At least two people are dead and searches continue for others missing after the inland city of Toowoomba was hit by an extraordinary deluge.
Cars and houses were swept away in the torrent in normally inconsequential West Creek, which flows though the heart of Toowoomba. The region's mayor, Peter Taylor, said the floods were unprecedented.
Almost exactly 12 months ago the city's three dams were in crisis, holding just 7 per cent of capacity, he said.
Even before Monday's deluge all three were overflowing.
The event broke the main water main into the west of the city, but repairs were quickly made.
Mr Taylor said the disaster came on top of significant damage caused by weeks of monsoon-style rain.
"There are people in our region that have suffered severe property damage, but fortunately no loss of life before today.
"There's been a lot of property damage, a lot of crops lost, a lot of houses have had water in their lower areas."
He said people were still missing, but he could not say how many were being looked for. "Crazy weather, unprecedented weather," Mr Taylor said.
"I've talked to old timers in the street who've been here since the `50s - there was a fair bit of water `round in the `50s, but they can't remember it like this."
In the Lockyer Valley, up to 5000 residents in low-lying areas along the Lockyer Creek have been told to abandon their homes amid the worst flooding in more than a century.
Self-evacuations are under way in Gatton, Laidley and Forest Hill.
"It could be four or five thousand people," Lockyer Valley Regional Council Mayor Steve Jones told AAP.
"It's very severe, it's a very, very big concern. It could be as big as (the) 1974 (floods)."
Police said all residents in low-lying areas from Gatton, east to but not including Ipswich, must get out of their homes.
The creek was at a record 18.92 metres at the valley town of Gatton at 6.30pm (AEST). The previous record was 16.33 in 1893.
The Bureau of Meteorology does not know how much further it will rise, saying only that "severe record major flooding" is expected in areas downstream of Gatton overnight and on Tuesday.
The valley town of Withcott was also hit hard, with a surge of water tearing petrol bowers from a service station and dumping them half a kilometre away, and sweeping cars into shop fronts.
Across Queensland, the multi-billion dollar flood crisis, now almost a month old, is escalating.
People in flood-prone areas on the Sunshine Coast, and at Esk between the coast and Toowoomba, were also told to evacuate on Monday night.
Floodwaters are continuing to rise in the southeast Queensland city of Gympie, where the Mary River is expected to peak at about 20 metres overnight..
More than 110 homes and businesses are expected to flood at that level, Ms Bligh said.
At Dalby, west of Brisbane, residents are preparing for a fifth flood event in three weeks, with between 200 and 300 homes expected to go under there, Ms Bligh said.
At 5pm, the Myall Creek at Dalby was at 3.74 metres - 200mm higher than the December 27 peak when 100 properties were flooded. Western Downs Mayor Ray Brown said there was "huge emotion" in the town after five significant water events through Dalby in the last three weeks.
Brisbane residents too have been warned they're not immune from the unrelenting tide, with people told homes and businesses could flood in coming days despite critical protection afforded by the Wivenhoe dam west of the city.
Ms Bligh said the dam, built after the 1974 floods devastated thousands of Brisbane and Ipswich homes, was seeing "massive inflows" to rival that disaster.
"We are seeing one million megalitres or two Sydney harbours flow into the Wivenhoe catchment every day," she told reporters.
"Without a doubt the Wivenhoe Dam has already saved Brisbane from a catastrophic flood in the next 48 hours but we have to keep releasing water from it so it can keep doing the job it's doing."
Brisbane City Council has ordered 30,000 sandbags, which will be filled and available for distribution from council depots.
Meanwhile, limited evacuations are under way in the southern Queensland town of Warwick, as the Condamine River continues to cause trouble.
And residents in low-lying parts of the Darling Downs town of Chinchilla, northwest of Toowoomba, are also moving out of their homes.
Western Downs Mayor Ray Brown told AAP 140mm of rain fell in just one hour into Charleys Creek which runs through Chinchilla. "We know Charleys Creek had risen 1.6m in an hour," he said.
Large parts of the town, which services agriculture and mining industries, were flooded on December 27.
Nearby Condamine, which was totally evacuated at the height of its recent flood emergency, received 100mm in an hour.
