Project update

29 November 2023

Project Lead Landscaper Sam Guerin inspects the natives being planted alongside the Mimi stream, south of the future bypass.

Planting a legacy at Mt Messenger

A stretch of north Taranaki streambank is being given a new lease of life by Te Ara o Te Ata – Mt Messenger Bypass.

The project’s riparian or riverside planting programme has just seen 16,635 plants going into a 3.75 hectare area alongside the Mimi stream.

Riparian planting helps prevent erosion, filters sediment and nutrients and improves the habitat for native water dwellers by providing shade to keep the water cool in summer. Many of our native freshwater fish species prefer cool water conditions that are typically found under a bush or forest canopy.

The riparian zone just south of Mt Messenger extends 10 metres either side of the waterway and is fenced to keep stock out.

Mt Messenger Alliance Senior Project Ecologist Roger MacGibbon says years of planning have gone into the project’s mitigation, restoration and riparian planting programmes and it’s great to see boots on the ground.

He says they’ve tried to keep a local focus, cultivating seeds from the area and employing local contractors including a team from Tāmoremorenui, an affiliate and project partner to Ngāti Tama.

Mr MacGibbon says along with iwi, nearby landowners have been crucial to developing the programme and the project team is appreciative of their support, and commitment to care for the plantings into the future.

“In years to come, people driving past will be able to enjoy the trees and shrubs, while the wildlife in the stream will be much better off with more shade and better water quality,” says Mr MacGibbon.

“As the project progresses, more than 289,000 natives will ultimately be planted, across 46 hectares and nearly 90,000 of those natives are destined to go into riparian offset planting across 17 hectares.”

Planting will also cover six hectares of kahikatea swamp forest, 9 hectares of dryland bush, and 15 hectares of roadside margins and fill slopes.

“Sedges and rushes will thrive in open wetlands, while hardy shrubs, small trees, and towering canopy species will flourish in dryland bush and wetland margins.,” says Mr MacGibbon.

The mitigation and restoration programme is part of a comprehensive environmental strategy which includes pest management and aims to leave the wider project area in a much better condition for future generations.

A bird's eye view of construction zone 7 on the southern side of the future Te Ara o Te Ata - Mt Messenger Bypass.

Cuts, fills, bridges and a tunnel - construction surges ahead on numerous fronts

With the new construction season well underway, our team is busy on multiple sites throughout the project footprint.

The cableway is being put to good use ferrying equipment and materials into 'Fill 12', which will lead to the northern entrance of the project's 235m tunnel. Our focus is currently on installing piping for temporary stream diversions as part of safeguarding waterways.

We’re also preparing to work on the southern entrance to the tunnel. We’ve been trialling shotcrete, which will be used for wall lining, and we’re refurbishing our 110-tonne roadheader machine which will do the excavation grunt work.

A major focus for the summer construction season is building access from the cableway’s south anchor point to the tunnel’s future southern entrance. This requires temporary stream diversions and pipework to lay a foundation for work in 'Fill 13'.

At the southern base of Mt Messenger, we’ve installed our first permanent culvert and have been focused on environmental protections ahead of pushing towards the site of the future 125m bridge.

The final rock drape anchors have been installed at the top of the 27m-tall 'Cut 15' (pictured), with mesh installed to protect the cut face and a catch ditch dug to safely secure any falling debris for easy removal.

We’ll shift 1.1 million cubic metres of earth and rock over the lifetime of the project. 950,000m3 of this will be used for fill as we build up and level out the land along the 6km route.

Clockwise from Top left: Tom and Jackie’s chick Taiho, Martian’s chick Rover, Conrad’s chick Tracey, Muriwai and Tara.

Kiwi care continues

Our kiwi experts have put in the miles this breeding season, collecting eggs from around the project area.

Mostly the nests are sited away from construction, but we’ll establish a 40-metre exclusion zone and stop work near any that have kiwi incubating eggs, as we did with Tom in early spring this year.

When it’s safe to uplift the eggs, we take them for hatching at the Gallagher Kiwi Hatchery near Taupō. And once they’re big enough to successfully forage for themselves (at about 400g), the chicks will be transferred to predator-free Wairakei Golf + Sanctuary near Taupō.

There they’ll be raised until they’re big enough to fend off stoats (at about 1200g) and then returned to live out fruitful lives back in the pest-managed area of Parininihi between the coast and the new road.

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.