State Highway 6, Nelson to Blenheim to be closed for seven weeks, storm repairs

State Highway 6 will be closed for seven weeks for repairs after heavy rain caused slips and prompted a state of emergency in August. Photo / NZME

The main highway between Blenheim and Nelson will be closed for seven weeks as the road is repaired after heavy rain and flooding in August.

Waka Kotahi NZTA said State Highway 6 from Hira and Ronga Rd near Rai Valley will close between November 1 to December 18.

"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," Waka Kotahi's top of the south system manager Andrew James said.

"Another serious weather event could seriously damage it and see it closed for months. We must get this work done as quickly as possible."

The road was impacted by landslips after heavy rain caused flooding and prompted a state of emergency in August. The highway was initially closed, but Waka Kotahi opened the road to allow people between the two towns while another state highway was closed for storm-related repairs.

State Highway 6 will be closed for seven weeks for repairs after storm damage in August. Photo / Waka Kotahi

James said, "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 sites will require us to significantly cut back the road before it can be built back up again."

James said contractors would work "as quickly as possible" to repair the sites, but that ongoing work would be needed when the road is reopened.

"We are making every effort to get the route restored before the busy Christmas period," James said.

The repair works were "complex structural projects" and faced risks from "unexpected geotechnical factors" and potential weather delays, James said.

But he said, "all efforts will be made to meet deadlines."

The Rai Valley will be more isolated as a section of State Highway 6 between Nelson and Blenheim will be closed for repairs following extensive storm damage in August. Photo / NZME

Waka Kotahi would use the closure for other planned maintenance work, which will be brought forward. Pavements would be "renewed", and drainage will be improved to bolster the resilience of the state highway network.

Culvert inlets and outlets would be "improved", made bigger and stronger, Waka Kotahi said.

Waka Kotahi understood the closure would inconvenience people, particularly residents of the Rai Valley.

"This is the best option on the table, and we appreciate their patience while this crucial transport link is repaired," James said.