Homer Tunnel $29 million safety project – avalanche and rockfall shelter construction starting November

The Homer Tunnel, the entrance to Milford Sound Piopiotahi, has been getting safety improvements over the past 2 years.

The next and final piece of work is the replacement of the old avalanche shelter on SH94 at the mouth of the tunnel on the Te Anau/ eastern side, starting in November, says Waka Kotahi NZ Transport Agency.

“People will see work underway around the tunnel during daytime hours which won’t affect their journey times,” says Waka Kotahi Senior Project Manager Chris Collins. “But we will need some night-time closures for the first two weeks of demolition early in November. Given very few people travel at night, there should be minimal effect upon road users and we will advertise the closures well in advance.”

The Government-funded project’s new avalanche and rockfall shelter, a 45-metre extension of the Homer Tunnel itself on the Te Anau/eastern side, has been designed for portable, modular, quick installation. This will enable efficient construction at the entrance to the tunnel, says Mr Collins.

“The old structure has reached the end of its useful life and will be demolished at night with full road closures for around 2 weeks between 8 pm and 6 am,” he says.

This work can only start once the winter/spring avalanche risk is over – expected in coming days.

More than 150 concrete, pre-cast units are being made in Ashburton and will be transported to the site over coming months.

Night work closures in November

To minimise disruption to visitors, who largely drive to Milford Sound Piopiotahi in daytime hours, the tunnel will be largely unaffected during daytime hours from November through to May 2024.

Full night closures will be needed for the initial demolition works, dependent upon the avalanche season ending. The existing tunnel shelter is about 35 metres long.

At this stage the dates are Monday, 6 November to Monday, 20 November. Apart from emergency vehicles, the tunnel will be fully closed overnight 8 pm to 6 am for these nights of work.

A minimal number of evening closures, 6 pm to 10 pm will also be required, with the tunnel opening every hour for 15 minutes to let traffic through. These dates will be well advertised on roadside electronic messaging, via the Milford Road Alliance email and the www.Milfordroad.co.nz(external link)  website as well as the Homer Tunnel safety improvements project page: https://www.nzta.govt.nz/projects/homer-tunnel-safety-improvements/(external link)

• Journey Planner: https://www.journeys.nzta.govt.nz/journey-planner(external link)
• Facebook: facebook.com/NZTASouthIsland(external link)
• Twitter Otago/Southland: twitter.com/WakaKotahiOS(external link)

The work will run over six days Monday to Saturday inclusive, with Sundays included if weather causes postponed days.

Safety upgrades to date

An upgraded tunnel power system and lighting plus new speakers inside the tunnel to communicate with people in an emergency have been installed in recent years. A new protected duct has been built along the full 1.2km length of the tunnel to protect cabling, fibre and other systems during a fire, says Mr Collins.

An extra lane has been built at the eastern tunnel traffic signal (back toward the tunnel control building) for better management of traffic during winter, and more sophisticated in-tunnel vehicle detection systems have been installed. Other milestones include:

• A new and safer viewing area for visitors.
• A plant and equipment building to the side of the tunnel.
• Upgraded power supply.
• An upgraded solar-powered communications tower gives better coverage in this remote area of wilderness.

Construction timetable

 Minimising traffic delays