Kererū Gorge Culvert

Background

In February 2023, Cyclone Gabrielle destroyed about 50 metres of Kererū Road, washed away its culvert drainage, and eroded the streambed to 8 metres below its original level —creating an 18-metre-deep gully.

Kererū Gorge as it appeared in September 2021

Kererū Gorge was one of 18 bridges or culverts lost in the cyclone, cutting off a key route into Hastings. Residents have faced long detours via Salisbury Road, disrupting connections with schools and neighbours. Unlike other damaged sites, an interim fix here would have cost nearly as much as a permanent one, making it a priority for early reconstruction.

A feasibility study recommended a 15-metre-wide segmented culvert as the best long-term solution. Instead of a bridge, the large arch culvert was designed to raise the road while allowing floodwaters to pass. Precast concrete panels were used to speed up construction.

In November 2024, a structural evaluation found that weak ground conditions required deeper foundations. To reduce weight, expanded polystyrene blocks with extra steel reinforcement were used. As a result, the road was not able to be reopened by Christmas as planned but will open by Easter 2025.

Progress update (March 2025)

The structure is nearing completion with pavement (road surface) and drainage works underway. Over the next month, shotcreting (spray concrete) for tie-ins, stream diversion, revegetation, final surfacing, guardrail installation, line marking, and signage installation are all planned.

While the road will reopen to the public on Thursday 17 April, further works below road level will continue for approximately 6 more weeks to close out the project.