Te Ara o Te Ata - Mt Messenger Bypass

Project Update

21 July 2023


Great care is being taken to protect the existing State Highway 3 near the location of the future bypass.

Construction braces for winter

Construction activities have slowed for the winter on Te Ara o Te Ata: Mt Messenger Bypass, but one work-zone is still charging ahead, making the most of all and any fine weather.

At the northern end of the project's 1.1 kilometre cableway, excavation has been underway to establish a landing pad for heavy equipment, while the southern end of the cableway has seen great progress on an access track to the south entrance of the future 235-metre tunnel.

Meanwhile, at the southern base of Mt Messenger, work is continuing at pace where the new road moves away from the existing State Highway 3. At this location the Mt Messenger Alliance is making great progress in removing 56000 cubic metres of material in the first permanent cut of the project – 'Cut 15', a 27m-high excavation into the hillside.

Particular care is being taken at this 100m-long cut, which comes close to the current road.

Construction Manager Hardus Pieters says when work started, the team worked closely with specialist designers who provided a solution to help work safely and prevent any damage to SH3.

“We installed nine micropiles at a point where the cut face is closest to SH3 so we can continue to excavate while protecting the structural integrity of the highway,” he says. “We’ve also put in soil nails to strengthen a nearby area with a history of instability.

"This work required intermittent stop/go traffic controls over recent months but I'm pleased to say these have now stopped and we don't envisage any further delays until September at the earliest.

"We thank all motorists for their patience while this important work was completed."

Over winter, weather permitting, the team will continue excavation in this area and will soon be installing the project's first permanent culvert, which will allow work to progress towards the site of the project's 125m bridge.



Minimising impact on water quality is a key goal of Te Ara o Te Ata: Mt Messenger Bypass.

Top marks for clean water

We’re aiming for better than best practice at Te Ara o Te Ata: Mt Messenger Bypass, and our work in erosion and sediment control (ESC) is hitting the mark.

Our environmental experts are constantly working to reduce the amount of erosion during earthworks, while keeping clean water clean and treating any sediment-laden water so it can be safely discharged. This is extremely important for the health of our streams and rivers, and ultimately the sea.

We’re closely monitored by the Taranaki Regional Council, who started grading the project using an ESC scoring system in December. Since then, we’re pleased to have scored 336 ‘1s’ for ‘best practice, no further action required’ across 27 sites within our work areas. We have not scored any 2s, 3s or 4s in the weekly inspections.

Waka Kotahi Owner Interface Manager Caleb Perry says sedimentation of waterways contributes significantly to reduction in fish species and numbers, breeding habitat and water quality.

“We want to do the best we can to reduce this impact on the environment,” he says. “We are working in an ecologically significant and sensitive location, and we have the skills, experience to use techniques which we know work well.”

ESC is a large part of any earthworks project, but particularly so on Te Ara o Te Ata. The scale of the job and difficulty of the terrain are huge factors, as are environmental considerations and our commitment to tread as lightly as possible on the land.



Portable huts, used for temporary accommodation by our pest management teams.

Putting a dent in the pest problem

Work continues on putting a stop to the damage inflicted by pest species in the area around the project.

The Mt Messenger Alliance team has been doing the hard yards to tackle predators that have caused ongoing damage to the bush adjacent to the future 6km bypass.

Since August last year, we’ve trapped 449 rats in the project’s pest management area and wider Parininihi block. 171 possums have also been removed, along with 188 goats, 11 cats, and 29 stoats and weasels.

Additionally, the team has established more than 190km of a planned 250km of pest management tracks, and installed bait stations in damaged forest around the new section of SH3.

Predators such as rats, stoats and possums have caused serious long-term harm to the native forest surrounding the route of the future road, which has impacted on the local wildlife.

We’re committed to leaving the area in a better state than we found it.

Along with a major programme of restoration planting, our enduring pest management programme will help our iwi partner Ngāti Tama protect the whenua for generations to come.

Part of the programme includes an upcoming aerial bait application that will make further inroads into the pest population. This joint Waka Kotahi/Department of Conservation operation will target rats and possums that can’t be reached by ground-based pest management work.

From July, helicopters with calibrated buckets will distribute biodegradable 1080 bait along pre-determined and monitored flight paths over an area of 5,000ha.

A 'pre-feed' of non-toxic bait will be sown first, to prime the rodents and possums, ahead of the 1080 bait which will be distributed at least five days later. Each operation will take a day to complete.

Aerial application of cereal pellets containing 1080 is the most effective control method over large areas. It is the only viable method in large, remote, forest-covered and rugged locations.

Ground-based trapping and bait stations are effective in smaller more accessible areas, however the number of possums, rodents and stoats can sometimes overwhelm trapping networks. In these areas aerial 1080 can be used to supplement the existing ground-based work.

1080 dilutes rapidly to harmless levels in waterways – it is almost always undetectable after 24 hours. Because it is a natural compound (found in Australian and South African plants), 1080 is degraded by microorganisms in the soil and does not build up in insects, fish or plants.

More information on biodegradable 1080 is available at DOC’s website.



Waka Kotahi Owner Interface Manager Caleb Perry discusses Te Ara o Te Ata with members of the Taranaki Historic Speedway Association.

Keeping in touch with the community

Te Ara o Te Ata: Mt Messenger Bypass is Taranaki’s biggest roading project. The safety and resilience of the region’s northern access is vital to us all and we know there’s a lot of public interest in what we’re doing.

From iwi partnership to road construction, to the cableway, to our environmental restoration programme, there’s a lot to get excited about!

In recent weeks, we’ve been hosting groups on site and delivering presentations out and about in the community. These can range from specialist industry gatherings to service clubs, even school classes, and they provide an opportunity for people to learn more about our efforts and ask questions.

We’re proud of our mahi and are always keen to discuss our plans and progress. If your club or organisation would like to find out more about the complexities of the project, please get in touch: SH3@nzta.govt.nz. We’re sometimes limited by logistics and availability, but we'll do our best to bring you up to date.



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.