26-October-2004 |
2004-19 |
NOAA, USFWS, IDFG, ODFW, WDFW, NPT, SBT, CRITFC |
Tailwater elevation at Bonneville Dam to protect natural spawning of chum
and fall chinook salmon at the Ives/Pierce Island Complex, Multnomah Falls,
and partly influence the I-205 seeps.
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1. SOR request |
As required by the 2000 NMFS Biological Opinion, beginning when chum
are present and continuing until further notice, provide a minimum
instantaneous tailrace elevation of 11.5 feet at Bonneville Dam. On
average it is anticipated that daily average flows will not exceed 125 Kcfs.
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2. Participants |
NOAA Fisheries, U.S. Fish & Wildlife Service, Idaho Department of Fish and
Game, Oregon Department of Fish and Wildlife, the Washington Department of
Fish and Wildlife, Nez Perce Tribe, Shoshone-Bannock Tribes, and the Columbia
River Inter-Tribal Fish Commission.
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3. TMT recommendation |
Effective Thursday 10/28 at 0700 hours:
24 hours/day Hard constraint minimum 10.5' Bonneville tailwater
24 hours/day Soft constraint minimum 11' Bonneville tailwater
If chum salmon are present on Friday, 10/29, Dave Wills or Paul Wagner
will notify Cathy Hlebechuk or Julie Ammann.
Effective 0700 - 1900 hours daily starting Saturday, 10/30, target tailwater
11.5' and soft constraint 11.3' - 11.7'
Effective 0700 - 1900 hours daily starting Monday, 11/1, target 11.5' and
hard constraint 11.3' - 11.7'
If chum are NOT present on 10/29:
Effective 0700 - 1900 hours daily starting Monday, 11/1, 10.5' - 12'
hard constraint
If chum are present Tuesday 11/2, Dave Wills or Paul Wagner will notify
Cathy Hlebechuk or Rudd Turner
Effective 0700 - 1900 hours daily starting Wednesday, 11/3, target tailwater
11.5' and soft constraint 11.3' - 11.7'
Effective 0700 - 1900 hours daily starting Thursday, 11/4, target 11.5' and
hard constraint 11.3' - 11.7'
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4. AA decision |
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5. IT recommendation |
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6. AA decision (after IT) |
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7. Actual Operation |
Based on the observation of adult chum salmon at Ives and Pierce Islands,
a stable tailwater elevation in the Ives and Pierce Islands area started
on November 9 with an initial targeted daytime tailwater elevation of 11.3
- 11.7 feet. This elevation was increased to 11.7 - 12.1 feet on December 8.
The elevation was increased again to 11.9 . 12.3 feet on December 15.
On several occasions in December it was necessary to allow daily tailwater
change exceedences and expanded hours for higher discharges in order to
pass high river flows. Also flows were ramped up and back down during
day and night hours on 7 dates between November 17 and December 8 for a
chum spawning study. The Bonneville tailwater was increased from 11.5
feet up to 15.1 feet in 1.2-foot increments every other hour, then ramped
back down again on the same schedule, for the study.
At a TMT conference call on December 29, the salmon managers stated that
spawning had ended. As a result, the action agencies. changed the operational
goal from limiting spawning access to a redd protection operation for the
incubation/emergence period. At that time the daytime upper elevation
limit was ended and a 24 hr/day minimum tailwater level was set at 11.9 ft.
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8. If different from AA decision, why? |
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