U.S. Department of the Interior

Bureau of Reclamation Denver, Colorado April 2009 

## Water Resources Technical Publication



# Guidelines for Performing Hydraulic Field Evaluations at Fish Screening FacilitiesU.S. Department of the Interior

Bureau of Reclamation Denver, Colorado April 2009 

# Guidelines for Performing Hydraulic Field Evaluations at Fish Screening Facilities

## Acknowledgments

The funding for this work was supplied by the Bureau of Reclamation Technical Service Center’s Manuals and Standards Program and the Bureau of

Reclamation’s Science and T echnology Research Program.

These guidelines were written primarily by Connie DeMoyer, P.E., Hydraulic Engineer, and Tracy Vermeyen, P.E., Hydraulic Engineer, from the Bureau of Reclamation’s Hydraulics Laboratory. Review, comments, and guidance were provided by Steve Thomas, National Marine Fisheries Service; Warren Frizell, Bureau of Reclamation; Brent Mefford, Bu reau of Reclamation; and Dan Meier,

U.S. Fish and Wildlife Service. Te chnical editing was performed by Teri Manross, Bureau of Reclamation.



## Disclaimer

No warranty is expressed or implied rega rding the usefulness or completeness of the information contained in this report . References to commercial products do not imply endorsement by the Bureau of Reclamation and may not be used for advertising or promotional purposes. 

## Mission Statements

The mission of the Department of the Interi or is to protect and provide access to

our Nation's natural and cultu ral heritage and honor our trust responsibilities to

Indian tribes and our commitments to island communities.

The mission of the Bureau of Reclamati on is to manage, develop, and protect

water and related resources in an environmentally and economically sound manner in the interest of the American public.iii 

# Abbreviations and Acronyms

1D one dimensional

2D two dimensional

3D three dimensional ADC acoustic digital current ADCP acoustic Doppler current profiler ADFM acoustic Doppler flowmeter ADV acoustic Doppler velocimeter CDFG California Department of Fish and Game EM electromagnetic

ft ft ft/s feet per second

ft 3 /s cubic feet per second GCID Glenn-Colusa Irrigation District GPS global positioning system

Hz hertz MHz megahertz

NMFS National Marine Fisheries Service

Reclamation Bureau of Reclamationv 

# Table of Contents

Page

Abbreviations and Acronyms ................................................................................iii

Table of Contents.................................................................................................... v

Figures.................................................................................................................... vi

Introduction............................................................................................................. 1

Overview of Hydraulic Evaluations at Fish Screening Facilities ........................... 2

Fish Protection Criteria........................................................................................... 7

Positive Barrier Screens...................................................................................... 7 Fish Screen Velocity Magnitudes ................................................................. 10 Fish Screen Velocity Uniformity.................................................................. 10 Screen Submergence..................................................................................... 10 Fish Bypass System Velocities ..................................................................... 11 Flow Continuity ............................................................................................ 11

Behavioral Barriers ........................................................................................... 11

Instrumentation ..................................................................................................... 12

Instruments for Near-Field Screen Measurements ........................................... 12 Acoustic Doppler Velocimeter ..................................................................... 12 Electromagnetic Velocimeter........................................................................ 14 Instruments for Fish Bypass System Measurements ........................................ 14 Acoustic Doppler Velocimeter ..................................................................... 15 Other Velocity Meters................................................................................... 15 Acoustic Doppler Flowmeter........................................................................ 15

Ultrasonic Noncontact Flowmeter ................................................................ 16 Support Instrumentation.................................................................................... 17 Acoustic Doppler Current Profilers .............................................................. 17 Mounting System fo r Instruments .................................................................... 19

Types of Hydraulic Screen Evaluations................................................................ 20

Postconstruction Field Evaluations................................................................... 20 Long-Term Field Monitoring Programs ........................................................... 20

Field Evaluation Case Studies .............................................................................. 21

Glenn-Colusa Irrigation Dist rict (GCID) Diversion......................................... 21 Roza Fish Screens Facility................................................................................ 24 Red Bluff Research Pumping Plant .................................................................. 27 Submerged Cylindrical Screens........................................................................ 29 Tracy Fish Collection Facility .......................................................................... 31

References............................................................................................................. 35vi 

# Figures

Page

1 Government Highline Canal in-can al V-screen near Grand Junction, Colorado. This construction photo shows the wedge-wire flat plate screen panels (right), vertical ba ffles (left), and fish bypass intake (center)................................................................................................. 3

2 Flat plate screens installed at Wilkins Slough Pumping Plant on the Sacramento River (Reclamation District No. 108). On-river fish screens are common for large diversions............................................. 3

3 Multiple traveling screens at Roza Fish Screens Facility near Yakima, Washington.......................................................................................... 4

4 Inclined screens at Savage Rapids Diversion near Grants Pass, Oregon. 4

5 Coanda screen at Lake John near Walden, Colorado. ......................... 5

6 Rotating drum screens at Roza Fi sh Screens Facility near Yakima, Washington.......................................................................................... 5

7 Retractable submerged cylindric al screen on Sacramento River near Grimes, California. ...................................................................... 5

8 Cone screen installed by Intake Screens, Inc. Cone screens are typically used in shallow estuarie s or tidally influenced areas............ 6

9 Louver line at Tracy Fish Collection Facility near Tracy,

California. ............................................................................................ 6

10 Plan view of an in-canal fish screening structure ................................ 9

11 SonTek/YSI 10-MHz ADV probe and splash proof signal processing housing photo. ................................................................... 13

12 Nortek Vector velocimeter 6-MHz probe and submersible signal processing housing.................................................................... 13

13 Marsh-McBirney Flo-Mate 2000 portable electromagnetic sensor, cable, and splash proof electronics housing ............................ 14

14 OTT acoustic digital current mete r (photo courtesy of OTT). ............ 15

15 Teledyne ISCO 1.23-MHz ADFM Pro20............................................ 16

16 SonTek/YSI 3-MHz Argonaut-SW ..................................................... 16

17 Teledyne/RDI V-ADCP 2.4-MHz acoustic Doppler flowmeter ......... 16

18 Controlotron portable clamp- on flowmeter Model 1010WP............... 16

19 OTT QLiner acoustic Doppler profiler................................................ 17

20 SonTek/YSI RiverCat acoustic Doppler profiling system................... 18vii 

# Figures

Page

21 Linkquest’s line of ACPs (photo co urtesy of Linkquest, Inc.)............ 18

22 A typical setup using a Tele dyne/RDI Workhorse Rio Grande

ADCP with Trimble GPS to collect bathymetric survey data. ............ 18

23. GCID’s Hamilton City diversion facilities located in an oxbow along the Sacramento River................................................................. 222

24 Magnetic ADV mount used at GCID. ................................................. 23

25 Cross section of ve locity magnitudes collected in the GCID pumping plant approach channel......................................................... 24

26 Rotating drum screens in one bay of Roza Fish Screens Facility........ 25

27 A cantilevered steel mount with a horizontally adjustable

arm was used to measure veloci ties close to the screen face near the surface (as shown) and under the curvature of the screen. .... 25

28 Schematic of measurement locatio ns at a distance of 3 inches from the screen face and along the vertical projection of

the screen ............................................................................................. 26

29 Overview of Red Bluff Re search Pumping Plant................................ 28

30 Flat plate V-screen with a terminal fish bypass................................... 28

31 Adjustable baffles located be hind fish screen panels. ......................... 29

32 Plan view schematic of the Tracy Fish Collection Facility near Tracy,

California. ............................................................................................ 31

33 Mounting an ADV to the louver line................................................... 32

34 Positioning the ADP in front of the bypass intake. ............................. 321 

# Introduction

The Bureau of Reclamation (Reclamation) must comply with Federal and State

fisheries criteria at water diversion stru ctures and their components. Reclamation currently conducts field measuremen t evaluations with specialized

instrumentation at diversi on facilities used for irri gation, power generation, and water supply. Various structures such as fish screens, fish bypasses, screened pump intakes, and louver systems must co mply with Federal and State fisheries criteria in order to maintain uninterrupted operations.

