Defensible space helps prevent wildfires from destroying homes

When firefighters are called to fight a wildfire, they have a range of tools at their disposal.

Armed with everything from picks and shovels to jets designed to drop thousands of gallons of fire retardant, firefighters said one of the best things is a well-maintained yard.

By taking steps like keeping a well-watered lawn, keeping firewood and propane tanks away from homes and trimming trees, homeowners not only protect their homes from fires, but also give firefighters the space they need to fight wildfires in areas where suburbs collide with wildlands.

“It makes our job a lot easier,” said Highland Fire Chief Rick Woodall. “They give us a little more space so we can keep the fire away from the house instead of in the front or in the yard.”

The state Department of Natural Resources and various agencies, including local fire departments, will show homeowners how they can make their homes more defensible in the event of a wildfire, and possibly get a discount on homeowners insurance.

Create a stamp

The concept of defensible space was developed in the 1990s by Jack Cohen, a scientist with the U.S. Forest Service. Cohen studied how homes and buildings would catch fire simply from the heat of a wildfire raging nearby.

Fire experts say that a fire requires three elements: heat, fuel and oxygen. Simply removing one of these elements is enough to extinguish a fire or prevent it from starting.

Cohen’s research on radiant heat led to the recommendation to create a 100-foot buffer zone around a building to contain a wildfire.

But that doesn’t mean ripping out all the landscaping within that radius and laying gravel. Rather, a property is divided into zones radiating out from the structure, with various measures taken to reduce fire risk.

“It’s not really difficult at all. It’s basic maintenance around your yard,” said Nicole Parpart, a grant specialist and planner with the Yakima County Office of Emergency Management.

The farthest zone is between 30 and 100 feet from the house. In this zone, it is recommended to make sure there are wide spaces between trees and that branches are cut back to within six feet of the ground, Parpart said. This ensures that trees are less likely to catch fire or, if they do, spread the fire to other trees and structures.

The next area ranges from 5 to 30 feet, and this involves clearing vegetation around propane tanks and maintaining a green lawn, usually trimmed to about 4 inches, which ensures that if a grass fire starts, it will be small.

In the innermost zone, homeowners should keep house gutters clean, install screening over open spaces under decks to keep debris out and keep roofs free of flammable materials, such as dried leaves or pine needles, Parpat said.

And while people love seeing thuja trees next to their homes, firefighters warn that they are a fire hazard. The evergreens contain oils that make the needles particularly flammable, which is useful for starting a campfire but a worst-case scenario when a wildfire is headed toward a home.

While it may be convenient to stack firewood against the house, it poses a fire hazard, especially if you live in an area prone to wildfires.

To take part

Yakima County Fire Chief Doug Werts said people are increasingly aware of the need for defensible space around their homes.

“With the recent wildfires, it’s becoming more and more evident,” Werts said. The Thorp Road fire that started July 4 has burned more than 2,000 acres, while the Slide Ranch fire near White Swan has blackened more than 3,000 acres and destroyed 17 homes.

One factor contributing to increased awareness is that insurance companies are reluctant to insure homes – or insist that homeowners pay higher premiums – in a wildland urban interface area unless measures are taken to reduce fire risk.

“It’s still a public education process, and it’s an expense,” Werts said. “It’s not an expense that everyone can afford. We’re doing the best we can and keeping people as safe as we can.”

Ryan Rodruck of the DNR said the state has funding for people who are trying to create defensible spaces but don’t have the funds to do so. The DNR also has its Wildfire Ready Neighbor program, which offers wildfire safety tips to homeowners at https://wildfireready.dnr.wa.gov.

Through this program, the DNR and local fire departments can come inspect a property and advise the owner of what improvements are needed to prevent a fire from starting.

People living in areas affected by wildfires can request inspections from their local fire departments.

Woodall said defensible space is beneficial to firefighters for several reasons. First, it provides protection for a home or other structure, and second, it gives firefighters the space they need to safely respond to a fire.

And the evidence is clear on Rattlesnake Ridge, where pockets of green against the blackened hillside mark where homes had defensible space when the Thorp Road fire raged.

“The first house that was hit by the fire had a large defensible area,” recalled East Valley Deputy Fire Chief Ray Lamoureux. “They had a stone wall around the house, a green lawn, no flammable storage space up there.”

Lamoureux said other homes in the neighborhood, as well as a trailer park, had space that protected them from the fire.

With a defensible space, Lamoureux said, a fire could start within 30 feet of a home and be fine.

And it is in these places that, according to Lamoureux, the firefighters will intervene.

“We will defend those we can, against the house that has dry grass and shrubs and stores firewood. This makes the situation more dangerous for us.”