BAER summaries available online
By Natalie Johnson
The Okanogan-Wenatchee National Forest has released reports detailing fire intensity and damage to vegetation, roads, streams and other impacts of this summer’s Cedar and Cub creek fires.
The reports estimate 48% of burned area in the Cedar Creek Fire had high or moderate soil burn severity, and 41% in the Cub Creek Fire, meaning those areas are at a risk for the soil to become water repellant and cause mud and debris slides.
“Fire-damaged soils have low strength, high root mortality, and exhibit increased rates of water runoff and erosion,” both reports state.
The areas with moderate and high soil burn severity saw 80% to 100% vegetation mortality as well, according to the reports.
The Forest Service began its Burned Area Emergency Response (BAER) team on Aug. 25 to assess damage from the fires. The reports include soil burn severity and debris hazard maps as well as descriptions of the fires’ impacts.
Debris flows
The BAER reports show a significant possibility of debris flows in heavily burned areas in both fires.
According to the Cub Creek report, U.S. Geological Survey models predict a 40% likelihood of debris flows in the burn area, with a 60% to 80%, or higher than 80% chance in severely burned areas.
“These hazard areas mostly occur in drainages above Doe Creek, Falls Creek, Eight Mile Creek and the Chewuch River,” the report reads.
The Cedar Creek report estimates that a storm dropping 0.3 inches of rain in 15 minutes would have an 80% chance of causing debris flows in drainages including tributaries to Wolf Creek, the Methow River, Early Winters Creek, Little Bridge Creek and the Twisp River Drainage.
“Most of these watersheds are roughly estimated to produce more than 1,000 [cubic meters] of debris, resulting in a high debris flow hazard,” the report states.
Both areas are expected to see an increase in runoff and a decrease in water quality in streams due to ash and sediment.
Debris flows, as well as increased sediment, can lead to problems including blocked culverts, damage to roads or even damage to homes in the streams’ path, according to the reports.
The report lists a number of Forest Service roads in both burn areas that could be at risk, as well as bridges in the Cub Creek area including the Falls Creek Bridge, Falls Creek Utilities Bridge and the Eightmile Creek No. 1 Bridge.
“The proposed treatments include signs warning travelers of the increased danger, temporary closures of roads where safety is at particularly high risk, post storm inspection, drainage dips, clean ditches and inlets to handle increased flows, and fixing burned holes in the road prism,” according to the Cub Creek report.
Impacts to recreation
Recreation resources were damaged or otherwise impacted by both fires, the reports state.
Two campgrounds, three trailheads, several dispersed use sites, seven terra trails, one sno-park, groomed motorized and non-motorized trails and the Lake Chelan-Sawtooth Wilderness area are within the fire’s perimeter.
The Forest Service noted that Klipchuck and Early Winters campgrounds were not damaged, and though they are downstream from burned areas, are not at high risk for damage from debris flows.
However, dispersed camping could be dangerous in some areas. Responses could include temporary closures, warning signs or longer-term closures.
The Wolf Creek trailhead in the Cedar Creek area was burned, leaving damaged infrastructure and hazard trees, according to the report.
“The toilet burned, leaving an open vault containing human waste, resulting in high risk to life and safety,” the Cedar Creek report states. The report recommended temporarily closing the trailhead, treating or pumping the toilet and sealing the open holes.
A number of other trails were also impacted.
The Cub Creek burn area includes five trailheads, dispersed use sites, seven terra trails, one sno-park, groomed motorized trails and two rivers eligible for Wild and Scenic River designation, according to the report. The Falls Creek trailhead is unsafe due to hazard trees, and the Eightmile Ridge trailhead hasn’t yet been assessed because hazard trees are blocking the road to the trail.
Repeated damage
Both fires burned into areas recovering from previous wildfires, damaging riparian areas and increasing the threat of invasive weed growth, according to the reports.
“The Cedar Creek fire overlapped with five different fires that have occurred on USFS land within the past 35 years,” the report reads. “It is expected that 109 acres of shrub steppe communities and 23,215 acres of dry and hot forested plant communities that reburned within the past 35 years will face impacts given the invasion of cheatgrass, knapweed, dalmatian toadflax and whitetop that are changing the ecological response and fire resiliency of these ecosystems.”
In the Cedar Creek Fire, crews constructed 43 miles of dozer line and 8 miles of handline and in the Cub Creek Fire, there 38 miles of dozer line and 12 miles of handline.
The Cub Creek fire overlapped with seven fires occurring over the past 35 years.
“Forty-four percent of riparian habitat mapped in the burn area was potentially impacted by high to moderate severity fire effects,” the report reads. “If weed infestations are not detected and controlled within the first year post-fire, these previously intact native communities will likely type-convert into exotic species dominance.”
See the full reports:
Cub Creek 2 BAER: https://inciweb.nwcg.gov/incident/7830/
Cedar Creek BAER: https://inciweb.nwcg.gov/incident/7832/
