Salmon Recovery Grant to Fund Fish Passage in Mill Creek
December 15, 2022
WALLA WALLA – Tri-State Steeheaders will receive a grant of $4.7 million from the Recreation and Conservation Office for fish passage improvements in Mill Creek.
“This funding will allow us to nearly complete fish passage treatments in the concrete section of Mill Creek,” said Steelheaders’ Executive Director Brian Burns.
The grant will fund work at four sites in Mill Creek: 1) Roosevelt St, 2) between Spokane and Park Streets, 3) between 3rd and 6th Avenues, 4) and in the non-concrete channel above Roosevelt St. The work between 3rd and 6th will include a partnership with the City of Walla Walla to remove the 5th and 6th Avenue bridges. The scope of work for the grant is expected to be completed in 2025.
The non-federally owned portion of the Mill Creek flood control channel includes four miles of a levee-confined channel with regularly spaced energy-dissipating weirs and two miles of concrete-lined channel. A 2009 assessment by the Steelheaders identified and described barriers within the flood control project for Endangered Species Act (ESA) listed steelhead and bull trout and for reintroduced spring Chinook.
In the concrete channel, depth and velocity conditions present barriers to migrating adults and prevent the volitional passage of juveniles. The levee section also offers barriers to juvenile passage. The passage treatment remodels the concrete in the channel to provide depths and velocities of water favorable to fish passage.
Upstream of the flood control infrastructure is a critical and under-utilized area for spawning and rearing. Restoring fish passage to upper Mill Creek is an essential component of recovery for Mid-Columbia summer steelhead, providing good to excellent habitat for other native fish and reintroduced spring Chinook.
The first passage projects by the Steelheaders in Mill Creek occurred in 2011. As of today, six construction projects, in cooperation with the Walla Walla County Public Works Department, have improved fish passage to over half of the length of the concrete channel. These projects have been funded by the Salmon Recovery Funding Board, Brian Abbott Fish Barrier Removal Board, Confederated Tribes of the Umatilla Indian Reservation, and Bonneville Power Administration.