SH43 Forgotten World Highway

Project update

3 April 2025

Done and dustless – Tāngarakāu Gorge is sealed

Journeys along the iconic Forgotten World Highway are now safer, more accessible and a lot less dusty with the Roads of Regional Significance project to seal the Tāngarākau Gorge now complete.

The project site was recently blessed by Iwi at an event to mark completion of the iconic 3 year project to seal the 12km section of road, one of the last remaining unsealed sections of highway in the country.

With the sealing now complete, more people will be able to experience the beauty of the Forgotten World Highway and locals are already reporting an increase in vehicles on the road.

NZTA Senior Project Manager Complex, Sree Harsha Nutulapati says sealing the road was just one part of the project. 

"Crews have also built four new retaining walls and installed more than ten culverts to carry water under the road, improving the resilience of the road.

"More than 50 thousand tonnes of metal was trucked in to complete the pavement and 1500 square metres of rock walls were built.

"While the project was challenging due to the remote and constrained environment, contractor Inframax whose crew stayed onsite for the duration of the project, have completed the work on time and within budget," says Sree.

"On behalf of NZTA, I'd like to thank the contractors, local businesses, community members, and our Iwi and council partners for your ongoing support and cooperation while the project has been completed."

The final component of the $30 million programme of improvements for the highway, a series of sculptures developed by Ngāti Maru, Ngāti Hāua and Ngāti Ruanui Iwi, will be erected on the highway towards the middle of the year.

Rare plant thriving in the gorge

A key priority of the SH43 sealing project was protecting the pristine natural environment so when an extremely rare native plant was discovered in the Tāngarākau Gorge, local Iwi jumped into action.

The nationally endangered plant, Brachyglottis Turneri or Manawa Kawa as it has been named by Iwi, is similar to an orchid with a heart shaped leaf and small yellow flower that blooms from November to December. It can only be found in 11 locations in Taranaki and a handful of places in Whanganui.

To ensure the population wasn't impacted by the sealing project, in December 2023 Iwi representatives carefully took cuttings from the plants under the expert guidance of horticulturist Phillip Smith from Totora Glen Nurseries in Palmerston North.

Phillip then reared the cuttings over several months ready for replanting in the gorge. He describes the plant as interesting but very particular.

“In the wild, they grow under waterfalls and near drains and seepages. It’s very easy for them to dry out so they require constant care," says Phillip. 

In September 2024, Ngāti Maru and Ngāti Hāua Iwi representatives, accompanied by Department of Conservation (DoC) rangers replanted over 40 new plants on the mossy banks in the Tāngarākau Gorge. 

Ngāti Maru, Tumu Whakarae (CEO) Anaru Marshall says the plants love damp, low light conditions so are right at home in the gorge. 

"The new plants are thriving with many of them having flowered over the summer months.

"This is a special plant that is only found in Taranaki and Whanganui, so it was amazing to discover it growing in the Tāngarākau Gorge and to be able to protect and help increase the population." he says. 

DoC documented the locations of the plants, and will continue to monitor the population.

Image below: Joe Allen of Ngāti Hāua Iwi planting Manawa Kawa