The hole emerged late last week in Harfleur St, near the Macauley St intersection.
The hole is still open, and traffic cones and signage remain in place while council plans its next steps.
Council CEO Jack Bond said while the exact cause of the road failure is not known yet, there are some early indications of what might have gone wrong.
“I don’t know enough yet, but director technical services Mark Dalzell is preparing more information,” he said.
“But it sounds like that whole section of road wasn’t fully compacted when it was all built, decades and decades ago.
“That’s why it has failed in so many different locations.
“It was relined, a new liner in the pipe, but apparently more work will have to be done on the manholes in the future to stop future leaks and stop this movement going out.”
Mr Bond said a “band-aid fix” would be implemented in Harfleur St until the investigations are fully concluded, in case council does need to make repairs to the pipes.
But he said any work required would not be as extensive as repairs to the sinkhole that appeared in the entryway of the IGA supermarket in George St in December 2022.
That sinkhole was caused by a sewer collapse.
Mayor Ashley Hall said there are still challenges to the Harlfleur St repairs, however.
“That area is very deep, so it will require a full excavation; it will be a massive job,” he said.
“Another one in Harfleur St (in 2023) took a fair while.”
Council has said traffic diversions may be in place for up to one month while the sinkhole is investigated and repaired.
People driving in the area are advised to slow down and drive with caution, and obey any signage.
Council will release more information about the sinkhole and repair plans once its investigations have progressed.
23°C