Tri-State Steelheaders completed final designs for fish passage improvements for a 1,344-foot-long reach of the concrete-lined Mill Creek flood control channel between Spokane Street and Park Street in Walla Walla. The design connects a previous phase completed in 2013 with another phase completed in 2019. The plans developed in this project will be used in construction planned for 2023. Flood control measures on Mill Creek include a concrete channel that extends over two miles through Walla Walla. The Mill Creek Barrier Assessment completed in 2009 identified and described barriers for Endangered Speciaes Act (ESA) listed steelhead, bull trout, and reintroduced spring Chinook. Returning adults encounter flow-dependent depth and velocity barriers with a lack of resting opportunities. Juvenile fish encounter low spring flows and high water temperatures in late spring. By mid-May adults and juveniles can become trapped in the flood control channel where they experience lethal temperatures. These passage issues are considered imminent threats in the Snake River Salmon Recovery Plan. Mill Creek upstream of the flood control project, is a critical and under-utilized area for spawning and rearing of ESA-listed species. It provides important recovery opportunities for those listed fish, as well as good habitat for other native fish and reintroduction efforts for spring Chinook.