Work has now been finalised on the design of a modular retaining wall to be installed at the Waikura slip site on State Highway 35.

This stretch of road, between Pōtaka and Wharekahika/Hicks Bay has been closed every night since the weekend, following the discovery of further cracking between the hillside and the guardrail.

The site was initially severely damaged in the January storm which also saw 200,000 cubic metres of material slide across the road at the Punaruku slip further east.

Since the weekend, every morning the Waikura slip site has been subject to engineering assessment before reopening.

Urgent stabilisation work is required to control movement in the affected area.

This work could take 4-6 weeks to complete and the restrictions will remain in place during this time.  

Traffic management work

While the majority of this stablisation work will take place during the night closures, the initial work will need to take place during daylight hours.

That means next week for four days, between Monday 4 May and Thursday 7 May, the road will be open during the day under stop/go traffic management, before closing again each night.

At this stage, the road will reopen without stop/go traffic management from Friday.

Retaining work

Once the ground is stabilised and movement is controlled, construction of what’s called a ‘Hex‑Loc’ wall can proceed. This staged approach ensures the long‑term repair is built on a stable foundation and provides a durable, permanent solution for the Waikura underslip.

The Hex-Loc wall is a modular retaining wall. This involves laying interlocking modular hexagonal blocks that will form a strong retaining structure. Each block is designed to interlock, and when combined and stacked, they form a robust, self-supporting structure.

At the same time as the wall construction, crews will also install a new stormwater inlet on the uphill side of the road to better manage water flowing through the area, along with rock rip rap, which is made up of large rocks laid in place to help reduce erosion.

The restrictions currently in place are disruptive. Our priority is to restore full access as quickly as possible, while ensuring the safety of everyone driving on and working on the road.