The family of three tried to drive through the flooded creek in Netherdale the Mackay region about 8pm on Tuesday, according to the Queensland Ambulance Service.

The car carrying a man and woman, both aged in their 40s, and a primary-school-aged girl overturned because of the force of the water.

The Queensland Ambulance Service said all three got out of the stricken vehicle and the man and child got to safety but the woman was swept off her feet.

She grabbed hold of a tree downstream and pulled herself to safety before making her way home, where all three were assessed by paramedics and taken to Mackay Hospital.

Townsville residents are beginning the clean-up operation, schools are gradually reopening and power is being restored as the floodwater recedes.

Meanwhile, 12 Townsville state schools reopened on Wednesday morning.

Forty-four state schools, eight Catholic and independent schools and 83 childcare centres remained closed.

About 9400 Townsville homes were still without power on Wednesday but fresh recovery crews had arrived in the region to speed up the process.

An Ergon Energy spokesman said a break in the weather on Tuesday had allowed crews to make good progress but heavy rain set in on Wednesday, hampering efforts.

The conduct of police officers will be examined as part of the investigation into the deaths of two men in Townsville, whose bodies were found in a stormwater drain after water levels fell.

The bodies were found near the Aitkenvale Library just before noon on Tuesday.

The men, aged 21 and 23, were last seen near a Townsville bottle shop that had been robbed and a resident said they may have been sucked into pipes that led to the drain from the scene of the crime.

The Ethical Standards Command will investigate the matter for the state coroner, with oversight by the Crime and Corruption Commission.

Communities Minister Coralee O'Rourke, whose electorate of Mundingburra covers Aitkenvale, described the news as an "absolute tragedy".

"I think the Townsville community has been in a situation where they've experienced something they've never experienced before and to hear they've lost two young lives, I think it will hit hard," she said.

"I'm sure everyone will send condolences to the family and friends of these two young men because this is something that should never have happened."

Early on Wednesday, an emergency alert was issued for the central Queensland town of Hughenden because the Flinders River was expected to cause flooding for homes on the north side of the river.

On Tuesday afternoon, police urged residents on Palm Island to boil their drinking water until further advised because recent rain had impacted the water treatment plant.

Meanwhile, the police car swept away in the floods about 8.15pm on Sunday was recovered from behind the Townsville RSL on Tuesday.

However, as one vehicle was recovered, another one popped up.

A ute was spotted wedged under a pontoon by a passer-by in Mackay on Tuesday morning.

Police concluded later in the day that it was an abandoned vehicle.

Bureau of Meteorology acting state manager Richard Wardle said many north Queensland rivers were continuing to recede, meaning the clean-up operation would soon be in full swing.

"We expect this active monsoon to remain active for the coming days, potentially easing over the weekend, so there is an end in sight," Dr Wardle said.

"But we are expecting further periods of heavy rainfall, some of it very heavy, about the north-east tropics for the next few days, between about Cardwell and Mackay, and with that there is the real elevated risk of flash flooding.

"A severe weather warning is current for heavy rainfall and likely flash flooding around the Herbert and lower Burdekin, and the central coast, and this will likely remain in place for several days.

"As the monsoon trough moves south there is a flood watch for catchments down to Mackay.

"We can’t be certain where those heaviest falls will be at this stage because of the showery and thundery nature of the rainfall but we do expect that flash flooding to remain a risk."

As of Wednesday morning, the State Emergency Service had received a total of 2675 calls for help for the duration of the extreme weather event.

- with AAP