Since diversion structures have site -specific geometry, components, and operational goals, and fisheries criteria va ry by species, life stage, season, and region, it is not possible to recomme nd one standard method for conducting hydraulic evaluations at all fi eld sites. The intent of these guidelines is to offer general field methodologies and instrumentation that can be applied to field evaluations. Keeping in mind that each si te requires unique consideration, these guidelines will be a resource for field pe rsonnel in planning an efficient testing program with appropriate instrumentation.

Reclamation published Fish Protection at Water Diversions (Bureau of Reclamation, 2006) to provide design guida nce for fish protection at small dams

and water diversion structures. This techni cal publication will be used internally by Reclamation and as a technology transfer to other agencies and the public. As a supplement to Fish Protection at Water Diversions , these guidelines provide information on conducting hydraulic fiel d evaluations at water diversion

structures.

These guidelines address field evaluations at diversion stru ctures with fish screens, including an overview of various types of positive barrier and behavioral fish screens that are commonly installed at diversion structur es. The regulatory agencies that typically develop screeni ng criteria are identified. Information is provided on how to obtain current crit eria for the region where hydraulic evaluations are being conducted.

Important parameters needed for hydrauli c evaluations will be summarized. The guidelines identify typical measurement loca tions that are considered critical to fish passage and survival by fisheries ag encies and acceptable, practical methods

that can be used to evaluate these criti cal locations. The guidelines also identify specific areas where the best methodology is unclear. Several field instruments are discussed and compared. Postconstr uction evaluations for baffle adjustment and performance validation, as well as long-term monitoring programs, are discussed. The guidelines conclude with case studies of several hydraulic fish

screen evaluations. These case studies de scribe some of the challenges that a researcher may encounter during field evaluations.Guidelines for Performing Hydraulic Field Evaluations at Fish Screening Facilities

2 

# Overview of Hydraulic Evaluations at Fish Screening Facilities

Fish protection structures may be instal led at water diversions to prevent or reduce fish entrainment into the diversion. The objective of water resources agencies and organizations installing fish protection structures is to abide by State and Federal laws to preserve endangered species while continuing to meet current water deliveries and allowing for futu re water development. Hydraulic

evaluations are needed to ensure that the hydraulic pe rformance of the structure optimizes fish exclusion efficiencies and satisfies all applicable State and Federal

fisheries criteria.

The primary component of a fish protecti on structure is a pos itive barrier fish

screen or behavioral ba rrier. Reclamation’s Fish Protection at Water Diversions manual contains a comprehensive discu ssion of fish protection alternatives, including detailed descrip tions, advantages and disadvantages, and examples of installation locations (Bur eau of Reclamation, 2006).

Positive barrier screens create a physical boundary to fish passage. Off-river barrier screens contain a fish bypass component to return fish safely back to the river. Positive barrier screens are highly effective at reducing fish entrainment, but hydraulic conditions must be monitored to prevent fish injury or mortality from impingement on the screens or delay in migratory passage. Since positive barrier screens are highly susceptible to debris fouling and sediment deposition, cleaning mechanisms and sediment contro l devices are typically included in the design. These types of devices can aff ect hydraulic field evaluations by hindering access to the screens or altering flow patterns near the screens.

Positive barrier screens include flat plat e screens (figures 1 and 2), traveling screens (figure 3), bottom screens such as inclined and horizontal flat plate screens (figure 4), Coanda screens (figure 5), drum sc reens (figure 6), submerged cylindrical screens (figure 7), cone scr eens (figure 8), and closed conduit (Eicher and modular inclined screen [MIS]) screens.

Behavioral barriers produce a stimulus that elicits a fish response to avoid entrainment. As a structural guidance device, vertical louve rs (figure 9) are intended to achieve fish exclusion by genera ting disturbances in the flow field that fish respond to and avoid. Fish maintain a distance off the louver face, while the sweeping flow is intended to guide fish along the louver line and into the bypasses. Alternative behavioral technol ogies include light and acoustic devices, electric fields, air bubble curtains, hanging chains, and water jet curtains. Although fish exclusion efficiencies can be much lower than positive barrier screens, behavior barriers are generall y less expensive to install and easier to maintain. They may be a viable opti on at sites where 100-percent exclusionOverview of Hydraulic Evaluations at Fish Screening Facilities

3 is not required or where installation of a positive barrier is difficult or inappropriate due to site-specific issues.

Figure 1. Government Highline Canal in-canal V-screen near Grand Junction, Colorado. This construction photo shows the wedge-wire flat plate screen panels (right), vert ical baffles (left), and fish bypass intake (center).

Figure 2. Flat plate screens installed at Wilkins Slough Pumping Plant on the Sacramento River (Recl amation District No. 108). Onriver fish screens are common for large diversions.Guidelines for Performing Hydraulic Field Evaluations at Fish Screening Facilities

4 Figure 3. Multiple traveling screen s at Roza Fish Screens Facility near Yakima, Washington.

Figure 4. Inclined screens at Savage Rapids Diversion near Grants Pass, Oregon.Overview of Hydraulic Evaluations at Fish Screening Facilities

5 Figure 5. Coanda screen at Lake John near Walden, Colorado.

Figure 6. Rotating drum screens at Roza Fish Screens Facility near Yakima, Washington. Figure 7. Retractable submerged cylindrical screen on Sacramento River near Grimes, California.Guidelines for Performing Hydraulic Field Evaluations at Fish Screening Facilities

6 Figure 8. Cone screen installed by Intake Screens, Inc. Cone screens are

typically used in shallow estuaries or tidally influenced areas (photo courtesy of Intake Screens, Inc.)

.

Figure 9 . Louver line at Tracy Fish Co llection Facility near Tracy, California.Fish Protection Criteria

7 In addition to a fish barrier, several ot her components may be present at a water diversion, including debris booms, tras hracks, fish bypass systems, cleaning mechanisms, sediment control devices, and pumping or dewatering facilities. Hydraulic field evaluations may be require d at any or all of the fish protection components at a diversion facility.

At fish protection structures , postconstruction field eval uations may be required to validate design performance or to adjust fl ow baffles or weirs to obtain effective performance. Hydraulic evaluations may be requested to identify optimal operational conditions during critical fish protection periods. Long-term monitoring tests are used to ensure prope r performance and to address cleaning or

maintenance concerns.

Field evaluations are generally conducted by qualified personnel from the agency or organization that owns the diversion structure. If sp ecialized expertise or local employment is desired, evaluations ma y be performed by private consulting companies, irrigation districts, or other State or Federal agencies.



# Fish Protection Criteria

Positive Barrier Screens

Federal and State agencies develop, update, and enforce fish screening criteria to protect fishery resources at water diversions. Fish Protection at Water Diversions gives a synopsis of fish protection legisla tion and lists the Federal and State agencies that have authority over, or a ve sted interest in, fishery resources in the United States (Bureau of Reclamation, 2006).

Federal governance of fish screening cr iteria is dictated by the Endangered Species Act, Federal Power Act, and Fi sh and Wildlife Coordination Act. The National Marine Fisheries Service (NMFS) prepares fish prot ection criteria for anadromous fish (species that migrate up rivers from the sea to spawn in fresh water) listed under the Endangered Species Act. The U.S. Fish and Wildlife Service applies fish protection requi rements for endangered nonanadromous species on a project-sp ecific basis. State fish and game agencies enforce and, in some cases, design local criteria govern ing the protection of endangered and nonendangered species. If State or local agencies have more stringent screening criteria, the more conservative criteria are generally followed. See Attachment A

of Fish Protection at Water Diversions for examples of Federal and State fish screening criteria.

