The timber flume is one of the oldest project structures still in use, and is essential for getting water from the White River to Lake Tapps. This ensures Cascade can meet its commitments to the Tribes and Lake Tapps community including in stream flows, fish operations, and maintaining lake levels. The current flume is not efficient because:
- The structure continues to leak
- Low volumes of water traveling through the flume means sediment and debris build up
- High water levels in timber flume put stress on structure
- The flume could fail due to its age. If it fails, Cascade cannot fill the lake
Approximately 2315 lineal feet of the existing wood flume will be replaced with a new concrete flume. Construction began in September and continue into March 2015. The existing wood flume’s interior dimensions are approximately nine feet deep by 28 feet wide and is currently made of a combination of treated and untreated wood timbers, planking, and steel cross beams. The new structure will be concrete.
Work began Sept. 18
Work is complete.