Emergency alerts for Queensland towns Surat, Roma and Mitchell

Queensland's Department of Community Safety has issued emergency alerts for areas near three towns, urging people to move to higher ground.

Queensland's Department of Community Safety has issued emergency alerts for areas near three towns, urging people to move to higher ground.

The warnings are for areas near the Maranoa Regional Council towns of Surat, Roma and Mitchell.

The warning says all rural residents downstream of Surat on the Condamine/Balonne River are urged to move to higher ground or to neighbours in flood free areas.

All rural residents downstream of Roma on the Lower Bungil Creek are to move to higher ground, and all rural residents downstream of Mitchell on the Maranoa River are also to move to higher ground.

If residents are unable to safely evacuate, they should call 132500, and triple zero if they find themselves in a life threatening situation. People are also asked to check on neighbours.

Earlier, Premier Anna Bligh said the levee banks holding the Warrego River back from the southwest Queensland town of Charleville were holding.

With water lapping the top of the earthen defences, there were fears today that the levees could be breached, sending a catastrophic tidal wave of water through the town.

But the premier, who visited the flood region says it looks as though the banks will hold.

"Right now the levee is holding and on all current forecasts it's likely to keep doing that, but there's not very much room for error,'' Ms Bligh said.

"There's a 24 hour watch on the levee and if there's any change we'll be actioning it immediately.''

More than 500 people registered with the town's evacuation centres will spend tonight being cared for even though their homes have so far escaped the flood.

"Right now their homes are dry, but they'll be sleeping in the evacuation centres tonight just as a precaution, and that's the right thing to do,'' the premier said.

Ms Bligh said the people of Charleville were coping with their third major flood in as many years.

"That's too many, and there's a lot of heartache here today.

"I've spoken to people who are very close to tears and they certainly don't want to see those floodwaters come over the levee.

"Right now though it's very pleasing to see that levee holding those waters back, the last time the waters got to this level there was no levee in town and the water was devastating Charleville ... the levee has never been tested like this and we'll see what it's made of.''

The premier said communities like St George were now nervously waiting for the water to move downstream.

At Mitchell and Roma the flood levels were stable this afternoon, she said.

Ms Bligh said many towns and properties throughout southwest Queensland had been isolated but relief efforts had been boosted by helicopters deployed by the Australian Defence Force (ADF).

With more water coming downstream, the premier said it was possible the river height may stabilise over the weekend then peak again on Monday or Tuesday.

Mayor Mark O'Brien said the town was holding up well under the strain.

Premier Bligh has declared a state of emergency for the region, prompting Julia Gillard to pledge federal financial support to its flood-stricken communities.

The emergency unfolded as the northern NSW town of Moree remained cut off in the worst flooding to hit for 35 years, stranding up to 10,000 people.

NSW Premier Barry O'Farrell said the flood had created an "extraordinary" landscape.

"As you fly over the centre of the town, there are streets that look like canals that have more relevance to Venice than northwestern NSW," he said.

Moree Plains Shire Mayor Katrina Humphries said it would be days before water levels subsided.

The Prime Minister said she had spoken to Ms Bligh several times through the day, as the emergency deepened in Queensland's southwest, evoking memories of last summer's flood disaster. "I have reassured her that the federal government stands ready to assist the people of Queensland to respond," she said.

Nearly half the 750-strong population of Mitchell fled to a refuge at the local RSL sports complex after the Maranoa River rose more than 1m in an hour, breaking a century-old flood record.

Ms Bligh said the town had entered "uncharted waters".

When the flood threatened to isolate the RSL compound, helicopters were sent in to lift the 300 people to a back-up location at the local council depot.

The fact that nearly half of Mitchell's population of 750 had sought refuge highlighted the gravity of the flood, the Premier said. Much of Mitchell's main street was last night swamped, and 50 residential properties were affected by flooding.

"The safety of those people is our first priority," Ms Bligh said, detailing the effort to move people between evacuation points.

"I do understand this is very frightening for people and they would be very distressed."

At Charleville, 180km further to the west, the Warrego River was expected to lap the top of levees protecting the town of 3200.

Ms Bligh said the waters would go "within millimetres" of breaching the barriers when it peaked at a predicted 7.4m, probably early today. At worst, the town would be inundated and "full-scale" contingency planning was under way to cope with this.

To the south, St George would be threatened by a wall of water coursing down the Balonne River, with a peak of more than 13.4m expected by Tuesday. Plans were being finalised to fly 40 nursing home patients out.

The town of Alpha in central west Queensland, 1000km from Brisbane, was bracing for homes to be inundated late last night.

The state disaster co-ordinator, deputy police commissioner Ian Stewart, said saving people was the priority. "Personal safety is critical," he said. "We can replace houses, we can replace the bridges but we cannot replace people."

Additional reporting: AAP and Mitchell Nadin