Are we building fuel for flames?
Putting homes next to forested areas now comes with increased risks
When the final bills are tallied for the two major fires raging uncontrolled in Nova Scotia at the moment, it will almost certainly be the smaller of the two that will bear the larger price tag.
The Barrington Lake fire in southwest Nova Scotia is by far the larger; at 21,515 hectares, it’s now the largest in recorded provincial history.
It’s caused the evacuation of some 67,000 people, about half the population of Shelburne County.
But the Tantallon wildfire — though 25 times smaller — has prompted the evacuation of some 16,000 people and left some 150 razed homes in its wake.
To a large extent, that potentially bloated price tag will have to do with the desire of many to get back to nature, to build their homes next to forested areas. And although that lifestyle comes with a great many perks, it can also come with significant risk.
Those developments are called wildland-urban interfaces (WUI) and part of the risk comes in the knowledge that fires are a natural part of many forest ecosystems. And when a fire begins to burn a forest with an urban development in it, that subdivision just becomes so much fuel for the fire.
These WUIs are significant because in terms of percentage of land considered WUI, the Maritimes leads the country by a long shot.
And Nova Scotia is at the forefront of those three provinces by significant margin with 45 per cent of its area being a WUI.
Two years ago, as a fire was devastating the town of Lytton, B.C., the National Research Council published the National Guide for Wildland-Urban Interface Fires.
At the time it said: “The threat posed by WUI fires is growing as urban areas expand into wildlands, rural areas increase in population, and wildfires become more frequent and severe due to climate change. In the coming decades, the risk of WUI fire is expected to increase both in regions of Canada with a long history of wildfires and in those with no such history.”
“If you build a house in a forest, you’re actually removing trees to build the house. So, you’re replacing one flammable fuel with another,” said Jen Beverly, assistant professor of wildland fire at the University of Alberta.
“They’re putting themselves in a flammable landscape — (they’re) not the cause of the flammability — (but) if you’re building something embedded in a sea of fuel — which is a forest — there is potential for fire.”
When those developments are built, she continued, many of its occupants are not anticipating climate change and droughts and atypical springs such as the one Canada is experiencing.
But as climate change continues to change global weather patterns, the frequency and severity of wildfires is also increasing.
According to the Ministry of Natural Resources, wildfires so far this year have burned more than 2.7 million hectares of forest. By contrast, the 10-year average of hectares burned by this time in the year is about 230,000.
That increase translates to WUIs too.
Lynn Johnston, a forest fire research specialist at the Canadian Forest Service, was co-author of the research that first mapped Canada’s WUIs. A more recent study she undertook looked at climate change and how much more fire activity we’re going to see in WUI communities.
“It was shocking,” she said. “It’s a lot more.
“Fire activity is going to increase in most places in Canada, but those increases near the communities are very concerning. And the largest increases we found were in more remote and, in particular, First Nations communities.
“So yeah, it’s going to get more and more challenging in the future, that’s for sure.”
But those communities have already been built, and people love living in them. It would be the rare person who would abandon their home for an increased fire risk, as evidenced by residents of California’s Orange and San Bernardino Counties, as an example, who suffer almost annual wildfires.
Priority then turns to mitigating the risk for existing communities and prescient planning for those that don’t.
“Rather than a wildfire control problem, we have a problem with homes and structures that are way too easily ignited by small embers or just creeping low flames,” said Alan Westhaver, a wildland urban fire expert, and the owner of ForestWise Environmental Consulting. “And that needs to be our point of attack. And that’s what wildfire risk mitigation is all about.”
It’s important to realize that in WUI fires houses aren’t generally burned by a wall of flame, he said, rather in most cases they’re ignited by burning embers from the forest that can travel on the wind a long way from the fire itself.
His studies on the fires that ravaged Fort McMurray found that two-thirds of the hazard of ignition of a house is related to the vegetation around that house.
Other studies showed that in the Slave Lake fires in 2011, a number of houses were ignited by fire burning along wooden fences that attached to the house. There is even a case documented of a house being ignited by embers falling on a welcome mat.
So, the first step is making the house more resistant to ignition.
FireSmart, whose goal is to help homeowners address the challenges of living in WUIs, defines what it calls the Home Ignition Zone, the area 30 metres around a home where a homeowner can remove combustible materials — like bark mulch and piles of leaves and needles and trees up against the house.
FireSmart also makes recommendations for the actual structure of the house — sidings and roofing that are less flammable and screens over outside vents.
But a lot of the fire hazard can be mitigated by early planning too, if developers plan the community with an increased fire hazard in mind.
Sometimes, however, that’s easier said than done.
“Our development standards haven’t kept pace with the changing environment,” said Ray Ault, the director of FireSmart. “That whole notion of bylaws or development and planning? That really hasn’t kept pace with our understanding of the potential risks that folks face. And I think that that’s one of the concerns.”
The aforementioned National Research Council guide, he said, contains a slew of recommendations for developers for planning communities that mitigate the risk of fire damage — things like reducing the area of the community in contact with the forest, planning golf courses or big box stores on the outskirts as de facto fire breaks, and even carefully planning what kinds of trees are planted in the community.