Bid to protect at-risk snail and lizard species from new motorway in lower North Island

Powelliphanta traversi snails have been found at the site of the yet-to-be-built Ōtaki to north of Levin road. Photo / Kath Walker, Department of Conservation

New Zealand Transport Agency Waka Kotahi (NZTA) could spend up to $1.1 million protecting snail and lizard species from a long-awaited motorway in the lower North Island.

The Ōtaki to north of Levin road (Ō2NL), which includes a shared walking and cycling path, is estimated to cost $1.5 billion and will connect with the recently opened Peka Peka to Ōtaki expressway.

It is expected to improve journey times and safety: the existing stretch of State Highway 1 has been labelled a “killing field” after former coroner Philip Comber noted the road is marked like a battlefield with white crosses.

The motorway has been made a Road of National Significance and construction is due to start late next year.

An NZTA briefing to Transport Minister Simeon Brown said ecological surveys have been undertaken at the site.

The existing stretch of State Highway 1 has been labelled a “killing field” after former coroner Philip Comber noted the road is marked like a battlefield with white crosses. Photo / Mark Mitchell

They have revealed the presence of a threatened snail species called Powelliphanta traversi.

The Department of Conservation’s website said Powelliphanta snails are among New Zealand’s most threatened invertebrates.

“Powelliphanta are giants of the snail world. They are also beautiful. Their oversized shells come in an array of colours and patterns, ranging from hues of red and brown to yellow and black,” the website said.

NZTA also reported in its briefing an at-risk skink species and a non-threatened skink species had been discovered.

“The snail and ornate skink have high ecological value and are protected under the Wildlife Act. Accordingly, prior to construction of the Ō2NL new highway project, NZTA is required to search, salvage and relocate these animals from within the construction area [including non-threatened lizard species].”

The briefing from May 17 was released to the Herald under the Official Information Act.

Fauna management plans were being prepared including suitable areas to relocate the species and “comprehensive guidance” about how they should be salvaged and handled.

The cost was estimated to be between $700,000 and $1.1m.

NZTA infrastructure delivery central North Island regional manager Rob Partridge told the Herald he did not expect road construction would be delayed because of the requirement to relocate wildlife.

“This work will be ongoing throughout the construction of Ō2NL and carried out as site preparation progresses.”

NZTA expected to have more clarity on the approach and associated costs by the end of 2024, Partridge said.

“The costs provided are an estimate, and further options are continuing to be explored and efficiencies sought prior to final confirmation.”

Construction on the new highway is expected to be completed in 2029.

Road reaches important milestone

In June, it was announced NZTA had signed interim alliance agreements with two design and construction teams who will develop and ultimately build the new expressway.

Downer, McConnell Dowell, Beca and Tonkin+Taylor will focus on the section south of the Ōhau River while Fulton Hogan, HEB, WSP and Aurecon will focus on the north.

Brown said Ō2NL was a crucial part of the Wellington northern corridor.

“It builds on the success of Transmission Gully, and the Mackays to Peka Peka and Peka Peka to Ōtaki roads of national significance.”

Georgina Campbell is a Wellington-based reporter who has a particular interest in local government, transport, and seismic issues. She joined the Herald in 2019 after working as a broadcast journalist.