SH1 Mangamuka Gorge slip repairs

Project update

27 February 2025

Slip A9 – Anchors are being installed from the closed shoulder of the road.

SH1 Mangamuka Gorge slip repairs – February 2025 update

Kia ora koutou,

After the successful reopening of the road before Christmas, we have now returned to complete the final stages of the repairs.

The gorge remains open throughout with temporary traffic management in place. We are on track to complete all work and leave the site in April 2025.

Below we share an update on the final slip repairs as well as the stories behind the cultural designs.

We appreciate your patience – please continue to take care while traveling through the gorge and around worksites to ensure the safety of workers and road users.

Slip updates

Despite the challenging ground conditions on Slip A9, good progress is being made with all the remaining ground anchors now installed and testing underway. Once the anchor team complete their work on A9, they will move to Slip A7 to install the last anchors on the project.

To minimise disruption, we are working on a maximum of 2 slip sites at a time to reduce the need for long single-lane closures. Our final pieces of work include grouting of anchor pockets to secure and protect the anchor fixing points along the capping beam, installing the last motorcycle rail on the guardrails, and ensuring all areas are left tidy by removing construction debris and materials.

Slip A13 – Worksite clean-up is complete. Coconut matting has been laid to prevent erosion and support growth at the base of the walls.

Cultural design and working with hapū through the gorge

A key factor in the success of the repairs has been the strong relationships formed with hapū connected to the Maungataniwha Ranges and the Mangamuka Gorge—Te Paatu (northern side of the summit) and Ngā Hapū o Mangamuka (southern side of the summit).

Hapū representatives have been actively involved since the project's inception, working closely with us to integrate Te Ao Māori perspectives into every aspect of the work. Their representation spans from the Project Management team to hands-on involvement during construction. While onsite, they have helped ensure that the environmental values and cultural heritage of the area are protected—a priority that remains as work continues through to April this year.

Beyond their involvement in decision-making, hapū representatives have played a key role in communicating project progress to their wider communities. This ongoing engagement has helped build trust, dispel misinformation, and ensure a shared understanding of the project's decisions.

The collaboration has also led to culturally significant design elements. It is hard to miss the stunning pou at each entrance and the intricate design on the upslope wall. The pou and wall design at A27 symbolize the deep connection hapū have with the gorge and their significant role in this project.

Northern pou - Kakaitawhiti, Koropeke, Moroki (left) and Kahutianui (right).

Kakaitawhiti, Koropeke, Moroki

This pou whakairo (carved post) depicts Kakaitawhiti, a revered ancestor of the Ngai Tamatea tribe. His leadership, wisdom and resilience laid the foundation for establishing enduring connections to the land. His sons Koropeke and Moroki became key figures in establishing and solidifying Te Paatu, each brother contributing to the expansion and fortification of the tribe.

The descendants of Kakaitawhiti, Moroki and Koropeke are spread throughout Peria-Oruru, Mangataiore, Te Konoti, Takahue, Oturu, Kareponia, Parapara-Toatoa and others areas in Ngāti Kahu and Te Rarawa. The three figures of the pou represent Kakaitawhiti, Koropeke and Moroki.

Carver: Campbell Goodnight (Ngāti Taranga, Kohatutaka, Ngāti Kahu, Ngāpuhi).

Kahutianui

This pou whakairo (carved post) depicts Kahutianui, the daughter of Tūmoana and Kahukuraariki. Tūmoana was the rangatira (chief) of the Tinana waka (canoe) of Te Rarawa tribe. His mokopuna Parata is said to have refashioned the Tinana at Rangiātea following the return of Tūmoana from Tauroa. After refashioning the waka, Tinana was renamed Mamaru and guided by Te Parata back to Aotearoa.

Te Parata married Kahutianui, the ancestress of Ngāti Kahu, and lived alternately at three important headlands of Tokerau: Karikari to the north, Otengi at the centre and Taemaro on the east.

The pou whakairo of Te Parata located on the east coast near the Taipa Bridge connects to the pou of Kahutianui situated here at Raetea, where both ancestors greet and farewell visitors to Te Hiku o Te Ika (Far North).

Carver: Billy Harrison (Ngāti Tara, Te Paatu, Ngāti Kahu, Te Rarawa).

Pou whakairo (carved post) of Te Parata near Taipa Bridge.

Southern pou - Tauira Taniwha.

Tauira Taniwha

This pou stands as a tribute to the strength, resilience, and enduring legacy of Ngāpuhi. It draws inspiration from two significant elements of Ngāpuhi’s heritage: Tauira Ata, a skilled toki (a sharp axe like tool) that re-adzed the waka Matawhaorua—originally gifted by Kupe to his mokopuna (grandchildren), Nukutawhiti—and Maunga Taniwha, our sacred mountain, one of the pillars of the Wharetapu o Ngāpuhi, beneath which this pou stands.

The pou symbolises the journey of Ngāpuhi’s people. Just as Nukutawhiti re-adzed Matawhaorua to guide Ngāpuhi’s ancestors, Waka Kotahi and the workers who restored the Mangamuka Gorge have forged a path for the continued growth and unity of our communities. This 7-metre toki serves as a bridge between past struggles and modern achievements, honouring the tireless efforts of those who reopened the gorge and safeguarding Ngāpuhi’s future for generations to come.

Ko Tauira Taniwha te ingoa o tenei pou!

Multidisciplinary Designer: Arapeta Wharepapa.
Carver: Campbell Karanga.

Ko Maunga Taniwha te maunga.
Ko Hokianga te moana.
Ko Matawhaorua te waka, ko Kupe te ariki o runga.
Ko Kōhatutaka me Te Ihutai ngā hapū.
Ko Ngāpuhi te iwi.

Slip A27 mural - Hawaiki.

Hawaiki

Hawaiki encapsulates the profound interconnectedness of the Pacific nations, weaving together the ancestral homelands of Hawai'i, Rapa Nui, Raiatea, and Aotearoa. Central to the composition are three mangōpare, (design representing the hammerhead shark) each representing a distinct part of the Pacific: Hawaiki roa (Hawai'i), Hawaiki pāmamao (Rapa Nui), and Raiatea, the spiritual heart of the Pacific triangle.

These mangopare, with their dynamic and flowing forms, are linked by the puhoro—a continuous, spiral pattern symbolising the movement and connection of all the lands across the vast ocean. The puhoro mirrors the shape of a waka's prow, signifying the journey and the carrying of ancestral knowledge.

While Aotearoa's connection is felt through the presence of whenua beneath our feet, the entire piece reflects the shared cultural legacy that ties these lands together, evoking unity, resilience, and the enduring spirit of the Pacific. Through this design, the artwork speaks of a living, breathing relationship between the nation’s, their people, and the ocean that binds them.

Multidisciplinary Designer: Arapeta Wharepapa.

Click the image above to watch our project wrap-up video.

Behind-the-scenes project videos

If you missed them last year, check out our playlist of behind-the-scenes project progress videos. These updates provide a glimpse of the project, and the people involved during the project:

Mangamuka Gorge slip repairs - YouTube playlist

More information

For more information on the SH1 Mangamuka Gorge slip repairs, contact us at northlandproject@nzta.govt.nz

Visit our website www.nzta.govt.nz/mangamuka