North Fork Walla Walla River RM 4-8 Restoration Design Project

The North Fork Walla Walla River is identified in numerous natural resource management guidance manuals as a priority location for restoration and protection. Designs focused on converting the channel back to the appropriate form and function with subsequent improvements to salmonid habitat suitability. The initial design phase was completed from river mile 3.6-4.4 and will be covered in this report. Landowner agreements were secured for a 10-year period and the majority of the valley width was made available for holistic floodplain restoration. Initial conceptual design alternatives were developed and circulated to review teams to solicit professional direction and attain decisions in regard to choice of preferred alternative chosen. As part of the alternative assessment, a matrix was developed to encompass the attributes and drawbacks to each alternative. Preliminary designs concepts were presented early in the development process to review teams and landowners to assure timely utilization of resources towards developing a viable design that could be approved, permitted and implemented in a timely manner. Upon receiving decisions in regard to the chosen alternative, designs were advanced through engineer review stages at the 15%, 30%, 80% and 100% levels. Upon acceptance of the 80% design package by review entities, permitting was initiated. Input from the BPA review team at the 80% design level was used to shape development of the 100% final design level. Final, stamped designs were successfully produced and implemented during the instream work window of 2023.

As stated, this project completed designs for restoration from river mile 3.6-4.4. The acres were overestimated at proposed and the actual acres accurately represents the acres encompassed by this design project.

Recent counts of adult steelhead at McNary Dam migrating from the ocean to natal headwater streams are significantly (33-50%) below all-time lows. Mid-Columbia Steelhead and bull trout inhabit the NFWWR project area and are listed as Threatened ESA species with local populations declining in size and status trending towards a high risk of extinction. The NFWWR is one of the last remaining primary steelhead spawning destination strongholds in the Walla Walla Basin. Therefore steelhead suitability and inhabitance is potentially a key component towards recovery through protection, restoration, and enhancement managerial actions in the NFWWR. WWBWC fish habitat restoration efforts target species of focus is steelhead, with indirect overlapping benefits to bull trout, spring chinook salmon, mountain whitefish, freshwater mussels, western brook lamprey, redband/rainbow trout. The magnitude of the NFWWR design project being 4-miles in length, and implementation duration being through 2027, and the benefit of having controlled access in regard to being behind a locked gate, coupled with our ridgetop to ridgetop watershed approach offers an opportunity to make a significant opportunity towards the recovery of the species. Our intent is to potentially expand onto public land from RM 8 upstream after 2027 and concentrate on enhancing habitat complexity specifically for these species of concern. Our design of habitat restoration plans intends to address all life stages of salmonids to prevent bottlenecks suppressing population growth with the ultimate goal of supporting the removal of Mid Columbia Steelhead from the Threatened and Endangered Species List by reaching levels of viability.

The Status of Oregon’s Bull Trout by ODFW and the USFWS 2014 upper Walla Walla Bull Trout reports identify the NFWWR as 1 of 4 remaining bull trout strongholds but classifies the NFWWR as marginal in regard to suitability, which corresponds with low population status. The value of the NFWWR is that seasonal use by bull trout occurs and preserving the interconnectivity between the NF and SF Walla Walla forks is important to the long-term viability of the migratory component of the species.