A $50 million work programme along State Highway 35 north of Gisborne will include reshaping a nearby riverbed, believed to be the first work of its kind in New Zealand.
Major work in Mangahauini Gorge started this month, as the final and largest phase of Cyclone Gabrielle recovery efforts in Tairāwhiti.
Transport Rebuild East Coast (Trec) project manager Richard Bayley said the upgrade will restore the highway to two lanes and will include realigning, repairing and rebuilding the road to make it straighter, smoother and safer.
“A key part of this project is working with local contractors, who’ve been onsite since the cyclone, ensuring SH35 remained open and communities connected.”
Chris Bishop, Minister of Transport, said in a statement that Trec and local contractor crews had worked hard since Cyclone Gabrielle to keep one lane of the highway through the gorge open.
“The upcoming programme of work is all about protecting the highway for the long-term,” Bishop said.
“Once complete in mid-2026, SH35 through the gorge will be fully open to two lanes for the first time since Cyclone Gabrielle. Much of the work will take place in and around the Mangahauini River, where repeated weather events have shifted the riverbed and eroded the land beneath the highway.
He said the river was constantly shifting, but the dramatic changes caused by Cyclones Bola and Gabrielle had moved the riverbed several metres in every direction.
“These shifts weaken the land, cause slips, and undermine the highway, leading to closures and major disruptions for the community.
“A key innovation in the work to be delivered is the construction of a ‘roughened channel’, believed to be the first of its kind in a New Zealand river.”
Bayley said creating a “roughened channel” in the Mangahauini River would be a crucial aspect of the project.
“Half a kilometre of riverbed will be shaped with interlocking hanbars, rocks, and other materials – slowing the river where it’s steepest and most aggressive. The new channel will protect the highway from erosion,” Bayley said.
“This is a large piece of work that will make a real difference in this area going forward.”
Bayley said iwi, hapū kaitiaki and local contractors with experience in the gorge played a key role in shaping the designs, ensuring native fish habitats were protected and the improvements could be maintained locally.
Lillian Te Hau-Ward, Te Akau o Tokomaru Civil Defence lead, said working closely with Trec meant local voices were part of the design.
“We whakapapa to this whenua, we whakapapa and live with our river’s moods. When our ideas are taken seriously and embedded like this – that’s when recovery becomes resilience,” Te Hau-Ward said.
“This isn’t just about reopening a road. For us, it’s about restoring connection, protecting our taonga and taiao, and leaving something stronger for our mokopuna. This mahi means a huge amount to our Ngāti Porou communities.
“To work with Trec and help design and deliver something this impactful – that’s special. When this highway is fully reopened, it’ll bring relief, opportunity and connection back to the Coast.”
Bishop thanked local contractors and communities.
“Local contractors did an excellent job building a temporary track through Mangahauini Gorge after the cyclone, and I want to thank them for their rapid response that reconnected communities when it mattered most,” Bishop said.
“I want to thank local communities for their patience as the team has worked hard to get us to this point and I look forward to the works through the Mangahauini Gorge being completed in mid-2026.”
Larger earthworks and river works are expected to start in September, with the new roughened channel laid in the summer, followed by the new road surfacing.
According to NZ Transport Agency Waka Kotahi (NZTA), the work is being delivered in packages, with local firms Blackbee Contractors Limited, Lattey, Pro Worx Limited and Tairawhiti Contractors Limited already engaged.
Further packages are being procured or will go to tender soon.
During construction, SH35 will remain one lane in parts with stop/go traffic and slower speeds in place.
NZTA advised there would be a lot of truck activity over the coming months while landslide material was relocated.
Drivers should plan ahead and expect delays when travelling through the area.