When a field evaluation is requested, th e researcher must identify the fish screening criteria that apply to the water diversion. Pump intake screening criteria may be described separately from general fish screening criteria. There isGuidelines for Performing Hydraulic Field Evaluations at Fish Screening Facilities

8 not one universal set of fish eries criteria. Fisheries cr iteria vary by species, life stage, region, and season. Water reso urce managers and resource agency staff with working knowledge of the fish pr otection structure are often the best resource for obtaining this information. If there is a discrepancy over which criteria to use or whether updated criteria are available, the field researcher can obtain updated criteria from the regional re source agency that maintains screening criteria for fish species that are affected by the water diversion. It is possible that certain elements of the criteria may be waived due to site constraints or for screens constructed prior to enactment of criteria.

Since there is a broad range of screening cr iteria, the specific details of criteria will not be discussed. However, several important parameters and critical

measurement locations are common to most hydraulic field evaluations. Important definitions related to hydraulic field evaluations include:

Channel velocity : Velocity of the flow approach ing the fish screen or louver, consisting of the approach and sweeping velocity components (depicted as Vc in figure 10).

Approach velocity : Velocity vector component perpendicular to, and in front of, the screen face (depicted as Va in figure 10).

Sweeping velocity : Velocity vector component parallel and adjacent to the screen face (depicted as Vs in figure 10). For pump intake screens, the sweeping velocity is measured with the pump turned off (National Marine Fisheries Service, 1996).

Baffle system : Perforated plate, flow contro l louvers or vanes, stoplogs, or

other flow restriction or resistance element installed behind fish screens (or inside the screen for cylindrical screens) . When adjusted properly, the baffles generate localized head loss to produce a more uniform velocity distribution

near the screen face.

Bypass flow : Flow rate necessary to effec tively attract fish into the bypass entrance and through the bypass system.

Bypass ratio : Ratio of the water velocity entering the bypass to the water velocity in the main channel

Effective screen area : Total submerged screen area, excluding structural members. For rotating drum screens, it is the projected area onto a vertical plane.

Fish bypass system : Component of a downstrea m passage facility that transports fish from the diverted wate r back into the original body of water, usually consisting of a b ypass entrance, a bypass conduit, and a bypass outfall.Fish Protection Criteria

9 Impingement : Prolonged physical contact of fi sh with a structure due to its inability to swim agains t the approach velocity.

Pump intake screen : Screening device attached directly to a pressurized diversion intake pipe. Ty pically, active pump inta ke screens are equipped with a cleaning mechanism, while pass ive pump intake screens do not have a cleaning mechanism.

Figure 10. Plan view of an in-canal fish screening structure. The channel velocity (Vc) approaches the screen face. The approach velocity component (Va) is perpendicular to the screen face, and the sweeping velocity component (Vs) is parallel to the screen face.

During a hydraulic field evaluation of a fish screening facility, velocity measurements are typically made near the screen face, at the bypass entrance, and inside the bypass channel or conduit. Wate r depths in the forebay, at the upstream face of the screen, and in the bypass may need to be measured.Guidelines for Performing Hydraulic Field Evaluations at Fish Screening Facilities

10 The following critical measurement loca tions and generalized criteria are commonly identified for hydraulic field evaluations:

Fish Screen Velocity Magnitudes

• Approach velocity must be less than a specified allowable value at a location, typically 3 inches perpendicu lar to, and in front of, the screen face (deviations from the 3-inch requi rement may be necessary when the total screen surface is not readily av ailable, as for cylindrical-shaped screens).

• Sweeping velocity must be greater th an approach velocity. An optimal sweeping velocity or sweep-to-approach velocity ratio may be specified.

• Sweeping velocity shall not decreas e in the downstream direction along the length of the screen face or in the bypass channel.

Fish Screen Velocity Uniformity

• A uniform velocity distribution should be maintained over the screen surface to minimize approach velocities. (Note: Adjustable porosity

control or baffles on the downstream si de of screens and/or flow training walls may be installed to improve uniformity.)

• Approach and sweep veloci ties should be measured at a specified distance from the screen face (typically 3 inches). Multiple sampling points are collected over the screen face, with each point representing the flow conditions over a particular per centage of the open screen area.

• Criteria may or may not define “uniform ity.” Specific criteria may state that uniform approach conditions are achieved when no individual approach velocity measurement exceed s the allowable criteria value by a specified percentage. If uniformity is undefined, fishery resource agency staff may have general guidance for acceptable distributions at the site.

Screen Submergence

• A minimum effective screen area must be submerged so that the allowable approach velocity can be achieved. For rotating drum screens, the design submergence will be defined as a percentage of the drum diameter. For cylindrical pump intake screens, the depth of submergence will be defined as a specified screen radius below the minimum water surface.Fish Protection Criteria

11 Fish Bypass System Velocities

• Criteria may specify that the minimum bypass entrance flow velocity be greater than the maximum velocity upstream of the bypass entrance by a specified percentage.

• A maximum increase rate per foot of travel (acceleration) may be required between the screens and the bypass system.

• A design velocity range for the bypass conduit may be specified.

• A maximum impact velocity from the bypass outfall may be specified.

Flow Continuity

• Flow continuity is a comparison of the calculated water diversion rate using the approach veloci ties and the submerged screen area from the field evaluation to the measured water diversion rate from facility flow

measurement instrumentation.

• If the calculated discharge values ar e significantly different from the measured values, the approach velocities may not be fully describing the flow conditions along the en tire screen or may not have accounted for hot and/or cold spots. If continuity is not conserved, it is possible that the instrument mounting technique may have interfered with velocity collection or the experiment al setup was in error.



### Behavioral Barriers

Behavioral barriers are generally not accepted by regulatory agencies since

exclusion rates tend to be lower than conve ntional positive barrier screens. Fish species and life stage, along with si te-specific hydraulic and environmental conditions, often cause the effectiveness of behavioral barriers to vary. Specific

criteria for behavioral barriers are not published; however, some guidance on the experimental process for researching expe rimental fish guidance devices can be found in NMFS literature (National Mari ne Fisheries Service, 1994). When behavioral barriers are employed at a site, regulatory agencies will likely require site-specific field studies to show that fish exclusion performance is acceptable.

Postconstruction or periodic efficiency evaluations at louver systems involve many of the same critical measurement locations as fish screening systems. Effectiveness of louver systems depends on maintaining uniform sweeping flow across the louver face and guiding fish efficiently into the bypasses. Passage delays throughout the system should be mini mized. Fish should not be exposed to

the louver line for more than 60 seconds without access to a bypass to minimize loss through the louvers. Fish should be accelerated into the fish bypass. TheGuidelines for Performing Hydraulic Field Evaluations at Fish Screening Facilities

12 bypass ratio, defined as the velocity in th e bypass divided by the channel velocity in front of the bypass, should always be greater than 1.0 to e ffectively transport fish into and through the bypass.

The effectiveness of acoustic and light barriers, electric fields, air bubble curtains,

and other behavioral exclusion methods ar e analyzed primarily using fish release and capture tests. These tests quantify barrier efficiency under a wide range of environmental conditions such as day and night, tidal cycles, and flow rates. Hydraulic evaluations typically include measuring velocities and mapping flow fields near to the barrier because hydrauli c conditions can greatly contribute to the

overall effectiveness of these barriers.



# Instrumentation

Hydraulic field data are collected with a combination of portable instrumentation and permanent facility equipment. Seve ral types of portable instruments can be

used to measure velocities and flow rates at fish screening facilities. Instrument capabilities, performance sp ecifications, costs, and availability may dictate which type of equipment is chosen. Selection of instrumentation may be dependent on site-specific factors such as site loca tion and geometry, water quality, support structure interference (cleaning arms, divi ding piers), and difficulties related to mounting and retrieving the instruments.

To assist in selecting th e most appropriate field instrumentation for a hydraulic study, a description of vari ous available technologie s is provided, along with some advantages and disadvantages of using the instrument for the specified application. There are many high-qual ity instruments available in each instrumentation category. Specific propr ietary products and materials are only mentioned to provide examples of the in struments but this should not in any way be construed as an endorsement by Reclam ation. The appropriate instrumentation and mounting technique must be determined by the practitioner.



