AUTHORITIES are confident St George will avoid inundation as the Balonne River edges towards a peak below worst-case predictions.

Bureau of Meteorology senior hydrologist Chris Leahy said the river had crept up to 13.86m at 8am, and would gradually reach an expected peak of about 14m.

Floodwaters had been tipped to reach 15m, forcing the mandatory evacuation of 2500 of the town's 3000 residents to Dalby and Brisbane.

A makeshift earthen levee was hastily constructed to protect the town, but only from river levels of about 14.5m.

Balonne Shire mayor Donna Stewart said today she was confident the levee would hold.

"It's compacted to hold 14.5m out and it's not going to get there. It's obviously not going to get there," she told ABC Radio.

"It's very good news and I know those people that have been evacuated will be very relieved to hear that."

Ms Stewart said dozens of homes outside the levee bank had been damaged by floodwaters.

"There are still reports of about 50 houses with water in them, so there are going to be some very emotional times ahead for those householders," she said.

The Department of Community Safety closed the Moonie Highway at St George this morning, as water reached 60cm above a bridge over the Thuraggi Channel.

Mr Leahy said the floods would affect the town for days.

"It's going to hang around for quite some time," he said. "It'll be very slow to subside."

Charleville residents who had been subject to a voluntary evacuation order were permitted to return to their homes today.

Mayor Mark O'Brien said the 150-odd people at the town's evacuation centre were thrilled to hear the news.

"The whole place is going back to normal. The (Warrego) river's down to about 6.5m," he said.

"Everybody's breathed a big sigh of relief. There's no damage in (the) town, so what do you know, our levee bank works."

However, Mr O'Brien said several rural properties not protected by the levee had been inundated.

"There will be a number of those," he said. "Some of these properties have had unprecedented river runs.

"There'll be a hell of a lot of stock and fence losses."

Floodwaters have damaged 280 homes in the town of Mitchell, where evacuations also occurred at the weekend.

Residents walked back into town because the damaged Maranoa River Bridge remained cut off to all but a few emergency vehicles.

Residents were also able to return to nearby Roma, where about 380 homes have been damaged.

The Department of Education said most schools, TAFE and early childhood centres in St George, Roma, Mitchell, Charleville, Bollon, Begonia and Dunkeld would be closed today.

The BoM issued a severe thunderstorm warning today for the Maranoa, Warrego, Darling Downs and Granite Belt - parts of the state already badly affected by floods.

Mr Leahy said the storms would bring hail and intense rain, but were unlikely to have a significant impact on the region's already swollen rivers.

"I don't think so at this stage. The storms are moving fairly fast and (are) not expected to have too much of an effect," he said.

Meanwhile, the RSPCA sent two inspectors to St George to care for stranded pets and livestock.

A statement from the organisation said 93 animals - mostly dogs and cats - had been provided with food, water and attention.

No animals are believed to be in danger.