SPOKANE — The number of acres burned so far in Washington’s wildfire season this year is on trend with what ecologists predicted. But the damage has been catastrophic, and it could be weeks before fire danger subsides.
Dryer, hotter summers and changes to the state’s vegetation mean the fire season spans longer than it once did.
“Over the last 10 years we have seen the fire season expand a bit on both edges — both the beginning and end of the season,” said Matthew Dehr, a wildfire meteorologist for the state Department of Natural Resources. “Last year, we saw active fire behavior through October.”
This week, Dehr camped near the 6,000-acre Sourdough fire in the North Cascades that burned dangerously close to the hydroelectric dam supplying the Seattle metropolitan area with power. Dehr worked 12-hour days alongside fire crews, attempting to contain the fire and protect the power infrastructure.
Across Washington, hundreds of firefighters and scientists this month worked to respond to a slew of destructive fires ignited in a heatwave.
In July, the Newell Road fire sparked in Klickitat County and grew to more than 60,000 acres — nearly doubling the size of the state’s largest fire last year.
This month in Spokane County, two lives and hundreds of structures were lost in the Gray and Oregon Road fires.
‘Near-record fire danger’
Rainy conditions the past couple springs primed the land for the high fire danger conditions on Aug. 18 that sent the Gray and Oregon Road fires quickly roaring through Spokane County, scientists say. The rain helped grow a lot of cheatgrass, a fast-burning invasive species .
“There was much more fuel available this year when we’ve had a very dry summer,” Dehr said. “We were pushing near-record fire danger indices when we saw those fires ignite. The amount of fuel that was available for them to burn helped them burn hot and fast, through thousands of acres.”
Long-term trends show grassland and sagebrush fires in Washington are becoming much more common.
The day the Gray and Oregon Road fires ignited, relative humidity was around 6%, and wind gusts measured at speeds of 30 mph for hours.
The Gray fire and the Oregon Road fire had forest and structure components to them, too, Dehr said.
“But what’s really carrying starting that fire is that finer brushy and grassy fuel,” he said. “The weather that day was just about the driest I have seen in Washington in my two years of working out here.”
It could take until October for the state to see rainfall substantial enough to end the fire season, Dehr added.
‘What can we alter?’
In the 20th century, fire suppression and exclusion in the American West by European colonizers prevented a lot of fires that would have otherwise naturally occurred.
“If you look at historic averages in the West, we don’t match the acreage of fire that would touch the West precolonization,” said Mark Swanson, a fire ecology professor at Washington State University.
Nowadays, where fires ignite, they tend to burn in ecosystems where fire was excluded for much of the 20th century. A buildup of grown vegetation as a result means those fires will likely burn at a higher intensity and severity — intensity being heat release and severity being what the flames do to the vegetation.
“We deliberately excluded fire, or suppressed it, for much of the 20th century in the West in the belief that fire was bad,” Swanson said. “The irony is that it allowed fuel to accumulate.”
Buildup of fallen pine needles and branches on forest floors coupled with fir trees that have crowded into more historically spread-out, ponderosa pine forests mean fires travel faster. And when fires move through these fuel-heavy, newly denser forests, they burn from the ground up to the crowns of the trees and travel from branch to branch.
Historically, fire traveled on the ground in more spread-out ponderosa forests.
For ponderosa pine and dry Douglas and grand fir forests, Swanson suggests landowners look into forest-thinning and potentially prescribed burns for fire safety.
“I would encourage landowners to contract with a qualified forester or a forestry consultant to determine if that’s needed for their particular property,” he said.
The state Department of Natural Resources and Washington State University both have wildfire preparedness programs where foresters will visit a landowner and offer help or advice.
“Another factor that’s significant is that Native Americans used fire as a tool,” Swanson said. “And the landscape benefited. We need to learn from that cultural example of these people who have lived in the West for thousands of years and really understood the landscape, and still do, and take lessons that we can incorporate into contemporary management.
The landscape is not short on ignition sources — whether it’s power lines, or hot mufflers, or cigarettes flicked out of a window. That means humans must look elsewhere to mitigate fire danger.
“What can we alter? We can’t really alter the weather so much, except indirectly through things like climate change,” Swanson said. “But we can alter the fuel bed. We need to manage our grasslands, shrublands and forest lands in ways that will make them safer and more resilient when fire does come.”
