Hundreds of roads were cut and rivers had burst their banks as heavy downpours continued to lash south-east Queensland.
As much as 224mm of rain fell in 24 hours in some areas, with more forecast overnight.
Fourteen state schools had closed due to the flooding and more than 530 roads had been closed or were impacted.
The Bureau of Meteorology warned of further heavy rainfall over the next 24 to 48 hours, before lowering in intensity and easing following the weekend.
Emergency crews had been responding to calls for assistance across Queensland.
One man spent Wednesday night clinging to a tree in flood waters near Bundaberg.
The man, in his 60s, was driving when his car became swamped by rising waters. He managed to get out and cling to a tree before the car went under, and spent the night there before being spotted by farmers on Thursday morning.
Suffering hypothermia, he was flown by an RACQ LifeFlight Rescue chopper to hospital, where he was in a stable condition.
A camper was also found safe and well after chasing his dog near flood waters.
Police said the 36-year-old man was reported missing from an Imbil campsite, south of Gympie, on Thursday morning.
Another five people escaped flooded cars in Caboolture, north of Brisbane.
Authorities urged residents near Cooby Creek to secure property and prepare to move to higher ground if the situation worsened, as Cooby Dam was spilling.
Parts of Grantham in the Lockyer Valley, west of Brisbane, had been inundated and authorities warned residents that multiple roads would remain underwater on coming days.
To the west, the Bureau of Meteorology was warning Roma, St George, Blackwater, Mitchell, Rolleston and Injune residents that severe thunderstorms could bring heavy rainfall and flash flooding in coming hours.
Sunshine Coast Hinterland and Wide Bay-Burnett residents had been told to prepare for severe weather and possible flash flooding in the early hours of Friday.
The forecaster said six-hour rainfalls of 160mm were possible as a low-pressure trough crossed the coast overnight and the weather deteriorated on Friday.
“Locally intense rainfall which may lead to dangerous and life-threatening flash flooding is possible with thunderstorms during Friday afternoon,” the BoM said in an alert on Thursday.
Major flooding was forecast for Laidley Creek and the Mary River at Gympie with moderate flood warnings for the Bremer, Lockyer and Brisbane rivers on Thursday and Friday.
Flood waters claimed the life of a woman on Wednesday after a dual ute was swept away north of Mackay. Two passengers, a man and a woman, escaped the vehicle and were taken to hospital as a precautionary measure.
Severe thunderstorms were forecast for Queensland’s central coast and Whitsundays region, with dangerous and life-threatening flash flooding also possible.
All CityCat and ferry services were suspended in Brisbane, with total rainfall of 50mm forecast for Brisbane on Thursday. Gold Coast beaches were closed as dangerous surf and huge swell were expected along the coastline.
While the far west started to dry out, the Bureau of Meteorology warned the rain would continue. Heavy downpours and possible thunderstorms were forecast for the central, southern and south-east regions of Queensland on Thursday.
“These could produce damaging wind gusts and also intense rainfall that could lead to life-threatening flash flooding,” meteorologist Christie Johnson said.
“Moving into Friday, we see the focus move to the south-east and, after that, the system moves away to the east and conditions improve on the weekend.”
Rainfall totals across the east of the state were generally between 50mm and 70mm, with areas between the Daintree and Mackay, the Sunshine Coast and central Queensland recording more than 100mm on Wednesday.
