Kiama Municipal Council has pleaded with an executive government agency to help fix Jamberoo Mountain Road once and for all.
The council was forced to close the road after the 300mm-plus drenching of the last few days ended in a landslip and numerous tree falls.
But on top of that was there also was the "complete failure" of a 60-metre stretch of tarmac.
The storms and flooding have caused a number of landslips and tree falls along Jamberoo Mountain Road particularly between The Abbey and Misty's Lane," the council's Director of Engineering and Works, Mike Dowd, said
"More than 60 metres of road has totally failed at one site, with the landslip and flood waters eroding the base and fracturing the tarmac."
Mr Dowd said Jamberoo Mountain Road was now closed to all through traffic between The Abbey and Misty's Lane and motorists needed to use Macquarie Pass or Picton Road.
The closure is expected to last several months.
Residents are able to access their properties and visitors can reach the Illawarra Fly from Robertson and Minnamurra Falls from Jamberoo.
Mr Dowd said a significant amount of work and significant costs were now needed to clean up and then repair the damaged section of road.
"To have a total road failure of such a size and in such a difficult location means this is not going to be easy, quick or cheap to fix.
"We are still looking at a number of months and a major bill to get it back in operation."
Mayor Neil Reilly said the council was already in discussions with the state government about the situation.
"Our CEO Jane Stroud yesterday (Monday) talked to Resilience NSW to discuss the major challenge this presents not just to our municipality, but our region.
"Jamberoo Mountain Road is a vital part of the Illawarra's road network and when it's out of action it presents more than an inconvenience to residents and tourists, it has a real-world effect on our region's economy," Cr Reilly said.
The council, like so many across the state the mayor said, was still in the throes of dealing with the damage left by March's floods.
"So being hit by another round of storm and flood damage is especially difficult," he said.
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