The NZ Transport Agency says that State Highway 1 both north and south of Kaikōura is unlikely to reopen to traffic until at least mid-next week, a week after Cyclone Gita. The likely reopening date for one lane of traffic will be reviewed on Monday, 26 February. Multiple road and rail sites are blocked with rocks and soil.
“Our crews are working hard to repair the damage and restore access via SH1, but the extreme rainfall this week has left us with a big job ahead. Around 300,000 cubic metres of material needs to be cleared from 60 sites both north and south of the town, from Parnassus on the south side, to Clarence on the north,” says Tim Crow, Transport Agency Earthquake Recovery Manager.
“The biggest of these is just south of Okiwi Bay (Site 8), at Jacob’s Ladder, north of Kaikōura and is around 200,000 cubic metres alone.
The completed work around the biggest area damaged by the 2016 earthquake at Ohau Point has stood up well to the storm as has other completed reconstruction work by the North Canterbury Transport Infrastructure Recovery (NCTIR) team.
The new seawalls, well underway, the new Irongate Bridge and the Mangamaunu road and rail realignment were undamaged by Gita. A range of sites with rockfall protection from bunds and nets has also performed very well.
“Two debris flow bridge areas under construction north of Kaikōura in Half Moon Bay, south of Ohau Point, took a significant hit from large amounts of material pouring off the hills, sluiced off by the record downpour,” Mr Crow says. “Much of this material is sitting on steep hillsides and gullies, loosened by the earthquake, and will continue to pour off the hills whenever there is significant rain – which this was.”
One debris flow bridge area has already been cleared by crews working since Wednesday morning in Half Moon Bay.
More than 200 mm of rain fell in 24 hours, and at Rosy Morn, south of Kaikōura, more than 300 mm. Around 5,000 cubic metres of material washed down the hill at Rosy Morn with two nearby houses, not inhabited the night of the storm, filled with debris.
“Once we reopen, there will be several more single lane sections of highway while the road is restored to pre-storm condition as soon as possible,” says Mr Crow. “People will need to factor in some additional time for this journey for several weeks until we get all the material removed and back to our rebuild and resilience work.
While State Highway 1 is closed to traffic, and all this weekend, people can get to Kaikōura via the inland road (Route 70) via Waiau and Mt Lyford. Drivers need to build in time for this trip, and be aware of active worksites and the winding nature of the road.
Drivers travelling between Picton and Christchurch need to take the Lewis Pass Route via Murchison and St Arnaud.
Footage from the main slip site and along the northern coast
Previous storms to cause damage along SH1 through Kaikōura:
The recent cyclone caused the most cyclonic/ storm damage to the highway through Kaikōura since 1975’s Ex-Cyclone Alison which brought down 83 slips north and south of the town.
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