Te Oreore slip replacement roadworks project on State Highway 4 will cost up to $25 million

NZTA staff surveying the Te Oreore slip site on State Highway 4.

Work to reinstate part of State Highway 4 near Raetihi remains in the design phase, several years after a major slip.

In October 2019, a slip 400m long and 200m wide caused significant damage.

The highway was closed until a temporary road was constructed through the middle of the slip area two months later.

NZ Transport Agency Waka Kotahi (NZTA) project manager Gareth Howie said the Te Oreore slip replacement project was complex.

“As with all roading projects, drainage is key and getting rid of water and diverting it away from the highway and into the nearby river is equally crucial in this project,” he said.

“The design for the 700m section of State Highway 4 would add more wells to the existing bores installed in 2019 to ensure as much water as possible is continually diverted away from the site.

“We continue to closely monitor both the temporary road and the main slip site.”

He said three retaining walls had been built in the past few years to help ensure the area remained resilient.

“Monitoring equipment is in place to detect any signs of movement and, at present, there is no indication of instability on the temporary road.”

Parapara Rd was closed for about two months after the 2019 slip. Photo / NZME

Whanganui and Raetihi are linked by an 80km stretch of SH4, known as Parapara Rd, that goes through steep hill country.

In October 2024, the Government announced funding for five projects on the road, including rockfall near the YMCA’s Camp Raukawa and a slip opposite Raupiu Rd.

At the time, Ruapehu Mayor Weston Kirton said managing the road was “a huge undertaking”.

“Some roads are vulnerable and, regardless of what you do, they just keep on moving,” he said.

“All you can do is repair it to a reasonable standard and hope like hell it lasts.

“On the Parapara, I’d say the warranty is five years at best.”

A major flood in 2015 resulted in 40 sites on the road needing repair, with the largest, the Auraki Stream retreat project, completed at the end of 2023.

Howie said Te Oreore work would be submitted for funding approval within the next three months, with estimated project costs ranging from $20 million to $25m.

“Following engagement with hapū, iwi and landowners, a preferred design for the permanent road reinstatement has been selected and resource consent was granted by Horizons Regional Council in 2025.

“Construction of the permanent road reinstatement will begin once funding is secured and we’ve worked through property matters.”

The temporary road at the site runs through land owned by Ātihau-Whanganui Incorporated.

Mike Tweed is a multimedia journalist at the Whanganui Chronicle. Since starting in March 2020, he has dabbled in everything from sport to music. At present his focus is local government, primarily the Whanganui District Council.