Findings of Congress
• The Endangered Species Act is the last resort for species at risk of extinction.
• Under the ESA, the National Marine Fisheries Service (NOAA Fisheries) is accountable to ensure that salmon and marine species are preserved for future generations.
Scope of FederalSalmon Recovery
Initiatives
WASHINGTON
IDAHO
OREGON
MONTANA
Snake River
Columbia River
Listed Salmon & Steelhead
Chum (1 Stock)
Sockeye (1 Stock)
Chinook (5 Stocks)
Steelhead (5 Stocks)
Federal Dams
Non-Federal Dams
Canadian Dams
Dams without Fish Passage
Salmon & Steelhead Range Affected by Lower Snake River Dams
Effects of Dams on Salmonids
• Restrict access to habitat• Alter habitat• Alter hydrology• Alter gradient• Passage hazard• Creates recreational opportunities and
expectations. • Creates opportunities for further water
development within the basin.
Actions called for in NMFS’ biological opinions
• Dam Operations• Spill at Dams• Flow Measures• Transportation• Dam Modifications• Research Monitoring & Evaluation• Hatcheries• Habitat
Status of Adult Passage
• Successful for adult salmon, generally in the range of 98% conversion per dam.
• Lamprey passage success is poor
• Sturgeon passage is poor
Turbine Survival
• Varies by project
• Survival range is 85 to 100%
• Most projects are in the range of 90%
Most fish are transported
• 1993-2006– 60-99% of non-tagged stream-type
Chinook– 70-99% of non-tagged steelhead
Transport study results
• Transportation appears to benefit hatchery stream-type Chinook and steelhead
• Transportation does not appear to greatly benefit wild stream-type Chinook
Spillway Survival
• Spillway survival varies by project
• Survival range is 90 to 100%
• Most projects are in the upper 90% range
Bypass Survival
• Varies by project
• Range of survival is 90 to 100%
• Most projects are in the mid to upper 90% range.
Wild chinook salmon
1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 20050.0
0.5
1.0
1.5
2.0
1 2 3 4Number of detections
Notdetected
* P<0.05
2.5
3.5
4.5
5.5LGR only
*
** * **
** *ns**
**
*
% of fish in thenot-detectedcategory
13.6 28.8 29.3 17.5 14.1 29.6 1.0 24.8 26.9 7.9 4.0
Year of outmigration
Rela
tive r
etu
rn r
ate
s to
Low
er
Gra
nite
Dam
Flow Management Program
• Spring Season– Yearling migrants
• Summer Season– Subyearling migrants
Spring Flow Management
• Largely achieved by having reservoirs operate no lower than their flood control rule curves by April 10.
• Rationale is it passes the freshet into the river as opposed to refilling reservoir space.
Historic estimated juvenile chinook traveltime from Lewiston to Bonneville Dam
(after Raymond 1979)
0
10
20
30
40 no dams
Low flow Moderate flow High FlowSnake R. (35-53 kcfs) (71-106 kcfs) (106-177 kcfs)
Columbia R. (141-177 kcfs) (212-318 kcfs) (353-494 kcfs)
Tra
vel t
ime
(d
ays
)
Estimated yearling chinook travel time -Lewiston to Bonneville Dam
0
10
20
30
40no dams4 dams8 dams
Low flow Moderate flow High FlowSnake R. (35-53 kcfs) (71-106 kcfs) (106-177 kcfs)
Columbia R. (141-177 kcfs) (212-318 kcfs) (353-494 kcfs)
Tra
vel t
ime
(d
ays
)
Basis for Managing Flow
• Evolutionary Considerations
• Recognition there was a flow/travel time relationship for juvenile salmon.
• Data suggesting survival benefits over the life cycle of salmon (SARs).
• Beneficial effects of a freshwater plume to estuary and near ocean environmental processes.
Flow Objectives
• Flow levels sought during the spring juvenile migration.
• Columbia River
Spring: 220 – 260 kcfs depending on runoff volume
Snake River
Spring: 85 – 100 kcfs depending on runoff
Recent and Near Term Project Modifications
• Lower Monumental Dam RSW - 2008
• Spill Wall extension at The Dalles – 2008
• Ice Harbor RSW – 2005
• Bonneville Corner Collector - 2004
• The Dalles Spillway Wall – 2008
• John Day Surface Bypass - 2008
Chinook salmon
1965 1970 1975 1980
0.0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
1995 2000
Nodata
Outmigration year
Est
imat
ed h
ydro
pow
ersy
stem
sur
viva
l
1970 1980 1990 20000
1
2
3
4
5
6
2-oceanonly
Raymond (1988)
afterPetrosky et al.(2001)
Williams et al. (2005)(updated)
Estimated Snake River wild spring-summerchinook salmon returns (escapement to upperSnake River dam + catch)
CSS PIT
Outmigration year
Sm
olt-
to-a
du
lt re
turn
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