The planned reopening of State Highway 1 over the Brynderwyn Hills has been pushed out to the end of June after delays caused by an active slip.
The NZ Transport Agency confirmed the planned reopening date but warned any further unexpected rain or instability could delay the timing.
SH1 was due to fully reopen on May 13 but two significant slips on April 26 and April 30 had NZTA and its contractors scrambling to stabilise hillside.
NZTA infrastructure delivery national manager Mark Kinvig says the priority has been to undertake geotechnical and safety assessments to determine the best solution.
The team is “committed to completing these vital recovery works as quickly as possible to ensure a safe and reliable SH1 Brynderwyn Hills for the short to medium term”, he says.
Excavation has already started, with operators working from a platform at the top of the ridge. Removing soil from the top of the ridgeline reduces the likelihood of further slips, which will then enable safe work to be undertaken from the bottom to remove material.
Up to 55,000 cubic metres of earth will be excavated to stabilise the site where the two slips occurred at Kauri Tree Corner.
“Our team is working seven days a week, where weather allows, to get the road open,” Kinvig says.
“We are maximising the number of trucks, diggers and workers on site to ensure the soil removal is a continuous operation, utilising daylight hours, to get it clear.”
Detour routes to access Northland include SH12/SH14, Paparoa Oakleigh Road and Cove Road.
Road transport diversions
National Road Carriers Association chief executive Justin Tighe-Umbers says road transport operators will continue to utilise the diversion routes that add between 60 to 140 kilometres to their journey.
Increased costs caused by the diversions are being passed through to customers, he says.
“This delay is another reminder of the urgency needed to replace this vulnerable section of State Highway 1,” Tighe-Umbers says.
