Civil Defence has been activated in the Tasman district, after flooding from heavy overnight rain throughout the region.
The Aorere and Anatoki Rivers are swollen, with the Aorere running at eight metres which is the highest since records began in 1977.
The Maitai River is at a seven year flood level, but is now receding.
The fire service says a vehicle that's trapped in water near Havelock, is reported to have people inside it.
In Marlborough, a tree is blocking the northbound lane of State Highway Six, about 5km north of Havelock.
State Highway 60 between Takaka and Collingwood is closed due to flooding.
Tasman Regional Civil Defence Controller Jim Frater says numerous roads are blocked and power and phones are off in places.
He says campers near the Aorere River were advised on Monday to move and he can only hope they took notice of the warning.