Work to fix a sinkhole described as the “biggest engineering job in south Wales” has cost more than £4m.
Homes were evacuated in Merthyr Tydfil last year when a 10m wide and 14m deep crater opened up at the bottom of a driveway in December.
The BBC has now discovered the hole has cost £4m to repair.
Merthyr Tydfil council said it had been a “complex and technically demanding challenge” but due to the “commitment and dedication of the team undertaking this work, the progress made to date has been completed successfully”.
Families had to be moved to hotels or stay with relatives as engineers and contractors initially filled the sinkhole with stone following extensive temporary repair work for families to move back in before Christmas last year.
Specialist civils contractor Edwards Diving Services site manager Craig Howe told the BBC it was the “biggest engineering job in south Wales” this year, adding: “It’s believed there was a landslide further up the valley which washed a load of debris through the tunnel during the storm which caused the collapse.”
Project manager Jack Muldoon said it had been a complex operation.
He said: “You make yourself a metal box inside the hole so it’s safe to work and then we put bracing in and we used 15 tonnes of hydraulic bracing and that secured everything to make sure the pressure from the soil was supported.
“When this Victorian era culvert was built it was all bricks and stone, now we have the beauty of steel and concrete which makes it easier for us.”
A spokesperson for Merthyr Tydfil Council said: “The council has every confidence that the remainder of the work will be completed shortly, and we thank the residents for their continued patience and co-operation over the last few months.
“The work is on schedule to finish mid-November, with the cost totalling just over £4m.”
