NOAA Fisheries has worked with the U.S. Army Corps of Engineers and the Bonneville Power Administration to improve fish passage
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.
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.
|
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 |
|
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
|
An oceanic whitetip shark swims near the surface of the water. Photo courtesy of John Carlson.
Veteran intern Antonio Jones at an oyster farm in Drayton Harbor, Washington, checking traps for European Invasive Green Crab. Credit: Northwest Straits Commission
