Queensland in grip of deadly flood crisis

Queensland is in the grip of another flood crisis, as cities and towns across the state go under.

Dramatic rescues are underway in Bundaberg, where the city's worst flood on record has left dozens of people trapped on rooftops.

At least 1200 Bundaberg properties are already flooded, and there are fears that could reach 2000.

The communities of Gympie and Maryborough are also flooding.

There is also a major flood crisis developing in the Lockyer Valley, where 19 lives were lost in the state's 2011 floods.

Brisbane and Ipswich are bracing for flooding expected on Monday night, with further flood peaks expected on Tuesday and Wednesday.

So far, three flood deaths have been confirmed:

- An 81-year-old man whose body was pulled from the water near Bundaberg

- A 27-year-old man who tried to cross a flooded creek near Gympie

- A man whose body was found in the Oxley Creek south of Brisbane.

In Bundaberg, entire suburbs have been evacuated but some people waited too long and about 30 are stranded on rooftops in atrocious conditions that are preventing rescuers from reaching them.

The situation in the city is now so bad that police are advising people trapped in homes in north Bundaberg to seek refuge on the roof.

"If your house is currently inundated with water and you require rescuing, you are either to make your way to the roof if safe - I repeat - if safe," Senior Sergeant Grant Marcus said in an urgent public alert issued on Monday morning.

"Alternatively find a way by which you can hail rescue helicopters which are currently hovering over your area."

Choppers with winching gear are battling to get to those already on the rooftops.

At Ipswich, west of Brisbane, flooding is predicted from late on Monday, but it's not expected to be anything like what was seen in 2011 when 600 homes flooded.

That's also true for Brisbane, where a minor flood is expected, affecting about 5000 homes and businesses.

Two evacuation centres have opened in Ipswich, with the Bremer River now expected to peak at 15 metres - a metre beyond what was expected just a day ago.

"We're doing everything we can," an emotional Ipswich Mayor Paul Pisasale told ABC radio on Monday.

"We've got a lead time until midnight tonight so it'll be all hands on deck to help those people," he said, his voice breaking.

"From an emotional point of view it's going to be most horrendous for me. I'll have to get in counsellors for those people who have just been kicked in the guts again."

Brisbane Lord Mayor Graham Quirk says the city is in for a very difficult few days, but it isn't going to be as bad as 2011.

About 3600 residential properties and 1250 businesses are expected to experience some flooding.

Two flood peaks are expected, the first from late on Monday at Ipswich and the western Brisbane suburb of Moggill.

"We're going to see it then through Jindalee and along the river system, peaking at the city by noon on Tuesday," Mr Quirk said.

"Then as the tide goes down that will be relief. But then it will come again, peaking again in the city at lunch time on Wednesday."

The premier says people should remain calm and prepare if they are in areas marked as at risk of flooding in maps prepared by the Ipswich and Brisbane councils.

"It is a significant event. This is a big challenge for our community but we are up to it. We did it in 2011 and we will do it again," Mr Newman said.