Dangerous search for teen after Qld floods

The search for a Victorian teenager last seen in floodwaters in southeast Queensland is continuing in an area police say looks like a "war zone".

Krystal Cain became separated from her father after their car became submerged in floodwaters near Booubyjan, northwest of Gympie, about 3am on Saturday.

Emergency services and volunteers in helicopters, boats, trail bikes, 4WD vehicles and on horseback have been looking for the 14-year-old.

The extensive search was continuing slowly in an "incredibly dangerous" environment, Gympie Patrol Group Inspector and District Disaster Coordinator Paul Algie said on Thursday.

Insp Algie told reporters it was admirable community members wanted to help, but asked for the search to be left to trained experts.

"We have experienced searchers already succumbing to heat stress, leg and ankle injuries due to the difficult terrain," he said.

"Just driving along the Burnett Highway towards Booubyjan looked like a war zone."

There was damaged infrastructure, dead livestock, fences down, large piles of debris and crashed and submerged vehicles.

The search was in an area within a 10 kilometre radius from where Krystal was last seen and would continue over days and weeks, with officers holding grave fears for the teenager who had disappeared "without a trace".

"We will change, as time goes on, the way we search, but no officers, nobody who's attached to this search will be giving up," Insp Algie added.

"We will just continue as we can access different areas and using different strategies to try and find this child."

Bauple farmer Steve Bottcher, 52, and a 22-year-old Sunshine Coast man died in the floods after ex-cyclone Seth dumped more than half a metre of rain on the Wide Bay-Burnett region.

There were tributes for Mr Bottcher after the father-of-five was swept away when his boat capsized on his property on Monday night.

"Steve was a very fun loving man who was always up for a yarn and some coldies," friend Haelee Faithfull wrote on a GoFundMe page set up to help pay for funeral costs.

North Burnett acting mayor Robbie Radel said the area will struggle to recover.

"More or less the entire community of Dallarnil has been inundated, with a house outside town washed away with a man and two dogs inside," he told AAP.

"They managed to locate him and one of his dogs. He had clung to a tree but if that branch had broken we could so easily have lost someone."

Mr Radel said there were reports of local families sitting on water tanks for up to six hours before being rescued, with some homes left uninhabitable after water levels reached the ceiling.

Meanwhile, the clean up is under way in Maryborough, where at least 30 homes and 50 businesses were damaged.