Nearly two years after sinkholes opened, fix for halted Sydney motorway remains unresolved
An engineering solution remains bogged down in complex negotiations between the NSW government and contractors building the project in the city’s south.
Nearly two years after sinkholes opened, fix for halted Sydney motorway remains unresolved
Almost two years after a large sinkhole halted construction of a $3.1 billion motorway in Sydney’s south, the NSW government remains locked in negotiations with contractors and unable to say what the engineering fix will be.
The cost of finishing the first stage of the M6 motorway between Arncliffe and Kogarah will hinge on the revised design of a 244-metre stretch of tunnels, and complex talks over liability for the three-year delay to the project’s opening.
The first sinkhole opened above one of the tunnels at Rockdale for the M6 motorway in early March 2024.Credit: Fire and Rescue NSW
Transport for NSW secretary Josh Murray said the project remained a “very complex technical and commercial issue” for the department.
Work has been paused indefinitely on the 244-metre section since March 2024, when a 10-metre-wide sinkhole suddenly opened up above one of the twin tunnels at Rockdale. Days later, another emerged about 150 metres away in a construction area on the eastern side of West Botany Street.
Budget papers from last June show the cost of the four-kilometre motorway is set to hit $3.193 billion, a $93 million increase on the most recent forecast.
Asked about the likely engineering solution, Murray said the department and contractors had brought in extra assistance to get the “best possible response”, adding that it was on the proviso that it was value for money for taxpayers.
“We’re not in a position to talk about any of the feasible technical responses … at this stage, except to say that we’ve asked for every idea to be brought forward that delivers the best result,” he said.
“What we want to see is the engineers put their best work forward that we can review and take that back to government.”
Murray said the latest cost estimate for completing the motorway would be determined by the revised design and construction time frame.
“We don’t have that final picture yet, but we are getting close,” he said.
CPB Contractors leads the consortium building the motorway project, which also comprises Ghella and UGL.
