More than 30,000 properties were without power, including about 10,000 customers in Wellington, said authorities, who have urged motorists to stay off roads, while several schools were closed as emergency crews tackled widespread damage.
The storm is forecast to bring heavy rains as it heads for the east coast of the South Island on Tuesday, the weather bureau said, with authorities warning of further disruption.
Raw sewage discharged after this month’s failure of Wellington’s main wastewater treatment plant in a storm was washed back onto the south coast by the weekend storm, in an incident some residents called a “poonami” on social media.
A low-pressure system east of the North Island has battered several regions since the weekend, bringing heavy rain and severe gales. A man was found dead on Saturday in a submerged vehicle on a highway.
The storm follows six deaths last month in a landslide triggered by heavy rains at Mount Maunganui on the North Island’s east coast, bringing down soil and rubble on a site crowded with families on summer holidays.