Overview: The Tucannon River in Southeast Washington flows north out of the Blue Mountains into the Snake River, and is the ancestral boundary between the Confederated Tribes of the Umatilla Indian Reservation and the Nez Perce Tribe. The Tucannon watershed supports the only remaining population of spring Chinook (Oncorhynchus tshawytscha) in the lower Snake River. Early fish estimates show the Tucannon once produced thousands of salmon annually, but now only produces a few hundred adult spring Chinook each year. In 1992, spring Chinook were listed as threatened under the Endangered Species Act as runs declined to less than 200 adult fish. Because of the Tucannon River’s importance to the Snake River Basin, BPA provides funding for a Programmatic Habitat Project in the Tucannon River.

The Tucannon Programmatic Project is managed by the Snake River Salmon Recovery Board (SRSRB) through a parent contract for operational support, organizational management, implementation assistance, and annual reporting. The goal of the Tucannon River programmatic is to restore natural channel processes in the spring Chinook priority restoration reaches of the Tucannon River, leading to improved population productivity and abundance. The CTUIR collaborates in the Programmatic Project, as a project implementer in support of programmatic goals, consistent with the CTUIR River Vision: a desired riverine system that is shaped and maintained by the dynamic interactions and interconnections of its natural physical and ecological processes. The restoration actions proposed for implementation in the prioritized river segments promote and enhance the interconnected nature of the five primary touchstones of the Tribes' Vision: a) hydrology, b) geomorphology, c) connectivity, d) riparian community, and e) aquatic biota.  

Background: After several years of opportunistic restoration in the Tucannon Basin, as a Model Watershed (1997-2008), the Columbia County Conservation District (CCD) brought all parties to the table to work on a new restoration planning document. The Tucannon River Geomorphic Assessment & Habitat Restoration Study (Anchor QEA, April 2011) identified and prioritized stream reaches and restoration actions which would best improve habitat for salmonids. Refocusing on the high priority areas for spring Chinook, the CCD coordinated the development of a habitat restoration plan that prioritized work from RM-20 upstream to RM-50. After 10 years of implementing the first plan, it became obvious that program managers needed to move further down the watershed and start working in the lower Tucannon River. In 2018, through the Tucannon River Programmatic Habitat project, the CCD initiated an update of the Tucannon Restoration Plan to help refocus restoration efforts and include the rest of the Tucannon River from RM-20 downstream to the confluence of the Snake River.

The Updated Tucannon Conceptual Restoration Plan (Anchor QEA, 2021) prioritizes projects into three Tiers (1-3) based on these prioritization goals: (1) increased complexity at low-winter flows, (2) increased complexity during spring and winter peak flows, (3) reconnection of disconnected and abandoned floodplains, (4) improved quantity and quality of pools, and (5) increased retention and storage of in-channel bedload sediments. The 2021 assessment and plan, with supporting appendices, is accessible at:   https://tucannonriver.org/reports-and-data/assessments-and-action-plans/.

Summary: In 2014, WDFW completed the development of the W.T. Wooten Wildlife Area Floodplain Management Plan, which was developed as a plan to define and conduct management activities for seven manmade lakes and their supporting infrastructure (e.g., diversion structures and riprap levees) located on the floodplain of the Wildlife Area. In 2011, the benefits of removing or changing the configuration of the lakes were not included in the project concept development nor within the prioritization framework, and consequently they were not considered in the Geomorphic Assessment & Restoration Prioritization update, completed in early 2021. Since then, significant spring flooding disabled the utility and function of several of the lakes and their supporting infrastructure, opening an opportunity for reconsideration of the restoration potential in this 14-mile reach of the river.  A broad group of partners, including the co-managers, have elected to evaluate the physical impacts of the lakes, consider alternatives, develop initial strategies and preliminary project concepts, and explore possible restoration approaches as a basis for priority actions that could contribute significantly to achieving the habitat restoration objectives and fish recovery goals for the watershed. The "Big 4" levee removal and lake restoration project, discussed below, was identified as a high priority opportunity because of the size of the project area and the potential for floodplain reconnection.

Current Emphasis: Supported by this contract, CTUIR is partnering with WDFW and NPT to: (a) utilize existing geomorphic data to summarize the impacts of infrastructure on the Wildlife Area; (b) develop conceptual restoration actions addressing floodplain habitat areas affected by the lakes; (c) evaluate proposed actions prioritized on the basis of improving functional deficiencies in spring Chinook habitat; and (d) work with local stakeholders in a process to identify solutions to infrastructure impacts and constraints in the recreational put-and-take fisheries supported by the lakes.  It is anticipated that going forward with a floodplain restoration plan focused on restoring habitat and minimizing infrastructure, if conducted as a partnership among WDFW, CTUIR and NPT, will lead to a more balanced program effort and outcome.   It is anticipated that the result of this assessment will lead to the prioritization of large project >1-2 miles in length focusing on increasing channel length within a larger floodplain for the purpose of reducing stream power and optimizing spring Chinook spawning and rearing.

The first floodplain project prioritized under the assessment has been identified and restoration designs initiated under contract (#73982 REL 222 Tucannon (PA8-10.3) Big 4 Levee Removal Design), managed by CTUIR.  The anticipated floodplain project will focus on levee removal (approx. 3655 ft), reconnection of approx. 50 acres of floodplain, and reconnection of over 4 miles of disconnected channels for the purpose of spring Chinook recovery.