Assessing wildfire risk in Boundary County

To some extent, people can limit wildfire devastation. 

Local, state, and federal agencies are responsible for managing and treating forestlands to reduce risk, and for responding quickly when fires do break out. Private landowners near forests also play a critical role in maintaining their property to slow or stop fire spread. And residents in at-risk communities must be aware of how easily human activity — campfires, fireworks, sparks from vehicles — can ignite and spread. 

But underlying weather patterns are beyond any one communities' control. 

Some contributing factors develop gradually, like snowmelt patterns and prolonged drought. Others can happen in an instant, a lightning strike or a sudden dry wind.

Wildfires are unpredictable. 

In August 2022, the Kootenai River complex of fires raged over 19,000 acres of Boundary County. But leading into late summer, the weather had been highly favorable, according to U.S. Department of Agriculture data. 

Water levels atop Hidden Mountain were the highest they had been since 2011. The entire Pacific Northwest experienced an unseasonably cold spring; Idaho’s temperature throughout April and May dropped to 5 degrees Fahrenheit below the norm. Bonners Ferry saw a favorable 11 rainy days in June, according to National Weather Service data.

But a July heatwave jolted most of the Pacific Northwest to 6 degrees above average temperatures. After June, precipitation was down by almost 80%. On July 14, Idaho’s first major wildfire of the year broke out south of Nampa. 

Then August 2022 was Idaho's hottest month ever, according to the National Centers for Environmental Information. It was also one of Idaho's driest. 

By September, five lightning-induced wildfires in the Selkirk and Cabinet mountains were on their way to consuming over 30 square miles of Boundary County. On Sept. 2, commissioners declared a state of emergency. 

Last week, Boundary County Commissioners declared another wildfire state of emergency, but of a different kind. There are no fires, yet. 

The declaration calls for “immediate mitigation actions” by the U.S. Forest Service, as most of the county’s land is dense forest owned by the federal government, and “extreme fire behavior, drought conditions and delayed federal action have created an imminent threat” of local disaster. 

The threat has grown rapidly over the last several decades with the heightened wildfire frequency in the Pacific Northwest, due to earlier spring snowmelt and moisture deficit, according to a research article published by the Royal Society, referenced by the Environmental Protection Agency. 

Throughout this winter, above-average mountain water and river runoff levels in the region marked early indicators of a mild dry season. 

The snow water equivalent in North Idaho’s mountains, for example, was right where it was supposed to be for most of the winter.  

At Myrtle Creek, it peaked just eight days early, within 0.3 inches of the median peak level.  

At Hidden Lake, it peaked April 10, six days early, one inch below the median peak.  

At Schweitzer Basin, the snow water equivalent exceeded the median peak by a wide margin of greater than seven inches. 

But like 2022, spring weather changed on a dime.  

Schweitzer Basin experienced its lowest April precipitation in almost 40 years, according to the Natural Resource Conservation Service. Its snow is forecast to be completely gone by June 13, two weeks before it usually melts. 

“April was very dry across Idaho with basins only receiving 6 to 75% of their normal precipitation,” according to state officials in the May NRCS Idaho Water Supply Outlook Report. “Since last month, moderate drought and abnormally dry conditions have expanded in northern Idaho and along the Idaho-Montana border into central Idaho. In northern Idaho, streamflow forecasts decreased from last month and are well below normal.” 

The U.S. Army Corps of Engineers recently released the Libby Dam June runoff forecast, in which it indicated water levels are at 77% of its 30-year average, the lowest percentile so far this year. For most of winter, the runoff hovered at 100% of the average.

June rainfall is also an important predictor of how early the wildfire season starts, said Idaho Conservation League Director Brad Smith. In 2022, substantial June rainfall contributed to the delayed onset of wildfires until August.

So far this June, there have been zero days of rainfall in Bonners Ferry. 2010 was the last time there was no rain for the entire month, according to National Weather Service data.

“I’m worried about the fact that we’ve had so little rain,” said Cliff Harris, a Coeur d’Alene climatologist, in a report by the Coeur d'Alene Press. “We've gotten 8.5 inches of rain since the first of the year and we should have 14 inches, so we're way behind." 

Weather may improve, as the forecast indicates a few mid-June showers, or it may not. 

“I think the severity of our wildfire season will just depend on if we have lightning strikes, or if people are out. A lot of fires have human-caused starts,” Smith said. “It’s super important that people be responsible, especially around Fourth of July. In general, making sure campfires are out, not parking on dry vegetation, following burn restrictions, and so on. There’s also a need for private landowners to do their part. Many people live on forest lands adjacent to national forests. If people don’t do fuels reduction on their adjacent private land, a fire can jump from fuel breaks.” 

Rain or shine, commissioners are intent on addressing what can be controlled: management of Boundary County forests. 

“We want to engage right now with all parties,” said Commissioner Lester Pinkerton. “We need to get to the table to be able to do everything we can to protect life and land in the community.”