- Hon Chris Bishop
Major works are getting underway in Mangahauini Gorge on State Highway 35 (SH35) north of Gisborne, as crews tackle the final and largest phase of Cyclone Gabrielle recovery efforts in Tairāwhiti, Transport Minister Chris Bishop says.
"Since Cyclone Gabrielle, Transport Rebuild East Coast and local contractor crews have worked very hard to keep one lane of the highway through the Mangahauini Gorge open, while a long-term solution was designed. The upcoming programme of work is all about protecting the highway for the long-term," Mr Bishop says.
"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.
"The Mangahauini River is constantly shifting, but cyclones like Bola and Gabrielle trigger dramatic changes, moving 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. Half a kilometre of the riverbed will be reshaped into the roughened channel, with specially made interlocking blocks (called hanbars), rocks and other material.
"The roughened channel will help keep the river on course and away from the road, ensuring SH35 stays open for East Coast communities. The highway will also be realigned, repaired, and rebuilt to make it straighter, smoother and safer.
"At a programme cost of around $50 million, the work is being delivered in packages with East Coast contractors. Crews have started early site set-up this month, with work expected to continue into mid-2026. Larger earthworks and river works are expected to start in September, with the new roughened channel laid in the summer season, followed by the new road surfacing.
"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. The final programme of work will upgrade that route to meet state highway standards, ensuring long-term safety, resilience, and reliability for SH35.
"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."
