Hydrologist Diane Hopster, Columbia River Gorge National Scenic Area and Mt. Hood National Forest, and Fish Biologist Chuti Fiedler, Mt. Hood National Forest, presented “Eagle Creek Fire: A Watershed Perspective” at the Hood River Watershed Group’s April 24 meeting, held at the West Side Fire Station on Barrett Drive.
Hopster and Fiedler worked as resource advisers on the Eagle Creek fire in the days after the fire started, as well as with the Burned Area Emergency Response (BAER) team.
From a soil and water perspective, the result of the Eagle Creek fire and the ongoing recovery effort is a mixed bag, complicated by the fact this “is a high-profile situation politically, and in the public view,” said Fiedler.
The Eagle Creek fire, which started Sept. 2 of last year, eventually combined with the Indian Creek fire, a separate burn event that began on the Fourth of July — both started by fireworks. The fire burned approximately 49,000 acres of scenic land.
Because of steep terrain and dangerous post-fire conditions, there are many sites within the burn area still too hazardous to enter, and even in areas deemed safe enough, Fiedler said they had “spotters” to make sure boulders didn’t crush them as they worked.
The good news:
“The Gorge is a fire-adapted ecosystem,” Fiedler said. “Lots of aquatic species have evolved to thrive with this recurring disturbance.”
Landslides and debris flow delivers sediment to streams, which can provide good lamprey habitat, and most studies show increased fish abundance and productivity post-fire, she said.
“Large wood comes in and sediment supply gets sorted out,” she said.
But there was extensive coho and sculpin mortality noted at Horsetail Falls and Multnomah Falls pools, said Fiedler.
“Firefighters were telling us of (fish) deaths, of ashfall and intense heat, rockfall and fish popping up dead and floating downstream,” she said. “The first thing I did was try to figure out what was wrong. I contacted the hatcheries, but they didn’t know. There was fish kill at Horsetail and Multnomah, but the hatcheries saw nothing.”
She’s still not sure what caused the deaths, but thinks it may have been “an interaction of effects,” namely elevation of stream temperatures into stress zones, heavy ash raising alkalinity and ammonium levels, and decreased oxygen levels from ash fall and higher temperatures.
“And possibly the last straw — this is my theory — is that the fire burned off moss and vegetation, which caused large boulders to fracture from sidewalls and the top of waterfalls, impacting concussively hard on the pool surface, which could incur internal injury to fish.
“But I wish I knew,” she added. “I still have no idea, actually.”
Other wildlife has fared better.
“There seems to be some displacement,” said Hopster. “We keep hearing about people seeing more wildlife than they would normally because their habitat has burned. But there’s not a high density of bear, deer and elk in that area anyway.
“Other than fish, nobody has seen any casualties of the fire. But there’s also a lot of backcountry that hasn’t been safe to explore,” she said.
Erosion is an issue, with the increased probability of rock fall and rockslides throughout the burn perimeter, said Hopster.
“The most affected areas are Eagle, Tanner, Moffett, McCord, Horsetail and Oneonta creeks,” she said. “Multnomah Falls and Oneonta Creek are big concerns because of the recreation that happens at both. There’s been lots of work at Multnomah Falls, but Oneonta is a big concern because it’s a very unsafe place to be, and there’s not a lot we can do to defend that.”
Many affected areas have been closed to the public, although that hasn’t stopped everyone. As of February, there were over 50 access points closed to the public, Hopster said, with 122 miles of trail closed. There were also nearly 4,000 “turnarounds” recorded, along with 600 verbal warnings and 50 citations given to those disregarding the fire closures.
Because it takes about five years before the root systems of dead standing trees begin to fail, said Hopster, it is likely landslides will occur in the future.
“But that doesn’t mean it’s going to happen,” she noted. “Along the interstate corridor, it would be hard to predict. But a rain or snow event in five years will probably not be a good thing.”
Natural recovery was noted as early as three weeks after the fire, with analysis of the soil showing fungal mats binding the soil to help in its recovery, as well as buds and other vegetation “popping up all over the place,” Hopster said. But it also showed that there was “lots of soil gone in high severity areas.”
It’s also probable that the fire will help spread invasive plants like blackberry and scotch broom.
Proposed treatments include trail stabilization and storm-proofing, building bridges and other recreational infrastructure, and simply getting trails cleared of debris, as well as putting up signs and gates along roads, adding more pipe and drainage, and the initiation of an invasive plants survey.
Funding has been secured for one year only, and the Forest Service is looking for partnerships with other agencies. The current trail recovery team includes Friends of the Columbia Gorge, Trailkeepers of Oregon, Pacific Crest Trails Association and the Washington Trails Association, Hopster said.