The source of a large scrub fire that had the potential to threaten lives and properties near a commercial site south of Whangarei is still a mystery.

It started on very steep gorse and grass off Marsden Pt Rd between Sime Rd and McEwan Rd just before 1pm yesterday and it took firefighters and a helicopter using a monsoon bucket nearly two hours to bring the fire under control.

Northwesterly winds blew the smoke across the road between Sime Rd and McEwan Rd which was closed while firefighters from Ruakaka, Waipu, New Zealand Refinery and a crew from the Rural Fire Authority battled the blaze.

Five homes were without electricity for a short time after the fire got to a power pole and burnt plastic on a transformer.


Northpower crews were at the scene together with emergency services.

Ruakaka fire chief Darrell Trigg said the fire burnt between 3000 and 4000sq m - enough to commit resources, including a helicopter which directly fought the fire while ground crews ensured lives and properties were not in danger.

Blasting and coating specialists Rudolphs and landscape suppliers Daltons were the businesses closest to the fire but were not threatened by the blaze because the wind was blowing in a different direction.

"Once the helicopter arrived, our tactic was to make sure buildings and lives were protected. Embers dumped on properties from the fire have the potential to start fires," Mr Trigg said.

Water from a hose connected to a fire hydrant on Marsden Pt Rd was used by ground crews.

Mr Trigg said that also could have been used to fill up the monsoon bucket, but they decided it was easier and quicker to source water from a nearby lake.

The cause of the fire was unknown, he said, and any investigation into how it started would be handled by rural firefighters.

He warned people to be careful while working near fire sources because the whole of Northland was incredibly dry.

"People see green gorse and think it's not dry but it is. They just need to be so careful, even throwing cigarette butts out their car windows. With a little bit of wind, they too can start fires," he said.

Housewife Gina Keremeta, who lives about 100m away from the fire, was in the kitchen when she saw smoke which reminded her of a similar fire behind her house last year.

"The grass being so dry could have sparked a fire. Luckily the wind is not blowing our way otherwise we could have been in danger," she said.

Dairy farmer and former volunteer firefighter Peter Batten owns a 130-hectare farm directly across the road from yesterday's fire and said hot embers were always a threat on tinder dry land.

"The winds are blowing in a northeasterly direction directly across my farm so the threat of hot embers in this situation never dies. Experts say this dry is the worst in a decade. It would be," he said.

Meanwhile, staff were evacuated from Arcwell Engineering on Robert St in central Whangarei after a quenching oil fire yesterday.

A staff member, who did not want to be named, said staff were putting hot steel into quenching oil when a flame got "quite big" about noon. He said staff used dry powder and carbon dioxide to put out most of the fire before fire crews arrive.

Two fire engines went to the building to douse the blaze. Arcwell Engineering staff were checked by St John for smoke inhalation.