One lane through Rotu has been closed since heavy rain in mid-August caused severe subsidence.
The NZ Transport Agency says the single lane will remain open through the works, which will improve drainage and construct a new retaining wall.
Motorists are advised there are likely to be delays until the work is completed in mid-October.
The second lane will then re-open to traffic.
We apologise for any inconvenience as we carry out this important repair work to improve journeys on State Highway 12 and make it more resilient to future bad weather events.
Check the Transport Agency’s website: www.nzta.govt.nz for the latest highway information or sign up to www.onthemove.govt.nz for up-to-date information on what is happening on the route you plan to travel; Freephone 0800 4 HIGHWAYS for national and regional travel updates.