An emergency flood declaration has been declared for the township of St George in the southern inland as floodwaters continue to rise in south-west Queensland.

Key points: St George has been placed under an emergency declaration as floodwaters rise

St George has been placed under an emergency declaration as floodwaters rise Swiftwater rescue crews are on alert following heavy rainfall across north and central Queensland

Swiftwater rescue crews are on alert following heavy rainfall across north and central Queensland The Balonne River is expected to exceed 12 metres late on Wednesday

The Balonne, Maranoa and Warrego rivers have major level flood warnings with flood levels expected to peak at St George on Wednesday night.

St George is on flood alert with residents in low-lying parts of the town preparing to evacuate.

Police have advised people to avoid the use of personal watercraft on the Balonne River until the emergency declaration is revoked.

Andrew Nixon Bridge at St George in southern Queensland on Tuesday morning. ( ABC Southern Queensland: Peter Gunders )

Minister for Fire and Emergency Services, Craig Crawford, said it was anticipated about 30 houses in St George would be affected by rising water and extra crews were standing by.

"We've got two swiftwater rescue crews — day shift and night shift — in case we have any sudden rise or any sudden emergency," Mr Crawford said.

"All of our councils that are downstream of this water are already putting in plans for what needs to happen when and if it does arrive at their locations," he said.

Expected flooding could match 1950 level

The Balonne River is expected to exceed 12 metres late on Wednesday, impacting homes outside the town's levee.

When it does, it will be on par with the 1950 flood level, which remains as the fifth-largest flood recorded in the small rural community since 1890.

Rural properties could be isolated and authorities have been urging residents to stock up on food and medical supplies.

Balonne Shire Council Mayor Richard Marsh said for the most part, locals had been welcoming the big wet, with the region under drought for the past decade.

"You can make more money from mud than dust," Cr Marsh said.

"It might be a pain for some that have got to move a little bit, but for the rest of the community it's an opportunity for us to really go forward."

The Yanna Bridge over the Warrego River near Wyandra on Tuesday morning. ( Supplied: Pete Fisher )

Severe weather warning follows ex-TC Esther

A severe weather warning remains in place for the Gulf Country in the wake of ex-Tropical Cyclone Esther.

The system has transitioned to a tropical low and will continue to bring heavy rain and damaging wind as it weakens.

It made landfall as a category one system on Monday afternoon and is now moving west through the Northern Territory.

Queensland Fire and Emergency Services' Emergency Management Coordinator, Elliot Dunn, said dozens of properties on Mornington Island lost power, but structural damage from the system was minimal.

"As far as cyclones go it was quite a well- behaved one," he said.

Mr Dunn said QFES was not expecting any major flooding from the system because most of the falls were on the coast.

Gulf property owners Gary and Dianne Gould said the rain from ex-tropical cyclone Esther has helped replenish their waterholes. ( Supplied: Dianne Gould )

Gulf of Carpentaria property owners Dianne and Garry Gould of Westmoreland Station near the Northern Territory border, welcome the rain brought by ex-tropical cyclone Esther.

Their property was falling well short of its annual rainfall average of 800mm but has received 260mm of rain since Sunday.

We pretty much rely on waterholes and surface water," Mr Gould said.

"They should be good now, they should all be topped up."

Charleville flood peak lower than expected

Murweh Shire Council staff sealed the levee at Charleville, although the flood peak was lower than expected. ( Supplied: Karen Tully )

Floodwaters in the Warrego River at Charleville are falling after peaking lower than expected overnight.The river reached 5.7 metres on Monday night, below the expected 6.3 metres.

Murweh Shire Council Mayor Annie Liston said the town's bridge was closed early on Monday night as a precaution.

"We took the fire trucks and the ambulance and all that over the other side of the river, just in case something happened over the river," Cr Liston said.

Murweh Council will assess damage in Charleville on Tuesday morning.

The Warrego River at Charleville reached a flood peak of 5.8m and flood levels are easing. ( Supplied: Karen Tully )

Central Queensland swift water rescues

Additional swift water rescue crews are being stationed at regional locations following heavy rainfall across north and central Queensland.

The Queensland Fire and Emergency Service (QFES) has responded to three separate swift water incidents in the Mackay region since Saturday.

Mackay area commander, Mat McFarlane, said the SES would continue to monitor the situation.

"We have got a couple of crews coming in today and they will go to Proserpine," he said.

"They will be there to support us in that area for the next couple of days."

Angelala Creek between Charleville and Wyandra, the Angelala flows into the Warrego River which is rising in that area. ( Supplied: Pete Fisher )

Thunderstorms likely in south-east

Bureau of Meteorology forecaster Gabriel Branescu said from Thursday the south-east quarter of the state could expect more rain which may lead to renewed river rises.

"With the next upper trough we will see a little bit of severe thunderstorm activity," he said.

"After we saw those hundreds of millimetres over the weekend over the southern interiors, the rivers are responding quite quickly," he said.