Project update

27 March 2025

Work continues at Cut 11, opening up the northern side of the project's 235m-long tunnel.

Project reaches multiple milestones

The first quarter of the year has delivered many milestones for the team at Te Ara o Te Ata – Mt Messenger Bypass project.

We’ve made the most of good weather to complete Cut 14 at the southern base of Mt Messenger. Finalising this 38m-tall excavation has concluded bulk earthworks in this work zone and opened the way to begin constructing our 125m-long bridge. We’re now installing piles for a temporary bridge to facilitate access.

Further along the future route, our tunnelling operations are continuing apace, including paving the team's workshop area and the approach to the tunnel, to maximise safety over the wet winter months.

A 110-tonne road header machine is excavating the upper portion (top heading) of the tunnel, and when that’s done, it will complete the lower section (bench), leaving a 9m-tall, 13m-wide tunnel capable of accommodating loads as large as house removals.

On the northern side of Mt Messenger, we’ve cleared Cut 11 to the top of the tunnel’s future exit, while at the other end of this work zone, we’re about halfway through the 42m-tall Cut 10. The project is split into work zones, which you can see in the graphic below.

In between, we’ve built a large sediment retention pond (SRP) capable of receiving rainwater runoff from a 5ha catchment. This SRP is part of our extensive erosion and sediment control measures and allows solid material to settle, protecting downstream environments.

Further north, we’ve begun work at the future connection of the bypass with the current State Highway 3. At this point, we’re establishing a laydown site for plant and material.

The bridge will have angled piers to keep the foundations out of the Mimi stream.

Bridge works get underway

Our bridge crew is in action following a period of detailed planning. This specialist team has experience working in demanding conditions all around New Zealand and beyond and they’re looking forward to focusing their expertise on our project.

Over the last few weeks, a site office and mobile workshop have been established next to the operational area at the southern base of Mt Messenger, with plant and materials being delivered, including a 280-tonne crane that towers above the existing SH3.

The team is currently building a temporary staging bridge to enable work on a 125m-long bridge across the Mimi wetland. The permanent bridge will be a steel girder structure with a concrete deck on raked pier supports.

These angled piers have been designed to keep the foundations out of the Mimi stream, as part of our commitment to tread as lightly on the land as possible.

When completed the bridge will be flanked by two pou (pillars) acknowledging the project's iwi partner Ngāti Tama as traditional guardians of the area.

Kiwi dog handler Martin, with kiwi dog Ash, ecologist Sian, and Jackie - one of 16 kiwi being monitored and cared for by the Mt Messenger project team.

Caring for kiwi

The Mt Messenger Bypass will bring major safety and resilience wins for SH3 in north Taranaki, while at the same time caring for native animals in the surrounding forest.

As constructors continue earthworks and progress the project’s 235-metre tunnel and 125m bridge, ecologists are onsite day and night protecting a wide range of native species including kiwi, lizards and long-tailed bats.

The ecologists have been working in the area since 2017, monitoring and protecting a wide range of species including birds, lizards, long-tailed bats, fish, eels and other freshwater species.

Along with the regular use of 'kiwi dogs' specially-trained to detect the birds, we’re currently tracking the whereabouts of 16 kiwi with radio transmitters, to keep them safe. During the next couple of months we’ll be changing transmitters and carrying out health checks on all monitored kiwi.

As well as protecting the kiwi that are here, we’re committed to help grow the local population that has long been threatened by predator species.

Our ecologists uplift kiwi eggs, for hatching and raising safely at specialist facilities. During the 2024-25 breeding season, which has just ended, eggs from the project area have produced 18 chicks at the Wairakei Kiwi Burrow and the National Kiwi Hatchery. 

Once they’re big enough to fight off the likes of stoats, these kiwi will be released in pest-managed parts of the nearby Parininihi.

Since the project began, 29 young kiwi have been returned to the area and are enjoying a much better chance of survival than before the project began.

Traffic updates

Most of our work takes place off the existing highway, however at the moment we have temporary traffic management in place at the northern edge of the project (see Z1 in our map above).

These measures are helping keep our project team members and the travelling public safe as we work in the area where the new bypass will join the existing SH3.

Please plan ahead for daytime STOP/GOs in this area until Tuesday 13 May, from 6am-6pm Monday to Saturday excluding public holidays.

• Monday 17 March to Wednesday 26 March, delays of up to 15 minutes are possible.

• Thursday 27 March to Tuesday 8 April, delays of up to 30 minutes are possible due to vegetation control works.

• Wednesday 9 April to Tuesday 13 May, delays of up to 15 minutes are possible.

Please allow extra time on your journey when travelling this route.

More information

For more information on Te Ara o Te Ata: Mt Messenger Bypass, please visit our website, email SH3@nzta.govt.nz or call 0800 BYPASS.