A landslide has taken out power lines and blocked a 50-metre section of road north of Dargaville.
Emergency services and council contractors are at the scene on Omamari Rd in Kaihu and have started the clean-up, but police said the road will likely be closed for most of the day.
They asked drivers to avoid the area if possible.
Traffic is being diverted along the coast towards Babylon Coast Rd, back to State Highway 12 through Parore.