Waka Kotahi - NZ Transport Agency will close State Highway 6 (SH6) between Hira and Ronga Road near Rai Valley from Tuesday, 1 November to Sunday, 18 December, to make emergency repairs.
People will be able to travel between Blenheim and Nelson by using State Highway 63 (SH63) through to Kawatiri junction, then SH6.
Andrew James, System Manager Top of the South, says after the recent weather event in August, Waka Kotahi opened SH6 quickly to help keep people moving, while more permanent fixes were being completed on SH63.
“Now that we have completed the repairs on State Highway 63, we need to get back onto State Highway 6 to fix five substantially damaged sites where there have been underslips. Three of these will require us to significantly cut back the road before it can be built back up again.”
Some of the worst sites along SH6 that will require significant engineering and repair work.
“To keep everyone safe and finish the work as quickly as possible, we must close the road for seven weeks. We realise this is a substantial amount of time, but the route is currently vulnerable, and another serious weather event could seriously damage it and see it closed for months. We must get this work done as quickly as possible.”
Mr James says contractors will work as quickly as possible to get these sites repaired, and ongoing work will be needed after the closure ends.
“When State Highway 6 reopens on 18 December, we plan to have two traffic lanes re-established for the holiday season. We will need to return to complete further minor repairs in the next year, but we are not expecting to close the road for this work.”
Mr James warns complex structural projects like this face risks from unexpected geotechnical factors and potential weather delays but promises all efforts will be made to meet deadlines.
Other planned maintenance work will be brought forward and completed during the closure. This includes pavement renewal and additional drainage work to improve network resilience, such as improving culvert inlets and outlets, increasing the size of some culverts, and strengthening drainage channels.
Mr James says Waka Kotahi understands the closure will cause inconvenience for people, particularly those living in or around the Rai Valley.
“This is the best option on the table, and we appreciate their patience while this crucial transport link is repaired. We are making every effort to get the route restored before the busy Christmas period.”
Residents and businesses within the Kokorua Road and the closure zone will be contacted directly by our crews in the coming weeks to work through access arrangements.
Frequently asked questions
Can the road be open at night or at intervals to let people through?
- We have looked at multiple ways to do this work while minimising disruption for people. Alternative options would have led to 24-30 weeks of work and longer overall travel delays.
- The road needs significant cutting out and rebuilding for the five worst sites. This means the road will become too narrow to allow people to pass through safely while we have crews and equipment in place.
- At times it will be impossible to open the road for intervals during the day or night due to the road’s narrowness and the work that needs to happen at the base of the slips. During the work, the crew will be 10m below the current road level and accessing the site from each side. While this is being done, there will be no road to drive on.
- At other times, it will also be logistically challenging and add significantly more time to the closure if we were to regularly move the crew and equipment so that people could safely pass.
- The route is currently highly vulnerable to damage should another severe weather event occur. If this were to happen, the road could end up being closed for months. This is why we are doing a full closure and getting the repairs done as soon as possible. Our approach reduces the overall impact on the public and gets the work done before the busy Christmas season.
Will further work be needed on SH6 after this closure?
- During the seven-week road closure, our focus will be to complete all work on the five significant sites that result in lengthy one-way sections that cause the most delay.
- Other planned maintenance work will be brought forward and completed. This includes pavement renewal and additional drainage work to improve network resilience.
- When we open the road back up on 18 December, we aim to have two traffic lanes re-established for the holiday season. We will need to return to complete minor repairs next year, but we are not expecting to close the road for this work.
Why wasn’t this work completed earlier?
- In August, we wanted to get people moving between Blenheim and Nelson as quickly as possible. We knew we could open SH6 with traffic management while we made more permanent fixes to SH63. This allows us to have a shorter detour than the 7–9-hour detour that was in place when SH6 and SH63 were both closed in August.
- We needed time to assess the scope of the works, undertake geotechnical assessments and complete the structural designs for fixing SH6. We are now ready to get this done before the busy Christmas period.
Will you combine maintenance and storm recovery works while the road is closed?
- While we are fixing SH6, we will also bring forward routine maintenance and pavement reseals to minimise later disruptions. This work includes road pavement repairs and resealing. Work on the diversion route on SH63 are being rescheduled to ensure travel times are not increased more than necessary.
- The work we will be doing during the seven-week closure will bring the road back up to the standard it had before the August weather event. While we are fixing the damaged sites, we will also undertake drainage works to make the corridor more resilient. As a separate exercise, we are continuing to investigate ways to make SH6 and SH63 even more resilient.
How much will the recovery work cost?
- Estimates of final costs are still being completed. There are a number of designs still to be finalised and approved across multiple areas of the Te Tau Ihu, Top of the South state highways in Tasman, Nelson and Marlborough from the August 2022 event.
