Missing boys found as Mackay declared a disaster area

Two boys riding bodyboards feared missing in floodwaters have been found as Queensland's emergency services chief says up to 1000 people may need evacuating from Mackay, which is now a disaster area.

Police commissioner Bob Atkinson had earlier said emergency authorities in the city were now looking for the pair.

But the Courier-Mail reports the boys were found safe and well soon after the call went out.

Emergency Management Queensland executive director Kevin Pagano said the worst hit area appeared to be Glenella, in the north-west of the central Queensland city.

Mr Pagano said four evacuation centres had now been set up, at the Andergrove Neighbourhood Centre, Mackay North High School, the State Emergency Service (SES) shed in Ness Street and Glenella State School.

"The latest information from the district disaster group is that they are planning for up to 1000 people to perhaps be moved into evacuation centres tonight depending on the condition of their houses," Mr Pagano said.

Prime Minister Kevin Rudd has also offered aid to the flood-hit residents of Mackay.

Mr Rudd said that joint state-federal natural disaster relief and recovery arrangements had been triggered for Mackay and 12 other areas of the state.

"This will enable local families, small businesses operators, primary producers and councils to access a range of assistance measures," Mr Rudd said in a statement.

"Our thoughts are with the families of Mackay," Mr Rudd said.

Meanwhile, floodbound residents are being warned to beware of crocodiles, following sightings of the reptiles today.

The Environmental Protection Agency (EPA) said sightings were so far unconfirmed but it would not be surprised to see crocodiles moving around the floodwaters.

"It's quite likely," EPA conservation services acting manager Joe Adair told AAP.

"I mean it's crocodile habitat up there, as is anywhere in central Queensland north of Gladstone.

"Crocodiles are along the coast in the estuary systems and waters all the way through and this time of year they're moving around.

"The floodwaters certainly have the potential to move them and disperse them."

He said residents should not wade into floodwater if possible as they could not see what lurked beneath.

And those in boats should not dangle legs or arms into the water.

"If they become close to a crocodile don't chase it or provoke it because they will lose," he said.

"It's dangerous but it's also illegal."

He said any crocodiles would move back to their normal habitats as the flood subsided.

Concerned residents could report sightings to the EPA on 1300 130 372.

Mackay was declared a disaster area this morning after receiving 625mm of rain in the 24 hours to 9am, and more rain later in the morning.

The monsoon trough over Mackay has dumped twice the city's normal monthly rainfall in just one day.

Weather bureau senior meteorologist Vikash Prasad said the record breaking 625mm in a day, compared with an average for the month of between 300 and 350mm, measured in different parts of the Mackay area.

"That is amazing," he said.

"They have already had 238mm so far (in February), so if you add that to the 625mm, they have had over 850mm for the first half of this month."

The previous highest daily February total recorded at Mackay airport was 386mm in 1958 and 304mm at the city's post office in February 1898, Mr Prasad said.

"At Mackay Post Office they had the highest daily rainfall for any given month in a given year, which was 627.4mm (on January 22) in 1918, so we are very close to getting the highest daily rainfall ever in Mackay for any particular month."

Localised rain from the monsoon trough was to blame, Mr Prasad said.

"According to the records, once a monsoon trough becomes stationary in that area it produces the heaviest rainfalls - like in 1954 and 1958 when they had some big floods through that region," he said.

"This year, there is an active wet season and there is high amount of moisture content in the atmosphere.

"Although it hasn't happened in recent times, it's not unusual to have this sort of rainfall in the Mackay region from the monsoon trough when it is really active."

Last month, a low embedded in the monsoon trough brought widespread flooding to a large area of central Queensland, including the towns of Emerald and Charleville.

Mr Prasad said there was no low affecting the Mackay area, but the rain there was likely to continue for the next few days although the falls were unlikely to be as heavy.

At 11am (AEST), the Pioneer River at Mackay was at 6.95 metres and rising but was expected to begin falling after the high tide at 6pm (AEST), a spokesman for the flood warning centre said.