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Middle Fork Project AQ 6 – Fish Passage Technical Study

Middle Fork Project AQ 6 – Fish Passage Technical Study. February 3, 2009. Fish Passage Barriers. Study Objectives. Document upstream fish passage barriers Bypass and peaking reaches River tributary confluences Inlets to Project reservoirs and diversion pools

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Middle Fork Project AQ 6 – Fish Passage Technical Study

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  1. Middle Fork ProjectAQ 6 – Fish Passage Technical Study February 3, 2009

  2. Fish Passage Barriers

  3. Study Objectives • Document upstream fish passage barriers • Bypass and peaking reaches • River tributary confluences • Inlets to Project reservoirs and diversion pools • Identify Project facilities and operations that may affect upstream fish passage

  4. Study Objectives and Related Study Elements

  5. Outstanding Study Elements • In collaboration with the TWG, identify if there are any barriers which require hydrodynamics modeling to assess fish passage at flows other than base flow Only barriers that prevent access to sections of river with important spawning or rearing habitat (as determined in collaboration with the Aquatic TWG) would be considered for modeling.

  6. Study ApproachData Sets A combination of data were used to identify and assess fish passage barriers throughout the MFP study area • Data Collected Prior to AQ 6 – TSP • 2005 Helicopter aerial video of all MFP streams • Ground-based aquatic mesohabitat mapping (2005-6) • Visual observations during helicopter fly-overs or hiking during other field work • Data Collected as Part of AQ 6 – TSP • Measurements at reservoir and diversion pool inlet streams and tributary inflows; • Measurements at Project infrastructure facilities • Measurements at key natural barriers identified from 2005-6 mesohabitat mapping • Low elevation helicopter fly-over barrier mapping and estimation in inaccessible reaches

  7. Study ApproachData Sets (locations)

  8. Study Approach Analysis • Quantitatively evaluated passage at base flow • Barriers were analyzed as: • Falls • Chutes • Cascades (separated into falls and chutes) • Critical Riffles (Powers and Orsborn 1985, Thompson 1972). • Barriers classified as: passable, potentially passable (trout only), impassable

  9. Barrier Assessment

  10. Quantitative Barrier Assessment Methods • Burst and prolonged swimming capabilities of trout and minnows • Range for trout (high and low from literature) • Minnow low end of trout range • Intermediate size of 12 inches (340 mm) for all species • Small stream maximum trout size 9 inches (230 mm FL) • Intermediate and larger rivers maximum trout size about 15 inches (380 mm FL)

  11. Sustained Speed Burst Speed Quantitative Barrier Assessment Methods(cont.) Videler, JJ. 1993. Fish Swimming. London, Chapman & Hall

  12. Quantitative Barrier Assessment Methods (cont.) Leaping Barriers (falls) Swimming Barriers (chutes, critical riffles) To pass both types of barriers, multiple criteria must be met

  13. Quantitative Barrier Assessment Methods (cont.) Leaping Barriers • Fish must leap the vertical and horizontal dimensions of the falls (leaping ability based on burst velocities)

  14. Quantitative Barrier Assessment Methods(Cont.) Leaping Barriers (cont.) • Plunge pool takeoff conditions • Passable – pool depth 1 body length or greater • Potentially Passable – pool depth < 1 - ½ body depth • Impassable – pool depth < 1/2 body length • Crest landing conditions • Passable – crest depth 1 body depth or greater • Potentially Passable – crest depth < 1 - ½ body depth • Impassable – 1) crest depth < ½ body depth and/or 2) crest velocity > burst velocity

  15. Quantitative Barrier Assessment Methods (cont.) Swimming Barriers • Can fish swim the distance of the chute at a prolonged swimming speed?

  16. Quantitative Barrier Assessment Methods (cont.) Swimming Barriers (cont.) • The chute/riffle depth must be suitable for swimming • Passable – water depth 1 body depth or greater • Potentially passable – water depth < 1 - ½ body depth • Impassable – Water depth < ½ the body depth

  17. Qualitative Barrier Assessment Methods • Aerial video • Identified reaches with frequent or infrequent potential barriers • Low elevation helicopter fly-overs • Photographs taken of each potential barrier • 5 accessible barriers were used to calibrate the estimates made from photographs • The GPS location was recorded at each potential barrier • If they appeared likely to be barriers, they were classified as “potential barriers”

  18. Example Photos from Helicopter Fly-over

  19. ResultsKey Findings • Fish passage in the bypass and peaking reaches • Many natural barriers to upstream fish movement were present throughout the peaking and bypass reaches • No reaches free of natural barriers

  20. ResultsKey Findings (cont.) • Fish passage at Project infrastructure • MFP facilities (4 dams, 3 diversion dams, 1 tunnel stream crossing, 1 road crossing, 3 gage weirs) created additional barriers to upstream fish movement • These barriers are located in reaches that contain natural barriers and as a result do not preclude fish from accessing large sections of river

  21. ResultsKey Findings (cont.) • Fish passage at tributary confluences • Nearly all of the tributaries to the MFP bypass and peaking reaches had natural barriers near their confluence (16 of the 18 evaluated) • Only North Fork of the Middle Fork American and Otter Creek (lower 1.5 miles of Otter Creek) were available to fish • Project operations did not affect access to the bypass and peaking reach tributary streams, except that a temporary potential barrier occurred at the Otter Creek confluence during minimum flow periods

  22. ResultsKey Findings (cont.) • Fish passage at diversion pool/reservoir inlets • Duncan Creek – No barriers • North Fork Long Canyon – No barriers • South Fork Long Canyon – Potential critical riffle barrier • French Meadows – No barriers • Hell Hole – Several natural barriers on Rubicon River and Five Lakes Creek. Natural barriers immediately upstream of the reservoir high water mark precluded upstream access to the rivers, regardless of the reservoir water surface elevation • Middle Fork Interbay – No barriers • Ralston Afterbay – No barriers

  23. ResultsKey Findings (cont.) • Hardhead and pikeminnow upstream passage limits based on AQ 2 Fish Population snorkeling results and AQ 6 Fish Passage results • Middle Fork American River • Large natural barrier complex 0.5 miles above Ralston Afterbay • Rubicon River • Hardhead -- A natural waterfall barrier at river mile 6.0 (5.4 miles above Ralston Afterbay) • Pikeminnow -- A large natural water fall at river mile 8.2 (7.5 miles upstream of Ralston Afterbay)

  24. ResultsKey Findings (cont.) • Hydrodynamics Modeling • No potential fish passage barriers were identified which required hydrodynamics modeling • No single barrier or series of barriers precluded fish from accessing large sections of river that contained important spawning or rearing habitat • Nearly all of the barriers observed in the bypass and peaking reaches were large waterfall type barriers that were relatively insensitive to flow alteration

  25. Project Dam Barrier LocationsLower Watershed

  26. Project Diversions/Dams Barrier LocationsUpper Watershed

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