Background:  The Tucannon River basin is located within the ceded area of the CTUIR in Southeast Washington State, in Columbia and Garfield counties. The system-wide restoration objective for the Tucannon River is to improve habitat conditions for Endangered Species Act (ESA) listed species (Snake River Spring Chinook and Steelhead) for all life history stages.  It is expected that improved habitat conditions will lead to an increase in the abundance of listed species returning to the river.  The long-term goal of increasing abundance should lead to de-listing of the species, which is the overall recovery goal for the system. Previous assessment efforts (CTUIR, WDFW, CCD and SRSRB) have identified the habitat-limiting factors associated with the decline of ESA-listed populations.  

The updated Tucannon River Geomorphic Assessment & Habitat Restoration Study (Anchor QEA, 2021) identifies and prioritizes stream reaches and restoration actions which would best improve watershed habitat conditions for salmonids. Earlier, focusing on the high priority areas for Tucannon spring Chinook, the Columbia Conservation District (CCD) coordinated the development of an initial habitat restoration plan for the Tucannon River from RM-20 upstream to RM-50; the CCD continued to work with the Snake River Salmon Recovery Board (SRSRB) and other programmatic partners (NPT, WDFW, CTUIR), through the Tucannon River Programmatic Habitat project, and extended the 2011 Tucannon River restoration plan from RM-20 downstream to the confluence of the Snake River.  This Conceptual Restoration Framework (2011 Plan) prioritized projects into three Tiers (1-3) based on the projected effects of implementation as a benefit to Snake River spring Chinook, cost-efficiency relative to those benefits, and the feasibility of construction.

The revised Conceptual Restoration Study and Plan (2021 Plan) continues this practice, prioritizing projects into Tiers (1-3), but now based on revised and more explicit prioritization goals derived from key parameters that characterize the geomorphic conditions in the river: channel and floodplain connectivity, channel complexity, reduction of excess transport capacity, in-channel (LWD) structure and pool frequency. In general terms, the plan’s focus is on: removing channel and floodplain confining features like levees; emphasizing additional LWD placements; and incorporating gravel augmentation to sustain sediment transport, as strategies to accelerate channel aggradation and lateral movement in areas where channel confinement and floodplain isolation are driven by incision.  

The 2021 Plan identifies loss of floodplain connectivity as the major driver in reduced channel complexity, degraded riparian areas, and diminished resilience -- including a loss of stream temperature regulation through the mechanism of hyporheic exchange. The restoration actions identified and outlined in the 2021 Plan are focused on instream methods to reduce floodplain confinement, increase channel length, and reduce excessive stream power. With these refined and refocused prioritization goals, the CTUIR contract staff and project implementers will select work areas and develop habitat restoration approaches in the Tucannon within a Program framework that better emphasizes floodplain connectivity as the key component in restoring habitat access and improving conditions for adult and juvenile Snake River spring and fall Chinook, steelhead, and bull trout throughout the watershed.

Overview: The Snake River Salmon Recovery Board (SRSRB) manages the Tucannon River Programmatic Habitat Project (2010-077-00) through a parent contract for the operations support, management organization, implementation assistance, and reporting described in this summary. The goal of the Tucannon River programmatic is to restore habitat function and natural channel processes in the spring Chinook priority restoration reaches of the Tucannon River, leading to improved population productivity and abundance.  The CTUIR manages this contract as a contribution 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.  

Major limiting factors influencing the condition of these touchstones throughout the project reaches proposed for treatment in the watershed, include:  
  • Anthropogenic modifications affecting and causing the loss of natural channel forming processes that link the Tucannon River to its floodplain;
  • Loss of key in-channel habitat complexity and structure, including diversity and quantity, especially in the form of gravel sorting, varied velocities, and pools associated with recruitment of large wood;
  • Excess stream power in reaches that are confined by levees, lack enough space for natural stream processes and/or have incised into the floodplain; and
  • Elevated summer water temperature, and reduced flow duration.
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Contract Summary: This contract continues the CTUIR role anticipated in the Accords (BPA) and the Tucannon Habitat Programmatic Project: to inform and conduct project evaluation, selection, management, implementation planning, data collection, monitoring, outreach and other tasks, where tribal staff can provide expertise; and to be an implementer of the on-the-ground project construction activities for projects identified in the Programmatic work plan, and sub-regional Snake River Salmon Recovery Plan. Contract tasks include identifying and sequencing projects for implementation pursuant to the prioritized restoration strategy of the Habitat Programmatic, and consistent with the Tribes' First-Foods paradigm and River/Upland Vision principles; the CTUIR staff will partner with Tucannon Implementer’s and others to implement the priority projects.

This yearly contract supports the recurring development of future habitat project concepts, refinement of restoration approaches, the production of engineered designs for selected projects, implementation work-planning and construction scheduling for approved projects, and the build-out of completed projects.

  • Ongoing: In this contract term, CTUIR staff continues to support and maintain watershed coordination with SRSRB, CCD, WDFW and Nez Perce Tribe, through ongoing communication and collaboration, shared work-tasks, and monthly and quarterly Tucannon Implementer’s meetings. The CTUIR is a member of and attends the meetings of the SRFB Lead-Entity committee, to review, rank and select projects for funding in the State of Washington (RCO) Salmon Recovery sub-regional process for the Snake River. CTUIR staff attend SRSRB (Board) Meetings monthly, and acts as the RTT Board Liaison to ensure pertinent information is transferred from the RTT to the Board. The CTUIR continues project development efforts and implementation tasks addressed to improving habitat structure and function at Project Areas (PA) throughout the Tucannon Watershed.

  • Current: Habitat project development, design and implementation emphases in the current contract period are the continuation of the Tucannon PA 5-15 assessment and conceptual design, including the focus of PA 8-10.3 as the first conceptual design the co-managers (CTUIR,NPT, WDFW) will take to final design in 2025\26 and Tucannon PA 27/28.1 phase 4 that includes multi-year planting at the Tucannon PA-27/28.1 site (2025-2030).  Longer-term efforts at PA-18 (Hartsock) continue to be evaluated and monitored. Actions proposed in these project areas are identified as a high priority for habitat improvements (Anchor QEA, 2021), and focus on promoting sediment transport and increasing the amount of large wood debris (LWD) to increase channel complexity and floodplain connectivity, the highest priority outcomes for spring Chinook in the Tucannon. Description of the project areas with respect to existing natural processes and habitat conditions is to be provided in the associated project Design Reports, along with the specific physical and biological objectives that the proposed restoration treatments are expected to achieve for each phase of the project design and the construction build-out of the habitat features for these project areas.