The North Burnett Regional Council reported the sink hole, which was reported to be more than 5m deep, had formed on Scanlon Rd.

North Burnett Mayor Don Waugh believed the sinkhole had opened on the right side of the causeway.

The mayor said after initial observations it was estimated the sink hole was six to 10m wide and dropped between five to 10m below the causeway.

The shocked mayor was lost for words.

"It's incredible - you've got to see it to believe it," Cr Waugh said.

The mayor reported there was only one residence past the sinkhole.

"If they'd come along without being aware, they could have ended up over the side," he said.

The North Burnett Regional Council is currently working to securing the area amid concerns the sinkhole could grow.

"I can see it getting bigger as the water comes over it - it will keep breaking away," he said.

Cr Waugh said the council was working to stabilise the area and create a temporary detour.