Fish Passage Technologies: Protection at

Hydropower Facilities

September 1995

OTA-ENV-641

GPO stock #052-003-01450-5
Recommended Citation: Fish Passage Technologies: Protection at Hydropower

Facilities, OTA-ENV-641 (Washington, DC: U.S. Government Printing Office,

September 1995).
iii

Foreword

he House Committee on Merchant Marine and Fisheries requested that the Office

of Technology Assessment (OTA) examine the role of fish passage and protection

technologies in addressing the adverse effects of hydropower development on

North American fish populations. After the elimination of the requesting committee, the report was continued on behalf of the House Resources Committee, Subcommittee

on Fisheries, Wildlife, and Oceans.

Hydropower development may adversely affect fish by blocking or impeding biologically significant movements, and altering the quantity, quality, and accessibility of necessary habitat. Fish moving downstream that pass through hydropower turbines can be

injured or killed, and the inability of fish to pass upstream of hydropower projects prohibits

them from reaching spawning grounds. Hydropower licenses issued by the Federal Energy

Regulatory Commission (FERC) may include requirements for owners/operators to implement fish passage technologies or other measures to protect, enhance, or mitigate damages

to fish and wildlife, as identified by the federal resource agencies. Although FERC is

directed to balance developmental and nondevelopmental values in licensing decisions,

many contend that balancing has been inadequate. Thus, fish passage and protection has

become a major controversy between the hydropower industry and resource agencies.

This report describes technologies for fish passage, and those for protection against turbine entrainment and mortality, with an emphasis on FERC-licensed hydropower projects.

OTA identifies three areas for policy improvements. First, to establish and maintain sustainable fisheries, goals for protection and restoration of fish resources need to be clarified

and strengthened through policy shifts and additional research. Secondly, increased coordination is needed among fishway design engineers, fisheries biologists, and hydropower

operators, especially during the design and construction phases of fish passage and protection technologies, to improve efficiency. Finally, new initiatives with strong science and

evaluation components are needed to advance fish passage technologies, especially for

safe downstream passage.

OTA sincerely appreciates the contributions of the advisory panel, workshop participants, contractors, and reviewers. We are especially grateful for the time and effort

donated by the federal and state resource agencies and the Federal Energy Regulatory

Commission. The information and assistance provided by all of these individuals was

invaluable.

ROGER C. HERDMAN

Director

T
iv

Advisory Panel

Don Kash, Chair

John T. Hazel Sr. & Ruth D. 

Hazel Chair of Pubic Policy

The Institute of Public Policy

George Mason University

Fairfax, VA

Paul Bisulca

Assistant to the Governor

Environmental Affairs

Penobscot Indian Nation

Oxford, ME

Tom Bowes

Director of Hydro Operations

Consumers Power

Cadillac, MI

Paul Brouha

Executive Director

American Fisheries Society

Falls Church, VA

Glenn Cada

Aquatic Ecologist

Oak Ridge National 

Laboratory

Oak Ridge, TN

Tom Carlson

Lead Scientist

Pacific Northwest Laboratory

Richland, WA

George Eicher

President

Eicher Associates, Inc.

Portland, OR

Christopher Estes

Statewide Instream Flow 

Coordinator

Alaska Department of Fish and 

Game

Anchorage, AK

John Hall

National Marine Fisheries 

Service (retired)

Vienna, VA

Mona Janopaul

Conservation Counsel

Trout Unlimited

Arlington, VA

Chris Katopodis

Habitat Management Engineer

Freshwater Institute

Winnipeg, Manitoba, Canada

Julie Keil

Director, Hydro Licensing

Portland General Electric 

Company

Portland, OR

Dale Kelley

Executive Director

Alaska Trollers Association

Juneau, AK

Jack Mattice

Senior Project Manager

Electric Power Research 

Institute

Palo Alto, CA

C. Paul Ruggles

Fisheries and Environmental 

Consultant

Western Shore, Nova Scotia, 

Canada

Jerry Sabattis

Program Coordinator

Hydro-Licensing

Niagara Mohawk Power 

Corporation

Syracuse, NY

Ted Strong

Director

InterTribal Fish Commission

Portland, OR
v

Ned Taft

Program Manager

Environmental Services

Alden Research Laboratory, Inc.

Holden, MA

Gary Whelan

FERC Project Coordinator

Michigan Department of 

Natural Resources

Lansing, MI

Ron Wilson

Attorney

Columbia, MO
vi

Workshop Participants

Ken Bates

Department of Fish and 

Wildlife

Olympia, WA

Ron Brockman

U.S. Bureau of Reclamation

Sacramento, CA

Christopher Estes

Department of Fish and Game

Anchorage, AK

James Fossum

U.S. Fish and Wildlife Service

Green Bay, WI

Roger Guinee

U.S. Fish and Wildlife Survey

Sacramento, CA

Alex Haro

National Biological Service

Turner’s Falls, MA

Darryl Hayes

Department of Water 

Resources

Sacramento, CA

Alex Hoar

U.S. Fish and Wildlife Survey

Hadley, MA

Robert Krska

U.S. Fish and Wildlife Service

Fort Snelling, MN

Larry Leasner

Department of Natural 

Resources

Annapolis, MD

Charles Liston

U.S. Bureau of Reclamation

Denver, CO

Estyn Mead

U.S. Fish and Wildlife Service

Arlington, VA

Duane Neitzel

Batelle Northwest

Richland, WA

John Nestler

U.S. Army Corps of Engineers

Vicksburg, MS

Dan Odenweller

Department of Fish and Game

Sacramento, CA

Rock Peters

U.S. Army Corps of Engineers

Portland, OR

Ben Rizzo

U.S. Fish and Wildlife Service

Newton Corner, MA

David Robinson

U.S. Bureau of Reclamation

Denver, CO

William Sarbello

Department of Environmental 

Conservation

Albany, NY

Price Smith

Department of Game and 

Inland Fisheries

Ashland, VA

Tom Squiers

Department of Marine 

Resources

Augusta, ME

Tom Thuemler

Department of Natural 

Resources

Marinette, WI

Stephen Waste

National Marine Fisheries 

Service

Silver Spring, MD

Gary Whelan

Department of Natural 

Resources

Lansing, MI

Marcin Whitman

National Marine Fisheries 

Service

Santa Rosa, CA
vii

Project Staff

Clyde Behney

Assistant Director

Robert Niblock

Program Director

Environment Program

Patricia Durana

Project Director

Joan G. Harn

Assistant Project Director

Matthew Draud

Analyst

Elise Holland

Analyst

Rebecca I. Erickson1

Research Analyst

Susan J. Wunder

Contract Editor

ADMINISTRATIVE STAFF

Kathleen Beil

Office Administrator

Nellie M. Hammond

Administrative Secretary

Kimberly Holmlund

Administrative Secretary

Sharon Knarvik2

Administrative Secretary

Babette Polzer3

Contractor

1

 Until August 1995.

2 Until February 1995.

3 From June 1995.
ix

Contents

1 Executive Summary and Policy Directions 1

Controversies 3

Policy Directions 7

Summary of Fish Passage Technologies 9

Conclusions 20

2 Fish Passage and Entrainment Protection 25

Part 1: Issues and Controversies 25

Part 2: Study Methods 45

3 Upstream Fish Passage Technologies: 

How Well Do They Work? 53

Upstream Fish Passage Design 53

Effective Fishway Design 63

Why Fishways Fail 65

Conclusions 67

4 Downstream Fish Passage Technologies: 

How Well Do They Work? 69

Design of Conventional Structural Measures 70

Other Methods for Providing Downstream Passage 76

Evolving Downstream Passage Technologies 82

Alternative Behavioral Guidance Devices 87

Perspectives on Technologies 93

Conclusions 94

5 The Federal Role in Fish Passage at

Hydropower Facilities 97

Licensing of Nonfederal Hydropower Plants 98

Mitigation Costs and Benefits 108

Research and Development: Federal Involvement 112

Conclusions 117
x

Appendix A: 

Overview of Fish Passage and Protection 

Technologies in the Columbia River Basin 121

Abstract 121

Introduction 122

Overview of Columbia River Basin Fish 

Passage Research: Past to Present 125

References 130

Appendix B: 

Experimental Guidance Devices: 

NMFS Position Statements 135

Experimental Fish Guidance Devices: Position 

Statement of National Marine Fisheries Service 

Northwest Region January 1995 135

Experimental Fish Guidance Devices: Position 

Statement of National Marine Fisheries Service

Southwest Region January 1994 138

References for Northwest and Southwest Regions Position 

Statements 141

Appendix C:

Suggested Reading 143

References 153
| 1

1

Executive

Summary and

Policy Directions

he focus of this report is technologies

for fish passage around hydropower

generation facilities and protection

against entrainment and turbine mortality. Emphasis is given to Federal Energy Regulatory Commission (FERC)-licensed hydropower

projects where fish protection is a subject of controversy and congressional interest due to the

Federal Power Act (FPA) and the Electric Consumers Protection Act (ECPA). Thus institutional issues related to FERC-relicensing are also

discussed. (Major points of controversy are highlighted in box 1-1.) Federal hydropower projects,

especially in the Columbia River Basin, and irrigation water diversions in the Pacific Northwest

and California are included to the extent that they

provide information on fish passage technologies

(see table 1-1). Many of the technologies discussed are applicable to other types of dams and

water diversions. In fact, there are many more

obstructions to fish passage that are not covered

by FERC-licensing requirements, than are

(approximately 76,000 dams versus 1,825

FERC-licensed facilities) (70).

Fish passage is considered necessary where a

dam separates a target species from needed habitat. Fish are generally unable to pass upstream of

a hydropower dam unless some fish passage

facility is present. Downstream passage facilities

may not always be necessary if the fish can

safely pass through turbines, spillways, or sluiceways, though there is significant debate about the

adequacy of these latter two passage methods. 1

Decisions about the need for fish protection

measures at dams are often based on the perceived or measured impacts on one or more species at the site (242). Fish populations may be

adversely affected by hydropower faci lities and

many other activities and facilities (e.g., mul tiple

use, flood control, and water supply dams; land

use practices like grazing and forestry; and facilities like coal-fired power plants that cause acid

rain). Migrations and other important fish movements can be blocked or delayed. The quantity,

quality, and accessibi lity of up- and downstream

fish habitat, which can play an important role in

population sustainability, can be affected. Fish

that pass through power generating turbines can

be injured or killed. Increased predation on

migratory fishes has also been indirectly linked

to hydropower dams (e.g., due to migration

delays, fish being concentrated in one place, or

increased habitat for predatory species). Habitat

1 Spillways are used to pass water over a dam. Sluiceways are used to p ass debris, ice, logs, etc.

T
2 | Fish Passage Technologies: Protection at Hydropower Facilities

BOX 1-1: Fish Passage At FERC-Licensed Hydropower Facilities: Controversial Issues

This study was initiated because of significant controversy about technical issues related to fish passage and the relicensing of a large number of hydropower facilities, beginning in 1993 and continuing

through 2010. Major con troversial issues that are discussed in this study are listed below:

Discussed in Chapters 1–4:

■ Do riverine fish need passage? (chapter 2)

■ Do riverine fish need protection from entrainment? (chapter 2)

■ Is experimentation with alternative behavioral technologies warranted? (chapters 1 and 4)

Discussed in Chapter 5:

■ Is FERC’s balancing of developmental and nondevelopmental values adequate?

■ How should the baseline goal for mitigation be defined?

■ How timely is the licensing process?

■ How well are license reopeners implemented?

■ Should dams be decommissioned and/or removed?

SOURCE: Office of Technology Assessment, 1995.

TABLE 1-1. Columbia River Basin: Downstream Fish Passage Methods And Research

Downstream passage

technique

Status Stakeholder views Effectiveness

Resource agencies Hydro industry

TRANSPORTATION

Barging Conventional Mixed Accepted Good

Trucking Conventional Mixed Accepted Good

SCREENS (low-velocity)

STS Conventional Mixed Contentious Good

Vertical traveling Conventional Accepted Accepted Good

Rotating drum Conventional Accepted Accepted Good

SCREENS (high-velocity)

Eicher screen Experimental Mixed Mixed Very Good

MIS Experimental Mixed Mixed Very Good

ALTERNATIVE BEHAVIORAL DEVICES

Acoustics (sound) Experimental Hopeful Hopeful Unknown

Surface collector Experimental Hopeful Hopeful Unknown

OTHER METHODS

Turbine passage Conventional Contentious Accepted Fair

Spilling Experimental Contentious Accepted Good

NOTE: Many of the downstream passage technologies and devices discussed in this report are being experimented with in the Columbia River

Basin. For further discussion of these, see chapter 4. For further discussion of the Columbia River Basin, see appendix A.

SOURCE: Office of Technology Assessment, 1995.
Chapter 1 Executive Summary and Policy Directions | 3

alterations and increased predation pressure

caused by hydropower dams are significant issues,

but fall beyond the central scope of this report.

This study was initiated because of significant

controversy about technical issues related to fish

passage and the relicensing of a large number of

hydropower facilities, beginning in 1993 and

continuing through 2010. Major points of controversy are discussed below.

CONTROVERSIES

The need for fish passage facilities is widely

accepted for anadromous fish (i.e., fish that

migrate from the ocean to spawn in freshwater)

(see box 1-2). Considerable controversy exists

between resource agencies and hydropower

operators about the passage and protection

requirements for riverine fish (i.e., the so-called

resident species that spend their entire lives in

freshwater) (see chapter 2). 

BOX 1-2: Chapter 2 Findings—Fish Passage and Entrainment Protection

■ The need for entrainment protection and passage for riverine fish is very controversial. There is a growing body of evidence that some riverine fish make significant movements that could be impeded by

some hydropower facilities. The need for passage for riverine fish is most likely species- and site-specific and should be tied to habitat needs for target fish populations. This will be difficult to determine

without establishing goals for target species.

■ The acceptability of turbine passage for anadromous fish is site-specific and controversial. There is

major concern when anadromous fish must pass through multiple dams, creating the potential for significant cumulative impacts. Passage of adult repeat spawners is also a major concern for most Atlantic Coast species.

■ The effects of turbine passage on fish depend on the size of the fish; their sensitivity to mechanical

contact with equipment and pressure changes; and whether fish happen to be in an area near cavitation or where shearing forces are strong. Smaller fish are more likely to survive turbine passage than

larger fish. Survival is generally higher where the turbines are operating with higher efficiency.

■ Riverine fish are entrained to some extent at virtually every site tested. Entrainment rates are variable

among sites and at a single site. Entrainment rates for different species and sizes of fish change daily

and seasonally. Entrainment rates of different turbines at a site can be significant.

■ Turbine mortality studies must be interpreted with caution. Studies show a wide range of results, probably related to diversity of turbine designs and operating conditions, river conditions, and fish species

and sizes. Turbine mortality study design is likely to affect results. Different methods may yield different results.

■ Methods for turbine mortality study include: mark-recapture studies with netting or balloon tags, and

observations of net-caught naturally entrained fish, and telemetry. Methods for entrainment studies

include: netting, hydroacoustic technology (used especially in the West), and telemetry tagging. These

methods have advantages and disadvantages depending on target species and site conditions.

Hydroacoustic technology and telemetry tagging can provide fish behavior information (e.g., tracking

swimming location) useful for designing passage systems and evaluating performance.

■ Early agreement on study design would help minimize controversies between resource agencies and

hydropower operators. Lack of reporting of all relevant information makes it difficult to interpret results.

Standardized guidelines to determine the need, conduct, and reporting of studies could help overcome this limitation.

■ Mitigation by financial compensation is very controversial. The degree of precision necessary for evaluation studies and how fish should be valued are items of debate.

SOURCE: Office of Technology Assessment, 1995.
4 | Fish Passage Technologies: Protection at Hydropower Facilities

This controversy over whether riverine fish

need safe passage relates to whether or not

movement to habitats blocked by a dam have

adverse impacts on the population. Although the

paradigm is beginning to change, the predominant thinking has been that riverine fishes have

restricted movements. This may be true at some

sites, but the generalization may in part be an

artifact of the movement studies that have been

done. Recent research has identified major differences in fish movements among different species of riverine fish and there are some studies

that document different movements of the same

species in different watersheds. The need for mitigation to provide passage for riverine fishes is

most likely site- and species-specific and should

be tied to the specific habitat needs for target fish

populations in a given river reach.

The controversy over whether riverine fish

need protection from entrainment is largely unrelated to issues about passage requirements (see

chapter 2). The controversy centers on the lack of

information on the impact of entrainment on the

overall fish population. Population impact studies would be exceedingly complex, time consuming and costly, and are rarely, if ever, done (146).

The hydropower industry and resource agencies

take very different positions about the need for

entrainment protection, given the lack of good

site-specific information. Industry generally says

that entrainment protection is not necessary for

riverine fish. Resource agencies consider entrainment a chronic loss of fish that requires mitigation, or at least compensation. As a result of this

controversy, entrainment and turbine mortality

studies are frequently done. These studies also

have limitations.

The National Marine Fisheries Service

(NMFS) and the U.S. Fish and Wildlife Service

(FWS), referred to throughout this report as federal resource agencies, have the authority to prescribe mandatory fish passage mitigation under

section 18 of the Federal Power Act, as amended

(FPA). These agencies, along with their state

counterparts, may also make additional recommendations to protect, mitigate, and enhance fish

and wildlife affected by hydropower development under section 10(j) of the FPA. The decision to include section 10(j) recommendations in

a hydropower license order rests with the Federal

Energy Regulatory Commission. FERC is

required to balance developmental and nondevelopmental values of hydropower development in

the licensing process. This requires an evaluation

of the need for (i.e., benefits) and costs of recommended mitigation compared to the benefits of

the hydropower project; such evaluations have

many limitations.

Apart from the controversies about the need

for fish passage and protection, there are issues

about the technologies (boxes 1-3 and 1-4). For

upstream technologies, the issues relate to proper

design, operation and maintenance, understanding fish behavior, and the need to develop technologies for additional species (see chapter 3).

These upstream technology issues are not particularly controversial.

For downstream technologies, the primary

controversy is the value of investing time and

money in alternative behavioral technologies,

especially for conditions where conventional

methods with high levels of effectiveness are

possible. This issue is highly controversial and

complex (see chapter 4). It is not readily

explained without an understanding of the technologies for fish passage and the different positions of key stakeholders, including:

■ resource agencies with responsibilities for protection of fish species, many of which are in

serious decline;

■ hydropower operators with the mission of providing a renewable form of electricity without

the emissions and adverse environmental

effects associated with alternative generation

methods; many operators are seriously concerned about their viability in anticipated

deregulated markets; and

■ developers of new technologies who are convinced they have viable approaches to fish

passage and protection that will cost much less

than conventional methods. 

Resource agencies take the position that conventional downstream passage technologies

should be installed because the alternative meth-
Chapter 1 Executive Summary and Policy Directions | 5

ods are unproven, will likely remain highly site

specific, and may never provide the levels of protection of well-designed and operated conventional measures under the wide range of

conditions present at a site. On the other hand,

hydropower operators and promoters of new

technologies want the opportunity to find lower

cost solutions to fish protection.

Hydropower licensing is a highly controversial issue among the many stakeholders involved

in the process (see box 1-5). State and federal

resource agencies, the hydropower industry, special interest groups (e.g., environmental), Native

American tribes, individual owner/operators, and

the public at large are all involved. Balancing all

of these competing interests in licensing is a

complex process, generating much dispute

among the participants. Key areas of controversy

include: adequacy of FERC’s balancing of

developmental and nondevelopmental values;

defining the baseline goal for mitigation; timeliness of the licensing process; license reopeners;

and dam decommissioning and/or removal (see

chapter 5).

BOX 1-3: Chapter 3 Findings—Upstream Technologies

■ There is no single solution for designing upstream fish passageways. Effective fish passage design for

a specific site requires good communication between engineers and biologists and thorough understanding of site characteristics.

■ Technologies for upstream passage are considered well-developed and understood for particular

species.

■ Upstream passage failure tends to result from less-than-optimal design criteria based on physical,

hydrologic, and behavioral information or from a lack of adequate attention to operation and maintenance of facilities.

SOURCE: Office of Technology Assessment, 1995.

:BOX 1-4: Chapter 4 Findings—Downstream Technologies

■ There is no single solution for designing downstream fish passage. Effective fish passage design for a

specific site requires good communication between engineers and biologists and thorough understanding of site characteristics.

■ Physical barrier screens are often the only resource agency-approved technology to protect fish from

turbine intake channels, yet the screens are perceived to be very expensive.

■ The ultimate goal of 100 percent passage effectiveness is most likely to be achieved with the use of

physical barrier technologies; however, site, technological, and biological constraints to passing fish

around or through hydropower projects may limit performance.

■ Structural guidance devices have been shown to have a high level of performance at a few studied

sites in the Northeast. The mechanism by which they work is not well understood.

■ Alternative behavioral guidance devices have potential to elicit avoidance responses from some species of fish. However, it has not yet been demonstrated that these responses can be directed reliably;

behavioral guidance techniques are site- and species-specific; and it appears unlikely that behavioral

methods will perform as well as conventional barriers over a range of hydraulic conditions and for a

variety of species.

SOURCE: Office of Technology Assessment, 1995.
6 | Fish Passage Technologies: Protection at Hydropower Facilities

OTA does not resolve these controversies in

this report. OTA does, however, discuss the

issues underlying these controversies and the

context in which they have developed. This

chapter continues with policy directions, a summary of technologies, and overall conclusions

related to technologies and hydropower licensing.

BOX 1-5: Chapter 5 Findings—Federal Role

■ The Federal Energy Regulatory Commission (FERC) has exclusive authority to license nonfederal

hydroelectric facilities on navigable waterways and federal lands, which includes conditioning of

licenses to require operators’ adoption of fish protection measures.

■ Section 18 of the Federal Power Act gives the federal resource agencies authority to prescribe

mandatory fish passage conditions to be included in FERC license orders. Section 10(j) recommendations relate to additional mitigation for rehabilitating damages resulting from hydropower development or to address broader fish and wildlife needs (e.g., minimum flow requirements). Yet, these

recommendations are subject to FERC approval.

■ FERC’s hydroelectric licensing process has been criticized as lengthy and can be costly for applicants and participating government agencies. In some cases, the cost of implementing fish protection mitigations from the utility perspective may render a project uneconomical.

■ FERC uses benefit-cost analyses in its final hydroelectric licensing decisions; yet economic methods for valuing habitat or natural resources are not well established and many economists feel that

they fit poorly in traditional benefit-cost analysis.

■ There is no comprehensive system for monitoring and enforcing resource agency fish passage prescriptions. FERC’s monitoring and enforcement authority has been used infrequently, and only

recently, to fulfill its mandate to adequately and equitably protect, mitigate damages to, and

enhance fish and wildlife (including related spawning grounds and habitat) affected by the development, operation, and management of hydroelectric projects.

■ Parties must perceive a need to negotiate in the FERC hydropower licensing process, beyond the

regulatory requirements of applicants and agencies, in order to achieve success. FERC must be

seen as a neutral party to motivate participants to find mutually acceptable agreements in accommodating the need for power production and resource protection. If FERC is perceived to favor certain interests, the need to negotiate is diminished or eliminated.

■ There are no clearly defined overall goals for North American fishery management, and Congress

has not clearly articulated goals for management of fishery resources and/or priorities for resource

allocation.

■ Fish protection and hydropower licensing issues return repeatedly to the congressional agenda.

The 1920 Federal Power Act (FPA) was designed to eliminate controversy between private hydropower developers and conservation groups opposed to unregulated use of the nation’s waterways.

Greater consideration of fisheries and other “nondevelopmental” values was called for in the Electric Consumers Protection Act of 1986 (ECPA) and oversight on these issues continued with the

passage of the Energy Policy Act of 1992. In the 104th Congress, efforts continue to address power

production (e.g., sale of PMA’s; BPA debt restructuring) and developing sustainable fisheries (e.g.,

Magnuson Act Amendments; Striped Bass Conservation Act).

SOURCE: Office of Technology Assessment, 1995.
Chapter 1 Executive Summary and Policy Directions | 7

POLICY DIRECTIONS

Three key areas exist for policy improvements:

establishing sustainable fisheries, improving performance of fish passage technologies, and

advancing fish passage and protection technologies.

First, to establish and maintain sustainable

fisheries, goals for protection and restoration of

fish resources need to be clarified and strengthened through policy shifts and additional

research. Congress could give FERC responsibility to sustain fish populations through legislative

language similar to that used in the Central Valley Improvement Act (title 34 of the Reclamation

Projects Authorization and Adjustment Act, PL

102-575), which elevates the importance of fish

and wildlife protection in Central Valley Project

management. Congress could direct FERC to

expand river-wide planning and cumulative analysis in the hydropower relicensing process by

synchronizing license terms on river basins.

Additional research would be needed on the

effects of obstructions and habitat alterations on

fish populations.

Second, mechanisms to ensure the good

design, construction, and operation and maintenance of all fish passage technologies are

needed. Improved coordination is needed among

fishway design engineers, and fisheries biologists, and hydropower operators, especially during the design and construction phases. Also,

institutional mechanisms must be improved for

adequate oversight, commitment, and enforcement of fishway operations and maintenance

activities. An increased emphasis on monitoring

and evaluation of fish passage performance

could provide useful feedback information on the

performance of technologies that could be used

to make improvements.

Third, new initiatives are needed to advance

fish passage technologies, especially for safe

downstream passage. This area, the focus of this

report, was addressed in an OTA-sponsored

workshop, and is discussed in detail below.

❚ Advancing Fish Passage Technologies

For the successful development of new fish

passage technologies, there is a critical need for

good science and independent evaluation of technologies. This is essential for experiments that

are currently underway, future site-specific studies, and for any efforts to create more systematic

and comprehensive research programs in the

long term. A sound scientific approach to developing, executing, and evaluating a field study is

critical to the successful advancement of fish

passage technologies. The elements of a good

test include the establishment of clear objectives,

agreement amongst all parties on the study

design including quantifiable standards of

acceptability that are measurable in the studies,

and a protocol that lends itself to repeatability.

Studies should be designed by an interdisciplinary team including not only those knowledgeable about fisheries, hydrology, hydraulics, and

hydropower operations, but also biologists

knowledgeable about fish behavior and sensory

response. In addition, there must be a proper

accounting of environmental variability and documentation of underlying assumptions. Studies

should span multiple seasons in order to collect

adequate data and include appropriate statistical

evaluation. Regular communication among

stakeholders should occur throughout the study

process. Evaluative reports on the work should

be peer reviewed by credible professionals with

no vested interest in the results, and then published. Agreement on performance criteria and

standards prior to study will facilitate acceptance

of data and recommendations (210). An effort to

systematically evaluate the potential for acoustic

technologies is underway in the Columbia River

Basin. This may serve as a useful model for systematic research. However, a mechanism to

transfer results and expand investigations to fish

guidance problems in other parts of the country

is needed (see box 1-6).

If Congress decides that a coordinated effort

to advance fish passage technology is desired, a

technology certification organization could be

established that would provide unbiased data.
8 | Fish Passage Technologies: Protection at Hydropower Facilities

This group would have no proprietary interest in

the technology under investigation. It would

carry out applied laboratory and field tests of

newly developed technologies (as well as conventional technologies) and verify claims of performance and cost. The certifying organization

would set the standards for methodology of

investigation, would test the system, and would

define the conditions under which certain levels

of performance could be expected. It could

arrange for pilot test locations on federal properties or private sites, and have a mechanism to

compensate vendors as appropriate. The organization would not actually approve a technology,

but would provide a controlled evaluation of its

effectiveness under specific conditions. It would

provide data on performance that would be the

equivalent of peer reviewed material, thus

removing the possibility of the misuse or misinterpretation of data. The work of such a certification organization would be considerably

enhanced with the availability of clear standards

and expectations for protection of species of fish

in different regions.

The certification organization could produce a

catalog similar to a physician’s desk reference.

Information would be provided on conditions

where the technology is likely to be useful,

BOX 1-6: Columbia River Acoustic Program—A Model For Systematic Research

The U.S. Army Corps of Engineers and Department of Energy initiated a program to develop acoustic

technologies to improve fish passage in the Columbia River Basin at the end of 1994 (165). This multiyear program provides a systematic guide for evaluating existing technologies; conducting needed

research that prevents immediate application of acoustic methods; developing prototype systems; and

evaluating their feasibility and potential effectiveness. It also demonstrates field performance of soundbased fish behavior modification systems under normal operating conditions for extended time periods.

Specific research areas include: sound characterization, fish hearing characterization, target behavior

stimulus identification, fish behavioral models, target behavior stimulus delivery, behavioral response

monitoring and evaluation, assessing predictive tools for sound fields, and evaluating other potential

behavioral stimuli. The program is directed at solving problems of downstream fish passage on the

Columbia River, including need for increased bypass screen guidance efficiency, enhanced surface collection, increased spill effectiveness, and reduced predation losses. The Columbia River Acoustic Program involves technical reviewers as well as resource agencies, Indian tribes, Bonneville Power

Administration, and the Corps of Engineers.

It is not clear how transferable results from these investigations will be for other smaller hydropower

sites and water diversions in other parts of the country. Basic research to develop evaluation tools for fish

behavior in sound fields, and information on fish hearing capabilities will be useful at other sites. If the

background studies resolve uncertainties associated with the use of sound to guide targeted fish, then a

similar effort to meet needs of targeted species in other parts of the country should be pursued.

It must be recognized, however, that other fish species in other locations will likely need different

behavioral stimuli and delivery systems. Thus not all of the results that emerge from the Columbia River

program will be applicable to other settings. However, a mechanism (e.g., a workshop) could be

designed to review progress and evaluate transferability of results to other fish guidance problems. A

parallel and broader research, development, demonstration, testing, and evaluation program, possibly

centered at the Conte Anadromous Fish Laboratory of the National Biological Survey, could be developed to meet the needs for fish guidance at FERC relicensing sites. Additional centers of research may

be needed to address other fish populations, such as riverine fish in the Midwest and declining populations in the Central Valley of California.

SOURCE: Office Of Technology Assessment, 1995.
Chapter 1 Executive Summary and Policy Directions | 9

counter-indications, possible problems, and performance at other sites. It would evaluate applications of the technology. All technologies to be

included in the catalog would need to undergo

the same levels of testing.

The certification organization should be adequately and independently funded and free of

political pressure. One option might be to have a

surcharge placed on all electricity generated

through hydropower plants; this would be placed

into an escrow account to pay for the operations

of the organization and the dissemination of data.

Alternatively, a portion of FERC license fees

might be diverted to support such an organization. Other sources of funding that could be considered would be a tax on utilities, or the

diversion of some public funds or taxes since

hydropower sites are often not the only contributors to fishery problems in a watershed. However, one can be certain that any efforts to

increase fees on electricity or raise taxes would

be strongly resisted.

Congress could give certification responsibility to the National Biological Survey. This may

only be feasible if NBS remains as an independent research group and is not reconsolidated

with the FWS. (The FWS has a key role in recommending and prescribing fish protection in the

FERC-relicensing process, and thus is not considered to be entirely objective in this arena.)

This option would take advantage of the unique

NBS Conte Anadromous Fish Laboratory. Other

research facilities may be needed in other parts

of the country.

Alternatively, Congress could create an independent, non-profit fish passage certification

organization, modeled as a research and educational foundation. Possible models might be the

Electric Power Research Institute (EPRI) or the

Rocky Mountain Institute. EPRI knows the

power generating industry, issues of concern and

the stance of most of the parties involved.

Although EPRI is now linked to industry, the

new organization would be independent and

impartial in its approach. The Rocky Mountain

Institute has a broader mandate, crossing boundaries and addressing a number of disciplines.

Both organizations provide an indication of the

form that such an organization could take.

SUMMARY OF FISH PASSAGE 

TECHNOLOGIES

This section summarizes fish passage research

programs and technologies for upstream and

downstream passage. Brief mention is given to

new concepts in hydropower generation.

❚ Fish Passage Research Programs

Federal agencies play a pivotal role in water

resources management and research and development of fish protection technologies. The

National Biological Survey (NBS), Bureau of

Reclamation (BuRec), U.S. Army Corps of Engineers (COE), Department of Energy (DOE), and

the Bonneville Power Administration (BPA) are

key agencies involved in current fish passage and

protection research, and development and evaluation of technologies. Research on fish passage

technologies under investigation by these federal

agencies is summarized in table 1-2.

The need for more research and development

in the area of fish passage is great. Federal

money for fish passage research is extremely

limited and funneled to a few research facilities.

Although these centers conduct hydraulic modeling and behavioral analysis and develop their

research agenda to generate broadly applicable

results, the task is much broader than what they

can accomplish alone. Partnerships between the

agencies and the private sector show some promise in this respect. For example, Alden Research

Laboratory and Northeast Utilities are testing a

new weir design at the NBS Conte Anadromous

Fish Research Center for application at projects

on the Connecticut River and elsewhere.

Many unanswered research questions remain,

and the scope and variety are extensive. Despite

this, the hydropower industry is becoming

increasingly unwilling to provide high levels of

financial support for research and development,

and many feel that the burden for developing

new and improved methods for fish protection

should be borne by the resource agencies who
10 | Fish Passage Technologies: Protection at Hydropower Facilities

prescribe their implementation. However, the

Electric Power Research Institute (EPRI), and

the Empire State Electric Energy Research Corporation (ESEERCO), organizations financed by

industry contributions, have funded a large part

of fish passage research in the field. EPRI has

produced numerous publications highlighting

experimentation with new and evolving technologies and summarizing performance of more

conventional methods. Hydropower operators

indicated to OTA that funds for research, including for support of research groups like EPRI, are

declining.

❚ Upstream Passage Technologies and 

Alternative Methods

Upstream passage technologies are in use at 9.5

percent of the 1,825 FERC-licensed hydropower

plants (242). The need for upstream passage is

well established for anadromous species,

whereas the need for upstream passage for riverine species remains controversial.

Upstream passage technologies are considered

well-developed and understood for certain

anadromous species including salmon, American

shad, alewives, and blueback herring. Upstream

passages have not been specifically designed for

riverine fish, although some of these fish will use

them. Special designs for catadromous fish (i.e.,

fish that migrate from freshwater to spawn in the

ocean) are used in Europe, but have not been

used in the United States.

The upstream passage or transport of fish can

be provided for through several means: fish ladders, lifts (i.e., elevators or locks), pumps, and

transportation operations. Ladders and lifts, or

fishways, are widely accepted technologies.