### Instruments for Near-Field Screen Measurements

Acoustic Doppler Velocimeter

Acoustic Doppler velocimeters (ADV) util ize the Doppler principle to measure three-dimensional (3D) velocity vectors in a small remote sampling volume. The ADV emits sound pulses (pings) at a speci fic frequency. At a fixed distance from the probe, the signal reflects off of particles present in the water, providing a precise instantaneous reading at a “point” (i.e., sample volume of about 0.01 cubic inches). The frequency shift of the returning sound wave increases or decreases, depending on whether the wa ter is moving toward orInstrumentation

13 away from the receivers. The difference between the emitted and received frequency is used to calcul ate the water velocity.

Typically, ADV probes are configured as “down-looking” or “side-looking,” describing the location of the sample volum e with respect to the probe axis, and can collect two-dimensional (2D) or 3D velocity data. ADVs are effective for measuring near-screen velocities because they can measure close to boundaries.

ADVs can fit into areas with minimal late ral clearance, but they cannot fit into areas with minimal vertical clearance, such as underneath the curvature of a drum screen, due to the configuration of the signal conditioning module. Particles in the water act as scatterers to provide ad equate return signal strength and signal-tonoise ratio. If the ADV does not have a st rong signal in clean water applications, the water may need to be seeded with s cattering material if possible. ADVs are

not able to collect data in water w ith heavy air entrainment because bubbles attenuate the acoustic energy.

It is good practice to check the factory calibration of an ADV before each use. However, an ADV does not require peri odic calibration unless the physical characteristics of the probe are changed (e.g., a receiver arm is bent). If an ADV probe is damaged during transport or use, factory repair and recalibration are required.

An example of a commercially availabl e acoustic Doppler velocimeter is the SonTek/YSI ADV (figure 11). The 10-megahertz (MHz) ADV can acquire data at sampling rates up to 25 hertz (Hz), allo wing for the measurement of turbulence. With no zero offset, the ADV performs at low flows and is bidirectional. The

6-MHz Nortek Vector velocimeter can colle ct data at a rate as high as 64 Hz (figure 12).

Figure 11. SonTek/YSI 10-MHz ADV probe and splash proof signal processing housing photo (courtesy of SonTek/YSI). Figure 12. Nortek Vector velocimeter 6-MHz probe and submersible signal processing housing (photo courtesy of Nortek).Guidelines for Performing Hydraulic Field Evaluations at Fish Screening Facilities

14 Electromagnetic Velocimeter

Electromagnetic (EM) instruments use Fara day’s Law to measure the velocity of a conductive fluid. Water is a conductor due to the presence of trace amounts of

ions from dissolved minerals. Farada y’s Law states that a conductor passing through a magnetic field produces a voltage that is directly proportional to the relative velocity of the conductor. EM velocimeters provide a magnetic field, and electrode sensors on the pr obe surface measure the voltage induced by flow moving through the magnetic field.

For screen measurements, a 2D spherical or a one-dimensional (1D) bulb-shaped probe are normally used. When orie nted properly, a two-dimensional probe simultaneously measures localized appro ach and sweeping velocities at a sample rate of up to 1 Hz. Since bulb or sphe rical shaped probes have electrodes on the side(s) of the sensor, the sampling volume is spherical in shape with a diameter of approximately 5 inches. The average flui d velocity is measured over the sample volume. If only 1D probes are availabl e, a pair of probes must be mounted together to measure both appro ach and sweeping velocities.

EM velocimeters can fit into small measurement areas, which may be useful for large diameter drum screen and cylindrical screen

evaluations. The calibration of

EM meters must be checked before

each use. Because ferrous metal

screen materials interact with the magnetic field, velocity

measurements must be taken at

a minimum distance of 3 inches from the screen. One specific

model of a 1D EM meter is the Marsh-McBirney Flo-Mate 2000 (figure 13).



### Instruments for Fish Bypass System Measurements

In addition to point velocity measurements near the fish screen, hydraulic screen evaluations also may include measurement of water velocities entering the fish bypass and flow rates through the bypass pipe . If onsite water measurement weirs or permanent flowmeters are installed, they can be used to measure bypass rates. Otherwise, portable instrume ntation must be used. Some examples of portable

instruments are discussed below. Figure 13. Marsh-McBirney Flo-Mate 2000 portable electromagnetic sensor, cable, and splash proof electronicshousing (photo courtesy of MarshMcBirney, Inc).Instrumentation

15 Acoustic Doppler Velocimeter

An ADV (discussed above) can be used to measure point velocities in or near the fish bypass system. These measurements may be required to determine if the flow is accelerating along the screen and in to the bypass. The rate at which flow is accelerating can be measured with successive readings.

If a discharge measurement is require d and permanent flowmeters are not available, the flow rate can be estimate d using stream gauging techniques with an ADV or propeller meter (Bureau of Reclam ation, 2001). For water depths greater than 2 ft, point velocities should be m easured at 0.2 and 0.8 of the water depth

from the surface in the streamwise dir ection, and the average of these values

should be used to calculate the flow rate. For water depths less than 2 ft, a point velocity measurement at 0.6 of the water depth from the surface in the streamwise

direction can be used to calculate the flow rate.

Other Velocity Meters

The OTT company has recently developed an acoustic digital current (ADC) meter, which includes depth measurement w ith a pressure sensor and temperature

measurement. This acoustic instrument uses the cross co rrelation method to calculate water velocity. The sampling volume is located about 4 inches from the probe face (figure 14).

Propeller meters are anot her option for measuring 1D point velocities in or near the fish bypass system.

Care must be taken to ensu re that the calibration is accurate and that the meter is oriented properly.

Acoustic Doppler Flowmeter

For discharge measurem ents, acoustic Doppler flowmeters (ADFM) 1 are typically mounted on the bottom of a channel or pipe for an “upward looking” measurement. Water velocity is measured by the Doppler principle via two, angled acoustic beams. Water depth is gauged by an uplooking acoustic depth sensor. The discharge is computed over the flow measurement area using the vertically integrated velocity. If the bypass channel is narrow and the water is deep, the acoustic signals may encounter boundary interference and cannot be used. Three examples of acoustic Doppler profiling flowmeters include the Teledyne ISCO 1.23-MHz ADFM Pro20 (figure 15),

1 The acoustic Doppler flowmeter may also be referred to as an acoustic Doppler current profiler (ADCP).

Figure 14. OTT acoustic digital

current meter (photo courtesy of OTT).Guidelines for Performing Hydraulic Field Evaluations at Fish Screening Facilities

16 the SonTek/YSI 3-MHz Argonaut-SW (figure 16), and the Teledyne/RDI 2.4- MHz V-acoustic Doppler current profiler (ADCP) (figure 17).

Figure 15. Teledyne ISCO 1.23-MHz ADFM Pro20 (photo courtesy of Teledyne ISCO, Inc). Figure 16. SonTek/YSI 3-MHz ArgonautSW (photo courtesy of SonTek/YSI).

Ultrasonic Noncontact Flowmeter

To measure the flow rate of a full-flow ing closed conduit, noncontact ultrasonic meters can be clamped to a pipe. The flow measurement is based on the principle

that sound waves in the fluid travel fast er in the downstream direction than traveling in the upstream direction. Th e difference in transit times of the ultrasonic signals is a measure of the average fluid velocity. There are many manufacturers of ultrasonic, noncontact fl owmeters. The Controlotron portable clamp-on flowmeter (shown in figure 18) is one example.

