The Transport Agency is advising that the slip site in Ngauranga Gorge has been assessed by geotechnical engineers, following the closure of lanes yesterday afternoon.
Contractors worked through the night to get two southbound lanes opened for commuter traffic this morning. One southbound lane remains closed with a concrete barrier in place as a buffer, should any smaller material come down.
With poor weather forecast for the next few days, contractors will wait until weather permits for specialist abseilers to work on the slip face to remove a large rock embedded on the upper slip face, and put up anchored netting.
The netting (approximately 15m x 15m) will allow any future loose material to fall behind the net curtain and be retained on the bottom bench.
This work is expected to take 3-4 days, subject to weather and opportunities to get the equipment on site.
Because it is a difficult site to access, helicopters may be used to lift equipment on to site. It is also likely there may be short term rolling closures during the day and some night time closures, to ensure the safety of road users, while this slip remedial work is undertaken.
NZTA Wellington Transport Systems Manager Mark Owen says with work starting once the weather has cleared, it’s likely to be completed by early next week.
Until then the southbound lane closest to the hill will remain closed and peak hour traffic travelling down Ngauranga Gorge can expect delays.
“We understand it is an inconvenience and we thank drivers for their patience while this area is made safe for drivers.”
The Transport Agency will also be looking further into the resilience of the slopes of the Ngauranga Gorge and along State Highway 2 from Ngauranga to Petone, to assess what other work may be required.