Pumps are a more controversial method. Transportation operations are often used as an interim

measure until fishways are completed, especially

when there is a series of dams that must be

passed. Transportation is also used as the longterm solution at some high-head projects. Siteand species-specific criteria, project scale, and

economics help to determine which method is

most appropriate. Fish passage success is highly

dependent on creating a “fish friendly” environment.

Fish Ladders and Lifts

Some fish ladders perform well because they

accommodate fish behavior and the target species’ ability to respond to particular hydraulic

conditions. An understanding of fish swimming

performance and behavior is essential to fish passage success. It is difficult to pinpoint the range

TABLE 1-2: Federal Agency Research on Fish Passage Technologies

Federal Agency

Upstream

Conventional and physical 

barrier technologies

Downstream

Conventional and physical 

barrier technologies

(and other methods)

Alternative

Behavioral guidance devices 

(and other methods)

Bonneville Power

Administration

Flat plate and rotary drum 

screens 

Surface collector

Acoustics

U.S. Bureau of Reclamation Hydraulic modeling Archimedes screw pump

Hydrostal-volute pump

U.S. Army Corps of

Engineers

Advanced turbine design Surface collector

Acoustics

U.S. Department of Energy Advanced turbine design

National Biological Survey/

U.S. Fish and Wildlife

Service

Denil

Steeppass Denil

Notching

NU-Alden weir

Cabot sampler

KEY: NU=Northeast Utilities.

SOURCE: Office of Technology Assessment, 1995.
Chapter 1 Executive Summary and Policy Directions | 11

of responses that fish might exhibit under natural

conditions, but significant knowledge exists

which must be applied to fishway design. Species require different types of flows and conditions to encourage and support movement, or in

some cases to prevent movement of unwanted

species. There is some controversy over the use

of certain ladder types for some species.

Fish ladders (e.g., pool and weir, Denil,

Alaska steeppass, vertical slot, hybrid) can be

designed to accommodate fishes that are bottom

swimmers, surface swimmers, or orifice swimmers, fishes that prefer plunging or streaming

flow, and weak or strong swimmers (102). But

not all kinds of fish will use ladders. Fish lifts,

including elevators and locks, are favored for

species that will not use ladders. Fish elevators

can move fish to a high vertical level. Locks, like

boat locks, where the water level is controlled to

move fish to a slightly higher elevation, can

move a large number of fish.

Poor fishway performance, on the other hand,

can generally be attributed to inadequate operations and maintenance including ill-maintained

flow regime; and poor design including inappropriate siting, inadequate capacity, inadequate

coordination between design of fishway and

hydropower generation, inadequate attraction

flow, or excessive fishway length (e.g., fish

become fatigued or delay in resting areas). Water

quality may also affect passage performance.

Lack of goals for fish passage often contributes

to design failures.

Attraction flow can make the difference

between fish passage success and failure. This is

true for fish ladders and lifts. A lack of good

attraction flow, or the inability to maintain the

appropriate flow, can result in delays in migration as fish become confused, milling around

looking for the entrance. The proper location and

position of the fishway entrance will help

enhance effectiveness by decreasing the time fish

can spend looking for a means past the obstruction.

Conventional fish ladder designs have been

experimented with and used often enough to pass

certain species that the design criteria are almost

generic. However, because river systems are varied and dynamic, each site presents the possibility of new challenges. The full involvement of

agency personnel with the experience and expertise necessary for designing effective fish passage systems may not be possible, due to lack of

sufficient staff and/or their time constraints. In

addition, the individuals responsible for fish passage may not be as experienced or may not have

the information necessary for proper design. As a

result, a fishway may be inappropriate. Therefore, a successful passage project will likely

depend on the cooperative efforts of the project

owner, the resource agencies, consultants, and

research scientists. In the Northeast, the FWS

reviews and comments on all fish passage facility final designs under FERC project licenses.

Fish Pumps

The use of pumps for fish passage at dams is

controversial and largely experimental. There are

several different types of fish pumps in existence, a few of which are new methods under

development, while others are technologies

being transferred from other applications. This

technology is relied upon in aquaculture for

moving live fish, and in fishing operations for

off-loading dead fish from boats. It has recently

been tested at government-owned fish hatcheries.

These pumps can be used to force both juveniles

and adults into bypass pipes for passage either

downstream or upstream of projects.

The FWS in the Northeast and some state

resource agencies do not support the use of

pumps due to the nature of the passage method.

Fish movement is completely facilitated and fish

are subjected to an artificial environment. Pumping of fish can lead to injury and de-scaling as a

result of crowding in the bypass pipe (196).

Pumping fish may also cause them to be disoriented once released back into the river environment. These conditions support the conventional

wisdom of the agencies to use passage methods,

like ladders, which allow fish to move of their

own volition (196). The agencies also have concerns about capacity, and reliability of parts, and

overall system operation. However, the resource
12 | Fish Passage Technologies: Protection at Hydropower Facilities

agencies have approved the use of a fish pump as

an interim measure for the upstream transport of

adult alewives at the Edwards Dam on the Kennebec River in Maine. In the Northwest, the

Bureau of Reclamation is currently testing two

types of pumps for downstream passage of juveniles at the Red Bluff Diversion Dam on the Sacramento River.

Transportation

The use of trucks to move adult migrants

upstream is somewhat controversial. (Downstream transportation is discussed below.) Some

practitioners have concerns regarding the effect

that handling and transport has on fish behavior,

health, and distribution. On the other hand, transportation using trap and truck operations has

been successful in some cases for moving adults

upstream of long reservoirs where they might

become lost or disoriented on their way to

spawning grounds.

The trap and truck technique for transporting

upstream migrants has been used as an interim

measure until upstream fish ladders or lifts are

constructed. In some high-head situations, transportation is the long-term passage method.

Where dams occur in series and fishway installation occurs as a staged process, trucking may be

used as an interim measure. For example, on the

Susquehanna River in Pennsylvania, fish elevators are in operation at the downstream-most

dam to assist a trap and truck operation which

supports the restoration of American shad, blueback herring, and alewives. The fish are transported upstream of the four projects on the river

and released in the highest headpond near to

spawning grounds. The 10-year-old program

supported by state and federal resource agencies

is considered to be successful.

Trap and truck techniques can work well for

some species, provided there is a good method

for collecting and handling fish. However,

resource agencies have concerns about potential

adverse effects of handling on some species, the

potential for trapping non-target fish, and the

intensive labor requirements to implement trap

and truck operations. In addition, objections can

be raised by some fishing interests if fish are

removed from key stretches of a river. For example, the proposed trucking of Atlantic salmon

around the proposed Basin Mills hydropower

project on the Penobscot River in Maine would

remove fish from the usual and customary fishing locations of the Penobscot Indian Nation—

one of their negotiated treaty rights.

❚ Downstream Passage Technologies

Downstream passage technologies are in use at

13 percent of the 1,825 FERC-licensed hydropower plants (242). The primary passage method

at other sites is through turbines. The need for

downstream passage is well established for

anadromous species, whereas the need for downstream passage for riverine species remains controversial.

Accepted Downstream Passage Technologies

There are regional differences in the recommendations of resource agencies for downstream passage. Variations relate to differences in target

fish, including differences in swimming ability

of down-migrating juveniles, susceptibility to

injury, and the history of concern for endangered

and threatened species. Structural methods,

including screens that physically exclude fish

from turbine entrainment and angled bar racks

and louvers that may alter flow patterns and rely

on fish behavior for exclusion, are the most

widely accepted technologies for downstream

passage. Downstream technologies that are

accepted by resource agencies in different

regions of the country, and those that are considered experimental, are summarized in table 1-3.

Resource agencies generally prefer physical

barrier screening techniques with associated

bypasses for downstream passage (e.g., drum,

traveling, and fixed screens). This type of technology is well understood. Physical barrier and

bypass systems can prevent entrainment in turbines and water intake structures. Design criteria

incorporate hydraulic characteristics and take

into account the swimming ability and size of

fish present to avoid impingement problems. A

commonly cited advantage of these systems is
Chapter 1 Executive Summary and Policy Directions | 13

that they are effective for any species of the size

and swimming ability for which the system is

designed. This type of downstream passage technology is usually recommended in the Pacific

Northwest and California. Acceptance is based

on experience at many sites and non-peer

reviewed (i.e., gray literature) evaluations of performance. Design criteria are mandated for some

species by some state and federal agencies. Criteria vary among the agencies but generally

address approach velocities and flow-through

velocities, size of mesh, and materials, for different sizes and species of fish. Designs generally

must be tailored to the individual site and target

fish.

In the Northeast, resource agencies more frequently recommend the use of angled bar racks

with relatively close spacing and an associated

bypass for down-migrating anadromous juveniles. This approach is also supported by favorable evaluations in one peer reviewed study

(167) and a small number of gray literature studies, although the mechanism that leads to successful performance is not understood (198). A

similar approach is louvers, a behavioral system

that alters the flow characteristics of the water

that fish are able to respond to. Louvers are

viewed favorably by some, but have been

criticized by the NMFS NW region as having

unacceptably high entrainment rates for small

TABLE 1-3: Downstream Fish Passage Technologies: Status and Use

Downstream passage technology

Accepted in the

Northwest and

California

Accepted in the

Northeast and

Midwest

In use Considered

experimental

PHYSICAL BARRIER DEVICES

Drum screen ✓ ✓

Travelling screen (submersible;

vertical)

✓ ✓

Fixed screen (simple; inclined) ✓ ✓

Eicher screen ✓ ✓

Modular inclined screen ✓

Barrier net ✓✓ ✓

STRUCTURAL GUIDANCE DEVICES

Angled bar/trash rack ✓ ✓

Louver array ✓ ✓

Surface collector ✓ ✓

COMPLEMENTS TO TECHNOLOGIES

Bypass chute or conduit ✓ ✓✓

Sluiceway ✓ ✓

ALTERNATIVE BEHAVIORAL 

GUIDANCE DEVICES

Acoustic array ✓ ✓

Strobe and mercury lights ✓ ✓

Electric field ✓ ✓

OTHER METHODS

Trapping and trucking ✓ ✓✓ ✓

Pumping ✓ ✓

Spilling ✓ ✓✓

Barging ✓ ✓✓

Turbine passage ✓ ✓✓

SOURCE: Office of Technology Assessment, 1995.
14 | Fish Passage Technologies: Protection at Hydropower Facilities

fish, even with favorable hydraulic systems (see

appendix B) (236,236a). In the Northwest, many

poorly performing louvers have been replaced by

physical barrier screens and bypass systems.

Screens built prior to the mid-1980s sometimes experienced poor performance in guiding

juvenile fish. Since then, new screen designs in

the Pacific Northwest and California have

achieved nearly 100 percent guidance efficiency

(59,245). However, these screens can be expensive. A significant portion of costs are due to

structural measures required for proper anchoring and installation and there are frequently operation and maintenance deficiencies. Incompatible

operation of hydropower facilities or water

diversions may also reduce the effectiveness of

the technology. These accepted technologies are

usually designed to withstand normal variations

in flow; however, flow conditions can be highly

variable. In some cases, changes in the river

itself can cause problems; the position of the

river can actually change over time, resulting in

screen failure.2 This is more likely to be a problem at water diversions where there are no dams

controlling water flow.

Adequate operation and maintenance is

required to optimize the performance of these

accepted technologies. Preventive maintenance

can minimize failure. Manual methods of cleaning are generally favored to reduce capital costs,

but few resources are devoted to ensuring that

manual cleaning occurs. Frequent cleaning may

be needed where there is a lot of debris. Some of

the more sophisticated and expensive designs

provide automated cleaning, but these are rarely

installed due to the high capital costs.

Controversial Downstream Passage 

Techniques

There are some downstream techniques in use,

especially for juvenile salmon in the Columbia

River Basin, that are controversial. These techniques include: transportation (trap and truck,

2 The Glenn-Colusa Irrigation District in Hamilton City, CA, is an example. A drum screen was built for the site, then the river changed

course and gradient, and the technology was no longer appropriate.

and barging) and spilling. Controversy centers

around whether the techniques are actually beneficial to the fish populations. Both the trap and

truck method and barging depend on the successful collection of fish. Methods are being explored

to improve collection for transportation, including surface collectors and behavioral guidance,

which are described below.

Transportation

Transporting juvenile out-migrants around dams

in trucks or barges helps to prevent the loss of

fish in long reservoirs, avoids the potential

impacts of nitrogen supersaturation3

 that may be

associated with spilling water, and decreases the

possibility of turbine entrainment and predation

problems at intervening dams and reservoirs. In

the Columbia River Basin the use of transportation to move juvenile salmon is controversial.

Benefits of transportation during low flow periods are generally recognized because transportation may reduce the time it takes fish to move

through the system. The controversy mainly centers around transportation during the mid-range

of flows. Delay in migration may have a negative

impact on the physiological development of

smolts which is critical to survival. Transportation may expose juveniles to disease, cause stress

from overcrowding, and increase the chance of

predation upon release.

Whether transportation contributes to more

adult returns to spawning grounds does not

appear to be conclusive. There is some agreement that barges are preferable to trucks. However, agencies indicate that barging should be

regarded as experimental (251). Yet transportation is only as good as the collection technology;

juveniles not collected pass through the turbines.

Efforts are ongoing to improve the collection

phase of this passage technology (see chapter 4).

3 As spill water plunges below the dam, the hydrostatic pressure causes air—mostly nitrogen gas—to be entrained in the flows. The pressure at the bottom of the stilling basins forces the gases into solution, creating a supersaturated condition. When a fish is exposed to this

supersaturated water, gas bubbles can form in its bloodstream and result in a variety of traumatic effects and even death.
Chapter 1 Executive Summary and Policy Directions | 15

Spilling

Spilling water to pass juvenile fish is a technique

used to move down-migrants past hydropower

projects in the Columbia River Basin. The COE

considers the use of spills to pass fish to be one

of the lowest mortality options for getting fish

past dams, yet recognizes that spill has its own

associated risks (231). There has been some dispute over the effects of spilling on the health of

fish. However, recently the NMFS NW office

and the Intertribal Fish Commission, which represents tribes in the Columbia River Basin, recommended that spilling should be implemented

on a broader scale to support juvenile downstream migration.

Experimental Downstream Passage 

Technologies

There is a strong desire to have downstream passage technologies that are less expensive to

design, install, operate, and maintain; easy to retrofit into existing facilities; and water-conserving with respect to the primary purpose of the

facility. This desire has led to the investigation of

methods to improve performance of currently

used methods (e.g., surface collector) and alternatives to accepted passage methods. These

alternatives include both physical barrier

approaches and behavioral guidance techniques.

(Fish pumps are also being investigated for

downstream passage of juveniles, but are discussed previously under upstream passage technologies.) Efforts are underway to develop new

turbine designs that reduce problems of turbine

entrainment and mortality. New concepts in

hydropower production that would eliminate some

of the dangers for fish passing through generation

systems also are being explored (box 1-7).

Improving current passage technologies

The COE has been working for decades in the

Columbia River Basin to identify modifications

that can be made at specific sites on the Columbia River to improve fish passage performance.

One example of this effort is a new emphasis on

surface collector technology that will capitalize

on the surface orientation behavior of the juvenile fish. The concept was derived from observations of high levels of safe juvenile passage at

Wells Dam, which uses a hydrocombine configuration where spill intakes are located directly

above turbine intakes. If successful, the method

may be useful for attracting juveniles to

bypasses, or allowing more efficient collection of

fish for transportation (40).

Experimental high-velocity screens

The development and application of the Eicher

screen and the Modular Inclined Screen (MIS)

have followed similar paths. Both have undergone a deliberate process of development which

has included extensive laboratory testing with a

variety of species, as well as prototype development and field evaluation. These efforts have

been championed largely by EPRI, in some

instances working jointly with Alden Research

Laboratory (ARL) and Stone and Webster Environmental Services. Successful laboratory experimentation led researchers to identify appropriate

sites for field testing of prototypes. These applications have shown both screening technologies

to be successful in guiding certain types and

sizes of fish under a range of high-velocity conditions. However, these screens only collect fish

when water is flowing over them. Operational

changes may be necessary to ensure adequate

flow to the screens, especially during seasons

when reservoirs are filling and little power is

produced.

Research and evaluation of the Eicher screen

has led to approval from agency personnel for

specific sites. Eicher screens are in use at the

Elwha Hydroelectric Project on the Elwha River

in Port Angeles, Washington, and at the Puntledge

Hydropower Project in British Columbia.

Resource agency approval for use at other sites

will depend on documentation that the design

performs well for target fish at velocities present

at the site.

A prototype (reduced-scale) MIS has been

constructed and will be field-tested in the spillway sluice gate at Niagara Mohawk Power Corporation’s 6-MW Green Island hydropower plant

on the Hudson River in New York during Sep-
16 | Fish Passage Technologies: Protection at Hydropower Facilities

tember of 1995. This test is important in the

development and acceptance of the technology.

However, resource agencies will be unlikely to

approve full-scale applications of the MIS without additional testing (12).

Barrier nets

Barrier nets are used to prevent fish entrainment

and impingement at water intakes. The ability of

the net to exclude fish depends on local hydraulic

conditions, fish size, and the size and type of

mesh used (59). Low approach velocities, light

debris loading, and minimal wave action are critical to success. Barrier nets are not considered to

be appropriate at sites where the concern is for

entrainment of very small fish, where passage of

fish is considered necessary, and/or where there

are problems with keeping the net clear of debris.

