Main road to Far North to close again for slip repairs after brief opening over Christmas

Saturday, 9 January 2021

Waka Kotahi NZ Transport Agency Northland system manager Jacqui Hori-Hoult explains the difficulty of opening State Highway 1 south of Kaitāia after the July 2020 storm. (Video first published October 2020.)

The main route to the Far North will soon close to all vehicles once again after it was briefly reopened during the Christmas holidays to ease traffic.

Apart from the last three weeks, State Highway 1 at Mangamuka Gorge, the quickest route to Kataia, Ninety Mile Beach and Cape Reinga, has been closed for the past six months after a one-in-500-year storm caused eight major slips in July.

It will be closed again from midnight on Sunday.

The Mangamuka Gorge after heavy rain across Northland in July brought down eight significant slips in the gorge.

Traffic has been diverted onto SH10, which serves the busy Bay of Islands and Doubtless Bay areas, causing an increase in congestion and traffic.

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This photo, taken in July, shows one of the large slips that closed State Highway 1 through Mangamuka Gorge.

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Crews have been working double time to get the work completed as quickly as possible.

The closure has added up to 30 minutes to a trip to Kaitaia from Whangārei, and up to 40 minutes each way for residents commuting from Mangamuka to Kaitaia.

Waka Kotahi NZ Transport Agency said the road needed to be closed again to resume repair work.

Northland system manager Jacqui Hori-Hoult thanked motorists who drove through the gorge over the Christmas period for travelling to the conditions and requirements of light vehicles.

However, Hori-Hoult said work was not finished and it needed to be closed again to finish building a piling wall that would support the road and make it safe for all users.

Prior to the Christmas break, Waka Kotahi said 31 concrete piles were drilled into the rock beneath the road but a further 15 are needed to make sure there is long term safety and the road remains stable.

“The drilling rig and other heavy machinery required for this work take up the full width of the road, so there’s no room for vehicles to pass during this phase of works,” Hori-Hoult said.

“Clearing the road to allow traffic through will take up too much of the work day and simply delay completion of the repair.”

Hori-Hoult said the agency understood the inconvenience of extended time added to trips having to go via SH10 but getting a permanent fix was the most “desirable solution”.

Crews would return to work on Monday and work 20-hour days to get the work done as quickly as possible.

Weather dependent, Hori-Hoult said it was expected the remaining piling work would take about three weeks.

“We will then look at whether the road can be opened to some vehicles for a time during the day. We’ll know more on that in a week or so.

“For now, we ask motorists and the local community to bear with us as we work as quickly as possible to complete the piling work. We will reopen the road in some form as soon as it’s possible to do so.”

The agency has planned to have the road reopened to two lanes by mid-2021. It could be quicker if work progresses faster.