Queensland residents flee amid fears burst Bolzan Quarry Dam will trigger flood

People living downstream from a failing Queensland dam have fled as huge hole opens up in dam wall.

The risk area around the burst Bolzan Dam quarry. Photo: Southern Downs Regional Council

People living on properties downstream from a failing Queensland dam have evacuated as engineers assess the situation.

A local spotted a hole in the dam on private property at Talgai, north of Warwick on Friday afternoon, but efforts to repair the damage have so far failed.

Residents on nine properties self-evacuated on Friday night after the Southern Downs Regional Council issued an emergency alert.

The council warned the failure of the Bolzan Quarry Dam would result in “dangerous downstream flooding in low lying areas”.

Southern Downs regional council mayor Tracy Dobie said nine properties had been evacuated and another 250 were at risk if the dam wall collapsed completely.

Cr Dobie told the Courier Mail a 3.5m x 1m hole had formed toward the bottom of the dam wall and “water is gushing out” at a rapid rate.

The dam is full after the recent deluge and holds 440 mega litres of water.

“The wall has not collapsed completely yet, that was the fear through the night,” Cr Dobie said.

“It’s punched a hole through the bottom of the wall and it is gradually increasing in size. We don’t know if or when the wall will let go ... we’ve prepared for the depth and width of the flooding and police and emergency services have been on site all night preventing anyone from being in the vicinity of the dam or directly downstream.”

Water gushes out of a hole in the Bolzan Quarry Dam. Photo: Southern Downs Council

An evacuation centre was established at Warwick Christian College but has since been closed after residents opted to stay with family and friends instead.

The local council has been advised by an engineer that a levy bank - or cofferdam - in front of the breached wall was so far containing the water spilling from the dam.

Southern Downs councillor Cameron Gow told the Courier Mail the levy bank had a capacity of 50 megalitres.

“His advice only a few minutes ago is the water running out of the hole has lowered the height of the water inside by half a metre – or between 15 and 20 per cent of its capacity,” Cr Gow said.

“Immediately below is a levy bank or cofferdam with a 50 mega-litre capacity and that is actually containing the water so far.

He added that immediately downstream from the dam wall breakpoint there is a large paddock which would provide an area for the water to spread.

“Which should take away the impact of any flooding,” he said.

Cr Gow told the Courier Mail the engineer had not so far recommended any repairs to the hole and that evacuation orders remain in place for the safety of residents.

“Evacuees aren’t being allowed back at this stage,” he said.

“We need to be really sure before that occurs and we will continue to reassess the situation over the coming hours. People are being really good, really patient.”

Meanwhile, showers and thunderstorms are expected to break a severe heatwave that has gripped much of northern Queensland.

Forecasters say the sweltering conditions will peak on Saturday and ease from Sunday, while the rest of the state gets some much needed sunshine. Temperatures in Townsville, Ayr and Woolshed were well into the 30s on Friday. Days of downpours in the southeast corner have led to flooding that is yet to subside.

The Bureau of Meteorology says there’s a medium chance of afternoon showers and thunderstorms for the region over the weekend, but nothing like the deluge earlier in the week.

The Southern Downs has experienced heavy rainfall recently. Photo: Supplied

On the Gold Coast, police are still searching for Yang Chen, 26, who disappeared in the hinterland area while walking near Gorge Falls in the Tallebudgera Valley earlier in the week.

With AAP