More than 1,800 concrete blocks, each weighing similar to a small tractor, will be used to retain the Waikura slip site on State Highway 35.

Crews have started working to permanently restore two lane access at the site, near Pōtaka, which saw a lane slip away down the hill during January’s storm and heavy rainfall.

During that storm, a slip approximately 32 metres wide and 12 metres high came down the hillside covering the highway.

Work has been continuing for the past few months to stabilise the site. The retaining wall work will help further stabilise the hillside.

Crews are using hexagonal-shaped blocks for the retaining wall.

Transport Rebuild East Coast is leading the recovery work. TREC Project Manager Richard Bayley says the six-sided, honeycomb-shaped blocks are impressive in size.

“Each one is around half a metre high, 1.5 metres wide and weigh approximately 620 kilograms, similar to the weight of a small tractor.

“They were made in Wairoa and delivered onsite.

“We’ll use more than 1,800 blocks to form a retaining wall, with around 25 being installed each day.”

The interlocking design of the hex blocks creates a strong, durable structure that helps hold the slope in place while allowing water to drain through, reducing the risk of future erosion and protecting the road above.

The blocks have also been used on smaller walls at recovery sites on SH2 in the Waioweka Gorge and Glencoe Gorge on SH50 in Hawke’s Bay.

Work at Waikura will continue through to spring.