At sites where icing is a problem, nets may be

difficult to use in winter and thus may only provide seasonal entrainment protection.

Alternative behavioral guidance methods

Experimentation with various stimuli (e.g.,

lights, sound, electricity) to elicit a response in

fish has been going on for decades. With a few

notable exceptions for specific species at specific

sites, there is no behavioral guidance technology

that has been used to meet resource agency

objectives and guide fish downstream at hydropower sites or at water diversions. Behavioral

methods can repeatedly elicit startle responses in

various species of fish, but the problem of getting

fish to move consistently in the desired direction

has proven to be more difficult. Given the limited

swimming ability of many down-migrating juveBOX 1-7: New Approaches to Hydropower Generation

Turbine passage in current settings potentially exposes fish to blades and physical contact, which can

either de-scale or kill them, and pressure changes, which may cause physical injury and/or death. Turbine entrainment has become a major issue in FERC relicensing. Turbine entrainment levels and mortality

vary widely from site to site. Results of studies of turbine passage vary and there is some dispute over the

necessity and interpretive value of these studies. Entrainment studies are most common when relicensing

applicants question the level of adverse impact and the need for protection measures, especially for riverine species. Nevertheless, the cumulative impact of entrainment on juveniles passing through turbines,

especially where dams exist in a series, can have a significant impact on the population.

The Department of Energy’s (DOE) Hydropower Program and the hydropower industry have cofunded the Advanced Hydropower Turbine System Program. It is an effort to look at innovative solutions

to problems associated with the operation of turbines at hydropower projects. DOE has the lead role in

program development, proposal review, and implementation. The program is meant to stimulate and

challenge the hydropower industry to develop new environmentally friendly concepts in power generation

by applying cutting edge technology and innovative solutions to support safe fish passage. The Army

Corps of Engineers-Portland District is also working to develop relatively minor modifications of existing

turbines in the Columbia River Basin to increase survival of downstream migrants.

Technologies that can produce large quantities of electricity without adverse effects to river ecosystems may be feasible. However, a significant commitment to research and development, demonstration,

testing, and evaluation will be required. The current hydropower generation technologies were developed

with the objective of producing power. Although the need for fish passage was recognized when many of

our nation’s existing dams were built, effective passage was not incorporated into designs. New designs

that simultaneously optimize for energy production, fish protection, and ecosystem integrity are conceivable. OTA received information on more than one concept of this nature during the course of this study.

However, evaluation of these ideas was beyond the scope of this study.

SOURCE: Office of Technology Assessment, 1995.
Chapter 1 Executive Summary and Policy Directions | 17

niles, behavioral mechanisms may not be able to

direct fish to bypasses that are small compared to

an intake or river flow. It is rarely economical to

devote a significant percentage of flow to a

hydropower fish bypass.

Successful guidance has been reported for clupeids (e.g., blueback herring and shad) using

ultrasound and strobe and mercury lights. Experimentation with sound has also shown some

promise with salmonids. General claims of high

performance and low cost cannot be verified

with the limited experience available. However,

there are indications that lower costs than conventional methods and good performance may be

possible for some systems at some sites.

Sound is a potentially useful stimuli to guide

fish. Advantages of sound are that it is directional, rapidly transmitted through water, not

affected by water turbidity, and unaffected by

light changes (i.e., diurnal changes). Sound is

used by fish to get a general sense of their environment (207). There is some evidence that

fishes may respond to sounds that are produced

in association with structures such as barrier

screens and turbines (6,164), although little is

known about the actual behavioral response to

these sounds.

Various species have narrow ranges of sound

which they can detect, and some species respond

differently at different times of the day. This may

be an advantage or disadvantage, depending on

which species are targeted for guidance. It may

be possible to develop systems that species

respond to differently, allowing management

objectives for different species to be met. One

disadvantage of sound stimuli is that they can be

masked by dam noises and other ambient sounds.

Experimental sound guidance technologies

include several methods that use various frequency ranges. For the purposes of this discussion, methods are loosely divided into three

frequency ranges: ultrasonic (above 30 kHz),

low-mid frequency (50-900 Hz), and infrasonic

(<50 Hz).4 The response of fish to ultrasonics

was discovered in experiments with a high-frequency fish counter. Most of the work has been

done with clupeids (especially Alosa spp.,

including blueback herring, alewives, and American shad). Signals from 110-130 kHz have been

used for clupeids. The COE is completing testing

of a system at the Richard B. Russell pumped

storage site in South Carolina. A commercial

system, FishStartleTM, by Sonalysts, Inc., has

been tested at hydropower facilities on the Connecticut and Susquehanna Rivers and at other

kinds of generating stations.5

 Other species have

been evaluated in laboratory cage tests with variable, species-specific results.

Low-mid frequency sound experiments have

included historic tests of pneumatic poppers and

hammers conducted by Ontario Hydro. Results

with these technologies were variable, and problems with the reliability of the equipment led to

the utility abandoning the effort.

Another low-mid frequency concept of playing back modified fish sounds was developed

and tested by American Electric Power (141).

This system has been further refined and is currently being marketed by Energy Engineering

Services Company (EESCO) and has been

undergoing testing since 1993 at a number of

water diversion sites on the Sacramento River.

Much of the work on this system has been

focused on defining the appropriate array of

transducers, dealing with equipment anchoring

and reliability problems, and establishing appropriate testing protocols and statistical methods.

Investigations have been hampered by difficulties

installing equipment due to extreme flows and

high water levels. There have also been delays in

the studies due to the presence of endangered

species. The experience at several sites has been

very contentious and the evaluations have failed

to reach the efficiency goals of the resource

agencies. The process has been proceeding best

at Georgiana Slough, a natural diversion site

4 OTA did not identify any mid-high frequency (900 Hz–30 kHz) systems.

5 Full-scale sound system tests of the Sonalyst, Inc., Fish Startle System at a nuclear power plant on Lake Ontario have been peer

reviewed and are highly regarded. However, the hydraulic conditions at this site are very different from those at hydropower facilities.
18 | Fish Passage Technologies: Protection at Hydropower Facilities

which carries about 15 percent of the flow, where

there are no practical physical barrier alternatives. An interagency group is involved in the

tests, and results during the spring of 1995 were

considered encouraging (50 percent overall guidance at a statistically significant 95 percent level)

by at least one agency (100).

The EESCO technology is also undergoing

tests on the Columbia River system in 1995 as

part of the new Columbia River Acoustic Program, sponsored by DOE and COE to evaluate

existing sound-based fish guidance and deterrence systems for the Columbia River system

(see box 1-5). The EESCO system uses military

grade speakers, originally designed for use by the

U.S. Navy, that weigh 50 pounds and can be

installed on buoys (170). The speakers produce a

sound field with very little particle motion (39).

Field test results are not consistent with what is

known about sound detection capabilities of

salmonids, thus some reviewers are very critical

of this system (179). However, the mechanisms

that fish use to respond to other more accepted

technologies are not well understood either.

Infrasound has shown some success in highly

controlled field experiments in Norway with

Atlantic salmon. A consistent behavioral response

was demonstrated in laboratory experiments. The

developers of this approach are now working

with the Columbia River Acoustic Program on

Pacific salmonids. This approach requires large

displacement transducers of special design that

generate a sound field with large particle motion.

The current system only works with fish within a

few meters of the sound source. This finding is

consistent with what is known about the sound

detection capabilities of salmonids (39). Other

private initiatives are underway to develop infrasound systems (50, 219).

Lights are also a potentially useful stimulus to

guide fish. Light is directional, is transmitted

rapidly through water, and is not masked by

noise. However, light may be hampered by turbidity. Although it is most effective as a stimulus

when there are sharp contrasts between the light

and background (usually at night), this may not

be an issue if the target species move downstream primarily at night (as is the case with

juvenile American shad).

Mercury or other forms of incandescent illumination and strobe lights have undergone laboratory testing for a number of species. Field

testing also has been conducted for a few

selected species. The effect of the lights varies by

species and the type of lights. Some species are

attracted to the lights, others are repelled. And

the response may change with age of the fish,

physiology, motivation, etc. EPRI has supported

research in this area and has developed guidelines for implementing light systems at water

intakes (60). These guidelines recognize the need

for careful site-specific evaluation of field conditions.

Strobe lights have been receiving considerable

attention in recent fish guidance studies in the

mid-Atlantic region and New England. A multiyear testing effort has been underway to guide

juvenile American shad to a bypass at the York

Haven Hydropower Plant on the Susquehanna

River (61,152). These tests have often been hampered by water conditions, years when there were

few fish, and other environmental variables.

Nevertheless, there are positive indications that

the lights can increase use of the bypass,

although effectiveness varies with environmental

conditions. At this site, preliminary tests combining strobe lights and ultrasonic methods have had

encouraging results. Tests of strobe lights are

also being conducted at other hydropower sites

in New England. These tests are primarily being

done as enhancements to conventional trash rack

measures. Yet, the installation of some of the

conventional measures and dam operation has

not been in accordance with resource agency

expectations at some of these sites.

Electrical barriers have been successfully

used to prevent upstream passage of fish. Systems are operating in Salt River Project irrigation

canals in Arizona to prevent the mixing of species of fish from the Colorado River and other

Rocky Mountain streams.

Development of downstream protection is

more challenging. Key requirements are favorable flow conditions and adequate security to
Chapter 1 Executive Summary and Policy Directions | 19

ensure safety of people and other animals. There

have been field trials that were abandoned due to

problems in these two areas. Other problems

have been encountered with corrosion of electrodes. A number of questions about the impact

of electrical pulses on fish have been raised by

resource agency biologists reviewing experiences with electric barriers (111). Field tests of

the Smith-Root Graduated Field Fish Barrier

(GFFB) are underway at a water diversion on the

Sacramento River. In this test, major efforts have

been devoted to ensuring appropriate flow conditions with the installation of structural devices

(209). Tests by the manufacturer have indicated

that flow (i.e., velocity) requirements will vary

with different species. Yet, results of the 1995

tests were inconclusive and indicated that flow

and velocity conditions were still difficult to control (100).

Alternative behavioral guidance issues

Several generalizations can be made from experiments to date with alternative behavioral guidance measures. Response to various behavioral

stimuli is very species specific and is variable

even for a single species, depending on conditions at the site. Site conditions are influenced by

environmental variables (e.g., weather, time of

day, flow conditions) as well as the way the facility is operated. It is also likely that the response

of a single species will vary depending on its life

stage and motivation. Favorable hydrology is a

key element to the success of any of these systems. Fish must be capable of moving in the

desired direction for a stimuli to be effective.

Many juvenile fish have very limited swimming

abilities.

For the most part, knowledge of fish behavior

is very limited. Nothing is known of how fish of

many species respond to various stimuli, flow

conditions, and structures. In the more well-studied species, major informational gaps remain in

our knowledge of behavioral responses and

mechanisms.

Field investigations of behavioral methods

have for the most part been weak. Analysis and

statistical methods have been too limited to

assess the effectiveness of the techniques. Much

of the work is not peer reviewed, and the gray literature often does not contain sufficient information to allow critical analysis and possible

replication of the experiment. In some cases,

claims of high levels of guidance and reliability

of equipment have not been supported in further

field tests.

There is general consensus among resource

agencies and scientists that development of new

behavioral approaches requires a combination of

lab and field experimentation. Because there are

many variables at work when dealing with living

organisms, especially in uncontrolled environments, there have been many cases when lab

results of response to stimuli have not been

repeatable in field tests. Thus, laboratory investigations of fish behavior are not sufficient. Nor

are field tests alone. Data from field studies need

to be evaluated in the lab to fully understand the

nature of the results.

Studies to determine the basic sensory abilities of fishes are best done in the laboratory,

while studies of overall fish behavior in response

to environmental variables might be started at

field sites. But there needs to be close interaction

between lab and field work if the mechanisms by

which behavioral methods work are to be fully

understood. Understanding mechanisms of response

is necessary to design widely applicable systems

to control fish behavior.

Many of the technology vendor companies are

frustrated in their efforts to conduct field investigations. Generally, they must obtain agreement

from the hydropower operator and resource

agencies to conduct a test. Hydropower operators

are motivated by a desire for lower cost fish protection, yet they have little interest in participating in a test, let alone helping to finance it, if they

cannot be assured that positive results will be

viewed favorably by the resource agencies.

Hydropower operators are concerned that they

may be forced into paying for conventional measures after having invested in testing new

approaches, or even penalized with fines if the

experimental methods result in significant loss of

fish.
20 | Fish Passage Technologies: Protection at Hydropower Facilities

A technology company may be successful in

getting an initial field test sited at little or no cost

to the hydropower operator. If positive results are

obtained, the next hurdle is locating another

appropriate test site and possible sale. Yet, major

questions exist regarding the transferability of

performance information from one site to

another.

Performance of any passage technique is generally considered to be site specific. Information

that is most transferable from one field site to

another concerns what went right and what went

wrong. One would also generally expect that the

operation of the device would be similar from

site to site. It is the species response that may be

expected to vary, due to different site and environmental conditions.

In general, the resource agencies’ responses to

requests to test new technologies have been negative. Yet they are under considerable pressure to

allow field testing. Resource agencies are skeptical about performance claims, and are concerned

that testing of unproved technologies is time consuming, expensive, and may detract from hydropower operators’ willingness to spend funds to

install the technologies agencies prefer. Resource

agencies are concerned that technologies

installed for experiments tend to become the permanent solution at the test site, despite substandard performance relative to conventional

measures. Resource agencies are concerned that

experiments with alternative technologies may

be used as a delay tactic to avoid expenditures

for conventional technologies. Resource agencies are more willing to entertain innovative

approaches, either as an enhancement to conventional measures or at locations where conventional measures are not practical. The NMFS

regional offices in the Northwest and Southwest

have developed policy statements that allow testing of experimental systems, provided a tiered

process of research and evaluation is followed,

along with the simultaneous design for a physical

barrier/bypass system for the site (237,238,239).

By setting standards and criteria for effectiveness, NMFS establishes goals for technology

vendors and state agencies to follow. The FWS

has no similar policy.

The current system of site-by-site investigation, short-term funding of experiments, lack of

rigorous scientific methods, and lack of wide dissemination of favorable and unfavorable results

is unlikely to result in robust technologies

acceptable to agencies within a time frame relevant for relicensing activities in the next 10

years. Even with a major coordinated research

and development effort to advance alternative

behavioral technologies, it is unclear whether

significant progress will be made in developing

behavioral systems to guide fish past hydropower generation facilities and water diversions.

And yet, if behavioral methods prove successful,

they could mean large cost savings for the industry.

Is it worth pursuing a significant research program on behavioral methods, for settings where

conventional approaches are available? On the

one hand, there are few demonstrated successes

with behavioral systems and so little is known

about the behavior of fish that further investment

may not be warranted. The process of applying a

system developed for one site to another will

require significant expenditures and time for testing and fine tuning. Also, too many species are

involved at most sites to assume that a single

control system will be effective. On the other

hand, the successes with sound and lights suggest

that behavioral systems have real potential for at

least some species. Alternative behavioral systems, if perfected, may be very cost effective;

and they may be particularly useful when several

are combined, or they are used to enhance the

performance of physical barriers.

CONCLUSIONS

The incomplete state of knowledge regarding

fish population dynamics, the impacts of hydropower development on fish, the need for mitigation in various contexts, and the protection/

passage effectiveness of available mitigation

technologies exacerbates the sometimes adversarial relationships among stakeholders. This situation is unlikely to be alleviated unless a solid,

science-based process for mutual understanding

and rational decisionmaking can be developed

(see box 1-8).
Chapter 1 Executive Summary and Policy Directions | 21

A combination of academic, government, and

industry expertise is needed in a concerted effort

to focus science and technology resources on the

question of the effects of hydropower development on fish population sustainability; and on the

assessment of available and developing fish passage and protection technologies at hydropower

facilities.

❚ Technologies

Technologies for upstream passage are more

advanced than for downstream passage, but both

need more work and evaluation. Upstream passage failure tends to result from less-than-optimal design criteria based on physical,

hydrologic, and behavioral information, or lack

of adequate attention to operation and maintenance of facilities. Downstream fish passage

technology is complicated by the limited swimming ability of many down-migrating juvenile

species and by unfavorable hydrologic conditions. There is no single solution for designing

up- and downstream passageways; however,

both types must be designed and applied in such

a manner that in theory, model, and reality they

should suit the range of conditions at the site—

structurally, hydraulically, and biologically.

Effective fish passage design for a specific site

requires good communication between engineers

and biologists and thorough understanding of site

characteristics.

BOX 1-8: Development of Fish Passage Technologies: Research Needs

There are no “sure things” in the world of fish passage technology. The technologies themselves,

which are based on hydraulic engineering and biological science, can be designed to accommodate a

wide range of environmental conditions and behavioral concerns, but in the real riverine world anything

can happen.

Upstream and downstream fish passage problems differ considerably and both present a range of

obstacles and challenges for researchers and practitioners. Despite these differences, common considerations in design and application exist, including: hydraulics in the fishway, accommodating the biology

and behavior of the target fish, and considering the potential range of hydrologic conditions in the waterway that the passage technology must accommodate. Engineers and biologists in the Northeast and

Northwest are collaborating in a number of research programs designed to improve understanding of the

swimming ability and behavior of target fish. Understanding how fish respond to different stimuli, and

why, is critical to improving passage methods.

