sunday. Two men swept away by flooding in separate incidents in Queensland were also found dead on Monday.
New Zealander Kate Smith, who lives in Bundaberg, told Radio New Zealand's Checkpoint programme that residents are bracing for the worst on Monday.
"Five kilometres to my left around the ring road I know that 70 percent of north Bundaberg is preparing to actually lose houses, not just have houses flooded. "
On Saturday afternoon and evening, five mini-tornadoes ripped through the coastal region near Bundaberg, injuring more than a dozen people, damaging 250 homes and destroying two in Burnett Heads.
Brisbane braced for flooding
Brisbane, Ipswich and other centres in Queensland's south-east are preparing for their own flood threats.
Authorities say parts of Brisbane and Ipswich will flood on Monday night, but the levels will not be as devastating as they were in 2011.
Brisbane is expecting a 2.6-metre flood peak, a little over half of the 4.46m peak in 2011. The Ipswich peak is expected to be 5 metres less than the 19.4m level in 2011, AAP reports.
The worst of the projected flooding would be seen further downstream about noon on Tuesday, with another peak expected at noon on Wednesday.
New South Wales warnings
Hundreds of people have been isolated by floodwaters in northern New South Wales as people in state are told to prepare for 100km/h winds and flash flooding from ex-tropical cyclone Oswald.
The State Emergency Service said on Monday it has received more than 1500 calls for help and 2000 people are cut off by flooded rivers.
SES deputy commissioner for the state Steve Pierce says rescue teams are gearing up for a challenging 24 hours.
Meanwhile, winds of up to 140km/h hit parts of the northern rivers while flooding on the Bellinger River upstream of Thora had left about 500 people isolated on Sunday.
Another 800 people were isolated by flooding on the upper Clarence River at Ewingar and were expected to be cut off for two or three days.