Blue Mountains highway avoids worst-case scenario for fix

Fixing a critical highway across the Blue Mountains will be possible – avoiding the prospect of a more costly alternative route – but the time to repair it will hinge on the exact solution experts decide on.

A stretch of the Great Western Highway at Victoria Pass has been shut indefinitely since March 12 after engineers discovered serious cracking and ground movement in a stone causeway built by convicts nearly 200 years ago.

Geotechnical testing over the past month has found the bedrock under the causeway remains strong, but stone and other rock used above it as fill between two sandstone walls has deteriorated significantly, resulting in voids and gaps within the structure.

Serious cracking and defects in the road, and bulging of the sandstone walls, risked the causeway collapsing.

The findings from the geotechnical investigations will be used to decide on a solution for the closed section of the highway, which had been used by up to 12,000 vehicles a day.

Roads Minister Jenny Aitchison said the geotechnical work had confirmed the underlying bedrock remained strong, which meant the government could focus on repairing the damaged section and reopening it as quickly as possible.

“We know we can restore the road on the same alignment. This will save a significant amount of time. It will mean we won’t have to go into finding another route,” she said.

Aitchison again declined to put a timeframe on the likely length of time the highway will be shut, although Premier Chris Minns has previously conceded it will require a “complicated rebuild”, which would “not be quick”.

“It’s clear that it will be longer than three months, but I’m not going to put a figure out there because that would be irresponsible,” Aitchison said on Friday. “We want to be having a solution, and then that will inform the timeframe.”

She said the government wanted the best engineers and other experts to give options to “restore access, not necessarily trying to rebuild the causeway, but on the same alignment”.

Motorists, who are enduring high fuel prices due to the Iran war, have been forced to use Darling Causeway and Chifley Road for a 25-minute detour, which is also placing financial pressure on business owners who rely on passing traffic.

NSW Coalition leader Kellie Sloane said residents and businesses disrupted by the closure deserved timely answers from the government about how long it would take to repair, as well as reassurances about the support they would receive if it was not fixed soon.

“There is no clarity about how long these repairs will take,” she said.

Blue Mountains Labor Mayor Mark Greenhill said early indications suggested the causeway was fixable, avoiding the prospect of a costly alternative alignment such as a tunnel or a new highway, which would take years.

“If they can fix this at site and get the Great Western Highway reopened faster, that is a much better outcome,” he said.

Greenhill said financial support for businesses severely disrupted by the failure of a state government road remained unresolved. “To my mind, the state government needs to address that issue,” he said.

Aitchison acknowledged the toll the highway’s closure had on locals and businesses across the Blue Mountains and Central West, who relied on the arterial route to Sydney.

“We are working our way through what kind of assistance can be done. But my priority as roads minister is restoration of the route as soon as possible,” she said.

Adding to woes for local businesses, another road in the Blue Mountains, Mount Wilson Road, has been closed to visitors since April 3 due to increased safety risks following severe weather.

Greenhill said he hoped the council would be able to repair Mount Wilson Road, which connects to the Bells Line of Road, within two months.

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