The Far North Deputy Major says major arterial roads have been left looking like an ‘earthquake zone’ after wild weather hit the region last week.

Waka Kotahi says a temporary track has been cut through this large slip at the southern end of Mangamuka Gorge.
Photo: Supplied / Waka Kotahi

Highly unstable slips have closed part of the State Highway 1 through Mangamuka Gorge, between Kaitaia and Kerikeri.

Waka Kotahi say there are five major slips under the road and multiple others from surrounding hillsides that have covered the highway in some areas.

The Far North deputy mayor Ann Court says the region has been profoundly damaged.

“We have other local roads that are closed due to slips and we have SH1 that’s closed due to floods. So we are not in a good position here in the Far North.”

Waka Kotahi regional transport systems manager Jacqui Hori-Hoult said a timeline for rebuilding and re-opening the highway was unknown until geotechnical engineers had carried out detailed assessments of all of the damage sites.

“Today contractors have managed to cut a track through the largest slip covering the road to allow access for construction vehicles to pass through, and the crew is currently clearing two slips further south from that track.

“Under the direction of the specialist geotechnical engineer, crews are working to prevent any further damage to the current under slips, with bunds constructed to divert any further rainfall away from the slips,” she said.

Damage on SH1 through Mangamuka Gorge.
Photo: Supplied / Waka Kotahi

The access was difficult because some slips were still moving, Court said.

“The geology and geography of the Mangamuka is such as the land is constantly moving, so at the moment the road has collapsed underneath and it is in danger of collapsing above.”

In March this year, the Waitangi River Bridge – south of Kerikeri- on State Highway 10 was closed for heavy traffic until further notice due to safety concerns.

With the flood damage closing SH1, Waka Kotahi has reopened the bridge with speed restrictions.

State Highway 10 was not designed for heavy traffic and the detour could represent danger for drivers, Court said.

“We have a network that is not necessarily safe and certainly not fit for purpose that is going to have to pick up the task for the next months, if not years, as we work through the process to fix State Highway 1.”

A Waka Kotahi map shows the detour route while SH1 through the Mangamuka Gorge is closed.
Photo: Supplied / Waka Kotahi

She said the situation in the Far North was extremely risky and it should be looked at closer by authorities.

“We need significant investment, we need a significant commitment to sustainable solutions. We can’t simply risk having the 5000 odd people that live north of the Mangamuka at risk of being cut off. That’s not a good economic outcome and it’s certainly not a good outcome in terms of meeting their social needs.”

Through a statement Waka Kotahi said it had reinstated temporary access for over dimension vehicles to use the SH10 Waitangi River Bridge while SH1 remained closed through the Mangamuka Gorge.

The agency said restrictions on use of the bridge were put in place earlier this year, following the detection of deterioration during a routine inspection and the condition of the bridge was being very closely monitored, with a structural engineer checking the bridge daily.