Though it may seem like the Bootleg Fire’s damage has already been done after crews contained the blaze last month, the 647 square mile scar spells trouble for the entire Klamath Basin once the wet season arrives. If actions aren’t taken quickly to protect streams and drainages in the burn area, water quality in Upper Klamath Lake — and the endangered c’waam and koptu that call it home — could suffer.
For decades, suckers have been plagued by excessive phosphorus loading into the lake through its main tributaries — the Sprague, Williamson and Wood rivers. Though the Upper Basin is naturally rich in phosphorus due to its volcanic soils, land use changes and agricultural practices have channelized streams, reduced natural water storage and accelerated riparian erosion, all of which increases the amount of nutrient-carrying sediment flowing into Upper Klamath Lake.
Having passed a natural threshold, the additional phosphorus has given rise to a monoculture of cyanobacterial algae that dominate the lake ecosystem in the summer. Fish biologists say dramatic declines in water quality related to the algae’s bloom-and-crash cycle stress out juvenile c’waam and koptu in the lake, causing almost all of them to succumb to disease and predation by the end of each summer — before they’re able to reach sexual maturity.
The more phosphorus that enters the tributaries, the harder it will be to repair Upper Klamath Lake and bring the suckers back from the brink of extinction. It’s yet another blow to the Klamath Tribes, who watched as their ancestral homeland went up in flames this July, destroying cultural resources and sacred sites.
Stan Swerdloff, aquatics supervisor for the Klamath Tribes, said the Bootleg burn area is a nutrient bomb waiting to go off.
More than 340 river miles of tributaries and seasonal drainages burned in the fire, most of which will flow into Upper Klamath Lake. The Sprague River, which contributes the largest share of phosphorus to the lake, was severely impacted — 85% of the river’s north fork burned, along with 67% of the Upper Sycan River, which flows into the Sprague.
“We’re very concerned that we’re going to have massive erosion and sediment flowing into the rivers, and of course that means a lot more phosphorus. That’s all going to end up in the lake,” Swerdloff said. “It’s going to make a dire situation much worse.”
Sediment loading is a common problem after wildfires, as the loss of vegetation that holds soil together causes it to erode into streams — along with all the chemicals and nutrients buried within — when precipitation returns. Additionally, when soil burns, it becomes hydrophobic, causing water to run off instead of soak into the ground. That has implications for flash flooding and debris flows, even exacerbating future droughts by limiting a forest’s ability to store water in its soils or allow them to percolate into aquifers.
Given the already precarious state of the Klamath Basin, a megafire in its headwaters was the last thing the watershed needed.
The Burn Area Emergency Response (BAER) Team sent in by the Forest Service to evaluate immediate impacts to life, property and natural resources following the Bootleg Fire surveyed the topography and burn severity within the fire scar. Sedimentation is a function of how severely the soil burned and how steep of a slope it’s on. The less intact and steeper a slope is, the more it will erode once a major precipitation event occurs.
Leah Tai, one of the Bootleg BAER Team’s hydrologists, said she was pleasantly surprised by what the team found. The majority of soils appeared to have burned at moderate or low severities because the fire ripped through vegetation so quickly. And thanks to the gently sloping landscape of the Sprague and Sycan watersheds, water may run off at a relatively slower rate than in a place like the Klamath Mountains in the Lower Basin.
“I came in pretty concerned, and I think when we saw the mix of soil burn severities, we were happy to see that some of the watershed areas fared okay,” Tai said.
Still, some drainages — particularly smaller, higher-altitude waterways — are ripe for erosion once significant rains arrive. Tai said soils near Deming Creek and other creeks flowing off Gearhart Mountain, along with the area surrounding Spodue Mountain, burned more intensely than the rest of the fire.
“It was those smaller watersheds higher up that had the higher burn severity,” she said.
Steve Rondeau, natural resources director for the Klamath Tribes, said the BAER analyses were straightforward but didn’t adequately address the concerns over nutrient loading in Upper Klamath Lake, which itself is outside the burn area, and its effects on endangered species there.
“’Sedimentation is a concern, but it’s not a huge concern. Let’s keep most of it out of the water system, and it’ll be fine,’” he said, paraphrasing the reports’ discussion of watershed impacts. “Not in this system, though, that’s already hypereutrophic.”
The Tribes are eager to mitigate some water quality impacts before winter sets in. They hope to help the Forest Service install straw mats and beaver dam analogues in key rivulets, which would slow the movement of water and allow eroded sediment to settle out before entering larger streams. Runoff from forest roads, which already contribute to sedimentation, also needs to be contained.
Swerdloff said the work needs to happen before a major influx of water arrives to the burn area. That usually takes the form of spring snowmelt or a rain on snow event, so measures need to be put in place before snow begins accumulating later this year.
“There’s a sense of urgency, because we’ve got to do some of these remedial actions before the snowmelt...assuming we have some snow this winter,” he said.
How much of a setback the Bootleg Fire will prove in improving the health of the Klamath Basin remains to be seen. Swerdloff said he worries that the state’s emergency board, from which the Tribes’ aquatics department has requested money to carry out mitigation activities, won’t provide adequate funding in time.
“We’re really concerned that this could turn into an ecological disaster,” he said.