Large slip between Kawakawa and Opua to be cleared by end of month

Work is progressing on a massive slip at Lemon's Hill, on State Highway 11 between Kawakawa and Opua. Photo / Supplied

A huge slip that has cut off State Highway 11 between Kawakawa and Opua for almost two months should be cleared and the road reopened by the end of this month.

SH11 has been closed to all traffic since heavy rain from ex-tropical Cyclone Fehi brought down a huge slip on February 13 that's hanging above the road.

"We should have reached a point in stabilising the hillside over the next couple of weeks where we can safely open the road to traffic in the morning and evening for a limited time under traffic control," NZTA's Northland system manager Jacqui Hori-Hoult said.

"It will depend on the weather and continued monitoring of the slip and the risks it presents. We will have to stop work while the road is open, but it will allow locals and tourists to get through and not have to drive the detour route, which can add up to 30 minutes to their journey."

She said favourable weather had helped crews make good progress on the slip.

''They've been working from the top down on the hillside high above the road. After initially removing about 200 cubic metres of loose material a day, they are now taking out 800–1000 cubic metres a day,'' Hori-Hoult said.

''We have reached the unstable material above the slip by cutting two 5m-wide benches or steps in the hillside and have so far cleared about 12,000 loose cubic metres of earth and rock.

"Safety is paramount. We can't work on the hillside when it's wet and we haven't opened the road because of the risk of the unstable material falling on to the road.''

She said a layer of about 8500cu m of material is on top of other loose materialand the risk since February has been that it could move at any time.

"We had planned to use explosives to break up the layer, but we've worked our way down to a level where we can remove it now without blasting."

The slip clearance is entering a new phase this week where instead of carting material off the top of the hillside, crews are pushing it down the slip face and will start removing it from the road.

Locals can sign up at http://www.nzta.govt.nz/sh11-lemons-hill-slip to receive an email update on slip clearing progress and details of how and when the road will be reopened. Or go to http://www.journeys.nzta.govt.nz/sh11