Wednesday August 27, 2025
Elkhorn Media Group —
The U.S. Army Corps of Engineers, Walla Walla District has awarded a $15 million construction contract to Syblon-Reid Co. of California to build a new fish ladder at the Mill Creek Diversion Dam located next to Rooks Park in Walla Walla.
The current fish ladder at the diversion dam, built in 1982, no longer meets the standards set by the National Marine Fisheries Service for successful fish passage – raising concerns for steelhead, Chinook salmon and bull trout returning to spawn in Mill Creek.
The new fish ladder will have a better design to help fish navigate the diversion dam more quickly and reach important spawning areas. The project will also improve the dam’s downstream basin, create a bypass channel for young fish going downstream, and add gates to move sediment past the dam.
Construction will involve replacing parts of the dam and levee, and it will allow for future fish monitoring facilities. Work is set to start this summer and finish by fall 2027, with advance notifications for closures affecting public access.
The improvements aim to benefit fish populations and enhance flood management in the Walla Walla Valley.