In southeastern Washington, Tucannon River habitat project improves conditions for fish and wildlife, reconnects floodplain

The image on the left shows a stretch of the Tucannon River, a tributary to the Snake River in southeastern Washington, prior to a habitat project. The project succeeded in slowing the river's current and creating better conditions for fish and wildlife, which is shown in the image on the right. Image credit: Snake River Salmon Recovery Board

Throughout the Columbia River Basin over the past 170 years, humans have made its rivers and streams tidier, simpler, and straighter by damming, diking, dredging, logging, and developing, among other activities and impacts.

From the perspective of fish and wildlife, the messier and more complex the habitat - the more braided channels, the more riffles, pools, and log jams - the better. The Council's Fish and Wildlife Program has recognized the importance of restoring, protecting, and enhancing these kinds of habitat functions throughout the Basin. It makes the water cooler and cleaner for fish, it provides suitable conditions for incubation and rearing, and it supplies lots of food to eat. Planting vegetation and trees along streambanks provide shady places that cool the water and attract insects.

At its November meeting in Portland, the Council listened to a presentation on an ongoing habitat project to restore, protect, and enhance habitat in the Tucannon Subbasin in southeastern Washington state. Kris Buelow, Tucannon Program Coordinator for the Snake River Salmon Recovery Board, led the presentation. (Read slides | watch video) The project is supported by the Council's Fish and Wildlife Program and uses a comprehensive watershed management approach.

Under the Northwest Power Act, the Council's Fish and Wildlife Program relies heavily on protecting, maintaining and improving habitat as an effective means of restoring and sustaining fish and wildlife populations affected by the hydropower system in the Columbia River Basin. The Power Act authorizes offsite mitigation outside the immediate area of the hydrosystem, including tributaries and subbasins like the Tucannon.

The Tucannon project is coordinated by the Snake River Salmon Recovery Board (SRSRB), which is a regional organization for salmon recovery in Washington state. The SRSRB has managed the project in close collaboration with the Confederated Tribes of the Umatilla Indian Reservation, Columbia Conservation District, Nez Perce Tribe, US Forest Service and Washington Department of Fish and Wildlife.

The Tucannon River is a tributary of the Snake River and flows out of the Blue Mountains. The watershed sustains the only remaining population of spring Chinook in the lower Snake, which was listed as threatened under the Endangered Species Act in 1992. Other protected species in the Tucannon Subbasin include fall Chinook, summer steelhead, and bull trout.

The Tucannon River watershed supports numerous resident and anadromous fish species in addition to ESA-protected populations of salmon, steelhead, and bull trout.

The first major human activity to impact the Tucannon was the development of commercial timber harvest, followed by further straightening to assist livestock and agricultural operations. Originally, stretches of the river had multiple channels and braids separated by forested islands that divided up flows. The river had more equilibrium with riparian forests and was more ecologically functional and productive.

After a series of floods caused significant property and infrastructure damage, throughout the 1960s the US Army Corps of Engineers supported land managers in straightening and leveeing large sections of the river, confining it to a single channel. From 1937 to 1978, possibly as much as half of the Tucannon' s total river length was lost due to channelization and confinement.

Work has occurred over the past 20 years toward the project's goal of restoring the Tucannon to an ecologically functioning watershed, bolster its resilience to future climate changes, and support recovery goals of sustaining 750 returning adult spring Chinook and 1,000 summer steelhead.

Buelow's presentation focused on a subset of projects that's occurred over the past five years, as well as those coming up over the next five years. The habitat objectives include floodplain connectivity, channel complexity, stream power, increasing the channel length, improving pool frequency and quality, riparian health, and flow and temperature mediation. Since 2020, these projects have been implemented on approximately five river miles, with 2.3 river miles planned for 2025 and 3.4 miles planned between 2026-29.

They've succeeded in making the channels braided and reconnected, setting levees back, slowing the river down, reconnecting floodplain and growing the number of wetted areas, increasing the number of logjams and woody debris, and overall increasing the complexity of the habitat.

"It took a long time for the river to do the work," Buelow said, reviewing the many years of work on the Tucannon. "Although it took a very long time, it actually turned out very good."

The total number of adult fish returning to the Tucannon exceeded goals between 2008-2015 but has dipped below those marks since then. The returns of wild and endemic steelhead have grown significantly since 2021 and exceeded the goal of 1,000 in each of the last three years. Total trap captures of adult bull trout have also increased annually since 2019, when they hit a 10-year low of 50 fish. 300 were recorded through trap capture in 2024.

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