This is an excerpt from EERE Network News, a weekly electronic newsletter.
Army Corps Selects "Adaptive Migration" at Snake River Dams
The U.S. Army Corps of Engineers has chosen a combination of operational and structural changes to improve the survival of salmon on the lower Snake River. The Corps announced the decision on September 11th, concluding a process that began in 1995. Alternatives examined by the Corps ranged from doing nothing to breaching the dams, options that were explored extensively in public meetings held by the Corps.
The Corps' chosen approach, called "adaptive migration," includes operational changes to improve the coordination and implementation of spilling water past the dams, improved efforts to maintain minimum stream flows, and increased transportation of juvenile fish around the dams. Near-term structural changes include spillway improvements, upgraded fish passage systems, improved facilities for juvenile fish, and additional fish transportation barges. Proposed long-term improvements include turbine upgrades, removable spillway weirs, and new surface bypass structures. See the Corps' Lower Snake River Study Web site.
According to a July report from the General Accounting Office, 11 federal agencies have spent roughly $3.6 billion since 1982 in efforts to recover salmon and steelhead populations in the Columbia River Basin. Despite these efforts, the number of salmon and steelhead returning to the basin has averaged only 660,000 per year in recent years, compared to an estimated 16 million in the early 1800s. See the GAO report abstract or go directly to the full report (PDF 6.31 MB). Download Acrobat Reader.
Although the Snake River dams have been spared, American Rivers, a non-profit conservation organization, noted in July that 63 dams in 15 states plus the District of Columbia are scheduled for removal in 2002. But although there are 75,000 dams greater than 6 feet in height in the United States, less than 3 percent are used to generate electricity. Most dams that are being removed no longer serve an economic purpose. See the American Rivers press release.