The financial cost of the West Auckland tornado has been put at $13 million.
Three people were killed in the storm at Hobsonville and Whenuapai on Thursday afternoon and more than 300 houses were damaged.
Initial estimates put the cost of repairing the damage at about $11 million.
Auckland Civil Defence controller Clive Manley said that has been revised up to about $13 million and the total could still rise.
Vector said around 30 properties can't be reconnected because they are uninhabitable or because they need repairs before the electricity can be switched on.