Large swathes of the Darling Downs region are awash after days of heavy rain with some areas recording up to 90mm in one hour amid a La Nina weather event.

One man drowned when he became trapped in his ute after it was swept off a flooded causeway and into an overflowing creek north of Toowoomba on Wednesday morning.

Goondiwindi Mayor Lawrence Springborg has been coordinating efforts to protect people and homes after both the Macintyre River and Dumaresq rivers broke their banks.

He said the border town of Texas has been spared the worst, but some homes have been inundated with the Dumaresq River at 8.67m on Thursday morning above the major level of 8m at Texas.

Mr Springborg is with police doing welfare checks on locals living on the Texas flood plain and is confident most of the downstream town of Yellarbon where 50 people have been evacuated will be spared.

"It's got a bit of water backing back there, but we think that'll be okay," he told AAP via phone from a water police boat.

"It all depends how the water moves over the course of the day. And with that community is now completely isolated by roads, so we're not able to, we wouldn't be able to evacuate it anyway.

"There are some high spots, but we think it'll be right."

The focus is turning downstream to the major regional centre of Goondiwindi with Mr Springborg optimistic the flood levee will protect the town.

Deputy Police Commissioner Steve Gollschewski said planning was under way to ensure smaller communities and isolated homesteads were in touch with emergency services and on alert to evacuate if needed.

To the north, the Condamine River has already surpassed major flood levels in the villages of Pratten, Tummaville, Cecil Plains and Condamine Township, while the Balonne River set to peak at major flood levels in at Surat and Warkon.

In Banana Shire, the Dawson River is set to hit major flood levels at Taroom on Thursday night and into Friday.

After days of overcast skies there are some patches of blue sky over the Darling Downs on Thursday, but there is concern any more rain in catchments could cause problems.

"We've got blue skies, let's hope we keep them for another month," Mr Springborg said.

"That would be good because this water will get away before there's any more rainfall if there is going to be anything."

Mr Gollschewski urged people not enter floodwaters after the death of a 73-year-old Roma man who drowned in his ute after it was swept into Oakey Creek, north of Toowoomba, on Wednesday.

"Sadly, we saw the loss of a life where it appears a vehicle has entered waters when it shouldn't," Mr Gollschewski said.

"The message is clear: if it is flooded, forget it.

"For us, we don't want to see any of our officers or members of the community at risk. Listen to the messages and don't go into flooded waters either in vehicles or on foot."

Australian Associated Press