Image: Image: NSW Fire and Rescue
Sydney South’s $3.1 billion M6 Motorway project is now facing significant delays after two sinkholes appeared earlier this year.
The underground motorway project in south Sydney was designed to ease traffic congestion by 2025, connects the M8 at Arncliffe to President Avenue in Kogarah through four-kilometre twin tunnels.
However, in March two sinkholes emerged, close to the M6 project, halting work on a 244-metre section of the first stage of the M6 toll road.
Sinkhole Incidents at M6 Stage 1 Project
The first sinkhole, a 10-metre-wide sinkhole above one of the twin tunnels emerged on March 1.
This incident posed a risk of collapse to a nearby two-storey building and led to the evacuation of 20 workers on site.
Just over a week later, another sinkhole appeared on March 9 at the M6 Stage 1 project in Sydney.
Transport for NSW stated, “The location is within a contained construction area not accessible to the public and the site is not located near any residential or commercial properties,” at the time.
On Thursday, Transport for NSW deputy secretary Camilla Drover confirmed the estimated 2025 completion date would be pushed back.
“It could be many years before the project completes”, she said.
M6 Motorway Halted with Minimum Two-Year Delay Expected
Drover stated that their contractor advised it would be “definitely more than 24 months” for the project delay.
“Whether it’s up to three years or longer, we’re still working through that,” she added, as reported by the Sydney Morning Herald.
Drover also noted that the delays and additional work required to complete the 244-metre stretch of tunnels are expected to incur extra costs, although she did not provide a specific figure for the budget blowout.
“That is subject to very complicated insurance and commercial processes,” she said. “Insurance is quite complicated – it goes to causation.”
CIMIC Group’s CPB Contractors and UGL, in partnership with Ghella (collectively known as CGU), were awarded the contract to deliver M6 Stage 1 by the New South Wales Government in May 2021, following a competitive tender process.
According to the NSW Government the average depth of the tunnels is 60 metres, with the deepest point over 90 metres. They have developed an online tunnel tool to illustrate the depth at each location.
Proposed Benefits of M6 Stage 1
The M6 Stage 1 project aims to enhance access for communities and businesses to Sydney’s road network, allowing motorists to avoid congested routes and alleviating traffic on surface roads. Key benefits of the M6 Stage 1 include:
- Bypassing 23 sets of traffic lights on the Princes Highway
- Reducing traffic on General Homes Drive by 10,000 vehicles per day, which will enhance the foreshore amenity of Brighton-Le-Sands
- Removing 2,000 heavy vehicles from surface roads
The M6 Stage 1 is expected to reduce travel times by:
15 minutes between Kogarah and the ANZAC Bridge
- 15 minutes between Miranda and Macquarie Park
- 13 minutes between Kogarah and South Sydney
- 12 minutes between Taren Point and Mascot
- 8 minutes between Kogarah and Sydney CBD
The cost of Sydney’s four-kilometre M6 motorway has increased by $500 million, now totalling $3.1 billion.
Initially projected at $2.6 billion by the NSW government in April 2020, the budget was later “readjusted” due to higher tender pricing and additional costs, according to Drover.
The final costs for the M6 motorway have yet to be determined due to the ongoing delays.
