A new realignment of SH2 north of Napier could include the construction of one of NZ's highest bridges. Video / NZTA
The Napier-Wairoa highway stretch of State Highway 2 could have one of the highest road bridges ever built in New Zealand if a preferred route for the Waikare Gorge diversion gets the green light.
A single-span bridge is proposed over the gorge – more than 60 metres tall and over160 metres long - as part of the plan to do away with a gorge route alongside the Waikare River.
It compares with the 50 metre height of State Highway 5's Mohaka bridge between Napier and Taupo.
Proposals were released on Friday following consultation and community meetings in the Waikare-Putorino area, about the half-way point on the 116km highway between Napier and Wairoa.
National highways agency Waka Kotahi NZ Transport Agency senior project manager Rob Partridge said total length of the preferred route, known as the "white alignment" and northwest of Putorino, is 3.9km and will sit west of the existing 6km section of SH2.
"Now that we have confirmed our preferred route, we can progress to the next stage of this project where we can do detailed design," he said.
Drilling of rock samples to a depth of up to 70 metres is already taking place to help "inform" the design, which is expected to be completed by the end of next year.
It will kick-start the securing of funding and the construction stage, but no date has been given for possible completion of the project which is on a similar scale as the Matahoura realignment, on the same stretch of highway, including a new bridge replacing a gorge road, and which opened early in 2011.
The Waka Kotahi NZTA view of the proposed highway realignment midway between Napier and Wairoa. Photo / Supplied
Funding for the design phase of the project comes from the Provincial Growth Fund. Waka Kotahi NZTA says the Waikare Gorge is vulnerable to closures from slips and rockfall, resulting in long detours of up to six hours between Gisborne, Wairoa and Napier. It sits northwest of Putorino, a small close-knit rural community mid-way between Wairoa and Napier.
For the last two years Waka Kotahi has been working with stakeholders, the community and local iwi to examine the options as part of the business case process. The options considered how to improve safety, resilience, and access on this part of SH2.
The realignment is one of several projects that Waka Kotahi NZTA says will improve resilience and safety and enhance access to economic and social opportunities across the Tairāwhiti region.
It is also among several large-scale highways projects impacting on Hawke's Bay, including a realignment of a crash-prone sector of State Highway 2 between Hastings and Central Hawke's Bay, and the 11.5km Manawatu-Tararua Highway over the Ruahine Ranges, expected to cost over $600 million and replacing key State Highway 3 route the Manawatu Gorge road, which was closed in 2017 after constant slips made it impassable.
