Progress is underway to fix an underslip that has reduced the Mangamuka Gorge down to one lane since late last month.

Enabling works have already begun to prepare the site for a new 48m retaining wall.

As NZ Transport Agency Waka Kotahi (NZTA) explains, the location is complex due to the proximity to the Mangamuka River.

“During this first stage of works, the team is focusing on stabilising the underslip, which will allow heavy machinery to work safely at the top of the slip when we’re ready to build the wall,” says System Manager for Northland, Steve Matene.

The route will remain under 24/7 stop/go for the next 2 months during the enabling works for the safety for both motorists and workers at the site.

“Construction will stop ahead of Christmas, and the road will be fully open over the busy Christmas/New Years period,” Mr Matene says.

The team will return early January 2026 to start construction of the permanent retaining wall, which should be complete by late May 2026.

“The good news is – we can build the retaining wall without fully closing the road. But we will need to reduce traffic to one lane again from late January to complete the job safely.

“This is difficult terrain, and vulnerable to slips, but the recovery work we’ve been doing since the August 2022 weather event is paying off, with repairs on other slips standing up well,” Mr Matene says.

“A big thank you to everyone in the community for your ongoing support.”

If you’re travelling through, please be considerate to our traffic management teams and drive to the conditions, as it’s a winding road with many curves.

For real-time travel information, visit www.journeys.nzta.govt.nz or call 0800 4 HIGHWAYS (0800 44 44 49).

© Scoop Media