Figure 17. Teledyne/RDI V-ADCP 2.4-MHz acoustic Doppler flowmeter (photo courtesy of Teledyne/RDI, Inc). Figure 18. Controlotron portable clamp-on flowmeter Model 1010WP (photo courtesy of Controlotron).Instrumentation

17 

### Support Instrumentation

Acoustic Doppler Current Profilers

Acoustic current profilers (A CP) also utilize the Doppler frequency shift principle

to measure two- or three-dimensional velo city profiles in a user-specified number of depth cells. The acoustic frequency of the transceivers determines the range of the instrument and the depth size for the profile.

ACP instruments measure velocity over a large sampling volume (defined by the transceiver configuration) as opposed to point or localized velocity measured using an ADV or EM velocimeter. A lthough an ACP is not suited to measure near-screen velocities, it can be successfully used as a support instrument to examine approach conditions at various cr oss sections near the screening facility (Vermeyen and DeMoyer, 2002). Cross se ctions can also be taken along the length of the screens, in front or back , to identify hot spots on the screens. Examination of backscatter intensity da ta can provide qualitative information about suspended sediment concentra tions and areas of local scour.

Instruments such as the OTT QLiner meas ure velocity profile data in a single plane (either vertical or horizontal, depending on the instrument orientation), requiring input of channel cross section geometry for a discharge measurement (figure 19). Instruments such as the S onTek/YSI RiverCat calculate discharge by making alternating measurements of ch annel cross sectional area using bottom tracking techniques and veloci ty profiles to define the mean vertical velocity (figure 20). Teledyne/RDI offers a si milar system called the Workhorse Rio Grande ADCP. Linkquest, Inc., has also developed a line of ACPs (figure 21).

Figure 19. OTT QLiner acoustic Doppler profiler (photo courtesy of OTT).

ACPs are capable of measuring depth for each acoustic beam. As a result, ACPs can be used as multi-beam depth s ounders along with integrated global positioning system (GPS) data for local bathymetric surveys (figure 22). Bathymetric data are useful for documenting changes in the approach channel geometry due to aggradation, degradation, or dredging.Guidelines for Performing Hydraulic Field Evaluations at Fish Screening Facilities

18 Figure 20. SonTek/YSI RiverCat acoustic Doppler profiling system (photo courtesy of SonTek/YSI).

Figure 22. A typical setup using a Teledyne/RDI Workhorse Rio Grande ADCP with Trimble GPS to collect bathymetric survey data. Figure 21. Linkquest’s line of ACPs (photo courtesy of Linkquest, Inc.)Instrumentation

19 

### Mounting System for Instruments

Mounting instruments in and around structures is always a site-s pecific challenge. Devising a workable mounting system for th e instrument can take a great deal of time and effort, but it is a worthwhile investment in order to improve the efficiency and accuracy of data collection.

For fish screen measurements, portable in strumentation must be mounted close to the screen face to obtain velocity data. Probe orientation is critical when measuring directional flow. If the 2D or 3D probe is even slightly misaligned, the measured approach velocity may inco rporate part of the sweeping flow, producing significant inaccuracies in the data. Some data processing software include a way to account for probe misa lignment if a systematic problem is

identified after data have been collect ed. Reclamation has developed a Windowsbased viewing and postprocessing u tility for ADV files called WinADV (Wahl, 2009). WinADV provides an inte grated environment for reviewing and processing data collected using S onTek and Nortek acoustic Doppler

velocimeters.

Velocimeters should be clamped onto a sturdy support structure that minimizes

instrument movement and vibration. The most accurate way to position the instrument is to reference it directly off of the screen for each measurement. If a long cantilevered mount is necessary, th e mount must be rigid so it does not

deflect or vibrate in fast moving water. If movement is a concern, a stronger support should be used or the mount s hould incorporate intermediate supports wherever possible.

The mount should not block or disrupt th e flow field around the instrument. The mounting system must have a way to determ ine the lateral and ve rtical position of

the instrument. It is most efficient if the instrument can be moved between measurement locations quickly and accura tely. In most cases, accurate point velocity measurements cannot be made off of a boat because boat movement is incorporated into the measur ed velocity. If a floating platform must be used to access the site, it should be secure ly anchored to minimize motion.

Velocity and discharge measurements in fish bypass channels may require affixing an instrument to the bottom, or n ear the bottom, of the bypass channel. If the bypass cannot be fully dewatered, the instrument should be carefully secured

to the channel bottom or sidewalls in the wet. The location and orientation of the instrument must be known to get accurate results. A heavy weight or plate can sometimes be used to fix the position of the instrument. If interference from

sidewalls or other st ructures cannot be avoided, a point velocity meter may be required.

Acoustic Doppler profilers or current meters are ofte n mounted off of boats, bridges, or rope lines to collect s upporting hydraulic da ta. The deploymentGuidelines for Performing Hydraulic Field Evaluations at Fish Screening Facilities

20 mechanism depends on the channel geometr y, water depth and velocity, transect location, and other site-speci fic factors. Orientation of current meters is an important consideration because the trans ducer must be alig ned parallel to the channel centerline or perpendicular to a tagline. Compasses are often integrated into acoustic Doppler instruments to allow da ta collection in earth coordinates. If so, a compass calibration is required to compensate for local magnetic fields.



# Types of Hydraulic Screen Evaluations

Postconstruction Field Evaluations

The purpose of postconstruction hydraulic evaluations is to validate design performance, refine hydraulic conditions, and document facility effectiveness. Hydraulic tests may include velocity measurements along the screen face, at the bypass entrance and exit, and in the bypass ch annel or conduit to determine if fish will be guided effectively through the system.

Before conducting a postconstruction evalua tion, it is important to determine what

flow conditions should be evaluated. De pending on the facility, the appropriate time period may be at low water depth, nor mal or peak operations, or a critical time period such as during smolt passage. Hydraulic conditio ns and operational settings such as diversion and bypass flow rates, water depths, screen submergence, and the weir and baffle se ttings should be re corded during field

evaluations.

For facilities with flow control baffles downstream of the screens, hydraulic testing is necessary to properly adjust the baffles to achieve near-uniform approach velocities. A trial-and-error process is required to adjust multiple sets of flow control louvers, vertical vanes, pe rforated plates, or flashboards behind each screen. Several comparable rounds of ve locity data will likely need to be collected. Setting baffles for in-canal screening systems tends to be more straightforward than adjus ting baffles for in-river applications where variable hydraulic conditions and dynamic flow patte rns add complexity to the system. Hydraulic evaluations may also be reque sted to identify optimal operational conditions during critical fish protecti on periods or to adjust bypass weirs for effective performance.



### Long-Term Field Monitoring Programs

Long-term monitoring tests are used to en sure proper facility performance and to identify screen cleaning or maintenance concerns. Periodic hydraulic evaluations may be requested to measure approach a nd sweeping velocities across the screenField Evaluation Case Studies

21 face to verify screen and baffle performan ce. Diversion rates can be calculated from measured approach velocity values and compared with measured diversion

rates.

Structural changes, such as installation of new baffles or cleaning devices, and operational changes, due to altered flow rates or criteria requirements, may require special hydraulic evaluations. H ydraulic evaluations may also help to identify underwater screen damage, de bris accumulation, sedimentation, or problems with permanent instrumentation.



# Field Evaluation Case Studies

Glenn-Colusa Irrigation Dist rict (GCID) Diversion

Facility type : In-river flat plate screens

Challenges : Instrument mounting due to hi gh sweeping velocities, defining velocity uniformity for a large facility , data repeatability with dynamic flow

conditions

The GCID pump station is located in nor th-central California, about 100 miles

north of Sacramento. The diversion f acility is located on an oxbow of the Sacramento River (figure 23). Up to 3,000 cubic feet per second (ft 3 /s) of Sacramento River water is pumped into GCID’s canal after passing through the fish screens. A portion of the water bypa sses the screen and flows back into the

river at the downstream end of the oxbow.

To protect fish from entrainment in th e main irrigation canal, long flat plate screens with three fish bypasses were in stalled at the pump station in 2000 in partnership with Reclamation. The U.S. Army Corps of Engineers constructed a gradient restoration facility on the main stem of the S acramento River to stabilize the river channel, promote upstream and downstream fish passage, and maintain adequate water surface elevations and fl ow rates for safe fish passage and effective screening. More information on GCID’s Fish Screen Project can be found on their Web site (GCID, 2009).

