Lower Granite Dam
The U.S. Army Corps of Engineers is assembling a steel curtain that will stretch 1,100 feet upstream and reach as deep as 80 feet from the face of Lower Granite Dam along the Snake River in an effort to revive the river’s imperiled salmon and steelhead runs.
The $11.2 million steel curtain will weigh 4 million pounds.
Corps officials hope the curtain, known as the “behavioral guidance structure,” will steer young salmon and steelhead migrating downstream into the floating surface collector.
The collector, which weighs 2,500 tons and cost $42 million, functions like a steel chute to sweep the young fish over a spillway and around the dam’s turbines.
Brayton Willis Jr., the corps’ project manager at Walla Walla, said the curtain will be in place by April 1. The floating surface collector is an attempt to duplicate the design of Wells Dam on the Columbia River. That dam, which has its spillways directly above the hydroelectric turbine intakes, is among the best at safely passing young fish.