Overview of Topics  Swimming Ability of Juvenile Salmonids  Behavior of Juvenile Salmonids  Guiding Juvenile Salmonids  Design Development  Selecting the Screen Structure Site 2

Overview of Topics (continued)  Facility Design Criteria Velocity Screen Face Materials  Types of Positive Barrier Screens  Debris and Sediment Management  Approach Velocity Balancing 3

4 Swimming Ability of Juvenile Fish  See references/suggested reading in course notebook.  University of Washington Fisheries Research Institute study (Smith and Carpenter, 1987) was used to develop fish screen approach velocity criterion.  USFWS Bull Trout studies.

Design Fish – Smallest Fry, Coldest Water

6 Factors Affecting Swimming Ability  Approach velocity, sweeping velocity, and canal velocity  Water Temperature  Fish Size  Swimming Time Duration  Dissolved Oxygen Level

Swimming Speeds Classification 7

Juvenile Fish Swimming Speeds 8

Effect of Temperature on Cruising Velocity 9

Effect of Temperature on Critical Velocity 10

Effect of Fish Size on Critical Velocity 11

Potential Behavioral Factors Effecting Migrating Juvenile Salmonids  Physiology and migration triggers  Screen and bypass hydraulic design issues  Dams and water diversions – presence, size  Reservoir passage – velocity, predators  Guidance in dam forebays  Available routes of passage 12

13  Reluctance to enter small bypasses  Preference for either day or night migration past screen structures  Migration corridors in lakes (mostly follow shoreline, depth ?)  Lateral line function  Dissolved Oxygen Level Potential Behavioral factors (continued)

Physiology – Migration Effects  Body silvering increases  Salinity tolerance increases  Growth rate increases  Weight per unit length decreases  Body total lipid content increases  Blood glucose increases  Gill microsome, Na, K, ATPase enzyme activity increases 14 Smolt (migrating) characteristics compared with parr (non-migrating):

Fish Size - Migration Timing 15

Fish Size - Migration Timing 16

River Flow – Migration Effects 17

Diurnal migration effect Arrival of juvenile sockeye salmon at Rocky Reach sampler

19  Positive Barrier Screens (PBS) Fish screen or rack to prevent fish entry into diversion Preferred screen design - guide fish to bypass without contacting screen  Behavioral Devices Not acceptable as stand alone device Could enhance performance of PBS Methods of Guiding Juvenile Salmonids

20  Vertical Fixed-Plate Screens  Traveling Screens Panel screens Belt Screens  Pump Intake Screens/End of Pipe Screens Fixed Cylindrical Screen Cone screens  Eicher Screens (penstocks)  Modular Inclined Screens  Non-vertical Fixed Screens  Rotating Drum Screens (canal screens) Examples of Positive Barrier Screens

21 Examples of Behavioral Devices  Sound  Light  Electric Fields  Hydraulic Action

22 Design Objectives  Guide Fish Past Screens: Without contacting screen - impingement Without entrainment through seals, mesh, other gaps Without delay – good guidance to bypass Without injury or mortality Minimizing stress to fish Minimizing predation potential

Selecting the Screen Structure Site  Minimize delay  O&M considerations  On-River site  Off-River site  Hydraulics, Hydrology  Head needed for bypass operation  Bank characteristics  Data Collection (see Notebook) 23

Off-Channel Diversion 24

Off-Channel Screen

Site Selection – Off Channel

27 Turning Vanes to Correct Channel Approach Flow Conditions

On-Channel Diversion 28

Other Site Considerations  Diversion Canal as Fish Habitat  Diversion Operations – Pitfalls  Starting and Stopping of Diversions 29

Considering Screen Project Priority  Potential number of fish entrained  Existing level of protection  Funding  ESA  Land ownership  Proximity to other projects  Frequency of diversion  Type of diversion

Hypothetical Screen Prioritization Problem

Break

44 Screen Design  Design Features Flow-Screen Angle Uniform Approach Velocity Channel Configuration Trashracks Seals Cleaning System

Effective Flow Area  Effective Flow Area: Defined as the total submerged screen area, excluding area blocked by major structural members, but including the screen face material. For rotating drum screens, effective screen area consists only of the submerged area projected onto a vertical plane (i.e. a rectangular area).

46 Screen Velocity Criteria (NMFS NWR) Approach Velocity (V a ) Definition: V a is the canal velocity component perpendicular to the screen face. V a must be less than or equal to 0.4 ft/s, at all diverted flow levels and all water surface elevations.

47 Screen Velocity Criteria (NMFS NWR) Approach Velocity (V a ) The basis for the approach velocity criterion is that salmonid fry swimming for less than one minute, can avoid impingement if screen approach velocity is less than 0.4 feet per second. This was developed by testing salmonid fry for sustained swimming stamina in temperatures as low as 4 degrees Celsius. Stamina swim tests for salmonid fry conducted at U. of Washington in 1987 by L.S. Smith and L.T. Carpenter – repeated by others, with similar results.

48 Screen Velocity Criteria (NMFS NWR) Achieving Uniform Approach Velocity (V a ) The screen design must provide for nearly uniform flow distribution over the screen surface, thereby minimizing V a over the entire screen face. Uniform flow distribution avoids localized areas of high V a, which have the potential to impinge fish. Providing adjustable porosity control on the downstream side of screens, and/or flow training walls may be required. Large facilities may require hydraulic modeling to identify and correct areas of concern. More on this later.

49 Approach Velocity – Simplest Case

50 Screen Velocity Criteria (NMFS NWR) Sweeping Velocity (V s ) Definition: V s is the canal velocity component parallel to the screen face. V s must be at least twice the approach velocity, must not decelerate or rapidly accelerate. V s acts to move fish (and debris) toward bypass. Lab studies and field experience have shown that smooth sweeping velocity reduces migration delay.

51 Screen Velocity Criteria (NMFS NWR) Sweeping Velocity (V s ) V s must be sufficient to sweep a motionless fish to a bypass entrance in less than 60 seconds (exposure time criterion). Screens longer than 6 feet must be angled and must have V s greater than V a (tests at Battele Labs). This angle may be dictated by site-specific geometry, hydraulic, and sediment conditions. Optimally, V s should be around 3 ft/s.

Velocity Vectors – Va and Vs V canal = V V approach = V a Screen Face V sweep = V s ө ө V a = V * sin ө V s = V * cos ө Where ө is the angle between the screen face and the canal wall

Likely (but not always) Orientation of Juvenile Fish in Front of Screens 53

54 Screen Face Materials - Overview

Continuous Slots - Criterion To protect the smallest salmonid fry: Maximum Slot Size = 1.75 mm

56 Continuous Slots – Vee Wire

57 Continuous Slots - Profile Bar

58 “Continuous Slots” – Intralox (plastic)

Woven Wire Fabric - Criteria To protect the smallest salmonid fry: Max. Mesh Opening = 3/32 inch (2.38 mm) Minimum Porosity = 27% Open Area

60 Woven Wire (old galvanized – not used anymore)

Woven Mesh on Rotating Drum Screens

Perforated Plate - Criteria To protect the smallest salmonid fry: Maximum Opening = 3/32 inch (2.38 mm) Minimum Porosity = 27% Open Area

Perforated Plate on Rotating Drum Screens

64 Perforated Plate

Seals  Screens need to be fitted tightly to structural frames and other civil works.  Where moving screens attach to civil works, seals are mandatory and should be checked at least annual for tightness of fit and wear.  The entire face of the screen must not include gaps greater than the maximum slotted screen opening (1.75 mm).

Bottom Seals

Side Seals