1 Mainstem Passage Strategies In The Columbia River System: Transportation, Spill and Flow Augmentation Presented By: Albert Giorgi, Ph.D.

2 ASSIGNMENT Transportation, Spill and Flow Augmentation 1.Update And Synthesize Information On Benefits And Risks 2.Identify Shortcomings, Disputes, And Critical Uncertainties 3.Opportunities to Reduce Uncertainty

3 FOCUS 1.Information Gathered Since ~ Emphasize Most Recent Analyses and Estimates

4 TRANSPORTATION Objective of Smolt Transportation –Offset mortality incurred during migration by avoiding expanses of the hydro-system.

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6 KEY ESTIMATES Survival (Smolt-to-Adult) = SAR Survival Ratio (transport/inriver) = TIR Delayed Transport Effects = D Smolt Survival Inriver = Vc

7 CONNECTIONS SAR T /SAR I  TIR  (TIR)(Vc)  D 2%/1%  2.0  (2.0) (0.5)  %/1%  1.5  (1.5) (0.5)  0.75

8 INTERPRETING ESTIMATES Managers: TIR > 1.0 –Transport Survival greater than Inriver Controls Analysts: D > 1.0– No Delayed Effects 1.0 > D > Vc—Delayed effects but transport survival greater than inriver controls D<Vc– Delayed effects severe, control survival greater than transport

9 TIR: (NMFS & CBFWA) Yearling chinook Annual TIR Estimates –Generally  1.0 at Lower Granite and Little Goose dams. –Transport at Lower Monumental and McNary dams is questionable.

10 NMFS ESTIMATES ( )

11 CBFWA ESTIMATES, ( )

12 HYPOTHESIS TESTS TIR > 1.0, D >Vc None Explicitly Conducted Yet Some Years, Small Sample Size (n) Produce Poor Precision Limits Statistically Defensible Conclusions

13 SAR-TREND

14 WILD FISH PERFORMANCE Difficult to Ascertain with Confidence Very small Sample Sizes (n) Produce Poor Precision

15 HOMING IMPAIRMENT Form of Delayed Effect Can be reflected in SAR to Lower Granite Dam Evidence for impairment in some species –Steelhead, Sockeye, and Fall Chinook –Straying and Migration Delay –Radio telemetry studies

16 CRITICAL UNCERTAINTIES RESEARCH OPPORTUNITIES Data Gaps –Snake River Fall Chinook Evaluations (2002) –Mid-Columbia Stocks at McNary Dam (2002) Continue Research –Snake River Evaluations (SAR  ) –Adult Passage (Radio tags/PIT tags)

17 SPILL Objective of Spill –Maximize smolt survival at dams –Maintain acceptable water quality

18 ARE SPILLWAYS THE SAFEST PASSAGE ROUTE? Collective information =Yes Survival magnitude can vary by site and species Estimates reflecting total effects are most instructive

19 DIRECT AND INDIRECT EFFECTS PASSAGE EFFICIENCY

20 DO FLOW DEFLECTORS AFFECT SMOLT SURVIVAL? Typically 1-3% increase in mortality Depending on site and tool

21 DOES SMOLT SURVIVAL VARY WITH DISCHARGE? At some dams The Dalles Dam has the most dramatic decrease in survival

22 Survival X Spill Discharge

23 SPILL EVALUATIONS (Passage Models) Update parameters, post-PATH Models are practical tools for evaluating different spill scenarios Reflect responses at population level (smolts) Difficult to isolate spill effects in field studies (Zabel et al. in press)

24 INCIDENTAL EFFECTS OF SPILL Total Dissolved Gas (TDG) Adult passage

25 INCIDENTAL EFFECTS 120% saturation target is generally achievable with BO spill schedule, and mid-Columbia River operations Adult Passage –Some evidence that high spill levels may exacerbate delay and fallback –But, no convincing quantitative relationships

26 TDG – Mid-Columbia, 2000

27 CRITICAL UNCERTAINTIES & RESEARCH NEEDS Evaluate spill scenarios with updated passage models. Consider well-designed in situ experiments when river conditions are controllable (summer, or low flow) Clarify spill effects on adult fallback and migration delay.

28 FLOW AUGMENTATION Objectives –Increased H 2 O velocity (reservoirs) Increases smolt migration speed Increases reservoir survival –Decrease H 2 O temperature (summer) Improves rearing / migratory conditions Increases survival (juveniles, adults

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30 FLOW EFFECTS ON MIGRATION SPEED Influential variables –Steelhead = Flow –Sockeye = Flow –Yearling Chinook = Smolt development, Flow –Sub-yearling Chinook = Flow, temp., turbidity, size (confounded)

31 FLOW EFFECTS ON SMOLT SURVIVAL Yearling Chinook, (NMFS) –No apparent flow relationship Steelhead –No apparent flow relationship –But, pronounced decrease in survival, 2001 Low flows and early warming implicated Fall Chinook –Complex of variables implicated (confounded) Flow, temperature, turbidity

32 CAN FLOW AUGMENTATION- Substantively alter estuary and ocean plume characteristics within a year? Optimize timing of ocean entry?

33 Water Temperature Reduction Snake River Summer –Adult steelhead, fall chinook –Juvenile fall chinook < 20º C is advantageous > 20º C often occurs (Aug.- early Sept.)

34 Dworshak - Cooling Effects ~ 1-4º C at LGR, 0.5-1º C at IH Cool H 2 O sinks Deeper refugia Mixing at dams

35 COMPREHENSIVE EVALUATIONS Generally lacking Few at best –SOR – (BPA-funded study) Flow/speed/survival relationships  evaluations

36 FEATURES OF EVALUATIONS Document Volume and shape of FA Describe change in H 2 O velocity and temp. Predict change in smolt speed and survival Focus on key populations

37 CRITICAL UNCERTAINTIES & RESEARCH NEEDS Conduct comprehensive FA evaluations through 2001 Design experiments targeting Snake River fall chinook –Manipulate Dworshak and HC –Survival Continue mainstem survival monitoring

38 Estimated increase in water velocity attributable to flow augmentation springs (10 April – 20 June) and summers (21 June – 31 August)

39 Percent decrease in estimated smolt travel times for yearling chinook using base flows. Asterisk in 1993 indicates that the CRiSP model predicted no change in travel time associated with flow augmentation.

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