The "Cottonwood Island Slough Habitat Design" project completed a preliminary engineering design and preliminary permitting negotiations for implementing a subsequent project to restore Chinook rearing habitat in about 5,000 linear feet of relic Cottonwood Island Slough along the lower Skagit River. The site is owned by WDFW and managed as part of the Skagit Wildlife Area. Removal of log jams, levee building and placement of road fill in the slough over the past century gradually isolated the slough so that presently its thalweg averages several feet above low flow river stage, making most of it inaccessible to fish except during floods. SRFB-funded Project 06-2211N "Cottonwood Island Feasibility Assessment" modeled sediment transport in the reach and evaluated conceptual scenarios for reintroducing surface flow into the head of the slough. The study identified excavation of sediment from the relic channel as the most feasible and effective design approach. The present project completed hydraulic engineering and other detailed technical analysis to implement the selected alternative from the 06-2211N study. A channel restoration design was prepared that will provide sustainable flow velocity, depth, and other ecological design parameters for Chinook rearing over the long term. A key feature of the design is an engineered inlet structure, which is intended to minimize sediment deposition in the restored channel during flooding events. Upon implementation, the design will create 9.4 acres of additional off-channel rearing habitat, which is expected to result in roughly 8,370 to 19,020 addtional Chinook smolts annually. These figures equate to between 2.1 and 4.8 percent of the Skagit Recovery Plan's targeted recovery goal. The project gained broad community acceptance for the design through a stakeholder participation and review process. Unfortunately, WDFW declined to pursue the implementation of the project design because of its reluctance to commit to maintaining the project after construction.