Eight people have died and up to three people are missing in Queensland's "fast and furious" floods, which have damaged thousands of homes and businesses, after one year's worth of rain fell on parts of the southeast.
The Brisbane River banks have been evacuated near the CBD after a crane on a pontoon broke free of its moorings near the Story Bridge on Monday afternoon.
Police are concerned the crane could smash into the Howard Smith Wharves or damage the Story or Gateway Bridges, with a tugboat en route to try to secure it.
Emergency services are monitoring the pontoon carrying the crane which is tilting but largely stationary, with evacuation notices for the wharves and riverside walkways downstream still current late on Monday afternoon.
"It's associated with the construction of the green bridge there and has become partially compromised," Queensland Police Deputy Commissioner Steve Gollschewski told Seven Network.
A special boar tries to secure a floating crane as it comes loose near Eagle Street Pier, in Brisbane. Queensland's southeast is set to endure more wild weather as the state grapples with a days-long flood crisis. Source: AAP / JONO SEARLE/AAPIMAGE
There are also "grave concerns" for two men missing in floodwaters in inner Brisbane and at Glen Esk
Major flooding is underway on the Brisbane, Logan, Bremer and Mary rivers, and Warrill Creek ahead of another high tide on Monday night.
"We didn't know that was going to happen, this is Mother Nature,"" Premier Annastacia Palaszczuk said.
"I can't control Mother Nature, the people of this state can't control Mother Nature, and sometimes they throw stuff at us and we've got to deal with it."
Emergency services have made almost 600 swift-water rescues and responded to more than 9,000 calls since the rain began last Tuesday.
The Brisbane River peaked at 3.85m on Monday, below the 2011 flood peak of 4.46m, but it's set to rise again to 3.7m at 9am on Tuesday.
The premier estimated up to 15,000 homes could be impacted in Brisbane and around 3,600 in Gympie, north of the Sunshine Coast, with 1,544 people in evacuation centres.
Epidemiologist Hilary Bambrick is looking after two neighbours whose home is flooded, while water has also damaged her own Red Hill residence.
"Water came pouring through the wall. It was like someone had turned on a hose," she told AAP.
The Logan-Albert river has also broken its banks leaving hundreds of homes isolated and it's expected to start inundating homes on Monday night.
At Maryborough, north of Gympie, which was flooded last month, residents were bracing for flooding above the 2013 peak of 10.7m.
"Everyone's pretty much reluctantly settling into the fact that we're going to go through it again. There's not much we can do about it," Doug Cuzens, from the Maryborough Services Memorial Bowls club, told AAP.
Floodwaters in Maryborough, Queensland. Major flood alerts have also been issued for rivers in Gympie, Maryborough, Sunshine Coast, Noosa, Moreton Bay, Ipswich, the Lockyer Valley, Toowoomba, Darling Downs and the Gold Coast. Source: AAP / SUPPLIED/PR IMAGE
Schools have been closed and public transport has been mostly suspended across the southeast, while dozens of roads and major highways have been cut by floodwaters, but the Bruce Highway north of Brisbane has reopened.
Bureau of Meteorology forecaster Diana Eden said 70cm of rain had fallen in many areas in the past week, with Mount Glorious topping out at 1.5m.
"Some of the rainfall totals that we've seen over the course of this event have been approaching rainfall totals that we would normally expect over the course of a year," she said.
There have also been reports of looting in the Ipswich suburb of Goodna, where Councillor Paul Tully said up to 150 homes were facing inundation.
Prime Minister Scott Morrison said disaster assistance payments would be available for affected communities and the Defence Force would be deployed to help clean up.
The weather bureau said there could be more severe thunderstorm activity in the region from Wednesday, with damaging winds, hail and heavy rainfall.
However, it would not be as intense as the last week.
Queensland's southeast is set to endure more wild weather as the state grapples with a days-long flood crisis. Source: AAP / JONO SEARLE/AAPIMAGE
Brisbane Lord Mayor Adrian Schrinner said the floods are "very different" to 2011 because the rain pummelled the region for five days.
"We've seen incredible amounts of rain," he told ABC Radio on Monday.
"With 2011 in some ways it was a dry flood. The rain had stopped well in advance and then we had several days notice that the flood was coming.
"It is very different this time. It came very quickly and the rain was so strong, so it is a different event."
