Action agency responses to Current Year SORS

SOR # Response
During early November of 2011, Bonneville Tailwater Elevations were at a minimum of 11.3 feet (range 11.3-11.7ft). At the 11-23-11 TMT, the minimum tailwater ranged was increased to 11.7-12.5 feet. The Bonneville tailwater was not increased beyond the 11.7-12.5 ft range.
This SOR requested the minimal release outflow from Libby Dam during September (6,000 cfs minimum bull trout flow) and October (4,000 cfs minimum), 2011.

The Corps of Engineers ramped outflows from Libby Dam down to 6,000 cfs by September 6, 2011. Outflows were ramped down to 4,000 cfs by early October and remained at this level through the month of October.
Not Implemented
At the July 20, 2011 TMT Meeting, the COE stated that they needed more time to discuss the operation proposed in the SOR and would discuss their decision at the next TMT Meeting. At the July 27, 2011 TMT Meeting, the COE said they would not implement the SOR for the following reasons:

  1. No clear consensus at the last TMT Meeting
  2. A 2009 study did not show a clear benefit for implementing more spill at Little Goose Dam
  3. The majority of fall Chinook had already passed the project, raising doubts concerning the biological benefit of the SOR operation

The USFWS, WDFW and ODFW all voiced their concern that the 2009 study the COE referenced did not contain study conditions that were similar to the current year, but that they would not be elevating this issue any further.
Not Implemented
SOR 2011-2 was discussed at the April 13, 2011 TMT Meeting where the Action Agencies wanted more time to discuss this issue and thought that a policy decision was needed. This SOR was again discussed at the April 20, 2011 TMT where the COE stated that they were operating under a “rollover” and needed a compelling reason to change the LMN spill pattern. The COE cited a 2008-09 study showed slightly better dam passage survival using a bulk spill pattern. The salmon manager’s reiterated the justification in the SOR. This issue was raised to the RIOG. At the April 27, 2011 TMT meeting, the COE proposed an alternative operation that would implement a uniform spill pattern during involuntary spill – either when the system is at full load or lack of load causing involuntary spill. At the May 11, 2011 TMT meeting the COE stated that due to a lack of regional consensus, the COE would not implement the SOR. However, given no objections, the COE would implement the following alternative:

Switch from the Bulk to Uniform pattern at Lower Monumental Dam when either:

  1. Flows exceed turbine capacity plus Fish Operations Plan (FOP) spill (occurs at ~140 kcfs); or
  2. When spill over the FOP specified amount is required due to lack of market spill at any flow level. If either of these conditions is likely to occur for 3 or more days, the Corps will use the Uniform spill pattern instead of the Bulk spill pattern as specified in the 2011 Spring FOP.
The COE proposed a spill priority list that reflected the spill list presented in the SOR. TMT members did not object to the COE’s list. All agreed that this list should be monitored throughout the spill season.
SOR 2011-1
Partially Implemented
The Corps of Engineers proposed an alternative operation to address navigation safety concerns and reduce operations above MOP. The Corps alternative operated the Lower Granite forebay in variable ranges between MOP and MOP+2 dependent on inflow at Lower Granite Dam, rather than the MOP+2 operation requested in the SOR. The proposed alternative operation:
  • When daily average inflow is greater than or equal to 120 Kcfs, Lower Granite will be operated with a maximum elevation of 734 feet for flood control.
  • When day average inflow is less than 120 Kcfs but greater than or equal to 80 Kcfs, Lower Granite will be operated at MOP+1 (734-735 feet).
  • When day average inflow is less than 80 Kcfs but greater than or equal to 50 Kcfs, Lower Granite will be operated at MOP+1.5 (734.5-735.5 feet).
  • When day average inflow is less than 50 Kcfs, Lower Granite will be operated at MOP+2 (735-736 feet).
The Corps operated in accordance with the alternative MOP operation from early April through August.

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Page last updated on: February 21, 2013

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