State Highway 1 over the Brynderwyn Hills has reopened after a deluge of heavy rain overnight saw a number of "small" slips occur.
One slip was "quickly cleared" but another slip had covered both lanes.
In an update just after 6pm, the NZ Transport Agency said the road had reopened with a temporary 30km/h speed restriction in place.
"Crews have been hard at work on-site all day clearing slip material brought down by heavy rain early this morning," a spokesperson said.
"NZTA will continue monitoring the hill for any more movement to ensure it remains safe for road users.
"We thank our contractors for the great work to clear the slip material, and we thank road users for their patience while this work was completed."
While the road was closed, lighter vehicles were advised to use Cove Rd, while heavy vehicles were asked to detour via SH12 and SH14.
Paparoa Oakley Rd was unsuitable for freight due to a significant under slip.
It's less than a month since the vital route north reopened to traffic after an extensive closure. (Source: 1News)
The closure came after the official re-opening of SH1 Brynderwyns just last month, following 18 months of disruption.
Two fresh slips in April delayed the reopening from the originally planned May 13, and bumped up the project cost to $84 million.
NZTA Northland recovery project manager Mark Ware said at the time more than 900 people had worked on the site day and night, "in all sorts of conditions", to get the road open.
'We are absolutely gutted'
Whangārei Mayor Vince Cocurullo told 1News earlier today he did not expect to be standing alongside SH1 so soon after the road reopened, but said recent improvements should make the slips easier to clear.
"The great thing is they have made the section of road through the Brynderwyns wider, so it's at least allowed them to do the work," he said.
"The disappointing thing is it's actually also closed the road off in this one situation."
Northland Chamber of Commerce president Tim Robinson said Northland businesses were "absolutely gutted" by the closure, adding to the series of pressures hanging over the region in recent years.
"We're on our knees now," he said. "It's just been disruption after disruption — Covid, the weather bombs last year, now the Brynderwyns closed this year ... business is just about broken in Northland."
Transport Minister Simeon Brown told 1News NZTA was "working at pace" to fix the road and bring geotech crews onsite.
"I'm hoping to get it reopened as quickly as possible so this critical link north can reopen to motorists as quickly as possible," he said.
"[NZTA has] been working to get contractors in there to remove the dirt, get GeoTech [crews] to assess to make sure there's no other dirt potentially going to come down."
Brown said the slips highlighted the importance of designing and preparing roads to withstand long-term issues.
"That's why this government's committed to a four lane corridor from Auckland to Whangārei and we've got planning work already underway for that corridor, because we know that Northland needs a far more resilient, long-term solution."
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