Emergency Management Minister Mark Mitchell says Northland has been hit hard by flooding

Almost 300 millimetres of rain pelted the north eastern region between midnight and 6 this morning.

That's led to about a dozen roads being blocked or closed, and the suspension of the Russell to Paihia ferry service.

More than 700 homes are without power.

Civil Defence has activated centres at four marae and more than 300 campers are being cared for by various groups.

Mr Mitchell says people should stay alert and up to date, and follow the orders of first responders.