Anna Spark's container home was destroyed in the blaze, and she's disappointed by the lack of answers over the cause. Photo: Supplied/ Anna Spark
Christchurch's Port Hill residents are disappointed Fire and Emergency (FENZ) can not say what started the 14 February fire.
FENZ has released its investigation report, seven months after the blaze.
The inferno triggered a major operation of more than 100 firefighters, 15 helicopters and 30 fire engines, near the Worsley Track.
Fire and Emergency said the blaze started on private property about 50 metres from Worsleys Road.
But it could not say how the fire broke out, with no equipment or activities on the land the day it started.
Hundreds of homes had to be evacuated, and Christchurch City and Selwyn District councils declared a State of Emergency that lasted for a week.
A container home was destroyed and its owner Anna Spark said she was disappointed there were not more answers in the report.
"It's always in the back of your mind, you wonder what the initial cause for the ignition was, so yeah, I guess I'm a little disappointed but I've also moved quite far past it now."
The report stated the cause of the fire could not be proven to an acceptable level of certainty, therefore it was classified as "undetermined".
Dominique Leeming has fled her home twice in seven years from wildfires on the hills, and said while there did appear to be lessons in the report, she was worried.
"I'm concerned that with ongoing climate change and climate warming...any replacement of that fuel loads on the port hills, there's lots of talk in the report about relative to humidity and these types of technical things.
"I think it's it's not going to become less of a risk. It's going to become an increasing risk," she said.
Leeming said residents were taking it upon themselves to plant native bushes and trees, to try to make the environment less flammable.
"Right along the Port Hiills, private people, some of our neighbours not too far away, have been spending a lot of time planting and also in a lot of the public land.
"What I really don't want to see is more replacement pine planting," she said.
Fire and Emergency district commander Dave Stackhouse said these sorts of solutions were encouraged.
"Fire and Emergency New Zealand, has done extensive work with community groups providing information on low flammability species, natives as an example, and guidance on defendable spaces and how to make that safe for around their residential property. "
Meanwhile, Port Hills resident and Canterbury University Environment senior lecturer Matiu Prebble was not concerned about what caused the fire.
He said there needed to be a focus on preventing it from happening again.
''We're going to continually be in this vulnerable position here as a resident of the Port Hills, that the nature of the conditions here, with the underlying fuel sources of of grass, scrub and pine will continue to make us vulnerable every year."
He said reducing those fuel sources needed to be a priority.
"I think we do need to look at some fuel reduction practices, whether it's it's looking at clearing certain areas, maybe establishing some further fire breaks in really vulnerable places, that could be a strategy," he said
The report stated the combination of dry weather, low moisture content and a continuous available fuel load helped the fire ignite and spread.