Basic Tunnel Info



The facts on the tunnel plans from the recent Environmental Impact Statement (EIS) are:


  • Construction to take 7 years in total, potentially starting in 2023
  • Estimated cost of approx $12 billion (end-of-project cost in $-of-the-day) – yes, that’s 12,000 million
  • Unfiltered exhaust stacks at each tunnel entrance
  • Exhaust stacks will be between 8-10 storeys tall and located at the ends of the tunnels in Seaforth, Balgowlah, Artarmon and Cammeray. The stacks will release unfiltered exhaust from vehicles travelling the 7km length of tunnel, and there is no filtration of air either within, or outside the tunnel.
  • Balgowlah Golf course used as a large construction site, with 34 homes acquired and demolished on Dudley St. When complete, the site will hold a multi-lane access road, industrial facilities building to power and operate the motorway, with leftover space used for sporting fields, next to an unfiltered exhaust stack. The full green space will no longer exist and 421 mature trees will be removed, with another 158 potentially impacted.
  • Tunnel entrance near Kirkwood St, Seaforth impacting nearby residents with heavy truck movements, and widening of Wakehurst Parkway. This construction threatens numerous endangered plant and animal species and aboriginal rock art sites, with close to 2000 established trees removed in Garigal National Park / Bantry Bay and Manly Dam Reserve.
  • Road configuration changes near tunnel entrances, including a new traffic light in the middle of Burnt Bridge Creek Deviation, and changes that create rat-runs in local streets. Increased traffic is projected in numerous local streets including Wanganella St, Judith St and Woodbine St.
  • Construction sites for 5-7 years undertaking drilling, rock crushing, concreting and earth removal located at Balgowlah Golf course, near Kirkwood St, Seaforth and at Spit Reserve West, Mosman.
  • Steel and concrete tunnel tubes fabricated on a large pontoon stationed at Spit Reserve West, with tubes constructed on small stilts on the bed of Middle Harbour. Construction performed with the use of coffer dams and barges in the harbour.
  • Public transport not considered as an alternative to the tunnel as revealed by leaks to the media from cabinet discussions(2), despite claims in the EIS that alternatives were considered.
  • Toll for using the tunnel estimated at $7-8 each way(1)– with projected tolls estimated to the CBD of $23 return, airport $33 return and Blue Mts $60 return. This equates to over $5000 per year for a commute to the city, and much more to western Sydney.
  • Early government estimates of travel time savings at 14 minutes from Seaforth to Cammeray, if there are no other influences to traffic flow, and estimates are realised. Whilst travel time savings are expected through the tunnel, changes to traffic patterns are projected to significantly increase delays on local roads and intersections including Condamine St at Manly Vale / Balgowlah, Sydney Rd and Warringah Rd / Wakehurst Parkway, despite recent road upgrades. Any tunnel time savings will be eaten up by increased delays on local roads.
  • The EIS now advertises “up to 38 minutes” travel time saving from Balgowlah to the CBD – as locals know, this is a grossly exaggerated figure. Travel time savings such as this are based on extrapolated numbers incorporating other tollways not yet built, and are based on the ‘the worst of the worst’ peak conditions in 2037.
  • Government estimates of just 10% reduction in traffic on Military Rd in long-term projections in 2037.


TfNSW map of Balgowlah portal in EIS


TfNSW map of Seaforth portal in EIS

1) Revealed: $8 tolls each way planned for new roadway tunnels to Sydney’s north (SMH, July 18, 2017)

2) Revealed: The $14 billion Western Harbour Tunnel Beaches Link price tag