The notorious stretch of State Highway 1 through Mangamuka Gorge, south of Kaitāia, is slated to reopen by Christmas after being closed for over two years due to severe storm damage.
A major storm in August 2022 caused 15 slips that obliterated the 13-kilometre road, just over a year after it had reopened from a previous year-long closure. Repair efforts, which had been underway for less than six months, faced another setback in April 2023 when a second storm triggered an additional 20 slips, significantly delaying the work and escalating the cost from an initial $100 million to approximately $165 million.
Waka Kotahi NZ Transport Agency’s senior project manager Hendrik Postma told state media that the rebuilding efforts are progressing well, with an anticipated completion before Christmas, weather permitting.
The highway’s closure has forced motorists to detour via State Highway 10 or use back roads, doubling travel times and impacting the region’s connectivity.
Seventy-four percent of the project’s workforce are locals, driven by a vested interest in reopening the road. The complex project involves addressing the unstable geology, high rainfall, and treacherous terrain of the Mangamuka Gorge.
Special measures such as driving large piles deep into the ground and improving drainage systems have been implemented to ensure the road’s resilience against future storms.
