SYSTEM OPERATIONAL REQUEST: #2001-8

The following State and Federal Salmon Managers have participated in the preparation and support this SOR:
TO: Brigadier General Strock COE-NPD
William Branch COE - Water Management
Cindy Henriksen COE-RCC
Doug Arndt COE-P
Col. Randall J. Butler COE - Portland District
Lieut. Col. W. E. Bulen, Jr. COE - Walla Walla District
J. William McDonald USBR-Boise Regional Director
Steven Wright Acting BPA-Administrator
Greg Delwiche BPA-PG-5
FROM: Christine Mallette
Christine Mallette, Chairperson, Salmon Managers
DATE: July 3, 2001
SUBJECT: Dworshak Operations
SPECIFICATIONS: Beginning July 9, continue releasing 10 Kcfs daily at Dworshak, as long as the decision by the Federal Executive Group to not provide summer spill is in effect.  Maintain temperature regulation at 48°F.

JUSTIFICATION:

Research conducted by both National Marine Fisheries Service and the US Fish and Wildlife Service has concluded that flow augmentation from Dworshak Reservoir provides a significant survival benefit to juvenile migrating subyearling chinook salmon.  This benefit accrues from both a reduction in the water temperature in Lower Granite Reservoir and an increase in flow.  The temperature at the Lower Granite forebay monitor is indicating a daily average temperature of 68.9°F, with hourly readings as high as 73°F, increasing as anticipated based on weather conditions.  Water quality modeling conducted by both the EPA and U.S. Army Corps of Engineers has shown releases of cool water from Dworshak Reservoir can cool the water temperature in Lower Granite Reservoir.

In addition, flows at Lower Granite are far below the flow targets contained in the 2000 Biological Opinion.  The following graph shows flows this year compared to the past five years.  As seen in the graph the flows are considerably less than normally occur during this time period in more "near average" to "above average" years.  Flows over the past five days averaged approximately 25 Kcfs.

Lower Granite Flows

The migration of fall chinook from the lower Snake is well underway.  Passage indices of subyearling chinook had shown a steady increase for the past several weeks.  However, under the present flow regime the passage indices of subyearling chinook at Lower Granite Dam have steadily decreased over the past several days, a trend not usually observed at this time of the year based on past years' data.  Based on this information it is imperative to continue flow augmentation from Dworshak.

Source: Fish Passage Center Updated: 7/3/01 10:45

Two-Week Summary of Passage Indices
* See sampling comments http://www.fpc.org/currentDaily/smpcomments.htm
This means that one or more of the sites on this date had an incomplete or biased sample.
COMBINED SUBYEARLING CHINOOK
Date   WTB
(Coll)
IMN
(Coll)
GRN
(Coll)
LEW
(Coll)
LGR
(INDEX)
LGS
(INDEX)
LMN
(INDEX)
RIS
(INDEX)
MCN
(INDEX)
JDA
(INDEX)
BO2
(INDEX)
06/19/2001   --- 0 --- --- 10,880 410 30 53 109,060 22,270 25,293
06/20/2001 * --- 0 --- 2 11,740 215 12 43 196,000 22,200 27,505
06/21/2001 * --- 0 --- 0 12,300 264 68 52 157,250 11,440 ---
06/22/2001 * --- --- --- 1 4,940 724 144 51 87,281 8,150 22,667
06/23/2001   --- --- --- --- 12,160 1,584 60 122 188,200 8,760 28,218
06/24/2001 * --- --- --- --- 22,080 2,180 96 87 292,500 26,670 19,988
06/25/2001   --- --- --- 0 7,180 610 60 217 500,000 35,800 18,419
06/26/2001   --- --- --- 1 14,940 3,137 352 387 448,400 15,050 14,915
06/27/2001   --- --- --- 0 11,940 2,151 90 520 491,100 54,350 23,832
06/28/2001   --- --- --- 0 10,240 780 50 246 356,800 31,500 22,039
06/29/2001   --- --- --- 0 6,620 600 84 243 327,697 22,150 28,503
06/30/2001 * --- --- --- --- 6,800 2,556 132 184 525,360 65,250 39,645
07/01/2001   --- --- --- --- 4,140 1,485 196 200 665,200 28,100 19,842
07/02/2001   --- --- --- --- 4,860 955 64 128 440,900 11,970 18,633
07/03/2001   --- --- --- --- --- --- --- --- --- --- ---
Total:   0 0 0 4 140,820 17,651 1,438 2,533 4,785,748 363,660 309,499
# Days:   0 3 0 8 14 14 14 14 14 14 13
Average:   0 0 0 1 10,059 1,261 103 181 341,839 25,976 23,808
YTD   1 1 13 31 337,560 22,643 9,542 4,287 5,677,187 446,535 1,609,637

These data are preliminary and have been derived from various sources.  For verification and/or origin of these date, contact the operators of the Fish Passage Data System (503) 230-4099.