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It's about dam time

Deep in the Colestin Valley, between a meadow and a rolling oak woodland, there is a creek. And in that creek there is a dam. Willow branches are intertwined with fir logs, creating a structure that spans the width of the streambed. Its base is lined with grapefruit-sized rocks, covered by a thick coating of mud.

It’s a dam that would make a beaver proud, but this one was built by humans.

The Colestin is one of my favorite places. At the southern tip of Oregon, on the south side of Mount Ashland and the Klamath-Siskiyou Mountains, this beautiful valley has incredible biodiversity thanks to a great cross-section of habitats from mixed conifer forests to oak-studded meadows. Many of the people who live here care deeply about the natural world, and Lomakatsi has been partnering with the community to do ecological restoration on their lands for over 20 years.

Gen Creek, in the heart of the valley, is designated as an essential salmonid habitat waterway by the state of Oregon. It once traced a wide and meandering path into Cottonwood Creek, providing excellent wetland habitat for wildlife along the way. Now it follows a narrow channel and is facing issues from erosion, excess sediment and fast-paced flow events that threaten important native fish species.

I believe strongly in the power of nature as a restorative force. When we do ecological restoration, we want to work with nature whenever possible to support its natural healing processes.

One way to do this is to play beaver.

Last week, Lomakatsi and the U.S. Fish and Wildlife Service created three engineered structures along Gen Creek to slow and spread the flow of water. Using all natural materials, these “beaver dam analogs” are designed to enhance streamside habitat for fish and other wildlife, while reducing further erosion of the creek. They provide many benefits of actual beaver dams.

“One of the goals of the project is to slow velocities and encourage water in the creek to more frequently access its surrounding floodplain,” said Dave Johnson, wildlife biologist for the FWS office in Yreka, California. “Historically, before the stream became so deep and narrow, water used to frequently overflow into the surrounding meadow, supporting alder, willow, chokecherry and other plants that created a wealth of wildlife habitat.”

For centuries, beaver shaped the very makeup of the North American landscape. At one point, the United States was covered with enough water from beaver-created ponds to fill an area the size of California, Oregon and Washington combined. When beaver were eradicated during the fur trade, waterways lost their keystone stewards and hydrologic architects.

Combined with large-scale water diversions for agriculture and grazing — and extensive logging — the absence of the beaver has severely degraded aquatic habitat and devastated native freshwater fish populations in many areas.

Fortunately, beaver populations are on the rise as resource managers and private landowners increasingly recognize the essential role they play in ecosystems. In fact, when using beaver dam analogs to restore streams, there is a high likelihood that the restoration efforts will attract actual beavers to move in and maintain the structures as their own.

For this project, we hired a local business to use heavy equipment to drive approximately 45 Douglas-fir logs — byproducts from the Ashland Forest Resiliency Stewardship Project thinning work — in three strategic locations bisecting the creek. Lomakatsi restoration practitioners and FWS staff then wove willow branches, harvested from the surrounding area, around the poles. They encircled the base of the structures with rocks and coated them with a mud and straw mixture for added stability.

If beaver had made the dams themselves, they may have used many of the same materials.

“My favorite part about working with BDAs is that we’re using a process-based approach,” said Rebecca Reeves, habitat restoration specialist with the FWS office in Yreka, who helped on the project. “This is a simple, very cost-effective approach that replicates systems that already exist in nature. We’re giving nature a nudge, and then letting it repair itself.”

This project is a great example of how partners can come together to accomplish restoration. Here we have collaboration between our nonprofit, the U.S. Fish and Wildlife Service and a private landowner. We have a Lomakatsi ecosystem restoration workforce on the ground and hired a local contractor to help with the install. We’re grateful to the FWS Partners for Fish and Wildlife program for funding this important work, and sustaining local jobs in the process.

Landowners interested in implementing beaver dam analogs or other restoration strategies on their properties are encouraged to reach out to the FWS office in Yreka or Lomakatsi.

Marko Bey is executive director of Lomakatsi Restoration Project.

Sequoia Ahimsa and Kaiya Spain of Lomakatsi apply a mud and straw mixture to a beaver dam analog.