Temporary road used while work done on State Highway 4 near Whanganui

The New Zealand Transport Agency has a range of works planned around this SH4 slip. Photo / Bevan Conley

A temporary road will be used while contractors protect State Highway 4 from a slip between Otoko Pā and Kakatahi, near Whanganui.

The slip happened in the 2015 heavy rain event, NZTA regional transport systems manager Mark Owens said. It closed the road for two days in March last year.

The work began with the placing of environmental controls along the slip face on November 18. Further work will remove or remedy the overslip.

The total cost will be about $2.1 million.

While work is being done, traffic will be diverted around a 300m temporary road ready for just that purpose. It will be controlled by lights at each end.

Trucks will be continuously moving spoil from the slip site and tipping it at a site 1.5km north up the highway.

The work is expected to be finished by the end of January 2020, weather permitting.

Traffic on that stretch of road is expected to be relatively low, due to the closure further north at the Matahiwi slip.