Since construction, many hydraulic eval uations have been conducted by CH2M HILL, GCID, NMFS, and Reclama tion to adjust the baffle system, document screen performance and complia nce, and monitor intake and bypass channels. Several site-specific issues ha ve made data collection difficult at the GCID fish screens. It is important to design a monitoring program after site-specific issues are identified, so that a generic test plan does not lock theGuidelines for Performing Hydraulic Field Evaluations at Fish Screening Facilities

22 evaluators into a test pro cedure that is not appropriate for the facility. More

information on GCID’s Evaluation and M onitoring Program is available on their Web site (GCID, 2009).

Figure 23. GCID’s Hamilton City dive rsion facilities located in an oxbow along the Sacramento River.

The GCID flat plate screens are an u nprecedented 1,100 ft long. According to the California Department of Fish and Game (CDFG) screening criteria, approach

velocities for in-river screens should not exceed 0.33 feet per second (ft/s) over the entire screen face (CDFG, 2000). Meas uring multiple locations on each of the 85 screen panels to ensure adequate un iformity is prohibitively time consuming. However, one single velocity point meas urement per screen does not adequately represent the flow patterns over the entir e screen because a single measurement can be affected by localized de bris effects or recirculati ng flow patterns. In this situation, the number of scr een measurements that can be collected during a single evaluation is dictated by the design and flow conditions for the facility. The oversight agency should be contac ted to discuss potential options.

Screening criteria state that the sweeping velocity should be at least two times the allowable approach velocity at GCID. The flat plate screens were designed to have high sweep to approach velocity ratios, often around 10:1 or more. This larger ratio provides good hydraulics for safe fish exclusion, but it complicates screen evaluations. When mounting inst ruments in high velocities, the mount may vibrate or bend, particularly if the support is long or cantilevered (CH2M HILL, 2003). If a boat is necessa ry for installation, high velocities may make it difficult to maintain a steady boat position in the channel. High sweepingField Evaluation Case Studies

23 flows accentuate the influence of boundaries and obstacles in the flow. Since the approach velocity is a small component of the channel velocit y, slight changes in

flow conditions can substantiall y alter the magnitude of the a pproach velocity.

Unlike controlled canal systems, on-rive r screening facilitie s face dynamic flow

conditions. The GCID screens are locat ed on an oxbow with a curved intake channel. Flow conditions such as upwelling, eddies, and recirculation currents are common. For these conditions, data repeatability may be problematic.

Both ADVs and EM meters have been used successfully at the GCID site. Initially, the support structures for the sc reen cleaning brush masts were used to deploy multiple velocimeters. However, field tests at GCID have shown that the

brush masts affected near-screen velociti es up to 10 ft upstream from the masts, thereby skewing velocity data (Thomas, 2004). Consequently, a magnetic mount (shown in figure 24) was designed to be independent of the support structure in order to eliminate the hydraulic effects generated by the brush masts (Thomas, 2006).

An ADCP was successfully used as a support instrument at GCID during a field evaluation (Vermeyen and DeMoyer, 2002). Along with bathymetric and velocity data

collected in and around the gradient restoration facility, cross sectional current profiles were

collected across the GCID pumping plant approach channel and along the length of the fish screen. An example of the high resolution bathymetric and velocity field information collected by

the ADCP is shown in figure 25. Figure 24. Magnetic ADV mount used at GCID (photo courtesy of National Marine Fisheries Service).Guidelines for Performing Hydraulic Field Evaluations at Fish Screening Facilities

24 Figure 25. Cross section of velocity magnitudes collected in the GCID pumping plant approach channel.



### Roza Fish Screens Facility

Facility type : In-diversion drum screens

Challenges : Access to drum screen face, defini ng velocity uniformity for a large facility

Roza Diversion Dam is part of the Roza Di vision of Reclamation’s Yakima Basin Project. The dam diverts water from the Yakima River into the Roza Canal, which provides water for irrigation and pow er generation. Located at the canal headworks, a series of rotating drum scr eens protects fish from being entrained in the canal. The Roza Fish Screens Facility consists of 27 drum screens (17 ft in diameter and 12 ft wide) in five ba ys with a primary fish bypass at the downstream end of each bay (figure 26).

Hydraulic evaluations have been conducted at the fish screening facility since 1985 to document postconstruc tion performance (Abernat hy et al., 1989) and to evaluate potential operati onal changes such as reducing primary bypass flows (McMichael et al., 2003; DeMoyer, 2004) and using sluice gates behind the drum screens for velocity control (DeMoyer and Vermeyen, 2004). Anadromous salmonid criteria are governed by the regional NMFS division (1995). Although governing approach velocity criteria specifi es 0.4 ft/s, the faci lity was originally designed for an approach velocity of 0.5 ft/s. Evaluations have been conducted with consideration of the design criteria.Field Evaluation Case Studies

25 Figure 26. Rotating drum screens in one bay of Roza Fish Screens Facility.

There are unique challenges for measuring velocities near drum screens. Drum screens are designed for the expected appr oach velocity based on the vertically projected open area; however, for velocity evaluations, criteria require that the measurement occur 3 inches from the cylin drical screen face. A velocity meter can be easily positioned close to the screen face at or above the centerline of the drum. However, access to the screen face below the curvature of drum screens is difficult, particularly for large diameter screens such as the Roza screens (figure 27).

Figure 27. A cantilevered steel mount with a horizontally adjustable arm

was used to measure velocities close to the screen face near the surface (as shown) and under the curvature of the screen (DeMoyer, 2004).Guidelines for Performing Hydraulic Field Evaluations at Fish Screening Facilities

26 Due to limitations in the body shape ofthe ADV instrument, standard downlooking ADVs cannot measure velocities at 3 inches from the screen at depths far

below the screen curvature while maintaini ng a vertical probe or ientation. At the Roza Fish Screens Facility, the velocity in strument may be as far as 30 inches from the screen face at 0.8 times the dept h (figure 28). Inverting the probe may be possible, depending on the distance from th e floor, sturdiness of the instrument mount, and debris and silt accumulation on the floor, but it is not recommended for large diameter screens where lack of visual cues increases the probability for probe damage. If an ADV cannot be pos itioned at the required location, the evaluation report should in clude the actual measurement location. Depending on the geometry of the site, EM meters may be placed slightly closer to the screen face under the curvature of the screen, but the use of multiple instruments may require separate mounting devices.

Figure 28. Schematic of measurement locations at a distance of 3 inches from the screen face and along the vertical projection of the screen (Abernathy et al., 1989).

If the definition of velocity uniformity is not specified in the screening criteria, it is important to determine which data lo cations are required to adequately map

velocities over the face of the scree n. In a 1989 Pacific Northwest National Laboratory study at the Roza Fish Screens Facility (Abernathy et al., 1989), velocity measurements were collected at depths of 0.2, 0.5, and 0.8 on a vertically projected plane and at 0.05, 0.08a, and 0.9 near to the drum screen face, as shown in figure 28. Results indicated that velocities measured at 0.05 and 0.5 were accurately represented by measurements at 0.2 and 0.8 on the vertically projectedField Evaluation Case Studies

27 plane. Limited velocity data collected near to the screen face at 0.8a and 0.9

indicated that velocities ma y be higher at those locatio ns, possibly due to a 1-foot drop in the floor elevation at the drum screens or the influence of the sluicing panels.