Using a scientific approach to explore as many scenarios as possible, and collecting data in a careful

manner, can improve researchers’ abilities to design improved technologies. In addition, producing information that all parties can acknowledge as credible is key to the successful advancement of fish passage technologies. A sound scientific approach to developing, executing, and evaluating a field study is

critical to the successful advancement of fish passage technologies. The elements of a good test include

the establishment of clear objectives, agreement among all parties to the study design, and a protocol

that lends itself to repeatability. In addition, there must be a proper accounting of environmental variability, documentation of all assumptions, and sufficient replications to support findings. Regular communication among stakeholders and peer-reviewed research results are key requirements.

Employing a process of this type could increase the potential for information transfer between sites.

That information might include data regarding the response of the device to hydraulic parameters (e.g.,

flow/acoustical response), fish response to stimuli under hydraulic parameters, and basic biological information within species. Agreement on performance criteria and standards prior to study will avoid lack of

acceptance of data and recommendations in the long term.

SOURCE: Office of Technology Assessment, 1995.
22 | Fish Passage Technologies: Protection at Hydropower Facilities

Downstream passageways for fish and protective measures to reduce turbine mortality are

probably the areas most in need of research.

Many evaluations of conventional and alternative technologies have not been conducted with

scientific rigor. This results in unsubstantiated

claims and arguments. Moreover, some experimental results contradict others. Ambiguous or

equivocal results of many fish passage studies

have caused concern as to whether certain technologies are effective or generally useful. The

variability of results may reflect site variability;

uncontrolled environmental conditions in field

studies; or incomplete knowledge of fish behavior. Thus, some performance claims may be

based on incomplete assessments. Advocates on

both sides of the fish/power issue can select from

a diverse body of scientifically unproved information to substantiate their points of view. Care

must be taken in interpreting much published

information on fish protection, arguments drawn

from it, and conclusions reached. When good

scientific research and demonstration is carried

out, results can be dramatic.

❚ Hydropower Licensing6

Controversy abounds in the FERC hydropower

licensing process. In part, this may be a result of

the lack of clearly identified goals to be achieved

through mitigation. Although objectives exist in

the legislative language of the FPA, as amended,

these lend themselves more to a philosophy than

to hard goals that describe numbers, timeframes,

and methods for achieving and measuring the

stated goal. Clearly defined goals for protection

and restoration of fish resources might refer to

numbers or percentages of fish expected to successfully pass a barrier and/or projected population sizes. Since resource management goals are

rarely articulated, mitigation and enhancement

measures are judged on a case-by-case basis,

with no means for assessment or comparison.

6 These conclusions are largely based on discussions with the OTA Advisory Panel for this project. Due to the elimination of OTA, this

project was terminated early, without an opportunity to analyze fully many of the issues addressed in this section.

The lack of clear goals is, in part, reflected in

the disjunction between section 18 prescriptions

and section 10(j) recommendations of the FPA.

Section 18 fish passage prescriptions are mandatory; however, section 10(j) recommendations

may be altered based on consistency with other

applicable law or the goals for the river (e.g.,

whitewater rafting/recreation, power production

needs). Yet, the recommendations made under

section 10(j) may be critical to maintaining habitat for fish populations or promoting timely

migrations for certain species. FERC, as the final

authority for balancing developmental and nondevelopmental values, is not specifically charged

with sustaining fish populations. Without clear

identification of the goal for mitigation, monitoring and evaluation become less meaningful and

fail to become critical to the process.

Monitoring and evaluation conditions for

hydropower licenses are infrequently enforced,

resulting in little information on how effective

available mitigation technologies are in improving fish passage and survival at hydropower

plants. Operation and maintenance failures have

been implicated in poor efficiency of fishways.

Forty percent of nonfederal hydropower projects

with upstream fish passage mitigation have no

performance monitoring requirements. Those

that do generally only quantify passage rates,

without regard to how many fish arrive at and

fail to pass hydropower facilities. Moreover,

most monitoring has dealt with anadromous

salmonids or clupeids; much less is known about

the effectiveness of mitigation measures for

“less-valued” or riverine fish. Research is needed

to determine whether river blockage is even negatively affecting riverine species.

Relicensing decisions often are not based on

river-wide planning and cumulative analysis.

FERC is required to review existing river management plans to assure that the project will not

interfere with the stated goals (pursuant to section 10(a) of the FPA). Yet, comprehensive river

basin planning is fragmented. Synchronizing
Chapter 1 Executive Summary and Policy Directions | 23

license terms on river basins could improve the

relicensing process and promote cumulative

impact analyses. Terms could be adjusted to

meet the ecological needs of the basin and to provide timeliness and predictability for licensees.

Under such a plan, multiple sites could be relicensed simultaneously, although operators may

be unlikely to respond positively to undergoing

the relicensing process “early.” On the other

hand, consolidation could yield benefits, allowing licensees to develop integrated management

plans to maximize the energy and capacity values of their projects; making it easier for all

involved parties to view the projects and their

impacts in their totality; and facilitating understanding of cause and effect relationships.

There is a need for further research on cumulative fish passage impacts of multiple projects,

and for consideration of fish needs at the watershed level. In several northeastern states, cooperative agreements between resource agencies and

hydropower companies have generated successful approaches to basin-wide planning for fish

protection. Carefully planned sequential construction and operation of fish passages could

provide significant opportunities for restoring

historic fish runs. In the western states, watersheds on national forests provide about one-half

of the remaining spawning and rearing habitat

for anadromous fish in the United States. Ecosystem or watershed management in these areas

could have immediate and long-term impacts on

fish populations.

The following chapters provide detailed information about current understanding about the

need for fish passage and protection associated

with hydropower facilities (chapter 2); the status

of fish passage technologies, both conventional

and emerging (chapters 3 and 4); and the federal

role in fish passage at hydropower facilities

(chapter 5). Appendices provide historical information on fish passage research in the Columbia

River Basin (appendix A); experimental guidance devices and resource agency policy statements (appendix B); and additional suggested

readings related to fish passage technology

issues (appendix C).
| 25

2

Fish Passage and

Entrainment

Protection

PART 1: ISSUES AND CONTROVERSIES

his chapter focuses on the need for fish

passage and entrainment protection at

Federal Energy Regulatory Commission

(FERC)-licensed hydropower dams

(see box 2-1). Hydropower-related habitat

changes, habitat accessibility, and predation are

discussed where they directly relate to the passage or protection needs of various fish species.

It is often unclear to what extent fish populations are affected by the impacts of blockage,

entrainment, and turbine mortality associated

with hydropower (71). Theoretically, considering the great diversity of fish species, hydropower dam designs, and river basin types

involved, fish mitigation should be highly sitespecific. In addition, the lack of information

regarding the biology of some target fish may

add further uncertainty to mitigation decisions

(215).

This study focuses on two categories of obligatory freshwater fish, since these are the most

common fishes that come in contact with hydropower facilities. The first category is the riverine

fishes (the so-called resident or non-migratory

species1) that cannot tolerate long-term exposure

to salt water (108). These fishes include all of the

freshwater species that use the river or stream as

residence for their entire life. Such fish include

the sunfishes, catfishes, minnows, suckers,

perches, and many other families. The second

category is the anadromous fishes, which are

born in freshwater streams and rivers, migrate to

saltwater for their adult phase, and return to

freshwater to spawn (see box 2-2).

This chapter is divided into two parts. Part 1 is

a discussion of the controversial issues concerning the need for fish mitigation at hydropower

projects. The emphasis is largely on passage and

protection for the riverine fishes, because at

present this is where the most controversy is. Part

2 provides more technical information regarding

experimental design for entrainment and turbine

mortality studies.

❚ Anadromous Fish Protection

The significance of delaying or blocking fish

movements within rivers and the possibility of

1 These two terms are highly controversial. The terms “non-migratory” and “resident” are often misinterpreted to mean that these fishes

do not engage in biologically significant movements within the river basin. As a matter of biological terminology, these fish are perhaps best

described as “freshwater dispersants.” This term is used by zoogeographers to describe fish that have evolved in freshwater and that cannot

disperse via marine routes due to their low tolerance for high-salinity water.

T
26 | Fish Passage Technologies: Protection at Hydropower Facilities

fish being injured or killed in turbines was rarely

considered when hydropower dams were initially

designed and built. However, stocks of some

high-profile anadromous fish species such as

Pacific salmon (157,162), Atlantic salmon

(152,154,155,166), and American shad (155)

have severely declined. These declines have been

linked to a combination of environmental

impacts, including hydropower dams, water

diversion projects, cattle grazing, water pollution, and over-fishing. It is unknown which of

these has had the greatest impact on fish stocks.

However, it is widely agreed that the recovery of

many of these socially and economically important fish species is in part dependent on providing safe and efficient passage around dams that

have excluded them from historically critical

habitat (155).

BOX 2-1: Chapter 2 Findings—Fish Passage and Entrainment Protection

■ The need for entrainment protection and passage for riverine fish is very controversial. There is a

growing body of evidence that some riverine fish make significant movements that could be

impeded by some hydropower facilities. The need for passage for riverine fish is most likely species- and site-specific and should be tied to habitat needs for target fish populations. This will be

difficult to determine without establishing goals for target species.

■ The acceptability of turbine passage for anadromous fish is site-specific and controversial. There is

major concern when anadromous fish must pass through multiple dams, creating the potential for

significant cumulative impacts. Passage of adult repeat spawners is also a major concern for most

Atlantic Coast species.

■ The effects of turbine passage on fish depend on the size of the fish; their sensitivity to mechanical

contact with equipment and pressure changes; and whether fish happen to be in an area near cavitation or where shearing forces are strong. Smaller fish are more likely to survive turbine passage

than larger fish. Survival is generally higher where the turbines are operating with higher efficiency.

■ Riverine fish are entrained to some extent at virtually every site tested. Entrainment rates are variable among sites and at a single site. Entrainment rates for different species and sizes of fish

change daily and seasonally. Entrainment rates of different turbines at a site can be significant.

■ Turbine mortality studies must be interpreted with caution. Studies show a wide range of results,

probably related to diversity of turbine designs and operating conditions, river conditions, and fish

species and sizes. Turbine mortality study design is likely to affect results. Different methods may

yield different results.

■ Methods for turbine mortality study include: mark-recapture studies with netting or balloon tags,

and observations of net-caught naturally entrained fish, and telemetry. Methods for entrainment

studies include: netting, hydroacoustic technology (used especially in the West), and telemetry tagging. These methods have advantages and disadvantages depending on target species and site

conditions. Hydroacoustic technology and telemetry tagging can provide fish behavior information

(e.g., tracking swimming location) useful for designing passage systems and evaluating performance.

■ Early agreement on study design would help minimize controversies between resource agencies

and hydropower operators. Lack of reporting of all relevant information makes it difficult to interpret

results. Standardized guidelines to determine the need, conduct, and reporting of studies could

help overcome this limitation.

■ Mitigation by financial compensation is very controversial. The degree of precision necessary for

evaluation studies and how fish should be valued are items of debate.

SOURCE: Office of Technology Assessment, 1995.
Chapter 2 Fish Passage and Entrainment Protection | 27

BOX 2-2: Fish Terminology and Life History Notes

Fishes Found At Hydropower Dams

Many different species of fish may come into contact with hydropower dams at various stages in their

life cycles. Depending on the site, the species may range in size from a few centimeters to a few meters

and display an astounding plethora of behaviors and life histories. Some species complete their life

cycles entirely within the boundaries of freshwater rivers, streams, and associated lakes (riverine), while

others move between marine and fresh water (diadromous).

In this report, fish that spend their entire lives in freshwater are referred to as riverine. This group

includes sunfish, perch, gar, catfish, minnows, suckers, trout, paddle fish, bowfin, some sturgeon, herring, lamprey, and many others. The terms resident and non-migratory have also been applied to these

fish, but can be misinterpreted to mean that such species do not engage in biologically significant movements within the river basin. The term riverine was specifically chosen for this report because it does not

group fish together based on their movement patterns.

The hundreds of fish species included in the riverine category have such extremely diverse life histories that

no generalizations concerning their propensity to make biologically significant movements can be made. Some

riverine fish species may be quite mobile and others highly sedentary. In addition, their movement patterns may

change from site to site (i.e., a species may be mobile in one river, and sedentary in another).

Some of the riverine fish may exhibit spawning migrations between lakes and rivers, or from one area

of a river to another. This migratory pattern is referred to as potamodromy. Some common examples of

fish that engage in potamodromous migrations include trout, sauger, mooneye, some redhorse, some

suckers, some sturgeon,a some lamprey, etc.

Some fish exhibit specialized migratory patterns involving regular, seasonal, more or less obligatory

movements between fresh and marine waters. This strategy is generally referred to as diadromy, and

there are three distinct forms.

First, in some species, sexually mature adults migrate from the sea to spawn in freshwater streams/rivers and associated lakes. This migratory pattern is called anadromy. Examples of fish that engage in

anadromous migrations are Pacific and Atlantic salmon, American and Hickory shad, Atlantic sturgeon,

alewife, searun lamprey, etc.b

Second, sexually mature adults of some species migrate from freshwater streams/rivers and associated lakes to spawn in the sea. This migratory pattern is called catadromy. The most notable example of

species that make catadromous migrations is the American eel.c

Third, some species make seasonal movements between estuaries and coastal rivers and streams.

This migratory pattern is called amphidromy and is typically associated with the search for food and/or

refuge rather than reproduction (149). Examples of fish that engage in amphidromous movements

include striped mullet and tarpon.

Diadromy is relatively rare, represented by less than 1 percent of the world’s fish fauna. Of the diadromous

fish, anadromy (54 percent) is most common, followed by catadromy (25 percent), and finally amphidromy (21

percent). In the United States, anadromy is by far more common than catadromy or amphidromy.

As with every artificial classification scheme for organisms, some species will not fit neatly into the

groups. Some species may have populations that would be classified as riverine and other populations

that make anadromous migrations. For example, steelhead, rainbow, and Kamloops trout are three different types of the same species. Steelhead stocks are anadromous, rainbow stocks are riverine, and Kamloops stocks are lake-resident.

(continued)
28 | Fish Passage Technologies: Protection at Hydropower Facilities

Life History Details

Riverine

The riverine fishes are an incredibly diverse freshwater group represented by nearly 1,000 species

from over 40 families. The various species exhibit a multitude of life styles, and within its scope, this chapter could not begin to describe all of the diversity. The different species occupy virtually every kind of riverine habitat.

Unlike the diadromous fishes, the riverine species do not require a marine phase to complete their life

cycles. The various kinds of habitats in the river (and associated lakes and streams) must meet all of the

biological needs of these fishes. For instance, the river must provide habitats to hunt prey, hide from

predators, engage in courtship, build nests, spawn, and over-winter. Quite often fish must use very different areas within a river to accomplish these activities. In addition, habitat requirements of most riverine

fish species change with their size, age, and with the season. In order for their populations to survive,

they must be able to access sufficient quantities of each important habitat type. For example, some species prefer deep pools with muddy bottoms and slow-moving water to feed and/or to seek refuge in, but

require shallow riffles with pebbly bottoms in which to spawn.

Because of the sheer diversity within the riverine fish group and the unique (site-specific) conditions

created by the interplay of different rivers with different hydropower designs, very few useful generalizations can be made concerning the potential impacts from hydropower dams on riverine fish populations.

However, the distribution and abundance of the various riverine fish species in a given river reach can be

altered by changes in the quantity and quality of macro- and/or micro-habitat. These changes will likely

favor some species while selecting against others that lose access to crucial habitat.

Hydropower dams do alter the natural riverine environment to varying degrees and, in the process, often

replace the original habitat types with different habitat types. For example, many hydropower dams create reservoirs which provide pool-type habitat. Bluegill, crappie, and largemouth bass which may have been rare or

even absent in the river reach prior to damming, may become the dominant species in these reservoirs.

On the other hand, the populations of some species may be diminished, displaced, or even extirpated

from a given river reach due to the changes in the environment up- and downstream of a hydropower

dam. For example, fish species that prefer or require riffle-type habitat may disappear from reservoirs.

Some hydropower dams have turbine intakes that draw cold and clear water from near the bottom of

their head ponds (hypolimnetic releases). These releases often change the pre-dam water flow, temperature, and turbidity patterns, as well as changing the topography of the river bottom. These tailwater conditions may support productive trout fisheries, even in a river reach where trout are not native and probably

could not have survived prior to the hydropower facility.

Anadromy

Fish that exhibit anadromous migrations are born in freshwater streams and rivers and spend a period

of time in their natal stream. At some point they begin a migration toward the ocean and then spend one

to several years there. After a period of growing in the marine environment they migrate back to a river

where they will ultimately spawn, thus completing the life cycle.

Various species of anadromous fish home in on their natal streams and rivers with different degrees of

precision. There is also a great deal of variation in the distance upstream that they migrate and the kinds

of freshwater spawning habitats they utilize, both within and among species. In addition, while some species, or some individuals within a species, may repeat the cyclic migration several times, others will die

after one completed migration cycle.

