The US Army Corps of Engineers will be starting an important project that will protect endangered fish in the White River and provide an opportunity for Cascade to put additional water into refill of the lake.
The Corps utilizes Cascade’s Buckley barrier structure as a component of its system to transport endangered salmon above Mud Mountain Dam. The Corps is required under federal mandate by the National Marine Fisheries Service’s recent biological opinion to repair the downstream apron on the barrier structure so as not to harm or kill fish.
To make the apron repair, the Corps must reduce instream flows and is authorized to do so in order to meet the federal requirement under the Endangered Species Act. This instream flow reduction is specific to the apron repair only. Cascade is not authorized to hold water back or change instream flows.
Cascade and the Corps are working together under a cooperative agreement to maintain the Buckley barrier structure. The apron is currently in such poor condition that it not only jeopardizes fish but threatens the entire barrier structure.
During the initial phase of the project, set for the first week of June, the Corps will manage water flow by holding water above Mud Mountain Dam. Flows will be reduced to approximately 350 cubic feet per second (cfs) in the White River to provide a safe work environment in the river. Water in excess of that amount will be held in storage behind Mud Mountain Dam. The Corps operates Mud Mountain Dam solely for flood control, but occasionally holds water when doing barrier repairs and maintenance of the system if needed.
Water stored will, upon completion of the work, be released into the river. Because it is expected to be in excess of the minimum instream flow requirements, Cascade will be able to divert a significant portion of that water to refill the lake.
“Cascade is working hard to refill the lake. This provides an opportunity for us to align the Corps’ mission — of flood control and a repair which will protect fish in the river– with our ability to take water for refill,” said Chuck Clarke, Cascade CEO. “As projected, this means that nothing will be going into the lake during the first week of June. But it also means that we will take the upper limit of allowable water after this phase is completed. We will lose NO water going into the lake with this project. In fact, we will gain significantly more water going into the reservoir than we would have had without this project.”
Projections are that this could raise the lake considerably by the middle of June. A second phase of the project will occur near the end of June and will also allow Cascade to put more water into the lake.
For current refill status visit http://cascadewater.org/project-overview.php and for lake levels visit http://cascadewater.org/lake_tapps_recreational_lake_levels.php For updates check Cascade’s Facebook page or follow them on Twitter.