Judgment should be used when selecting appropriate measurement locations for the evaluation under schedule and budget c onstraints. A hydraulic evaluation was

conducted in March 2004 to determine the effects of sediment sluicing panels on drum screen performance. Data were collected on all 27 screens in 5 bays for 2 different operational cond itions. Changing the position of the sluicing panels was time intensive and required a signif icant equilibrium period before data

collection could continue. In order to collect a full suite of data during similar diversion rates, six measurement locations were chosen per sc reen (two depths and three lateral locations). In an Au gust 2004 evaluation, detailed velocity data were collected on representative screen s in order to document the effect of lowering bypass flows. For this evaluati on, 35 locations (5 de pths and 7 lateral locations) were measured at 6 representative screens.



### Red Bluff Research Pumping Plant

Facility type : In-diversion V-screens

Challenges : Baffle installation due to hi gh approach velocities and poor uniformity, flow deceleration into bypass

Starting in 1966, Red Bluff Diversion Dam allowed gravity diversion from the

Sacramento River into the Tehama-Colusa Canal for water deliveries. Operation of the diversion dam adversely impacted th e fisheries resources in the river. In 1995, Red Bluff Research Pumping Plant (f igure 29) was constructed downstream

of the Red Bluff Diversion Dam to test a new concept in fish protection at a pumped water diversion. This “pump first, screen second” method employed existing technology such as fi sh-friendly pumps (Archimedes lifts and an internal helical pump), vertical wedge-wire sc reens, and fish bypass structures.

The fish-friendly pumps discharge water, fish, and debris into a concrete sluiceway. A V-shaped (or chevron) screen ing structure consists of twelve 5.25-ft by 5.25-ft steel panels. The screening stru cture concentrates the entrained fish into a bypass that conveys 10 percent of the total pumped flow (figure 30). The open channel bypass moves fish into the evalua tion facility or back into the river, while the water passing through the V-sc reens continues into the canal. No baffles were included in the original screen design. Continuously operating brushes sweep both sides of the scre en to minimize debris accumulation.Guidelines for Performing Hydraulic Field Evaluations at Fish Screening Facilities

28

Figure 29. Overview of Red Bluff Research Pumping Plant.

Figure 30. Flat plate V-screen with a terminal fish bypass.

Hydraulic evaluations were conducted throughou t the facility to test the new fish protection methods employed at Red Bluff. In order to evaluate fish passage through the two types of pumps, the V-sc reens needed to be operating properly. An acoustic Doppler velocimeter was used to collect velocity da ta in front of the screen panels. The V-screens were designe d to meet the CDFG approach velocity

criteria of 0.33 ft/s maximum at 3 in ches from the screen face. In 1997, CDFG accepted a fish screening criteria modification published by the SouthwestField Evaluation Case Studies

29 Region NMFS (1997) specifying that approach velocities 3 inches from the screen

face should not exceed 0.4 ft/s in canals. Initial screen measurements with no baffles resulted in approach velocities in excess of 1.25 ft/s. To reduce approach velocity magnitudes and improve flow uni formity, several baffle configurations were subsequently installed and tested.

Screening evaluations were conducted from 1995 through 1998 to determine which baffle configuration produced the best screen perfor mance (Frizell and Atkinson, 1999). Both fixed area baffles and adjustable porosity baffles installed

behind the downstream half of the screen panels on both sides were not successful at meeting criteria. In order to affect the entire flow field, fixed area baffles were also installed behind the upstream half of the screen panels. A full set of baffles was needed to produce acceptable

velocities in most areas of the screens (figure 31). Even with baffles, surface

waves caused inconsistent velocities at the water surface due to the pump outlet conditions and short approach channel length to the screens.

Mean channel velocities were measured at three locations ap proaching and inside of the screening structure. Results sh owed an undesirable deceleration of flow into the bypass. The bypass intake desi gn produced a recircul ation zone in the bottom 2 ft of the water column, causing the velocity to decrease. Although retrofits were difficult for this facility, structural modificatio ns may be made at

other sites if fish are not accelerated into the bypass.



### Submerged Cylindrical Screens

Facility type : In-river or in-diversion submerged cylindrical screens

Challenges : Instrument mounting, requires divers, variable approach conditions

A specific case study will not be presente d here, but the chal lenges of collecting cylindrical screen measurements will be discussed. Field evaluations of cylindrical screens on small diversions (less than 40 ft 3 /s) are not common because the impact to fish is likely to be minimal. Field evaluations of large submerged cylindrical screens (above 40 ft 3 /s) may be required by regulatory agencies. Figure 31. Adjustable baffles located behind fish screen panels.Guidelines for Performing Hydraulic Field Evaluations at Fish Screening Facilities

30 Alternative screening technol ogies, such as submerged cylindrical screens, are becoming more commonplace because of the lo wer installation costs. Cylindrical screens are fixed in place either on a burie d manifold system or to flanges on civil works projects. Other designs incorporate screens on retractable rails attached to the diversion pipe or the pumping plant structure, allowing maintenance to be carried out in the dry. When planni ng for the installation of submerged cylindrical screens, the approach conditi ons should be conservative to simulate the worst-case operational scenario. The screen should be placed in a location with uniform approach flow conditions, a nd the long axis of the screen should be parallel to the sweeping flow direction. Internal baffli ng is used to create more uniform velocity distributions over the screen face. Since baffles are not adjustable in most cylindrical screens, postinstallation modifica tions are typically limited to adjusting approach conditi ons or the angle of the screen.

Laboratory tests at Reclamation’s Hydrau lics Laboratory in Denver, Colorado, have shown that flow separation and eddies are generated off of the leading edge of the screen, causing water to flow out of the screen near the upstream end (Mefford and Hanna, 1997). During the sc reen tests, outflow occurred in the upstream 10 to 15 percent of the scree n, producing higher appr oach velocities along the rest of the screen than the sc reen was designed to accommodate. With this in mind, additional open area should be provided to account for flow separation effects at the leading edge.

Submerged cylindrical screens are of ten evaluated by manufacturers in a hydraulics laboratory for fisheries complia nce under a range of flow conditions. Although these are good baseline evaluations of screen performance, changes in river flow and stage affect the flow angl e and sweeping velocities near the screen in the field. Therefore, field evaluati ons should be conducted for a wide variety of flow conditions to fully evaluate scr een performance. Submerged cylindrical

screens are difficult to test in the field because of the complexity of installing and mounting velocity meters and uncertainti es about the instrument location and percent of area tested. Retrievable screen s can provide more flexibility than fixed screens in designing an evaluation plan. Regardless of screen type, divers will likely be needed to ensure proper placem ent of the velocity instrument and to reduce the possibly of damage to the inst rument. When high sweeping velocities exist, the risk associated with having divers in the wa ter is heightened. Holding the velocity meter in place is not a viable option; therefore, th e diver must either

move the instrument and reattach it betw een measurement points or an instrument mount must be designed to move the me ter along the screen without obstructing flow patterns.Field Evaluation Case Studies

31 

### Tracy Fish Collection Facility

Facility type : Louver system

Challenges : Maintaining high bypass flows, flow deceleration and eddying near bypasses, debris loads

The Tracy Fish Collection Facility (TFCF) is located at the head of the DeltaMendota intake channel at the south end of the Sacramento-San Joaquin Delta near Tracy, California. The facility was constructed in the 1950s to collect fish before entrainment at the C.W. “Bill” Jones Plant. The facility was designed to guide fish from the canal into one of four primary bypass intakes by way of a diagonal line of louvers in the primary channel. Two sets of louvers in a secondary facility guide fish through a bypass into the holding tank area. A schematic of the facility is seen in figure 32.

Figure 32. Plan view schematic of the Tr acy Fish Collection Facility near Tracy,

California.

Fisheries criteria for louver system s have not been published by regulatory agencies; however, standards for operati on of the TFCF are published in Decision 1485 Water Quality Standards for the Sacramento-San Joaquin and Suisun

Marsh (State Water Resources Control Bo ard, 1978). According to table II, the secondary channel velo cities should be held at 3.0 to 3.5 ft/s from February - May, while salmon are pres ent, and less than 2.5 ft/s fromGuidelines for Performing Hydraulic Field Evaluations at Fish Screening Facilities

32 June 1 - August 31 for striped bass, sh ad, and catfish. The bypass entrance velocity should exceed the lo cal channel velocity to guide fish into the bypass. This ratio, defined as the bypass ratio, s hould be greater than 1.0 to achieve efficient bypass conditions and to eliminate eddies and slack water zones that hold up fish movement.

