The Queensland premier says he will likely call in the army to deal with the state's unfolding flood crisis.
Southeast Queensland remains on alert after six tornadoes damaged homes and businesses in the Bundaberg region in the past 24 hours.
And hundreds of homes are at risk of flooding in the central Queensland cities of Gladstone and Bundaberg.
Floods are also expected at Gympie and Maryborough.
Brisbane, the Gold and Sunshine coasts, and northern NSW are also on flood watch as the low pressure system that was Cyclone Oswald tracks south.
Premier Campbell Newman inspected tornado damage at Bargara, near Bundaberg, today and said emergency services were being stretched by simultaneously unfolding emergencies.
He said the army would likely be called in to help authorities, with the Brisbane-based 7th Brigade on standby to provide support.
"The challenge now is that we've got multiple events going on," he told reporters.
At Gympie, north of Brisbane, residents are being rescued from rooftops.
A 27-year-old man is missing in floodwaters after trying to cross a flooded creek near Gympie. Two other people were rescued but a swiftwater rescue team lost its boat in the operation.
The city's CBD is expected to flood later today as the Mary River rises towards an expected peak of 17 metres - just shy of levels reached during the devastating 2011 floods.
"We have people on rooftops in Widgee and Sexton and we have a swiftwater rescue team currently deployed in Widgee," Mayor Ron Dyne told AAP.
"At this stage, we've got major concerns.
"Everything's occurred rather rapidly given the amount of rain we've had ..."