(continued)

BOX 2-2: Fish Terminology and Life History Notes (Cont’d.)
Chapter 2 Fish Passage and Entrainment Protection | 29

Even with the incredible diversity and variation within this life style, these fishes all have at least one

important thing in common: a need to enter freshwater to spawn and return to saltwater to feed and grow.

This biological requirement is the reason that such species are highly vulnerable to impacts related to

hydropower dams.

Hydropower dams may alter the quantity of spawning habitat for anadromous fishes. Adult upstream

migrations are blocked by hydropower dams unless fishways are in place. If fishways are present, they

must be designed to accommodate the biology of the target species and must be maintained properly, or

migrations can be delayed. Juveniles and adults that are migrating downstream toward the ocean may

be delayed in slack-water reaches of reservoirs or if they cannot locate a route past the dam. If the turbines are used as the migratory route, some fish will be injured and killed.

Catadromy

Catadromy is less common than anadromy in North America. In the United States, the American eel is

the only catadromous species that has been well documented. In general, fishes that exhibit catadromous migrations require a fresh- and saltwater phase to complete their life cycles. They are known to

migrate hundreds and even thousands of miles between their fresh and salt water habitats and, thus, are

highly likely to encounter dams and other blockages. Catadromy is essentially the ecological opposite of

anadromy.

These fishes migrate out of lakes and rivers into estuaries and finally to offshore marine waters where

they will spawn. The juveniles migrate from the ocean to an estuary and eventually swim up the river.

They grow and mature for several months or years in freshwater until they reach sexual maturity and

begin to migrate back to the ocean to complete the life cycle.

Adult fish migrating downstream may be injured or killed in turbines. They may also be delayed in

slack-water reaches of reservoirs. Juvenile fish migrating upstream can be blocked by hydropower dams

unless fishways are in place. Fishways must be designed to accommodate the biology of the target species and must be maintained properly, or migrations can be delayed.

Amphidromy

Amphidromous migrations are much less studied and understood than anadromous and catadromous

migrations. Fish species that spawn in freshwater (freshwater amphidromy) and in the sea (marine

amphidromy) can exhibit this migratory pattern (149).

Amphidromy is not directly related to spawning and may occur at many life stages. Some species may

not necessarily require a freshwater or saltwater phase to complete their life cycle, and thus amphidromous migrations may be less obligatory than catadromous and anadromous migrations. However,

coastal weirs, which are used to control water levels in fresh- and saltwater marshes, may block some

amphidromous movements, effectively eliminating or limiting important rearing habitat. Hydropower dams

located in proximity to estuaries could also block amphidromous movements, but at the time of this

report, we could not find an example in the United States of a request for fish passage at a hydropower

dam for a fish species classified as amphidromous (i.e., movements between rivers and marine waters

for purposes other than spawning).

a See box 2-5 for more detail on lake sturgeon.

b Some salmon and sturgeon have become “landlocked,” either naturally or due to human intervention. These fishes may

now migrate from lakes into rivers and streams to spawn. This migratory pattern (either between a lake and a river/stream or

entirely within a river/stream), which is also adopted by many riverine species, is referred to as potamodromy.

c In North America, the anadromous strategy is more common than the catadromous pattern. However, the catadromous

migratory strategy is more prevalent than the anadromous pattern in Australia (149).

SOURCE: Office of Technology Assessment, 1995.

BOX 2-2: Fish Terminology and Life History Notes (Cont’d.)
30 | Fish Passage Technologies: Protection at Hydropower Facilities

In addition, hydropower dams are also known

to kill fish that pass through their turbines. However, the percentage of fish that die from turbine

exposure is a matter of debate and also a great

deal of research. Prior to the 1950s, fish protection efforts were focused on establishing

upstream fish passage facilities at hydropower

plants. By the middle of that decade there were

growing concerns about the potential hazards of

turbine passage for some fish, especially those

that migrate between the sea and inland streams.

Since the 1950s there has been extensive

research on fish turbine mortality. Even with this

considerable base of research, there is still some

disagreement over the risk to various kinds of

fish that pass through turbine designs.

❚ Fish Passage for Anadromous Fish

Fish passage is widely accepted as necessary for

anadromous fish. This may be due to the fact that

anadromous fish migrations are conspicuous and

have been observed and studied extensively.

Although there is a great deal of variation in the

seasonal timing, duration, distance, and homing

accuracy, etc., it is widely known that anadromous fishes must migrate upriver to their spawning grounds to complete their life cycle. In

addition, it is also known that anadromous juveniles and some anadromous adults must migrate

downstream to the ocean. Consequently, there is

general consensus that anadromous fish need

safe and efficient passage routes around the dams

that are located between their marine and freshwater habitats.2

The catadromous migrations of eels have also

been studied. Adults must return to the ocean for

spawning and juveniles must migrate upriver to

their rearing habitat. Logically, fishes that have

catadromous migratory patterns (American eels

are the most conspicuous example in the United

States) need safe and efficient passage around

dams just as much as the anadromous fish. However, at least in this country, there is very little

knowledge as to how to provide this passage.

Consequently, resource agencies more commonly request passage for anadromous fish than

for eels (see box 2-3).

2 There is often argument over what constitutes “safe and efficient passage routes.”

BOX 2-3: Eel Biology and Protection

The American eel (Anguilla rostrata) is native to the North Atlantic and may be found in the United

States along the Atlantic coast and throughout the Gulf of Mexico. They do not occur on the Pacific Coast

of North America. The American eel is catadromous, migrating from inland freshwater lakes, streams, and

rivers to spawn in the open ocean.

American eels spawn in the southwest part of the North Atlantic Ocean, at a location known as the Sargasso Sea. The adults spawn at great depths and die after spawning. Unlike most fish, eels have a true

larval stage (called leptocephalus larvae), in which the young eels do not resemble the adults. Rather,

they are transparent ribbon-like creatures with very conspicuous eyes.

The eels spend several months growing in the ocean and arrive in coastal waters about one year after

birth. The larval eels metamorphose at about 2.5 inches, which typically takes place during the winter

months just prior to entering, or while swimming in coastal waters. Metamorphosed eels look more like the

adult eels and gradually become pigmented as they grow. When they become entirely pigmented, which

generally happens by the time they move into the streams and rivers, they become known as elvers. As

they grow and become better swimmers they are referred to as “young” or “small” eels.

(continued)
Chapter 2 Fish Passage and Entrainment Protection | 31

Turbine Mortality

If a dam has no downstream bypass, every individual of an anadromous fish population reaching the dam must either pass by the turbines,

sluiceways, or spillway during their seaward

migration. If fish migrate at times when sluiceways are closed and during times of no spill, the

majority (or all) of the fish must use the turbine

channels as their migratory route (56,193).

Therefore, the question of whether these anadromous fishes are being entrained is often moot.

However, the question of whether the fish are

Elvers often occur in great numbers and may be fished along the shores of some rivers and streams

with stationary nets. The elvers make their way upstream, where they may live in shallow streams or deep

rivers or even associated lakes and ponds. They typically bury themselves in muddy or silty areas or hide

beneath large rocks during the daylight hours and generally feed at night, consuming a wide variety of

fish and invertebrates.

Very little is known of the early life history of this species. Females generally grow to 25 to 40 inches in

length, while males seldom exceed 24 inches. Little is known concerning their age at reproduction, although

it is likely to be between six and 12 years. During their freshwater stay, they are generally yellow or orange in

color, leading to the term “yellow eel.” However, when they reach sexual maturity and begin their downstream

migration, they take on a metallic shine and are known as “silver eel.” Adults migrate all the way back to the Sargasso Sea (reportedly, as far as 5,600 km) where they will complete the life cycle (158, 208).

The European eel (Anguilla anguilla) also migrates to the Sargasso Sea to mate. The two species are

exceedingly similar and differ mainly in the number of vertebrae (103 to 111 for American eels and 110 to

119 for the European eels) and adult size (American eels are bigger). European eels apparently take

three years on average to get to coastal waters, as compared to one year for American eels. However,

most arrive as elvers at about the same size (2.5 inches) as the American eels and thus it seems that the

European eels grow considerably slower, at least during the early life stages in the ocean. They are similar in that

they migrate long distances upstream in many stream and rivers. Like American eels, they are often found in

great numbers and may make a significant contribution to the biomass of certain ecosystems.

The predatory habits, long stay in freshwater, large numbers, and migratory habits have caused some

authors to speculate that the decimation of the American and European species could have a considerable

impact on the nutrient cycles and energy relationships within lakes, streams, rivers and associated terrestrial

habitats (212). Hydropower dams may affect eels in a variety of ways, including killing or injuring some eels as

they pass through turbines (92), as well as blocking elvers from migrating upstream (183).

Some biologists, especially in Europe, have explored new technologies to protect eels at hydropower

dams and cooling-water intakes (92). For example, lights, air bubbles, and electrical screens have all

been tested to keep eels from being entrained. While most of these methods did not work, the experiments with lights were promising. In these tests, eels tended to avoid areas that were illuminated with

either incandescent or high-pressure mercury vapor lamps (or both). More research will be needed to

determine the efficacy of such technologies to protect eels from entrainment at hydropower dams.

Other scientists have been working on providing upstream fishways for elvers. They are relatively

small (10 to 40 cm) and are poor swimmers, thus some traditional fishway designs used for salmon, etc.,

may not be appropriate. In addition, fishways for elvers may need to accommodate millions of fish in a

brief time period. Specially designed fishways for young eels are being developed, mainly in France,

where this species is of considerable economic importance (183).

SOURCE: Office of Technology Assessment, 1995.

BOX 2-3: Eel Biology and Protection (Cont’d.)
32 | Fish Passage Technologies: Protection at Hydropower Facilities

injured or killed during turbine passage is still

somewhat controversial.

Scientists began studying turbine mortality in

the United States in the late 1930s. Nearly all of

this research was focused on juvenile anadromous salmon (19,199,224). Beginning in 1980

the experimental effort expanded somewhat to

include other anadromous species, especially

American shad and alewives (18,87,135,206,222).

There is much variation in the data gathered

from these experiments. In fact, turbine mortality

has been estimated anywhere from 0 to 100 percent (19,46). This wide variance is probably due

to the great diversity of turbine designs and operating parameters, as well as the different river

conditions and fish species where the mortality

tests were done. However, in some cases there

may be large differences in turbine mortalities

estimated by different studies at the same turbine, and using the same or similar fish species

(55).

Studies of turbine mortality have identified

four potential categories of dangers to fish:

mechanical damage, pressure changes, cavitation

damage, and shearing damage.

Mechanical damage is caused by contact with

fixed or moving equipment, and is a function of

the characteristics of the turbine (number of

blades, revolutions per second, blade angle, runner diameter, hub diameter, and discharge) and

the size of the fish. Models have been developed

to estimate the number of fish of various size that

will come into contact with the turbine machinery. Among other things, these models predict

that fish size is positively correlated with the

potential for physical strikes (35).

The pressure changes that entrained fish experience are a function of the turbine design and

flow rate, as well as the location of the fish in the

water column prior to entering the intake. Fish

that are swimming at depth will be acclimated to

relatively high pressure and will experience little

change in pressure when entering a submerged

turbine intake. Surface swimmers will be acclimated to near atmospheric pressure and will

experience an increase in pressure as they “dive”

to locate the intake. Just on the downstream side

of the turbine blades, fish will experience a

region of subatmospheric pressure and then

quickly be returned to atmospheric pressure in

the draft tube and tailwaters. The region of subatmospheric pressure will only be slightly less than

the pressure that a surface swimmer was adapted

to, but may be a substantial decrease for bottom

swimmers. The amount of pressure damage may

depend on the depth of the intake, net head, as

well as the pressure tolerance and the acclimation pressure of the target fish species or life

stage.

Cavitation is caused by localized regions of

subatmospheric pressure (on the trailing edges of

runner blades). Air bubbles form when the

hydrostatic pressure decreases to the vapor pressure of water. These air bubbles, which can be

relatively large, are then swept downstream into

regions of higher pressure, which causes them to

collapse violently, creating localized shock

waves that are often strong enough to pit metal

runner blades. The shock wave intensity dissipates rapidly with distance from the center of

collapse. Undoubtedly, if fish are passing near a

region of collapse, they will be damaged or

killed. However, it is difficult to predict how

many fish will pass nearby such regions. Cavitation is an undesirable and costly condition for

hydropower operators and fish alike. The interplay between turbine setting (centerline of the

runner in relation to tailwater elevation) and net

head affects turbine efficiency, and often measures can be taken to increase this efficiency. The

incidence of cavitation decreases with increasing

turbine efficiency, and therefore it is desirable to

maintain high turbine efficiency to reduce fish

mortality.

Shearing occurs at the boundaries of two adjacent bodies of water with different velocities.

Passing through such a zone can spin or deform a

fish, which could lead to injury or death. Shearing is most pronounced along surfaces, like walls

or runner blades, but is extremely difficult to

quantify in a turbine. Therefore it is difficult to

determine what percentage of fish deaths from

turbine exposure are caused by shearing forces.
Chapter 2 Fish Passage and Entrainment Protection | 33

It is often difficult to ascertain which type of

damage caused the visible injuries to the fish, as

they are often manifested similarly (205). In general, there appears to be a positive correlation

between turbine efficiency (less cavitation with

higher efficiency) and fish turbine passage survival and there is generally a negative correlation

between fish size and fish turbine passage survival (64,55).

Early studies of turbine mortality typically

only estimated immediate mortality. In other

words, investigators focused on fish that were

collected dead or dying after passing through the

turbines. However, some biologists assert that

delayed mortality is also possible and as a result,

some investigations have attempted to estimate

total mortality by studying both immediate and

delayed mortality (62,205). Bell has suggested

that, for salmon smolts, 72 hours is an acceptable

time period to judge total mortality (17). Delayed

turbine mortality estimates are often difficult

because of problems associated with maintaining

the fish for a period of time after turbine exposure. For example, if control fish have a high

mortality level (or a highly fluctuating mortality

level among control replicates) due to stress

caused by various parts of the experimental

apparatus, it becomes difficult to test for

statistical significance of test fish mortality

(62,64,203,206).

Resource protection agencies also suggest that

turbine mortality studies probably underestimate

the number of fish that die from turbine passage,

because many study designs do not take predation into account. They suggest that as fish

emerge from draft tubes they are often subjected

to high predation in the tailwaters (or even in the

draft tubes). This is due to a variety of tailwater

conditions, including the supposition that fish are

disoriented after turbine passage, fish getting

caught in hydraulics that detain them in the tailwater, increased predator habitat, and the general

concentrating nature of turbine passage. Some

study designs may be able to include predation in

their estimate of turbine mortality, but they may

suffer from low re-capture rates, which require

using very large sample sizes and may confound

statistical comparisons of control and test fish.

Scientists have also been concerned with the

general stress, shy of immediate physical injury

or death, that could be acting on fish that pass

through turbines. The hypothesis is that all fish

that are exposed to turbines are affected to some

degree. This hypothesis suggests that different

individuals react to turbine exposure to varying

degrees, and thus even though many fish may

survive the initial passage, their chances of future

survival are reduced by the exposure. However,

in a review of the salmon turbine mortality literature, Ruggles concluded that “... fish that survive

passage through turbines without physical injury,

by and large, do not have their chances for subsequent survival reduced” (205). However, some

studies have shown that even minor de-scaling

can reduce the ability of fish to cope with other

environmental stress (24).

In general, the experimental design used to

study turbine mortality is likely to affect the

results considerably (62). A good example is the

controversy over turbine mortality estimates for

the American shad, blueback herring, and alewife juveniles. Using standard netting techniques, scientists have estimated mortality rates

for American shad and blueback herring juveniles at between 21.5 and 82 percent in a Kaplan

turbine at Hadley Falls Hydropower Station in

Holyoke, Massachusetts, on the Connecticut

River (18,222). However, several studies using a

different collection technique (balloon tags) estimated turbine mortalities much lower, 0 and 3

percent on average, for these same species at the

same (144) and similar (103) Kaplan units.

In addition, other aspects of experimental

design may also affect results. For instance, the

way the experimenter defines “dead” is critical.

Some experiments have included fish that are

swimming “normally” but that are noticeably

damaged (i.e., scrapes, cuts, bruises, loss of

scales) in the “dead” column. If another experimenter included that type of fish in the “live”

column, the same study results may estimate

considerably different mortality rates (see Part 2
34 Fish Passage Technologies: Protection at Hydropower Facilities

of this chapter for more details on turbine mortality studies).

Despite some controversy over the extent of

turbine mortality, it is still widely believed to be

a significant factor in the reduction of many

anadromous fisheries around the country. The

concern is greater when there are multiple dams

in a system, because of the potential cumulative

impact (193). If there is only one dam to pass,

mortality rates lower than 10 percent may not

seem so alarming. However, when fish must pass

multiple dams, as is often the case with anadromous fish, the cumulative impact of several distinct low mortality rates can result in severe

losses (35). For instance, a group of salmon

smelts migrating downriver will be decreased by

half after passing seven dams, each with a 90

percent survival rate (see figure 2-l).

