Relief crews from outside the district were being called in as conditions were difficult and crews would be needed on the ground for at least another couple of days.
Mr McNamara said the weather forecast for the next few days was for hot, dry, windy weather which would be very challenging for fire fighters.
"There's a lot of heavy fuel in the way of this fire and we're going to need heavy machinery on the job; it's going to be a long, dirty grind," he said.
The fire was reported about 2.30pm this afternoon.
Road blocks are in place at each end of the Kaituna Track between State Highway 6 and Tua Marina.
Waikakaho Road is closed beyond the fire staging area.
Police are assisting with the evacuation.