Like screening facilities, to achieve effective fish ex clusion, the fish must be moved efficiently along the louvers with gradual flow acceleration into the bypass. Strong accelerations and decelerati ons can cause fish avoidance of the bypass (Bates et al., 1960). In 2004, the primary bypass intakes were replaced with a new design based on physical a nd computational hydraulic studies (Kubitschek, 2003). The new bypasses were designed to produce a near-uniform

vertical flow distributi on throughout the water column to improve the hydraulic conditions for fish collection. Laboratory modeling also showed that vertical approach flow velocity distributions st rongly influence velo city distributions within the bypass intake, so it was anticipated that the bypass intakes would perform best when debris fouling was minimized (Johnson et al., 2004). Hydraulic field evaluations were conducte d to verify the performance of the new primary bypass intakes (DeMoyer, 2007).

Vertical velocity profiles were collected at the bypass intake with an acoustic Doppler velocimeter. Since the bypass channel is only 6 inches wide, an instrument mount had to be designed to minimize flow blockage and disturbance to flow patterns. An angled rail was a ttached to the louvers with a vertically traversing sled (figure 33). The ADV was mounted on the end of an arm extending from the moveable sled to meas ure vertical veloci ties at the bypass intake. An acoustic Doppler profiler was used to measure velocity field distributions upstream of the intake. Th e instrument was teth ered to the louver cleaner platform in order to position the instrument properly in front of the bypass (figure 34).

Figure 33. Mounting an ADV to the

louver line. Figure 34. Positioning the ADP in front of the bypass intake.Field Evaluation Case Studies

33 Field results showed that bypass ratios gr eater than 1.0 minimize flow disruption and eddying and promote gradual flow accel eration into the intakes, indicating that the facility should be operated in th is manner whenever possible. However, tidal fluctuations, high pumping rates, a nd low water levels in the Delta prevent achievement of bypass ratio objectives at ti mes, regardless of facility operation. High debris loads adversely affected bypa ss performance by degrading uniformity in the vertical velocity profiles at the bypass entrances. This shows the importance of debris management at fish protection facilities.References

35 

# References

Abernathy, C. Scott, Duane A. Neitzel, and E. William Lusty. 1989. Velocity Measurements at Six Fish Screening Facilities in the Yakima River Basin, Summer 1998, Annual Report . Pacific Northwest National Laboratory, Portland, OR.

Bates, Daniel W., Orren Logan, and Everett A. Pesonen. 1960. Efficiency Evaluation, Tracy Fish Collection Facil ity, Central Valley Project, California. Bureau of Reclamation, Region 2, Sacr amento, California, and Bureau of Commercial Fisheries, Pacific Regio n, U.S. Fish and Wildlife Service, Seattle, WA.

Bureau of Reclamation. 2006. Fish Protection at Water Diversions . Water Resources Technical Publication, U.S. De partment of the Interior, Bureau of Reclamation, Denver, CO.

Bureau of Reclamation. 2001. Water Measurement Manual – 3 rd Edition . Water Resources Technical Publication, U.S. De partment of the Interior, Bureau of Reclamation, Denver, CO.

California Department of Fish and Game. 2000. Fish Screening Criteria

.

CH2M HILL. 2003. Glenn-Colusa Irrigation Di strict Fish Protection Evaluation and Monitoring Progr am – 2003 Annual Report.

DeMoyer, C.D., and T.B. Vermeyen. 2004. Roza Fish Screens Facility Velocity

Measurements With and Without Poros ity Boards at an Intermediate Canal

Flow Rate . Report No. PAP-928, Bureau of Reclamation, Water Resources Research Laboratory, Denver, CO.

DeMoyer, Connie. 2004. Roza Fish Screens Facility: Velocity Measurements at a High Canal Flow Rate . Report No. HL-2004-06, Bureau of Reclamation,

Water Resources Research Laboratory, Denver, CO.

DeMoyer, Connie. 2007. Hydraulic Performance Eval uation of the Replacement Primary Bypass Intakes and Transition Boxes at Tracy Fish Collection Facility . Tracy Fish Collection Facility Studies, California, Volume 40.

Frizell, K.W., and S.P. Atkinson. 1999. Engineering Evaluation of the Red Bluff Research Pumping Plant on the Sacramento River in Northern California:

1995-1998 . Red Bluff Research Pumping Plant Report Series Volume 6. Bureau of Reclamation, Denver, CO.Guidelines for Performing Hydraulic Field Evaluations at Fish Screening Facilities

36 Glenn-Colusa Irrigation District. 2003. Fish Screen Improvement Project. http://www.gcid.net/FishScreen.ht ml. Accessed on October 7, 2008.

Johnson, Perry L., Morris Campbell, and James A. Higgs. 2004. Physical Model Study of a Primary Bypass Intake with Louvers at the Tracy Fish Collection Facility, Tracy, California . Tracy Fish Collection Facility Studies, California,

Volume 28.

Kubitschek, J.P. 2003 . Physical and Computational Model Studies to Improve Hydraulic Performance at the Primar y Bypasses at Tracy Fish Collection Facility, Tracy, California . Tracy Fish Collection Facility Studies, California,

Volume 19.

McMichael, G.A., J.A. Vucelic k, and C.S. Abernathy. 2003. Roza Dam Fish Screen Evaluations, Summer 2003 . Battelle-Pacific Northwest Division, Richland, WA.

Mefford, Brent, and Leslie Hanna. 1997. Model Tests of Air Burst and Hydraulic Back-Flush Cleaning Efficiency fo r a Cook Cylindrical Screen . Bureau of Reclamation. Hydraulics Laborat ory Report PAP-770, Denver, CO.

National Marine Fisher ies Service. 1997. Fish Screening Criteria for

Anadromous Salmonids . National Marine Fisheries Service, Southwest Region, Santa Rosa, CA.

National Marine Fisher ies Service. 1996. Addendum: Juvenile Fish Screen Criteria for Pump Intakes . National Marine Fisherie s Service, Environmental

and Technical Services Division, Portland, OR.

National Marine Fisher ies Service. 1995. Juvenile Fish Screen Criteria

. National Marine Fisheries Service, E nvironmental and Technical Services Division, Portland, OR.

National Marine Fisher ies Service. 1994. Experimental Fish Guidance Devices

. Position Statement of the National Ma rine Fisheries Service, Southwest Region, Long Beach, CA.

State Water Resources Control Board. 1978. Decision 1485 Water Quality Standards for the Sacramento-San Joaquin and Suisun Marsh . California Environmental Protection Agency, St ate Water Resources Control Board, Division of Water Rights, Sacramento, CO.References

37 Thomas, Steve. 2004. Hydraulic Influence of the Traveling Cleaning System Assembly on Measurements of Approa ch Velocity at the Glenn-Colusa Irrigation District Fish Screen . National Marine Fisheries Service, Technical Report to the Bureau of Reclama tion and GCID Technical Oversight

Committee.

Thomas, Steve. 2006. Approach Velocity Measurements at Glenn Colusa Irrigation District’s Sacra mento River Pumping Plant . National Marine Fisheries Service, Technical Report to GCID Technical Oversight Committee.

Vermeyen, Tracy B., and Connie DeMoyer. 2002. ADCP Current Profile

Measurements at Sacramento River Gr adient Facility near Glenn-Colusa Irrigation District Pumping Plant . Report No. TR-02-05, Bureau of Reclamation, Water Resources Rese arch Laboratory, Denver, CO.

Wahl, Tony L 2009. WinADV. <http ://www.usbr.gov/pmts/hydraulics_lab/ twahl/winadv/>. Accessed on April 9, 2009.