Project introduction

Ongoing works to repair storm, flooding and slip damage on State Highway 4 between Whanganui and Raetihi.

  • Estimated project dates

    Jun 2015–Jun 2023
  • Project type

    Road maintenance

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Background

In June 2015 a major flood event in and around Whanganui caused substantial damage to parts of SH4 between Whanganui and Raetihi. SH4 Anzac Parade in Whanganui and SH54 between Cheltenham to Vinegar Hill were also affected. The storm left a lot of silt and debris on the road, slips covering the road and drop outs where the road has fallen away. Work to repair this substantial damage is ongoing and we are now working on the final major repair site – Auraki Stream. The current road is being affected by a slip at the Mangawhero River, so we are relocating the road away from where it has failed. This will mean a return to two lanes on this stretch of highway with no temporary traffic management or priority give way road layout. The large culvert where the Auraki Stream currently goes under the highway is being extended to facilitate the new road alignment.

On 2 October 2019, a major slip on SH4 south of Raetihi destroyed a large section of the road, forcing it to be closed. This is unrelated to any of the previous resilience works on SH4. On 20 December 2019 a temporary road connecting SH4 to Raetihi was opened to all traffic and in May 2020 we announced a reinstatement solution for SH4. The option would run through a stabilised Te Oreore slip site and scored strongly with network resilience. It also scored positively in protecting indigenous plants and animals and maintains the current path across the landscape. Stabilisation work at Te Oreore is now complete and we are working towards construction of the new permanent road as soon as possible.

Read more about our work at Te Oreore

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