Federal Columbia River Power System Dam Improvements and Spill Information

Dam Improvements

Fish (e.g., salmon, steelhead, eulachon, sturgeon) migrating through the Columbia and Snake rivers must pass up to eight Federal dams. NOAA Fisheries has worked with the U.S. Army Corps of Engineers and the Bonneville Power Administration to improve fish passage through each dam. Juvenile fish passage systems and enhanced operations have provided significant improvements for fish survival in recent years. The illustration below identifies specific passage improvements.

Dam Passage Improvements

Spill

The FCRPS Action Agencies (Army Corps of Engineers, Bonneville Power Administration, and the Bureau of Reclamation) release (or spill) water over the Federal dams in the spring and summer to help juvenile salmon and steelhead migrate safely to the ocean. With spill, these fish go past the dams in water that flows through spillway openings, rather than traveling through turbines.

The FCRPS Action Agencies have built spill into the 2008/2010 FCRPS Biological Opinion, tailoring it to scientific findings and consulting with the NOAA Fisheries to meet the FCRPS Biological Opinion performance standards of 96 percent average per-dam survival for spring migrants and 93 percent for summer migrating fish.

The effectiveness of spill to increase fish survival varies and depends on the configuration at each dam. While spill is effective, by itself it is not a simple or immediate solution to the issue of fish passage. For example, too much spill can create back-eddies where fish get trapped and become easy prey to predators. Too much spill can also cause gas bubble disease.

Each year, the U.S. Army Corps of Engineers (Corps) prepares Fish Operations Plans describing operations at each of the eight dams for safe fish passage. During the migration season, state and tribal fish managers work together with the Corps to manage real-time operations decisions for listed fish species.

Summary of 2012 Spring Spill at Lower Snake & Columbia River Projects

Project	Planned 2012 Spring Spill Operations (Day/Night)	Comments
Lower Granite	20 kcfs/20 kcfs	Same as 2011
Little Goose	30%/30%	Same as 2011
Lower Monumental	Gas Cap/Gas Cap (approximate Gas Cap range: 20-29 kcfs)	Same as 2011
Ice Harbor	April 3 - April 28: 45 kcfs/Gas Cap April 28 - June 20: 30%/30% vs 45 kcfs/Gas Cap (approximate Gas Cap range: 75-95 kcfs)	Same as 2011
McNary	40%/40%	Same as 2011
John Day	Pre-test: 30%/30% Testing: 30%/30% and 40%/40%	Same as 2011
The Dalles	40%/40%	Same as 2011
Bonneville	100 kcfs/100 kcfs	Same as 2011

Summary of 2012 Summer Spill at Lower Snake & Columbia River Projects

Project	Planned 2012 Summer Spill Operations (Day/Night)	Comments
Lower Granite	18 kcfs/18 kcfs	Same as 2011
Little Goose	30%/30%	Same as 2011
Lower Monumental	17 kcfs/17 kcfs	Same as 2011
Ice Harbor	June 21 - July 13: 30%/30% vs 45 kcfs/Gas Cap July 13 - August 31: 45 kcfs/Gas Cap (approximate Gas Cap range: 75-95 kcfs)	Same as 2011
McNary	50%/50%	Same as 2011
John Day	July 1 - July 20: 30%/30% and 40%/40% July 20 - August 31: 30%/30%	Same as 2011
The Dalles	40%/40%	Same as 2011
Bonneville	June 16 - July 20: 85 kcfs/121 kcfs and 95 kcfs/95 kcfs July 21 - August 31: 75 kcfs/Gas Cap	Same as 2011

More Information

Last updated by West Coast Regional Office on 09/27/2019

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