Project update

7 June 2022

Kia ora and welcome to the latest newsletter on Te Ahu a Turanga: Manawatū Tararua Highway – the 11.5km route to reconnect the Manawatū, Tararua District, Hawke’s Bay and northern Wairarapa, replacing the closed State Highway 3 Manawatū Gorge route.

Landscaping team members get the native plants ready ahead of planting at an offset site.

Thousands of native plants ready for Planting Season 2

The planting of more than 530,000 plants by the Te Ahu a Turanga: Manawatū-Tararua Highway team over the next few months started in May, as the project enters its second planting season.

As part of the project’s ecological offset programme, almost 2 million native plants grown from eco-sourced seeds will be planted along the highway and at five additional locations – known as offset sites – throughout the region across the duration of the project.

A total of 250,000 riparian and wetland natives were planted at two of the offset sites during the project’s first planting season in 2021. These plants are looking in great condition, having been maintained by the project's landscaping team over the offseason.

This work is a feature of the project’s intention to “tread lightly” on the whenua and to leave the environment surrounding the highway in a better condition than when the project began.

The planting teams have done a lot of work preparing the plants on several hectares of land ahead of planting at the three additional offset sites in the second season. They are eagerly anticipating seeing these efforts come to fruition as the project enters the winter months.

While the drier, summer months are ideal conditions for earthmoving activity, the opposite is true when it comes to planting. Rain loosens the earth, making it easier to get plants in the ground, while also providing a better environment for young plants to grow.

The remote nature of some the offset sites meant plants regularly needed to be flown in by helicopter, with the planting team often having to make their way onsite by foot.  The timing of the season also means they are often working in challenging weather conditions, so the project is extremely lucky to have a team who are incredibly dedicated and passionate about what they do.

In the time between planting seasons, teams have undertaken considerable preparation work at the offset sites, which has included trimming back overgrown vegetation, installing fencing and pest control.

The team has also been preparing Parahaki Island, on the Manawatū River, for its mitigation planting phase. This has included been working closely with the Parahaki Island Trustees, including chair Rob Karaitiana and Secretary Jean Te Huia.

In addition to the project's mahi, which includes marking out the planting area and cutting back vegetation, the trustees are planting an additional 40,000 harakeke flax on the island, which is to honour and continue the flax planting begun by the Te Kauru-Hapu Collective in 2014.

Along the highway, the planting and landscaping teams are preparing for permanent grassing on completed earthworks sections while also placing landscape mulch on permanent planting areas.

The second planting season is expected to end in October 2022.

Below: Te Ahu a Turanga's planters unload a delivery of native plants in windy, wet conditions. 

Palaeobiologist Dr Richard Holdaway discusses the moa bone sampling process with Te Ahu a Turanga Kaitiaki Terry Hapi at Te Manawa.

Moa bones discovered onsite may be 345,000 years old

Bones of two species of moa and of other large flightless birds unearthed in the Ruahine Ranges by the team working on Te Ahu a Turanga: Manawatū Tararua Highway have been sampled for analysis to determine their age and relationships.

The bones were discovered during excavation work on the western end of the highway alignment in March 2021. After the discovery, the bones were taken to Te Manawa Museum in Palmerston North for safekeeping while a decision was made about their future.

Te Ahu a Turanga’s Iwi partners; Rangitāne o Manawatū, Rangitāne o Tamaki nui-a-Rua, Ngāti Kahungunu ki Tāmaki nui-a-Rua, Te Runanga o Raukawa (Ngāti Raukawa ki te Tonga and Ngā Kaitiaki ō Ngāti Kauwhata), agreed for the bones to be sampled, with requirements for appropriate tikanga to be observed and for their immediate return to the maunga after the sampling.

The sampling for radiometric dating and isotopic and ancient genetic analysis took place across three days in December 2021, and was undertaken by palaeobiologist Dr Richard Holdaway.

The sampling process included photographing and 3D scanning the bones for replication and lodgement of replicas at Te Papa Tongarewa and Te Manawa. Previously, the sediments around, below and above the bones had been sampled for dating and for possible evidence of the vegetation at the site when the birds died.

Analysis of sediment samples has already provided a minimum age of 180,000 years for the bones, with a possible age of 345,000 years suggested by the nature of the sediment around the bones. The extreme age of the well-preserved bones makes them one of the most significant discoveries of such fauna in New Zealand.

Following the sampling, the bones were returned to the Ruahine Maunga in a private ceremony conducted by iwi.

Working alongside Dr Holdaway during the testing was Te Ahu a Turanga Kaitiaki Terry Hapi, who was entrusted by iwi with the responsibility of ensuring appropriate tikanga was observed throughout the sampling and repatriation process.

His role as kaitiaki (protector) of the bones included having daily karakia to acknowledge the wheua moa, and reassure them that they would soon be returned to the breast of Papatūānuku back on the Ruahine maunga.

He also ensured those who handled the bones cleansed their hands to ensure tapu was lifted at the end of each testing day, as well as providing crucial insight and advice during the testing process.

Results from the many analyses are expected to be available later this year.

An aerial shot of Zone 2 of the Te Ahu a Turanga: Manawatū Tararua Highway site.

Te Ahu a Turanga team reach important milestones

The Te Ahu a Turanga: Manawatū Tararua Highway team celebrated a significant milestone in May; moving the 3 millionth cubic metre of earth since construction began in January 2021.

A total of 6 million cubic metres of earth will be moved across the duration of the project, so this milestone marks the halfway point for the site’s earthworks.

The Te Ahu a Turanga site consists of 4 earthworks zones, named Zones 1, 2 ,3 and 4, which are comprised of areas of both cut and fill.

In Zone 1, at the Ashhurst end, work has begun on the road that will connect to the new Western Access Gateway Park, where the carpark to the Te Āpiti - Manawatū Gorge walking track will be located.

Great progress has been made in Zone 2, with more than 1.2M cubic metres moved into Fill 9 to date. Work at Cut 12 has now been completed and Cut 13, the largest cut on the project, has had about 1.2M cubic metres of earth moved so far.

In Zone 3, the teams have been busy building ponds, tracks and culvert sites ahead of the major earthworks getting under way in the next summer season. 

More than 1M cubic metres of earth has been moved across Zone 4 so far, and great progress continues to be made in Cut 28, with the benches now visible to the public.

Winter works consents have been approved for this year and these will allow earthworks to continue, where possible.

The team celebrated the 3M earthworks milestone at an Alliance hui held in Ashhurst in May. This was the first time a celebration of this kind has been possible this year because of the COVID-19 pandemic.

During the celebration, Zone 2 operator Willie Campbell, who moved the 3 millionth cube, was presented with a small digger statue in recognition of his involvement in the team milestone.

Considerable progress is also being made at the six structures along the alignment. Two of the minor structures, the Bridge 1 and Bridge 10 underpasses, are structurally complete, and now only require the completion of mechanically stabilised earth walls.

On Parahaki Bridge, across the Manawatū River, piling is completed on Piers 1 and 2, with piling on the third and final pier under way and expected to be finished by the end of June. 

The first two piles have gone in the ground at the Eco Viaduct Bridge, where unusually high levels of artesian water pressure have created challenging conditions, and work is under way on the third pile.

Work is now underway on the Bridge 5 underpass in Zone 3, and planning work is ongoing for the Bridge 7 underpass, at the Woodville end of the alignment.

The hard mahi of staff to ensure the project has a strong safety record has been recognised by New Zealand Workplace Health & Safety Awards 2022, which have named the Te Ahu a Turanga Alliance a finalist in the Safety-II category of the national awards. The winners will be announced in June.

To view the latest flyover footage, head to: https://www.nzta.govt.nz/projects/te-ahu-a-turanga/

Below: Operator Willie Campbell with the prize for moving the 3 millionth cubic metre of earth on the project. 

More information

For more information on the Te Ahu a Turanga: Manawatū Tararua Highway, please use one or more of the following methods:

• Website: www.nzta.govt.nz/teahuaturanga
• Facebook: facebook.com/nztacni
• Twitter: twitter.com/WakaKotahiCNI
• Email: teahuaturanga@nzta.govt.nz
• Phone: 0800 740 560