The Auckland Anniversary floods have reactivated a landslide that now threatens a new billion-dollar motorway north of the city.
The Pūhoi to Warkworth highway has only been open a month, but cracks have appeared in concrete barriers and an entire section may be moving.
Waka Kotahi has known for years the land in the area is unstable but thought the motorway would bypass it.
Reports, that were until now undisclosed, reveal this and other risks.
Phil Pennington spoke to Corin Dann.