Therefore, downstream protection to reduce

entrainment and also some measure of safe

downstream passage is often sought for anadromous fishes (i.e., fish bypass, spill measures, trap

and truck, etc.). However, all bypass systems are

not harmless to fish. Some fish may be killed in

bypasses, and thus the mortality rate from the

bypass should be compared to the mortality rate

of other possible routes (i.e., turbine, spill,

sluiceway) (78). In some cases hydropower operators have tried to establish that turbine mortality

on anadromous fishes is minimal, suggesting that

turbine passage is a viable migratory route for

some species at some sites (103). For example,

the Federal Energy Regulatory Commission

(FERC) has approved turbines as the preferred

passage route for juvenile American shad at Safe

Harbor hydropower facility on the Susquehanna

River in Pennsylvania and for juvenile blueback

herring at Crescent hydropower facility on the

Mohawk River in New York. The United States

Fish and Wildlife Service (FWS) has supported

the conclusion at Safe Harbor and is contesting

the Crescent case (29,30).

However, accepting turbine passage as a

migratory route is still highly controversial and

will certainly be highly site-specific. In addition,

many anadromous fish have repeat spawners.

These fish migrate back to the ocean after

0 5 10 15 2 0

Number of sites

SOURCE: Office of Technology Assessment, 1995.

spawning and return the following year to reproduce again. In fact, on the Atlantic Coast, every

anadromous fish species, except the sea lamprey,

has repeat spawners. Therefore in addition to

providing safe passage for down-migrating juveniles, many projects must also provide safe

downstream passage for adult repeat spawners

(32). Since turbine mortality is more severe with

increasing fish size (62,64), presumably turbine

passage would not be an acceptable route for

adults of most species (18,134).

■ Entrainment Protection for Riverine Fish

The relatively new interest in riverine fish at

hydropower dams has mainly been concerned

with entrainment and turbine mortality. Research

has focused on determining the magnitude and

the species and size composition of entrainment

and turbine mortality. Hydropower operators

may have the option to forgo these studies and

develop and implement an enhancement plan for

minimizing the entrainment of fishes at their

project(s).
Chapter 2 Fish Passage and Entrainment Protection | 35

Entrainment Studies

A wide array of study designs and methods has

been employed to study entrainment at hydropower dams. The diversity in experimental

design may be partly linked to site-specific logistical constraints or safety concerns. Dam and

powerhouse design, as well as river hydrology,

hydraulics and geo-morphology, may limit the

methods that can be used. In addition, study

goals, experimenter preference, and financial

constraints may also play a role in determining

what methods are employed.

Unfortunately, the diversity in study methods

limits our ability to compare entrainment results

from site to site. Two major reviews of recent

entrainment studies have been done. Both

reviews focused on studies done at sites east of

the Mississippi river, primarily Michigan and

Wisconsin. The Electric Power Research Institute (EPRI) contracted Stone and Webster Environmental Services (SWEC) to prepare a review

of entrainment (and turbine mortality) studies

(62). The Federal Energy Regulatory Commission also contracted SWEC to prepare an assessment of fish entrainment at hydropower projects

(71).

The following findings regarding entrainment

of riverine fish are largely drawn from the FERC

1995 review Preliminary Assessment of Fish

Entrainment at Hydropower Projects (unless

otherwise cited). In general, riverine fish of various species are entrained to some extent at virtually every site that has been tested. Entrainment

rates are extremely variable among sites. Smaller

fish tend to be entrained at higher rates (62,71).

For example, more than 90 percent of entrained

fish in several studies were less than 20 cm in

length (62). However, the entrainment of large

fish is not uncommon.

The location of the intakes relative to fish habitat may be a key factor in determining how

many and what types and sizes of riverine fish

species are entrained. Penstocks that are located

far from shore in open water may tend to entrain

different kinds (and quantities) of fish than

intakes that are located near the shoreline.

The species, size, and number of entrained

fish may differ significantly between units at the

same site. The operating time, flow volume, and

relative location of the various units may be

important in determining the entrainment rate of

each. In general, the longer a unit is operated and

the greater the flow volume per unit time, the

more fish are entrained. Intakes that are positioned near areas where fish like to spawn or feed

may entrain more of these fish than units that are

further away. Therefore, extrapolation of entrainment data from one unit to another is often controversial. State and federal agencies generally

do not like studies that attempt to sample entrainment from a subset of turbines and extrapolate

these values to other untested units. In addition,

the efficacy of extrapolating entrainment rates

will depend on how similar the sites are in fish

composition, powerhouse and dam design, as

well as on many physical characteristics of the

river.

Research concerning the entrainment of fish

eggs and larvae at hydropower projects is very

rare. Studies that collect fish eggs and larvae are

expensive and difficult. However, it is well

established that the egg and larval stages represent a critical period that often determines the

strength of a given year-class of many fish species (2,129,138). Some studies have suggested

that entrainment of larvae and eggs at hydropower facilities can be very high and can affect

the abundance of some species (256). Similar

results have been obtained at pumped-storage

facilities (184,214). However, at least one study

found no direct link between entrainment of larvae and population size (48).

Several models have been developed to estimate the impact of egg and larval entrainment at

nuclear power plants on fish populations, and

they may be applicable to hydropower dams

(116). This seems to be an area that deserves

more attention in the hydropower arena, but will

be difficult and costly. In addition, a recent

report on the potential for mortality of fish early

life stages (i.e., eggs and larvae) suggested that

turbine mortality may be low (35).

Some state and federal resource agencies have

drafted specific guidelines on how entrainment

and turbine mortality studies should be done
36 | Fish Passage Technologies: Protection at Hydropower Facilities

(35,264). Some argue that studies should be conducted over a period of at least three years, and

in some cases five, because of changing weather

patterns (which affect river flow, etc.) and natural fluctuations in fish population levels (264).

Presently studies are generally one year in duration and are relatively expensive. For example,

the mean cost of seven different 12-month

entrainment studies (using nets to capture fish)

was reported to be $273,006 (71). Extending

studies for three to five years would substantially

escalate these costs, especially when the costs of

a turbine mortality study are included.

Standardizing the types of experimental

designs that can be used would help in attempts

to compare data from several studies. Agreement

on study designs between resource agencies and

hydropower operators could minimize controversies about how to interpret results. Such comparisons could also be important in identifying

trends that might help to guide fish protection

mitigation. Suggested guidelines for determining

the need for entrainment studies, as well as for

conducting studies (e.g., defining target fish and

sizes, the appropriate use of hydroacoustic and

netting studies, sampling schedules) and reporting results (e.g., the type of information to

include, such as sampling times and frequencies,

entrainment rates and flows for different hydroplant units, appropriate information on environmental variables, methods used to account for

unsampled periods, statistical methods) are provided in the FERC 1995 Preliminary Assessment

of Fish Entrainment at Hydropower Projects.

3

Turbine mortality

Estimates of turbine mortality specifically for

riverine fishes were rare until recently, and they

are still less common than for anadromous species. However, a number of recent studies suggest that smaller fish experience less mortality

than larger fish, similar to findings for anadromous fish discussed above (62). Cada reviewed

the scientific literature pertaining to the kinds of

stresses that fish are exposed to in turbines (i.e.,

shear, cavitation, subatmospheric pressure, phys3 The Electric Power Research Institute is also currently preparing such guidelines (219).

ical strikes) (35). The review suggested that mortality rates may be low for fish eggs and larvae.

However, direct measurements of turbine mortality for fish eggs and larvae have never been done.

It is simply too early to make any generalizations about turbine mortality of riverine fish.

Resource agencies currently prefer that turbines

run at or near peak efficiency to reduce cavitation damage. More research is needed to better

determine the risk of death from turbine passage

for various sizes and species of riverine fish.

Guidelines for turbine mortality studies would

also help to standardize results.

Population perspective

Most research on entrainment and turbine mortality has not attempted to determine the fishery

impacts at the population level. The entrainment

and turbine mortality rates for riverine fishes,

which have been gathered now at many hydropower facilities, only represent part of the picture. While entrainment (risk of injury or death)

is obviously significant to the individual fish, it

is not necessarily significant to the population.

For instance, entraining 100,000 fish per year

with a 30 percent mortality rate may represent a

tragic consequence for one species, while the

exact same rates may represent a lesser impact

for another. The severity of the impact will

depend on many aspects of the population biology of the fish species being entrained. Such

parameters include the size of the population, the

length, weight and age structure of the population, the reproductive potential of the population,

and the natural survival rates (unrelated to

entrainment) of the population.

It would be ideal to know the effects of

entrainment and turbine mortality on fish populations. However, studies designed to determine

these impacts would be very time consuming and

expensive, if not impossible. The FERC has

recently issued a statement concerning the need

for proving population impacts when requesting

mitigation at hydropower projects (71).
Chapter 2 Fish Passage and Entrainment Protection | 37

Ohio Power’s argument appears to be that an

effect on fish population as a whole is necessary

before any mitigation may be required, and that

no such effect has been demonstrated here.

However, there are many other environmental

variables that influence fish populations, particularly in a large system like the Ohio River.

Consequently, it would be very difficult, if not

impossible, to isolate the effects of turbine mortality on fish populations in the vicinity of the

Racine Project. Clearly, there is the potential

for an effect on a fish population when a large

number of its individuals are removed. These

effects can range from the dramatic, such as a

reduction in numbers sufficient to affect the

long-term viability of the population, to the subtle, such as changes in the average size of fish

or their growth rates. Mitigation can be

required even if it cannot be proven that project

operation threatens the long-term viability of

the entire population (emphasis added).

There is disagreement on who should bear the

“burden of proof” (36). The agencies feel they

are often asked to prove that fishes are being

negatively affected by dams, and the dam owners

feel they are obligated to show that the project

does not have a negative impact on the fish. Neither objective is easy.

Controversy concerning entrainment

In general, the industry views entrainment and

turbine mortality as a minimal risk to the riverine

fish since the bulk of entrainment consists of

small fish (primarily young of the year) and the

turbine mortalities associated with these small

fish are low (35,62). In addition, in some cases

there are viable fisheries above and below dams

(48). They argue that any negative effects on the

population due to fish being entrained will be

countered over time by “compensatory mechanisms” at the population level. This theory suggests that as the population gets smaller due to

entrainment, the competition over limiting

resources between the remaining individuals

decreases. Those fish that are not entrained will

benefit from the decrease in competition for

important resources and this benefit may lead to

increased reproductive potential and/or survival.

Thus the positive impact of the “compensatory

mechanism” could counteract the negative

impact of the entrainment.

On the other hand, the resource agencies and

conservation groups view entrainment as a significant and chronic source of fish loss. Regardless of turbine mortality, entrainment decreases

the populations of upstream fisheries that cannot

be replenished by downstream stocks because of

the blockage created by the dam. The resource

agencies generally disagree with the “compensatory mechanisms” theory. They suggest that individuals in many fish populations are not limited

in reproduction, growth, or survival by intense

competition over limited resources with other

members of the population (88,259). Thus, eliminating “x” number of fish from a population

may free up “y” amount of resource, but if the

individuals were not limited by that resource in

the first place, they are not likely to benefit

appreciably from the additional amount. While

the compensatory mechanism may occur in some

populations for some animals, there has been no

research to date that shows that it does (or does

not) work for riverine fish species at hydropower

projects.

Financial compensation for fishery losses

At some sites, hydropower operators may have to

pay a fee equivalent to the value of the fish that

are killed by turbine passage. This is known as

“compensatory mitigation” and has also been

referred to as “fish for dollars” mitigation. This

type of mitigation is controversial for several

reasons as discussed below.

Techniques that can be used for environmental

mitigation have been identified and prioritized

by the President’s Council on Environmental

Quality (CEQ) (40 C.F.R. S 1508.20) as follows:

■ avoiding the impact altogether by not taking a

certain action or parts of an action;

■ minimizing impacts by limiting the degree or

magnitude of the action and its implementation;

■ rectifying the impact by repairing, rehabilitating, or restoring the affected environment;
38 | Fish Passage Technologies: Protection at Hydropower Facilities

■ reducing or eliminating the impact over time

by preservation and maintenance operations

during the life of the action; and

■ compensating for the impact by replacing or

providing substitute resources or environments (emphasis added).

Thus, financial compensation is an acceptable

form of mitigation when all of the other preferred

forms of mitigation are deemed impossible or

inappropriate. The United States Fish and Wildlife Service (FWS) defines “compensation” as

“full replacement of project-induced losses to

fish and wildlife resources, provided such full

replacement has been judged by the FWS to be

consistent with the appropriate mitigation planning goal.” It defines “replacement” as “the substitution or offsetting of fish and wildlife

resource losses with resources considered to be

of equivalent biological value” (253).

The hydropower operators pay a yearly financial compensation to the state resource agencies,

which is said to be equivalent to the estimated

yearly amount of fish killed by a project. Unlike

screens, monetary compensation does not

directly protect the fish that are being entrained

and killed, but rather the monies can be used to

support other fishery enhancement projects (habitat restoration, artificial production, etc.).

Compensatory mitigation is becoming more

common for projects that entrain riverine fish,

but it is controversial. For instance, there is disagreement over the degree of precision that

should be required for the entrainment and turbine mortality studies that are used to determine

the compensation amount. In general the utilities

believe that order-of-magnitude estimates are

adequate while resource agencies contend that a

higher degree of precision is required to ensure

that the level of mitigation is equivalent to the

fish loss. FERC discussed study precision in an

order issued concerning Ohio Power’s 40-megawatt Racine Project, on the Ohio River at a Federal Dam in Meigs County, Ohio, and Mason

County, West Virginia (71).

In this case, we understand that the Commission

staff sought to calculate a compensation amount

that is roughly equivalent to the replacement

cost of the fish lost. 44/ However, we think that

the parties misapprehend the nature of the

undertaking to the extent they believe that the

defensibility of the amount to be set aside for

compensatory mitigation turns on the precision

of the estimates of lost fish and their associated

replacement costs. No such precision is called

for; rather, the goal is to establish a reasonable

expenditure with which to compensate for the

project impact on fish....

44/ The Division Director referred to the

“value” of killed fish, but clarified that the

“value” reflected only the cost of hatchery production of the different species and size classes

of fish (71).

There is also debate over how to value the fish

that are killed. The American Fisheries Society

(AFS) Handbook on the Valuation of Fish Kills

is often used to determine the value of the turbine-killed fish. This publication values fish

based on the cost to replace the fish with hatchery-raised fish of equivalent size (5). The agencies claim that this is not appropriate and that this

type of valuation ignores the other intrinsic and

economic values of the fish (264). They claim

that the AFS replacement values underestimate

the “true” value of the fish by as much as 90 percent (see chapter 5).

Passage for Riverine Fish

Though some resource agencies are beginning to

make an issue of it, fish passage has rarely been

requested for riverine species (relative to the

number of requests for anadromous species).

Some argue that the fish populations that became

established after a hydropower dam was constructed (often 30 to 100 years ago) have been

relatively sustained without the existence of fish

passage. This argument would apply to fish passage requests during FERC relicensing. However, it is also argued that since the riverine

fishes spend their entire lives within freshwater,

they may not necessarily need to move past a

dam to complete their life cycles.

Some resource agencies have begun to argue

that some riverine fish species do make significant movements within the river. Depending on
Chapter 2 Fish Passage and Entrainment Protection | 39

habitat availability at a given river segment and

the biological needs of the target fish species,

dams may (or may not) separate certain riverine

fishes from critical habitat (e.g., spawning areas)

that could be important for enhancing or sustaining their populations. Some scientists have also

speculated on the ecosystem level impacts of

providing or denying fish passage (see box 2-4).

The assumption that riverine fish do not require

passage may reflect a lack of knowledge of the

magnitude and significance of their movements.

Methodology and fish movements

Though the paradigm is beginning to change,

the predominant thinking has been that riverine

fishes have restricted movements (i.e., “sedentary”).4

 The theory that riverine fishes are largely

sedentary is partially attributable to the methods

used to study their movements (89). The vast

majority of studies since the 1940s used the

“Mark-Recapture” technique which involves

capturing fishes, tagging them, releasing them,

and then attempting to recapture them. In many

of these studies those fish that were recaptured

apparently remained very near the initial capture

site, causing the investigators to conclude that

these fish are relatively sedentary. However,

only a small percentage of fish were recaptured

in many of these studies and thus conclusions

concerning the amount of fish movement ignore

the portion of fish that are not recaptured.

There are several ways that mark-recapture

studies may bias results about fish movements.

First, there is no information about the movement patterns of the fish that are not recaptured,

and in many cases this is the majority of the

tagged fish. This could mean that these fishes

have moved beyond the boundary of the study or

that they may have evaded recapture for some

4 The theory that most stream (i.e., riverine) fish are “sedentary” originated in 1959 with a paper entitled The restricted movement of fish

populations (86).

other reason (e.g., mortality, large population

size, etc.).

Second, by setting the spatial and temporal

boundaries of the study the investigator is presupposing how far and when the fish will move.

For instance, if the study concentrates recapture

effort on a small region of the stream and a

tagged fish ventures beyond the study boundaries, it will not be recaptured and thus its movements cannot be known or included in analyses.

To alleviate the bias, researchers can focus

recapture efforts over a larger area (e.g., by

including angler returns). Recapture efforts

should also have a broad temporal focus, so that

seasonal fish movements can be detected.

Third, fish that are recaptured in the same

stream reach where they were initially caught are

assumed to have been there all along. This could

considerably underestimate the propensity of a

species to move if the fish had left and returned

to the area between the two capture events.5

Mark-recapture studies can provide useful data

concerning fish movements and populations size

when they are designed to alleviate these potential bias problems.

