SEATTLE – The U.S. Army Corps of Engineers, working through the Cascade Water Alliance, has begun making interim repairs to Cascade’s barrier structure on the White River at Buckley, Washington.
Timing of the repairs has been coordinated to minimize interference with adult fish returning to the White River, particularly the biannual pink salmon run, which normally occurs in very large numbers in late August through early October during odd numbered years. The Corps’ fish trap, required for moving adult salmon, steelhead and bull trout upstream past Mud Mountain Dam, is located adjacent to the barrier. Under a cooperative agreement, the Corps and Cascade Water Alliance conduct the repairs to the barrier, which is necessary for proper function of the Corps’ fish trap.
The Corps is repairing the barrier apron, which is the horizontal downstream part of the structure, to implement the actions required by the National Marine Fisheries Service in their October 3, 2014, Biological Opinion on operation and maintenance of Mud Mountain Dam. The opinion required interim repairs to the barrier by August 2015. Cascade Water Alliance completed some repairs to the apron on the barrier structure in summer 2014 as an initial step toward the summer 2015 repairs. The intent of repairs is to reduce injury to fish from contact with the barrier structure until the barrier and fish trap can be replaced.
The planned repairs will require a reduction of White River flows to create safe working conditions in the river. Flows will be reduced using Mud Mountain Dam to a targeted minimum of 350 cubic feet per second during three separate occasions between June and mid-August 2015. During those events, the Corps will work with biologists from the Muckleshoot Indian Tribe, the Puyallup Tribe of Indians, Washington Department of Fish and Wildlife, National Marine Fisheries Service, U.S. Fish and Wildlife Service and possibly other tribal and resource agency biologists, to find and rescue fish that may become stranded as flows approach minimums. This is standard procedure for barrier repairs.
In addition to the interim repairs currently being conducted, the Biological Opinion from the National Marine Fisheries Service calls for the Corps to replace the existing 70-year-old fish trap and 100-year-old barrier. The planning and design of the new facility has been a collaborative effort using a Regional Design Team with representatives from the Corps, the National Marine Fisheries Service, U.S. Fish and Wildlife Service, Muckleshoot Indian Tribe, Puyallup Tribe of Indians, Washington Department of Fish and Wildlife, and Cascade Water Alliance.