200736400 - Determining the effects of load following on reservoir hydraulics and migration behavior of juvenile salmonids
Sponsor: Columbia River Research Laboratory
Budgets: FY07: $711,105 | FY08: $760,883 | FY09: $814,145
Short description: The goal of this project is to measure the behavioral response of juvenile salmonids to load following operations in the reservoir upstream of Little Goose Dam. To fully understand this response, both hydraulic conditions in the reservoir.
Final Council recommendation (Nov 2006)
Funding category: Expense
Recommended budgets: FY07: $0 | FY08: $0 | FY09: $0
ISRP final recommendation: Fundable
The need to better describe flow instability in Snake River reservoirs from daily load following at the dams (or other causes) in the summer low-flow season and possible relationships to disorientation by juvenile salmon outmigrants (fall Chinook) is well described, and the proposed work is well justified. The basis for the proposed work is primarily a response to a hypothesis by the ISAB (Report ISAB 2001-3) rather than subbasin plans or the Council’s Fish and Wildlife Program, although the proposal identifies links to the NOAA Biological Opinion. Relationships to several other projects are described in good detail, especially USGS studies of fish movements for the Corps and the Pacific Northwest National Laboratory’s hydraulics studies for BPA at Lower Granite and Little Goose reservoirs. The proposal could have been improved by mention of NMFS survival studies or the Comparative Survival Study that use PIT tags. The proposal identifies ongoing work that has the potential of data sharing. Sponsors were apparently unaware of Proposal 200733600, with which it is complementary. Objectives are clearly developed and sensible. The phased approach in Objective 4 is good, in case the study is unable to discern clear relationships in the first year. Whether it is realistic to operate one of the dam/reservoirs in an experimental fashion will depend on the strength of relationships seen in the initial research conducted with normal operating regimes. There is a high likelihood that this project will produce information of great significance in resolving primary uncertainties associated with the Council's Fish and Wildlife Program, NOAA Fisheries ESA processes, and state and tribal fisheries management programs, especially summer flow augmentation, summer spill, and survival of listed Snake River fall Chinook salmon. Although the proposal is fundable in its own right, the ISRP offers some comments that may aid the research. No response is required, but we believe the region would benefit by the proponents consideration of our comments While the proposal points out that NOAA Fisheries investigators (Smith et al. 2002) found a break point at 100 kcfs in the relationship between flow and survival of juvenile salmonids, it does not note that this flow coincides (approximately) with the hydraulic capacity of the lower Snake River hydropower projects, as pointed out by the ISAB. The frequency, magnitude and duration of fluctuations of flow were found by the ISAB to increase when base flows in the Snake River declined to below 100 kcfs and continued to increase the further the flow declined. The study will be most useful if both the “breakpoint” and the trend at lower flows are recognized. Because the base flow normally declines with time during the period of a summer study, the descriptions of fish behavior might possibly be interpreted as natural trends in behavior similarly associated with time (season). The study design might overcome this problem to some extent by simultaneous observations of fish behavior and hydraulic features in the reservoir. There is no mention of comparison of nighttime with daytime observations of fish behavior associated with load following operations. As base flows in the Snake River continue to decline through the summer, a point is reached where load following leads to virtual shut-down of the hydropower plants at night when electricity demand is lowest. A day-night comparison might provide contrasting flow scenarios, even though there would not be a true controlled experiment as suggested for subsequent years. The locations and number (2) of ADCP arrays may not be sufficient to relate to salmonid movements. If the ADCP will be used to validate an existing hydraulic model of the reservoir, the data may be enough for that purpose. But can the model predict velocities with sufficient accuracy and sufficiently small scale to be useful in the context of fish behavior (Objective 3)? Also in Objective 3, what are the models of fish movement that will be compared to hydraulic data? Is the study at risk of incorporating only conventional understanding in its hydraulic and fish models rather than seeking truly new insights? While the proposal states that reports of results will be available on BPA's website, there is no mention of what disposition will be made of the data and metadata. Will data and metadata be made available on StreamNet or some other regional data source? The ISRP reviewed two somewhat similar proposals, and these comments will be shared with each. It is apparent that neither group was aware of the proposal being developed by the other. While this proposal (200733600) and proposal 200736400 might appear to duplicate one another, the duplication is slight to negligible. Proposal 200733600 proposes work only in Little Goose Reservoir and puts primary emphasis upon radio tracking of juvenile fish to record their behavior in response to load following episodes, with secondary emphasis upon monitoring of hydraulic conditions associated with those episodes. The other proposal, 200733600, encompasses the reservoirs of all four lower Snake River projects, puts primary emphasis upon hydraulic conditions as affected by load following, and would depend upon information on fish behavior that would be available from ongoing projects. Both proposals are well prepared and submitted by well-qualified groups. Both studies have merit because information on hydraulic conditions in all four reservoirs is certain to be useful in extrapolating the implications for fish behavior observations beyond Little Goose Dam. We recommend that the BPA contracting officer arrange for the two proponents to agree among themselves as to whether there is any duplication of effort that could or should be avoided. Both groups would benefit from further thought given to the designation of the parameters that would serve as the basis for analysis. Proposal 200733600 is perhaps overly concerned about refining time intervals of turbine adjustment below hourly to include what are likely minor, fine-tuning adjustments not likely to have measurable effects on fish behavior. It is our feeling that since there are hourly coordination agreements in place among the hydropower operators, the hourly changes are likely to be those of most significance. Otherwise, particularly in the lower Snake River due to lack of storage capacity, operations of powerhouses in either upstream or downstream directions could lead to violation of reservoir levels established in the BiOp and elsewhere. Similarly the proponents of proposal 200736400, are advised to give further thought to the boundaries to be set in the analysis of load following episodes. Some sort of grouping would seem to be necessary in order to conduct a meaningful analysis of effects of magnitude, duration, and/or frequency of episodes on fish behavior, which in turn will probably differ according to those features of load following. Both studies should use the same groupings.
State/province recommendation: MS: Recommended Action
Review group: MSRT
Recommended budgets: FY07: (n/a) | FY08: (n/a) | FY09: (n/a)
Comment: This proposal should be evaluated with other load following studies.