Thousands of residents in the upper North Island are entering their third consecutive day without power, while concern is growing over problems with contaminated water in Northland, Radio New Zealand reports.
A storm system, described as the worst in a decade, that has been battering the region is forecast to bring more strong winds and heavy rain.
Floods and power cuts have made some treatment plants useless and Civil Defence officials say contaminated drinking water could be a concern in the coming days.
Phone and internet services have also been badly hit, with 12 Telecom and nine Vodafone cellphone towers out of action across the region.
In the Far North, Top Energy said 3500 of its customers were still without power on Friday morning.