Last week, the U.S. Forest Service released a report evaluating the effectiveness of fuel treatments during the Mountain Fire in July 2013.

The primary goal of the report was to assess the effect of the treatments on the fire’s behavior and intensity and their ability to improve fire suppression efforts near communities.

“Our trends suggest that fuel treatments can facilitate suppression activities and potentially reduce fire behavior and fire effects, depending on the fire weather or conditions,” the report’s authors concluded. The more recent the treatment, the more likely it reduced fire severity or aided fire suppression.

The Forest Service studied areas that had received fuels treatments such as tree removal, mechanical thinning, pile burns and prescribed area burns. The period covered started in the mid-1990s, but most of the work was accomplished in the past decade. The study also examined the effect of two previous fires in or near the Mountain Fire area.

Fuelbreaks in or near the burned area were generally beneficial. However, the authors noted that in areas where the fuelbreaks near private land were connected to treatments on agency land, they were more likely to reduce the fire’s effects. “Where this was not the case (e.g., around much of the Bonita Vista fuelbreak), the fire burned through untreated fuels on private land.”

Forest Service investigators also observed a “treatment shadow” where the value of fuel treatments extended beyond their boundaries. These treatment shadow benefits included diminished fire behavior when it moved to untreated areas; reduced production of embers; and eased fire containment activities.

The fire severity data indicated that areas with taller pre-fire shrub cover tended to have the potential for higher substrate (soil) and vegetation (shrubs) burn severity.

Another conclusion important to efforts on the Hill was the recognition that coordinated efforts of private landowners and the Mountain Area Safety Task Force in completing fuels reduction projects helped save homes in the communities.

“Everyone on the Hill should know that this analysis supports the basic principle that both we and the fire agencies have been acting on for years: reducing fuel around homes and the community increases the safety of both,” said Mountain Communities Fire Safe Council President Mike Esnard. “The report has other useful lessons for land managers in the design of fuel treatments, but overall it argues for the value of consistent fuel reduction in and around the mountain communities.”

The area burned during the Apache Fire in 2008 was also less receptive to the devastation of the Mountain Fire. This reinforced the principal of fire as a natural fuel treatment process.

The Forest Service assessment began even before the fire was fully contained on July 30. The fire severity monitoring was conducted between July 22 and 25, just following the major rainfall event of July 21 and 22. Areas sampled included key sites near the Keenwild Station, Living Free and the Bonita Vista fuelbreak.

The Mountain Fire started in the afternoon of July 15, 2013. The fire spread quickly from private property near the junction of highways 74 and 243 to the east through grass, chaparral and into timber. Considerable resources were deployed on the fire, including fixed and rotor-wing aircraft, ground crews and support infrastructure, at a cost of about $26 million. Two weeks later on July 30, the fire was declared contained after burning nearly 27,531 acres.

The report, titled “2013 Mountain Fire Fuel Treatment Effectiveness Summary” can be found online at: