Wednesday, October 14, 2009

Savage Rapids Dam removed

On Oct 9, another dam was removed in Oregon: the the Savage Rapids Dam on the Rogue River.

Water Watch and others worked for more than 2 decades to remove this 39-foot high, 500-foot long irrigation diversion dam. According to Water Watch, the dam has long been considered the biggest fish killer on the Rogue.

Dam removal was accomplished by constructing a coffer dam upstream to divert flows while the concrete dam was demolished. When the coffer dam was breached sediment was flushed naturally downstream. In this case, because of historic operations and limited storage the dam had trapped only 200,000 cubic yards . This volume is roughly equivalent to a 2-year sediment supply from the Rogue River. The reservoir sediments were found to consist of 71 percent sand, 27 percent gravel, and 2 percent silt and clay.

Project Benefits: Removing Savage Rapids Dam will provide important benefits for the Rogue River and local economies, including:
  • 114,000 (estimated) additional adult salmon and steelhead in the Rogue River
  • $5 million/year in additional economic activity for local economies
  • Removal of a major barrier to fish passage and to boating on the Rogue River
  • Permanent protection of significant streamflows in the Rogue River
Cost estimate: $40 milion, with the funds primarily coming from federal government.

Sediment Management: Natural transport

More Information: