Pool and Chute · PDF file · 2016-06-10Discussion and Design Process What is a...
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1 Pool and Chute Fishways Discussion and Design Process Discussion and Design Process What is a Pool and Chute Fishway? Hybrid type fishway that Hybrid type fishway that operates in two flow operates in two flow regimes, plunging and regimes, plunging and streaming flow streaming flow Low flow Low flow – Pool and Weir Pool and Weir High Flow High Flow - Chute Chute
Transcript of Pool and Chute · PDF file · 2016-06-10Discussion and Design Process What is a...
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Pool and Chute Fishways
Discussion and Design ProcessDiscussion and Design Process
What is a Pool and Chute Fishway?
Hybrid type fishway that Hybrid type fishway that operates in two flow operates in two flow regimes, plunging and regimes, plunging and streaming flowstreaming flow
Low flow Low flow –– Pool and WeirPool and Weir
High Flow High Flow -- ChuteChute
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Low Flow – 0.5 cfs
Medium Flow – 15 cfs
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High Flow – 35 cfs
Background
Rainbow CreekRainbow CreekWDFW Model StudyWDFW Model StudyTown DamTown DamBates, 1991 AFS PaperBates, 1991 AFS Paper
Photos by Ken Bates
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Pool and Chute - Definition
Weir
Baffle Baffle
Floor
Side Walls
Port
Pool and Chute - Cross SectionW
bPw
Pb
d
Xpc2
θ
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Fish Passage Corridor
Pool and Chute – Profile – Plunging Flow
So
L
Pw
H
SoL
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Pool and Chute – Profile – Streaming Flow
So
L
d
P
Equations
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CLH Q = Flow over a weir
0RSC V =
Open channel flow Chezy Eq.
QH/VolumeEDF γ=
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Research on streaming/plunging flow regimes
RajaratnamRajaratnam, N. and , N. and KatopodisKatopodis C. C. 1988. Plunging and Streaming Flows 1988. Plunging and Streaming Flows
in Pool and Weir Fishways. Journal of in Pool and Weir Fishways. Journal of Hydraulic Engineering 114:939Hydraulic Engineering 114:939--944944
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Lo
bSg0.25 t
Q =
Streaming/Plunging Flow RegimesTransitionTransition
Streaming
Plunging
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Streaming/Plunging Flow RegimesStreaming Flow Streaming Flow –– High Design FlowHigh Design Flow
Streaming
Plunging
EDF
Good/Fair Passage Corridor
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Streaming transition flow calculations
Example: b = 6 ft So = 10%
L = 4 ft Qt = 7 cfs
L = 6 ft Qt = 12 cfs
L = 8 ft Qt = 19 cfs
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Lo
bSg0.25 t
Q =
Case Studies - Parameters
Site W L b Pb So theta/2 SoL(ft) (ft) (ft) (ft) (ft/ft) (deg)
Fairchild Trib 12 5.5 2.0 3.0 0.145 76 0.8Fairchild Cr 12 5.5 2.0 3.0 0.145 76 0.8Rainbow Cr 12 6 1.5 2.5 0.125 79 0.75Percival Cr 10 5.5 2.0 3.0 0.145 76 0.8Morganroth 7 4 1.4 2.4 0.200 70 0.8Model Study 28 11 6.0 7.5 0.100 73 1.1
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Case Studies - Results d or H Q Qt C Xpc EDF Passage
(ft) (cfs) (cfs) (ft) RatingFairchild Trib 1.75 44 5.3 31.5 1.2 2.4 FairFairchild Creek 1.65 29 5.3 20.5 1.6 2.1 GoodRainbow Creek 1.90 88 3.9 13.6 0.0 14.9 FairPercival Creek 1.50 24 5.3 22.3 1.5 1.3 GoodPercival Creek 1.20 7 5.3 9.6 2.7 0.3 excellentMorganroth 1.20 7 3.2 12.0 1.6 0.9 FairWDFW Run 17 3.41 304 33.8 29.4 4.5 1.8 good-fairWDFW Run 19 4.00 305 31.0 30.2 8.7 0.2 poorWDFW Run 20 4.21 468 38.9 31.1 2.8 3.8 goodWDFW Run 21 1.80 106 33.8 28.0 10.7 0.0 excellent
Fairchild Trib: W = 12 ft
Q = 44 cfsQ = 44 cfsD = 1.75 ftD = 1.75 ftQQtt = 5.3 cfs= 5.3 cfsChezy Chezy C = 31.5C = 31.5XXpcpc = 1.2= 1.2EDF = 2.4EDF = 2.4Passage RatingPassage RatingFairFair
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Fairchild Creek: W = 12 ft
Q = 27 cfsQ = 27 cfsD = 1.65 ftD = 1.65 ftQQtt = 5.3 cfs= 5.3 cfsChezy Chezy C = 20.5C = 20.5XXpcpc = 1.6= 1.6EDF = 2.1EDF = 2.1Passage RatingPassage RatingGoodGood
Percival Creek: W = 10 ft
Q = 24 cfsQ = 24 cfsD = 1.5 ftD = 1.5 ftQQtt = 5.3 cfs= 5.3 cfsChezyChezy C = 22.3C = 22.3XXpcpc = 1.5= 1.5EDF = 1.3EDF = 1.3Passage RatingPassage RatingGoodGood
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Fairchild Comparison
44 cfs 29 cfs
Chezy C vs Qst
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101520253035
0 10 20 30 40 50 60
Unit Qst (cfs/ft)
Che
zy C
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Design Parameters
Overall Drop: Overall Drop: maximum 4 to 5 feetmaximum 4 to 5 feetFishway Width:Fishway Width:
10 cfs = 8 feet, 25 cfs = 10 feet10 cfs = 8 feet, 25 cfs = 10 feet50 cfs = 14 feet, 120 cfs = 20 feet50 cfs = 14 feet, 120 cfs = 20 feet
Slope/Drop per Weir = Slope/Drop per Weir = 0.5 to 1.0 feet0.5 to 1.0 feetMost u/s weir 0.2 ft lessMost u/s weir 0.2 ft less
Pool Length = Pool Length = 45 to 55% of width45 to 55% of widthWeir Length = Weir Length = 17 to 20% of width17 to 20% of widthWeir Height = Weir Height = minimum 2.5 feetminimum 2.5 feet
Design Parameters
Baffle Height = Baffle Height = WS @ 0.75QWS @ 0.75Qstst
Baffle Slope = Baffle Slope = 7676oo
Fish Passage Corridor: Fish Passage Corridor: 2 feet2 feetEDF: EDF: 22Submerged Ports: Only 16 cfs min flowSubmerged Ports: Only 16 cfs min flow
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Design StepsCalculate highCalculate high QQfpfp
Select: W, baffle slope, drop, L, b, Select: W, baffle slope, drop, L, b, PPww
Calculate: QCalculate: Qtt
Select d and CSelect d and CTrial and error until Q = Trial and error until Q = QQfpfp
Check: EDF, Check: EDF, XXpcpc
Design Spreadsheet: [email protected]
Limitations/Potential Research
Number of weirs and fishway lengthNumber of weirs and fishway lengthAlignment (half Pool and Chute)Alignment (half Pool and Chute)Roughness values (weir/baffle crest shape)Roughness values (weir/baffle crest shape)EDF EDF –– juvenile passage studiesjuvenile passage studiesScour potential at outletScour potential at outlet
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Summary
Applicable to low head dams and some Applicable to low head dams and some culvert retrofits with drops 4 to 6 feet.culvert retrofits with drops 4 to 6 feet.Improved attraction flows over other Improved attraction flows over other fishway fishway typestypesMany are self cleaning (gravel/small Many are self cleaning (gravel/small cobbles)cobbles)Diverse passage routes for all life stages of Diverse passage routes for all life stages of salmonidssalmonids
