Waioeka Gorge between Gisborne and the Bay of Plenty will be temporarily closed for one-hour periods next week so a large slip face can be blasted to speed up removal of rocks and debris from the slope.
Repair teams have been working at the site for weeks to restore State Highway Two from a one-way temporary bypass to a full two-lane highway, but it has been a painstaking battle involving a steep face and overhanging debris.
The New Zealand Transport Agency (NZTA) says the temporary road past the slip will be closed tomorrow at 2pm for about an hour to allow workers to dislodge material using explosives.
There would also be intermittent closures on Wednesday and Thursday for an hour at a time at 11am, 1pm and 3pm to allow for the remainder of the work to be completed.
Bay of Plenty state highways manager Brett Gliddon said he was aware of the importance of the road for the Gisborne and Opotiki communities, which was why the closures were timed to take place when heavy freight and traffic volumes were low.
The blasting work was required to speed up removal of bulk material from the slip face, said Mr Gliddon.
So far 45,000cu m of slip material had been removed.
"The decision to blast this section was made on the basis it was the safest and most efficient way to dislodge this material with minimal disruption to road users."
Mr Gliddon said closing the road while the work was carried out was essential to ensure the safety of road users and workers.
"As always, we will do our best to keep delays to a minimum and we encourage drivers to plan their travel either around the times the work will take place or, if they choose to travel at these times, then to factor in the extra one-hour delay.
"We'd like to thank people for their patience during these one-hour closures."
Drivers wanting to find out more about the road works or the detour in place should go to the NZTA's website at www.nzta.govt.nz/traffic/current-conditions/index.html; or freephone 0800 4HIGHWAYS (0800 44 44 49).
Rain has hampered progress a little at the gorge slip but activity on the slope is still progressing well, with a lot of slip material above the "whale-back" area now removed.
Mr Gliddon said an excavator had moved across to the Opotiki side of the slope and was continuing to remove material from that area by undercutting and collapsing the material.
Heavy rain hampered activity on Tuesday and Wednesday last week but by Thursday the machine was back on that section of the slope.
Heavy rain last week caused minor scouring of the embankment of the temporary diversion road and that had been repaired.
Meanwhile, south of Gisborne work is progressing on the Wharerata dropout. Design work to reinstate the road is under way.
Continual movement of the Kopua Hill dropout, at the foot of the Whareratas, has required the design to be modified, but NZTA says the work is well under way and about half complete.
Further along SH2 towards Napier, work on the Devil's Elbow slip is expected to be finished this week, depending on weather.
Timber poles and a retaining wall have been built at the Mohaka Hill dropout on SH2. The NZTA is happy with progress and pavement work will begin soon.NZPA