The U.S. Army Corps of Engineers plans to seek bids for construction of a drainage tunnel spur extension at Howard Hanson Dam on the Green River in western Washington.
Howard Hanson Dam, a 235-foot-tall earth and rockfill dam was completed in 1962 for flood control, fish enhancement, and water conservation. The Corps recruited bidders in 2007 for excavation and tunneling for a fish passage facility at the dam.
The Corps’ Seattle District said it plans to seek bids to construction a 225-foot-long addition to the drainage tunnel in the dam’s right abutment. Excavation dimensions are to be about 10 by 14 feet with initial ground support consisting of forepoling, shotcrete, and lattice girders. The final structure is to be 18-inch-thick cast-in-place reinforced concrete liner with a finished interior of about 6 by 9.5 feet. Geologic conditions are expected to include volcanic bedrock, landslide debris, fluvial sands and gravels, and lacustrine silts.
The Corps said it has not set a solicitation date or a projected cost of the project.
A pre-solicitation notice may be obtained from the Federal Business Opportunities Internet site, www.fbo.gov, by entering solicitation No. W912DW10R0065 in the “Keyword/Solicitation #” box.
For information, contact Sonia Frees, U.S. Army Corps of Engineers District, Seattle, ATTN: CENWS-CT, P.O. Box 3755, Seattle, WA 98124-3755; (1) 206-764-3516; E-mail: email@example.com.
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