What’s Burning Down Houses in Wildfires? It’s Not What You Think

Trees are not the enemy.

What's Spreading Wildfires in Neighborhoods? Houses with Wood Roofs and Decks, Not Trees
Paul Tullis is TakePart's Features Editor, and a Contributing Writer for The New York Times Magazine.

In Tennessee last year, a five-year-old girl drowned in the backyard swimming pool of a house she was visiting. The parents sued the home’s owner for negligence.

This August, a wildfire burned in a 174-square-mile area near Ketchum, Idaho. The community was lucky: Only one home burned to the ground. Still, firefighters were placed in harm’s way when assigned to save 30 others. The area fire chief told the Associated Press that many of those residences had roofs made of flammable material. The demand these homes placed on fire department resources put his men and women at a greater risk, and delayed their response to other people and places needing help.

So far, there have been no reports of lawsuits filed against those homeowners.

That’s because the owner of the swimming pool was allegedly in violation of a local ordinance requiring swimming pools to be fenced—a common and sensible imposition on private property rights, when weighed against society’s urgent interest in preventing the deaths of young children.

In Ketchum, though, there’s no law against building a house with a wood roof or a wooden deck. That’s true even if the house is at the edge of a national forest in the midst of a severe drought—and even though such houses put first responders and other residents in danger.

According to research conducted for a cover story I wrote for this Sunday’s New York Times Magazine, in fact, municipalities throughout fire country have been slow to adopt regulations that would require home builders and home owners to take basic steps for fire prevention and mitigation. This despite a steady increase in the number of acres burned nationally, according to data from the National Interagency Fire Center. Each year for the last decade, an area almost the size of New Jersey has burned.

Research from the U.S. Forest Service’s Fire Sciences Laboratory in Missoula, which I visited for two days in June, shows not only that there are simple and inexpensive engineering fixes on houses [pdf] that can save them from burning—screens placed over vents, for instance—but that when wildfire moves through a neighborhood, it’s houses, not trees, spreading the fire. This happens when the wind carries a burning ember from a house on fire to a neighboring property. With the resident evacuated and fire departments unable to put an engine in every driveway, the firebrand smolders for hours before finally heating up and involving the whole house. Because of this method of fire spread, it’s not uncommon to find trees still standing amid rows of homes that have been entirely consumed by flames.

A chimney is left standing after a structure burned in the community of Grass Valley October 23, 2007 in Lake Arrowhead California. (Photo by J. Emilio Flores/Getty Images)

In a part of the country where one in three homes is now in what fire people call the wildland-urban interface, or WUI (pronounced WOO-ee), these are significant findings. The part of Yarnell, Arizona, that the Granite Mountain hotshots were protecting when 19 of them died in a fire on June 30, and the two neighborhoods in Colorado Springs that burned this summer and last, destroying more than 800 houses, are all part of the WUI: Developed areas at the edge of a landscape susceptible to burning.

And yet, according to Forest Service research, large majorities in two fire-prone Colorado counties don’t believe that characteristics of vegetation surrounding their homes, or physical characteristics of the house itself, contribute to the risk of a fire damaging their property.

Nonetheless, fire is a natural fact of life in the west. It affects forest ecology as surely as do rain and sunshine. A century-long policy of putting out every wildfire we were able to has put us at a “fire deficit:” areas have gone without fire for far longer than they did in the past, so there’s a lot more fuel to burn. Along with drought, climate change and other factors, this is making fires burn hotter and spread faster. Consequently, we’re only able to put out the low-intensity fires. And when we’re successful—often spending millions to protect just a few homes in the WUI—it only makes the problem worse.

Part of the problem is inimical to human nature: We don’t want to replace tomorrow’s uncertainty with today’s certainty. We know fire is going to happen eventually, and we can change how it happens when it does, but we don’t: Although regulations require earthquake-resistant homes in California (and even Puerto Rico), the idea that those who live in a tinderbox should invest in a few fire-prevention measures remains exotic. There’s no accountability for inaction. The only people who get in trouble when fire does come are those trying to do what science tells us is the best policy: firefighters who try to manage low-intensity fires, or set carefully designed prescribed burns, so they can reduce the fuel load in a forest. When these efforts get out of control, as rarely happens (less than one percent of the time in the case of prescribed fire), they’re the ones we blame. But if we acted more sensibly, they wouldn’t need to go to such efforts in the first place.   

In New Mexico in July, I spoke with Tim Brickell, a member of a Wildland Fire Management Team (one of only two federal teams of fire experts tasked with managing, rather than suppressing, wildfire). His team was assigned to the Jaroso fire, which burned 11,000 acres in the Santa Fe National Forest until annual monsoons came, enabling it to come under containment. Brickell had spent the previous day conducting “triage” operations on houses that might be at risk if the fire spread. This involved evaluating how susceptible the buildings would be to flames based on their design and construction materials, and how well their owners had prepared their property through measures such as cutting down trees from within 100 feet of any structures, clearing dead vegetation and removing pine needles from roofs and gutters. Those homes that Brickell deemed as having a chance of withstanding the fire were tagged, with a flag of a certain color tied to a tree near the driveway, for firefighters to try to save. The property of owners who’d failed to prepare would not get such consideration.

It’s a grim, but necessary, consideration when we don’t want to come to grips with the reality of wildfire.

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