Dams

摘要

Kiewit Infrastructure West, Vancouver, Wash., breached Washington state's Con-dit Dam on Oct. 26, beginning the nation's second-largest dam-removal project. The $33-million demolition job will remove the 125-ft-tall concrete structure to meet standards for fish habitats. Kiewit burst a hole in the 90-ft-wide base, which emptied the 92-acre reservoir in two hours. The dam removal, set to begin next spring and wrap up by Aug. 31, will open 3 3 miles of new spawning grounds for steelhead. With the Glines Canyon (210 ft) and the Elwha River (108 ft), the three largest dam-removal projects in U.S. history are under way.