Authorities are still working to stabilise a leaking, privately owned 430-megalitre irrigation dam on Queensland's Southern Downs amid fears its wall could fail.
An emergency was declared in the area around the dam near Talgai, north-west of Warwick, on Friday night after the property owner found water gushing from a 3.5-metre by 1.5-metre hole in the wall.
Residents were evacuated on Friday, but most were allowed to return home on Sunday night when the emergency alert was lifted.
Southern Downs Mayor Tracy Dobie said one home remained at risk of flooding.
"There is instability in the dam wall, which is why the concern is still there the wall will give way," she said.
"A bypass channel will be constructed around the southern edge of the dam wall to take the water away from the wall in a controlled manner.
"That will be released down that valley and will contribute to the need for road closures because there will be flooding.
"Flood modelling has indicated that if that wall did break, the water that would go down that valley is about half of a 100-year flood event, so the reason why we're not letting that property owner go back is because we're not confident the wall will hold."
Cr Dobie said engineers would begin work today to relieve pressure on the leaking dam wall, with some roads to remain closed as they released water.
"There will be flooding across those roads," she said.
"The water release will be controlled and that will be aimed at taking the pressure off the dam wall.
"Those who don't need to be in the area shouldn't be in the area.
"I ask residents or visitors not to go through those road-closed signs. There is still the emergency relating to the dam wall in case it gives way. The wall is unstable."
