Holidaymakers heading to the Far North for Christmas can make plans to go by the shortest route on State Highway 1 through the Mangamuka Gorge. The road will open to light vehicles for the first time in five months at Midday on Friday, 18 December.
The road will open to a single lane for motorcycles, private cars and other class 1 vehicles, with traffic lights controlling vehicles past the slip that’s closed the gorge since July.
Single lane access past another slip a couple for hundred metres away from the main slip. This will have Give Way signs like on a one-way bridge. There will be a 50 kmh speed limit through the gorge.
“Drivers are advised to plan ahead, keep to the temporary speed limit and allow extra time for the journey through the gorge. There may be delays getting past the slip site but that will depend on the amount of traffic,” says Waka Kotahi NZ Transport Agency Northland System Manager, Jacqui Hori Hoult.
“Waka Kotahi understands the importance of the holiday period to the local economy. We’re very pleased to ensure the Far North is open for business over Christmas and the local community and holidaymakers can travel by the shortest route to Kaitaia and beyond.
“We understand the inconvenience and extra cost of having to travel on the recommended detour route (SH10) and we thank the local community and businesses on both routes for their patience and understanding while we worked as quickly as possible to fix the road.
“Last Friday, the repair team celebrated the completion of 31 piles needed to support the road so it can safely open to traffic later this week. They’ll be back in the New Year to complete the piling work and realign the road, restoring it to two lanes.
“They’ll spend the rest of this week tidying up the site and preparing the road for Friday’s opening. They’ll put in a safety guard rail, signage and new lane markings and there’ll be new asphalt laid.
“It’s been a great effort by the team, working in a difficult environment to get to this stage. They’ve worked double shifts (20 hours a day) and shaved more than four weeks off the work schedule to achieve the 18 December deadline.
SH1 through the gorge road was closed by eight slips during a 1-in-500 year rain event that hit Northland in July causing extensive flooding and road closures. The big slip under the road on the northern side of the summit has kept the road closed since then.
“The slip environment has been unstable and a difficult safety challenge. The repair team worked in stages, drilling temporary piles just to stabilise the road so they could bring in heavier equipment to complete the permanent piles.”
On 11 January, the road will be closed again to complete the piling and start on stage 2 of the repair, which is to cut into the hillside to realign the road and restore it to two lanes.
The drilling rig and other equipment used on the big slip will move a few hundred metres up the road to fix our second slip where the road has dropped and is reduced to one lane.
Concrete is poured into the last supporting pile needed to open SH1 through the Mangamuka Gorge before Christmas.
“The repair work at both slips takes up the full width of the road so we have to balance opening the road to let traffic through with just getting on and completing the repair as quickly as possible. We are asking our contractors if we can keep a lane open part-time as we finalise our building methodology to see what is achievable and practical,” says Jacqui Hori-Hoult.
“At this stage we plan to have the road at both slips restored to two lanes by mid 2021, but it could be sooner depending on the weather and work progress. We’re committing all available resources to getting it done.”
Until then, trucks and buses will have to continue using the detour route SH10.
SH1 Mangamuka Gorge slip repairs project website
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