State Highway 2 through the Karangahake Gorge will close over two five-day periods for rock-scaling work.

NZ Transport Agency Waka Kotahi (NZTA) said rope-access technicians will inspect the cliff faces above the highway and remove loose or unstable material using hand tools and specialist equipment.

The closures are planned for August 24-28 and October 12-16 from 8.30am to 3.30pm each day, weather depending, the roading agency said in a media release.

Waikato asset and operations area manager Andy Oakley said in the statement that a full closure was the only safe way to do the work as technicians would be working directly above the highway and rocks could fall on to the road below.

“The closure will cover a 500m section of SH2, beginning near the historic rail tunnel bridge and extending north.

“Road users should plan to travel through the gorge outside the closure times, while inter-regional traffic should consider using SH29 over the Kaimai Range.”

Oakley said the gorge highway carried around 7900 vehicles each day.

State Highway 2 through the Karangahake Gorge will close over several days for rock-scaling work. Photo / NZTA

“The closure hours have been chosen to reduce disruption on school traffic, commuters and freight while giving crews enough daylight to work safely.

“We recognise the closures will be disruptive and appreciate road users’ patience.

“Confirming the new dates early gives people, businesses and freight operators time to plan their journeys.”

Emergency services and first responders will continue to have access through the closure area.

State Highway 2 through the Karangahake Gorge will close over several days for rock-scaling work. Photo / NZTA

NZTA said the August closure would focus mainly on inspections and identifying areas that needed treatment, with some rock removal.

During the October closure, crews will remove unstable rock and complete any further work identified during the inspections.

The roadside section of the Hauraki Rail Trail’s Rail Tunnel Loop will close during the work while the walkway on the other side of the river will remain open.

NZTA will also use the closures to complete other maintenance and resilience work where possible, reducing the need for further disruption.

Subject to suitable weather and river levels, rock-armouring work on the historic riverside retaining wall may also be completed during the October closure.