Carlton flooding, debris flow demonstrate dangers of logging burned forests

Carlton flooding, debris flow demonstrate dangers of logging burned forests

Conservation Northwest / Jun 05, 2015 / Forest Field Program

State should halt hazardous logging operations in Carlton burn area, revise inadequate regulations on logging in post-fire landscapes to protect people, property, fish and wildlife.

Earlier this year, we joined with a local resident and others to appeal a risky so-called “salvage” timber sale on state Department of Natural Resources (DNR) land in the Methow Valley that had been burned during the Carlton Complex Wildfire and then experienced flash floods.

Fires like the Carlton blaze are natural events. Fires may burn trees and other plants, but they also can dramatically alter soil conditions by creating a “hydrophobic” (water-resistant) impervious waxy top layer that increases runoff and also mudslides or debris flows during heavy rain events. This can harm sensitive fish and wildlife habitat as well as threaten people and homes downstream.

The state’s timber sale proposed to remove the remaining trees from 1,200 acres of lightly to severely burned forests using ground-based heavy machinery on exposed fragile soils near several creeks in the middle Methow Valley. Research has shown logging after fires dramatically boosts soil erosion, crushes and impedes forest regrowth, harms fish and wildlife habitat and undermines forest recovery.

In short, DNR’s logging proposal for this area was hazardous for the ecosystem and local residents. It is expected to exacerbate erosion, debris flows and flooding threats already present after the Carlton fire. 

As local resident Kathleen Yockey put it during our appeal, “the area proposed for logging has an ongoing problem with mudslides, debris flows, and flooding. Just ask anyone living downstream.”

Unfortunately, our appeal was rejected by a state board in April, and logging began immediately in areas burned by the Carlton Fire.

Flooding and debris flows at Texas Creek on May 28th, 2015

Last week, Mother Nature, and the shortsighted logging sale, added a predictable and dangerous twist to the story.

Example of extensive sediment and debris movement within DNR salvage logging areas that merged into a debris torrent. Photo George Wooten / CNW

For the second time since the fire, a thunderstorm dropped up to an inch of rain on the Texas Creek drainage west of Carlton, parts of which had been logged under the DNR sale. Once again, water moved quickly downhill instead of soaking into the soil.

As it crossed into the logging area, where soil had been churned up by logging machinery and tree limbs and tops had been lopped off and scattered around, the flash flood quickly picked up soil and logging debris. Soon a wall of mud and debris several feet high was plunging downstream towards homes and property owners.

Local and regional news reports (Methow Valley NewsWenatchee WorldKCLY Spokane) tell of harrowing close calls and property damage, with videos of homeowners waiting out the flood on their rooftops.

One resident said that they knew the risks of flooding and debris flows were greater after the fire, and they prepared by cleaning up vegetation in the creek and adding a new culvert, “but never imagined anything like this.”

Erosion and sedimentation within salvage logged areas (left) compared with stable soils and healthy vegetation on National Forest (right background) Photo George Wooten / CNW

Although the state applied small buffers along streams, these buffers are designed for unburned forests on the premise that a blanket of living plants would filter out and restrict the flows. But burned areas lack living plants and logging removed many large trees in the Texas Creek area, along with the capacity of the forest to stop the flows.

As the torrent went downstream, it encountered undersized culverts that formed waterfalls and increased flood damage. Photo George Wooten / CNW

A day after the floods, Methow Valley resident and Conservation Northwest staffer George Wooten visited Texas Creek to see how the state’s preventative measures, and nearby homeowners, had fared.

Using on-the-ground observations and a GIS analysis, George found strong evidence that the logging had in fact increased the flood’s impact. presentation he compiled from his visit shows that the flood event started on federal Okanogan-Wenatchee National Forest land, but did not become a significant debris flow until it flowed through the state’s logged areas.

Speaking during our appeal, Tim Coleman of the Kettle Range Conservation Group (one of the involved groups) said “it’s not hard to see how a dramatic pulse of sediment caused by logging would overwhelm these tiny buffers on streams and wetlands.”

During the recent thunderstorms at Texas Creek, it appears the buffers and culverts were inadequate even though flooding and debris flows were predictable.

Logging Unit 4, a clearcut, acted like a funnel to collect many small flows into one giant debris torrent that traveled miles. Photo George Wooten / CNW

Making sure it doesn’t happen again

The flooding and debris flows near Carlton could have been much worse. Lives could have been lost and greater property damage could have occurred. But the threat of this happening again remains in Texas Creek and other areas where risky “salvage” logging sales are occurring on landscapes impacted by fire.

Conservation Northwest believes that the DNR should suspend all logging operations in the Carlton burn areas until there are sufficient safeguards to ensure that streams, wetlands and other aquatic habitat are fully protected.

Similar adequate safeguards should be mandatory for all “salvage” logging sales statewide and new policies for the review of all salvage sales are necessary.

“Heavy rain and thunderstorms are normal at times in the Methow Valley,” says Wooten. “Knowing that is the case, we need to plan for it.”

Peter Goldman, Executive Director of the Washington Forest Law Center, echoed that sentiment in recent remarks with KUOW Public Radio on our appeal and the flood events.

“The only thing we can do is to make sure this doesn’t happen again and that the DNR is held accountable for imprudently logging this place,” Goldman said.

Conservation Northwest believes that DNR’s rules intended to protect public lands, private property owners and fish and wildlife habitat from the risks of “salvage” logging are inadequate and in need of revision. Hopefully the close call at Texas Creek last week spurs a much needed change.