Flooding on the West Coast of the South Island has cut off Westport after heavy rain swamped the region overnight.
Westport was closed to all traffic because of serious flooding on the state highways to Greymouth and Inangahua, police said.
The Buller River was close to breaching its banks on the Westport side and there was concern that continued rain might lead to more serious flooding. At least one homeowner had been evacuated, near Carters Beach west of Westport.
Police were urging residents to stay at home and avoid "sightseeing...particularly in or around the breakwaters at the Buller river mouth, as flooding in that area has made it quite dangerous". The tide had turned and was on its way out.
Westport is particularly vulnerable to flooding because it is on the flood plain between the Buller River and the Orowaiti Estuary, an old channel of the river that carries a substantial flow during deluges.
The storm also caused minor flooding in Murchison, Nelson and Golden Bay, the region's Civil Defence said in a statement.
Five homes in Murchison had been inundated and the Takaka River had risen over the Waitapu Bridge, closing the Takaka-Collingwood Highway. Slips on state highway 65 near Murchison were being cleared but the road remained open.
MetService said the intense slow-moving weather front was moving gradually off the upper South Island, easing the heavy rainfall in Westland, Buller, Nelson and northwest Marlborough.
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