This page provides analysis, based on NMFS 2009 RPA II.2, of current and historical temperature conditions for fish using only observed data. Actual pre-season and in-season management decision processes are complex employing multiple sources of observed data, models, and forecasts. For further information, see the Target Analysis Criteria section.
|Total Period Analyzed||Criteria Exceedance|
|First Day||Last Day|
|Juvenile Rearing (3 days)||5/15-10/31||Below 65F||170||31||56.2F||31||18.2%||0||0.0%|
|Juvenile Rearing (1 day)||5/15-10/31||Below 68F||170||31||56.2F||31||18.2%||0||0.0%|
Jump to Detail Data
|Year||Month||Day||Value||3 Days Exceed 65F||1 Day Exceed 68F|
|Year||Month||Day||Value||3 Days Exceed 65F||1 Day Exceed 68F|
Please refer to the American River Group (ARG) Annual Report of Activities for details on within water year activities.
Target analysis and exceedance found on this page is based on criteria as described in NMFS 2009, pp614-5.
NMFS 2009. Biological and conference opinion on the long-term operations of the Central Valley Project and State Water Project. Long Beach, California. June 4. 844 pg. Plus appendices. Available online: www.westcoast.fisheries.noaa.gov/publications/Central_Valley/Water%20Operations/Operations,%20Criteria%20and%20Plan/nmfs_biological_and_conference_opinion_on_the_long-term_operations_of_the_cvp_and_swp.pdf
Direct quote from NMFS 2009, pp 614-615.
Objective: Maintain suitable temperatures to support over-summer rearing of juvenile steelhead in the lower American River.
Action: Each year, Reclamation shall prepare a draft Operations Forecast and Temperature Management Plan based on forecasted conditions and submit the draft Plan to NMFS for review by May 1 of each year. The information provided in the Operations Forecast will be used in the development of the Temperature Plan. The draft plan shall contain: (1) forecasts of hydrology and storage; (2) a modeling run or runs, using these forecasts, demonstrating that the temperature compliance point can be attained (see Coldwater Management Pool Model approach in Appendix 2-D); (3) a plan of operation based on this modeling run that demonstrates that all other non-discretionary requirements are met; and (4) allocations for discretionary deliveries that conform to the plan of operation. Reclamation shall use an iterative approach, varying proposed operations, with the objective to attain the temperature compliance point at Watt Avenue Bridge. Within ten calendar days of receiving the draft Temperature Plan, NMFS will provide a written review of this plan for the purpose of determining whether requirements in this Opinion are likely to be met. Reclamation shall produce a final plan prior to May 15 deliveries and implement the plan upon finalization. Reclamation may update the plan every month based on hydrology and must seek NMFS' concurrence on proposed deviations from the plan that may reduce the likelihood that the temperature objective will be met.
Temperature Requirement: Reclamation shall manage the Folsom/Nimbus Dam complex and the water temperature control shutters at Folsom Dam to maintain a daily average water temperature of 65°F or lower at Watt Avenue Bridge from May 15 through October 31, to provide suitable conditions for juvenile steelhead rearing in the lower American River. If this temperature is exceeded for three consecutive days, or is exceeded by more than 3°F for a single day, Reclamation shall notify NMFS in writing and will convene the ARG to make recommendations regarding potential cold water management alternatives to improve water temperature conditions for fish, including potential power bypasses. If there is a lack of consensus on actions to be taken, the ARG shall advise NMFS and be elevated through the WOMT standard operating procedures.
Exception: When preparing the Operations Forecast and Temperature Management Plan, Reclamation may submit to NMFS a written determination that, after taking all actions within its authorities, it is unlikely to meet the above temperature requirement. This determination must be supported by specific iterative modeling techniques that vary allocations and delivery schedules such as application of the Coldwater Management Pool model (see Appendix 2-D). In the event that Reclamation determines that other nondiscretionary requirements (e.g., D-1641 or requirements of the USFWS' Delta smelt biological opinion) conflict with attainment of the temperature requirement, Reclamation will convene the ARG to obtain recommendations. If consensus cannot be achieved within the ARG, the ARG shall advise NMFS, and NMFS will make a recommendation to the WOMT, per standard operating procedures.
During the May 15 to October 31 period, when the 65°F temperature requirement cannot be met because of limited cold water availability in Folsom Reservoir, then the target daily average water temperature at Watt Avenue may be increased incrementally (i.e., no more than one degree Fahrenheit every 12 hours) to as high as 68°F.
The priority for use of the lowest water temperature control shutters at Folsom Dam shall be to achieve the water temperature requirement for steelhead, and thereafter may also be used to provide cold water for fall-run spawning.
Rationale: As demonstrated in section 6.4 of this Opinion, steelhead are frequently exposed to water temperatures warmer than required for juvenile rearing, resulting in reduced fitness as is evident through the expression of visible thermal stress symptoms (i.e., bacterial inflammations). This thermal stress decreases steelhead immune system function and increases steelhead vulnerability to other sources of sub-lethal and lethal effects such as disease and predation. Monitoring of juvenile steelhead conducted by CDFG showed that bacterial inflammation was prevalent in steelhead throughout the river and the frequency of its occurrence increased as the duration of exposure to water temperatures over 65°F increased. The 65°F or lower daily average water temperature target was identified based on CDFG's monitoring as well as published scientific literature. Based on past convention of the ARG, the temperature compliance point is maintained at Watt Avenue Bridge, even though suitable rearing habitat is between Watt Avenue and Nimbus Dam.
SacPAS: Central Valley Prediction & Assessment of Salmon, University of Washington, Columbia Basin Research, www.cbr.washington.edu/sacramento/