Other studies have attempted to use radio

telemetry to study fish movements. This technology allows the investigators to track individual

fish from a population over long distances from

the point of initial capture. These studies do not

pre-suppose how far the fish move and thus are

less likely to bias the results. However, logistics

and cost may limit the number of fish that can be

followed, which has sometimes led to basing

conclusions about fish movements on data from

a relatively small number of fish. In addition,

transmitter life-span limits the length of time a

fish can be followed.

Telemetry and mark-recapture studies can

provide data on where a fish is at a particular

5 A fish may be captured and released at “point A,” swim some distance to “point B” and then swim back to “point A” and be recaptured.

This fish would be incorrectly counted as not having moved. For example, a walleye was captured, fitted with a radio transmitter, and

released at Prairie du Sac dam in Wisconsin. The walleye was then radio tracked for 10 months and found to have traveled a distance of 40.6

miles during that period. Three years later, the same fish was caught by an angler behind Prairie du Sac dam. Had there been no radio-tracking data this fish would have appeared (incorrectly) to have restricted movement.
40 | Fish Passage Technologies: Protection at Hydropower Facilities

time and the minimum distance it moved within

a given time frame. However, these data must be

carefully analyzed before making judgments

concerning the biological significance of the

observed movement patterns. Fish may move

within a body of water for many reasons (see

table 2-1). Studies of movement patterns using

telemetry or mark-recapture may provide little

evidence to draw conclusions about the reasons

for the observed movement patterns. Other

experiments and natural observations regarding

the fish and their habitat may provide supporting

evidence to help formulate such conclusions.

Sedentary and mobile hypothesis

Telemetry studies (as well as some mark-recapture

studies) have shown that some fish move long distances, while others remain very near the point of

initial capture. Some scientists believe there may be

a “sedentary” and a “mobile” portion of many fish

populations (84,95,102,104,148,216,218). The

proportion of the population that is “sedentary”

or “mobile” seems to vary from species to species, population to population, and even year to

year (89). Individual fish may be either “sedentary” or “mobile” for their entire lives or a fish

that is sedentary at one point may become mobile

at another time (89).

The significance of having mobile and sedentary subpopulations is not always well understood. However, some case studies have shown

that the mobile portion of the population benefited substantially from roaming. For example,

individual Arctic char that migrated from their

BOX 2-4: Ecosystem Perspective for Fish Passage

The need for fish passage can be considered at the population and ecosystem levels. Most research has

focused on the need for passage as it relates to the sustainability of a particular fish population or species.

However, some scientists have theorized about the potential ecosystem level impacts related to fish passage.

In other words, hydropower dams can preclude fish from migrating or moving to a given river reach. This may

or may not have a negative impact on that particular fish population, but it could have a negative impact on

other organisms that depend to a greater or lesser extent on the presence of those fish (146).

For instance, many species may depend on fish resources in a given stream reach. Some mammals,

birds, reptiles, amphibians, fishes, and invertebrates may prey on fish eggs, larvae, juveniles, or adults. These

predator-prey relationships may in some cases represent important ecological interactions between aquatic

and terrestrial ecosystems, or within the aquatic ecosystem. Such interactions can be affected (interrupted,

decreased, or severed) if some fish can no longer swim to a historic portion of their range.

In addition, many species of anadromous fish die after spawning and their carcasses provide energy

to some of the organisms that live in the area. Studies have shown that the carbon from salmon, shad,

and lamprey is recycled in the local stream environment and may make a significant contribution to the

energy flow of the local ecosystem (261).

Thus, hydropower dams may affect the natural flow of energy through the river basin by impeding natural fish movements, thereby fragmenting the environment and having a negative impact on the entire

ecosystem (140,261). Even though the movements of a particular fish population may not always be critical to its own sustainability, the movements may still be critical for other species and thus overall ecosystem health and stability.

These ecological interactions may be more profound in certain river basins and less important in others. Most of the current empirical evidence relates to anadromous fish movements, but the same concept

would apply to the riverine and catadromous fishes as well (212,261). More research is needed to examine the significance of ecosystem fragmentation at a level that can guide mitigation.

SOURCE: Office of Technology Assessment, 1995
Chapter 2 Fish Passage and Entrainment Protection | 41

home lake to a more highly productive lake 5 km

upstream grew faster and reached sexual maturity

two years sooner than their sedentary counterparts

that remained in the home lake (160,161).

Study examples

Lower Connecticut River Catfish and Perch: An

intensive mark-recapture study of several species

of riverine fish was done as part of a major ecological investigation of the Lower Connecticut

River (1968 to 1972) (143). Thousands of fishes

(9,817) were captured, tagged, and released. For

all the years that data were taken, recapture rates

ranged between 3.8 and 10.7 percent (918 total

recaptured; 9.4 percent). The data indicated that

the recaptured fishes of some species were far

from stationary and that some individuals occasionally traversed the entire 85.3 km of the lower

Connecticut River from Old Saybrook to Enfield

Dam. White catfishes (range: 23 km downstream

and 61.2 km upstream; average of 15.4 km from

tagging site) and yellow perch (range: 23.3 km

downstream and 54.7 km upstream; average of

13.5 km from tagging site) moved the furthest

from the point of initial capture and the brown

bullhead catfish (average 3.6 km from tagging

site) moved the least.

Smallmouth Bass (Wisconsin and New York):

Mark-recapture and telemetry were used to study

smallmouth bass movements between winter and

summer habitat in the Embarrass and Wolf rivers

in east-central Wisconsin. It was concluded that

decreasing water temperature at the summer habitat in the Embarrass River caused smallmouths

to travel 40 to 60 miles downstream in search of

deep pools for over-wintering in the Wolf River.

The following spring with increasing water temperatures the bass returned to the Embarrass

River, most to the same three-mile reach of river

where they were found the previous year (137).

The extensive migration pattern observed in this

study may be linked to wide spatial separation

between prime summer and winter habitat.

In contrast to this example of long-distance

directed movements by smallmouth bass (i.e.,

migration), other studies have concluded that

smallmouths are less mobile. For instance,

McBride, using mark-recapture, found smallmouth bass in the Mohawk Watershed in New

York to be highly sedentary (148). Ninety-one

percent of the bass were recaptured within the

same sub-reach of the river that they were initially caught and tagged. However, seasonal

migrations, if they occurred, may have been

TABLE 2-1: Some Widely Recognized Riverine Fish Movements

Dispersal

Passive fry dispersal with water flow

Active fry or juvenile dispersal, possibly mediated by competition

Specialized dispersal with patchy resources

Habitat shifts

Shifts in microhabitat related to life stage (age or size)

Seasonal movements between summer and winter habitat

Daily movements between feeding and resting positions

Spawning migrations

Potamodromous migrations between lakes and rivers

Movements in all directions when spawning and rearing habitats are interspersed

Homing movements

Following displacement (floods, capture and release, etc.)

Home Range Movements

Daily movements related to territory defense

Daily movements related to feeding

SOURCE: Office of Technology Assessment, 1995.
42 | Fish Passage Technologies: Protection at Hydropower Facilities

missed because sampling was concentrated in

one month only. Recaptures occurred from one

to 22 days after initial tagging. McBride interpreted these data to mean that Mohawk River

smallmouth bass populations had a relatively

large “sedentary” and a smaller “mobile” component, similar to earlier findings about smallmouth

bass movements in Missouri streams (84,148).

Largemouth Bass: Largemouth bass movements have also been extensively studied. Most

studies (mark-recapture) indicate that adult

largemouth bass exhibit limited movement

showing a high degree of fidelity to home areas.

For example, one study recaptured 96 percent of

the tagged fish within 100 m of their respective

release sites (139). However, radio telemetry

studies on Florida largemouth bass indicated that

adults moved out of home areas to locate suitable

spawning habitat (44,151).

A mark-recapture study of largemouth bass in

Jordan Lake, North Carolina, focused on the

movements of juveniles (young-of-the-year and

yearlings). Researchers tagged 1,619 fish over

two years and recaptured 87 (5.4 percent) of

these from one to 133 days after initial release.

The vast majority of recaptured juveniles (youngof-the-year and yearlings) were caught in the same

cove or area where they were initially captured and

released. A few fish (eight; or 9.2 percent of recaptured fish) did move beyond the point of initial

release. Unfortunately nearly 95 percent of the

fishes were not recaptured and no data is available

about their movement patterns (45).

Yellow Perch: Yellow perch from Lake Winnebago in Wisconsin migrate into the Fox River

in search of spawning habitat and travel as far

Eureka Dam, 40 km upstream from the mouth of

the river. After spawning they return to Lake

Winnebago and repeat the migration the following year, with the majority (85 percent) homing

to the same spawning sites that were used in the

previous year (258). In the Chesapeake Bay

region, yellow perch migrate from downstream

stretches of tidal waters seeking spawning habitat in upper reaches (less saline) of feeder

streams and rivers. The migration distance

depends on the location and availability of

spawning habitat (83).

Shortnose Sturgeon: Annual movements of

shortnose sturgeon were studied in the Connecticut (31) and Merrimack (125) Rivers in Massachusetts. In the Connecticut River shortnose

sturgeon exhibited two distinct migration patterns prior to spawning. Some of the sturgeon

(estimated 25 to 30 percent) spent the latter part

of the summer, the fall, and the winter about 24

km downstream of their spawning grounds. In

the spring this portion of the population migrated

the 24 km and eventually spawned. Following

spawning, the spent sturgeon moved back to

downstream feeding and overwintering sites. The

majority of the sturgeon (estimated 70 to 75 percent) spent the winter at the spawning grounds, thus

requiring no spring spawning migration. However,

after spawning these fish migrated downstream to

two distinct summering sites (23 to 24 km or 54 to

58 km). These sturgeon leave the summering sites

in fall (August to October) and migrate back

upstream to the spawning/overwintering sites.

In contrast, all of the sturgeon in the Merrimack River overwintered downstream of the

spawning site and made a spring migration to

those areas. The different movement patterns

observed for these populations of shortnose sturgeon are probably related to the availability and

the location of the critical habitat. If the spawning areas are far removed from feeding areas, the

fish may conserve energy by making an early

migration during the fall to coincide with low

river flows. On the other hand, if feeding and

spawning sites are in close proximity, spring

migrations are not as energetically costly.6

6 Shortnose sturgeon are anadromous in southern rivers (e.g., Savannah River), spending the summer, fall, and winter in saltwater. They

make long-distance upstream spawning migrations in the spring (between 175–275 km), traveling as many as 30 km a day. Shortly after

spawning they return downstream and enter brackish waters by two weeks post spawning (93).
Chapter 2 Fish Passage and Entrainment Protection | 43

Implications of riverine fish movements for 

fish passage mitigation

The need for passage for riverine fishes is most

likely site- and species-specific. An excellent

illustration of site variation is the biology of the

Colorado squawfish. Colorado squawfish have

been extensively studied in the Green, White and

Yampa Rivers in Colorado and Utah and results

indicate that adults make seasonal long-distance

migrations upstream (65 to 160 km) to locate

spawning habitat. After spawning the adults return

downstream, often homing within a few miles of

where they were prior to the spawning migration.

Squawfish larvae in these rivers drift to nursery

areas far downstream of the spawning sites (as far

as 100 to 160 km) (225,226,227,228,260).

However, McAda and Kaeding studied the

same species in the upper Colorado River and

found that adult squawfish had much shorter

spawning migrations (< 50 km; mean = 23.2 km)

than those described for populations in the

Green, White and Yampa Rivers (65 to 160 km)

(147). The availability of spawning habitat may

help explain the difference in the movement patterns of these populations. Spawning habitat was

abundant and widely distributed in the upper

Colorado River and consequently the fish did not

require long-distance spawning migrations to

locate suitable areas. In contrast, in the Green

River spawning habitat was less common and

was highly clumped, requiring fish to swim long

distances to locate acceptable areas.

These studies underscore the point that mitigation concerning fish passage will have to be

site- and species-specific and should be tied to

the specific habitat needs for target fish populations in a given river reach. Seasonal habitat

types (e.g., rich feeding habitats v. spawning

sites) are sometimes widely spatially separated

and may require extensive migrations of some

riverine species (169). Goals concerning the target species’ population sizes as well as size and

age class structure, etc., will be important in

determining whether fish passage is needed.

Some riverine fish may need to make longdistance movements past one or more dams to

locate critical habitat (e.g., spawning, overwintering, etc.). Some species that make long potamodromous migrations from lakes into streams

or rivers may need safe passage routes around

hydropower dams to allow access to spawning

habitat (see box 2-5).

BOX 2-5: The Lake Sturgeon

The lake sturgeon, Acipenser fulvescens, has one of the widest geographic ranges of all freshwater

fish. It is found in three major drainage basins: the Mississippi, the Great Lakes, and the Hudson Bay.

This species, which once ranged so widely throughout North America, is now nearly decimated throughout most of its native range (110,118). Lake Michigan in 1880 produced a commercial catch of over

3,800,000 pounds of lake sturgeon (15a). A combination of overfishing, dam construction and pollution

nearly eliminated these vast populations, to the point that today they are considered threatened or endangered species throughout most of their range. The Menominee River, a boundary water between Wisconsin and the upper peninsula of Michigan, is currently the only tributary to Lake Michigan that still contains

a fishable lake sturgeon population. This same scenario has been played out numerous times throughout

the historic range of these fish. The lake sturgeon is included on the U.S. Fish and Wildlife Service’s list of

candidate species being considered for listing as endangered or threatened. It is considered a “Category 2” species which comprises taxa for which information now in possession of the Service indicates

that proposing to list it is possibly appropriate, but for which conclusive data on biological vulnerability

and threat are not currently available to support proposed rule making.

(continued)
44 | Fish Passage Technologies: Protection at Hydropower Facilities

Lake sturgeon are considered living fossils. They have many primitive characteristics which have

been lost on most of our modern-day fish. These include a large cellular swim bladder, a heterocercal tail,

a cartilaginous skeleton and a notochord, instead of bony vertebrae. These fish are long-lived and often

reach a large size. On average females do not reach sexual maturity until they are 25 years old and

approximately 50 inches long, while males generally mature around 15 years of age when they are

around 45 inches in length. There are records of these fish living over 100 years and attaining lengths in

excess of six feet and weights over 200 pounds.

Lake sturgeon are generally found in large river systems or in lakes connected to these rivers. They often

move long distances, over 100 miles, to reach suitable spawning habitats. Seasonal movements of lake sturgeon outside of spawning time are not well documented. Lake sturgeon spawn in the spring or early summer.

Most spawning occurs in rivers below falls or in rapids. High-velocity water with a rock rubble substrate is preferred. Eggs adhere to these bottom substrates prior to hatching in 7 to 10 days after deposition.

Dams have impacted lake sturgeon populations in a number of ways. Lake sturgeon have been

blocked from obtaining their traditional spawning areas by dams that are located at or near the mouths of

rivers (15a,96). Brousseau and Goodchild describe how fluctuating flows in a spill channel can adversely

impact lake sturgeon populations (28). Low and/or fluctuating flows immediately after spawning will affect

spawning success as eggs experience variable water temperatures, low oxygen concentrations and

exposure to the atmosphere. Fry become trapped in shallow pools and are subjected to heavy mortality

through predation, temperature stress, and oxygen depletion. Water level fluctuations between dams,

both seasonal and periodic, have caused decreased production and loss of species such as lake sturgeon from some reaches (173). In addition Altufyev et al. (4), Khoroshko (124), Voltinov and Kasyanov

(255) and Kempinger (122) have all shown that changes in magnitude and timing of river flows below

hydroelectric dams have affected the reproduction and early life stages of several sturgeon species.

Auer has documented significant changes in behavior and population characteristics in the spawning run

of lake sturgeon when a project was converted from peaking to run of the river (8,9,10,11). The following

changes were documented: 1) an increase in the average size of the lake sturgeon; 2) an increase in

spawning readiness; 3) a decrease in the amount of time the spawning fish remained in the area of the

spawning grounds, thus decreasing their exposure to adverse conditions and poaching; and 4) an

increase in the overall size of the spawning run. Lake sturgeon are adversely impacted by daily flow

instability like that created by peaking hydroelectric projects, thus run of the river flows in the main channel and stable spillway flows are critical to the rehabilitation and restoration of lake sturgeon populations.

A key component to lake sturgeon restoration is to provide a means for fish to return upstream to suitable spawning, summer, and winter habitat. By allowing adult sturgeon to pass these dams, historic

spawning, nursery and foraging habitat could be utilized by these fish. This could be accomplished by

installation of upstream fish passage facilities. Upstream passage of lake sturgeon at dams with heads

higher than five to 10 feet has not been successfully accomplished with traditional-style fish ladders.

Resource agencies in the Midwest and Ontario are currently working on developing the technology to

safely and effectively pass lake sturgeon over these dams. Research is currently being conducted by the

National Biological Survey and researchers in Canada on swimming speeds of adult and juvenile lake

sturgeon and behavioral response of lake sturgeon to various fishway types. This information is critical to

designing an effective upstream fishway for lake sturgeon.

SOURCE: Thomas Thuemler, Area Fisheries Supervisor, Wisconsin Department of Natural Resources, August 1995.

BOX 2-5: The Lake Sturgeon (Cont’d.)
Chapter 2 Fish Passage and Entrainment Protection | 45

Other fishes may find adequate habitat within

the dammed portion of the river. For example,

hydropower dams often change the habitat

upstream by creating head ponds (i.e., reservoirs)

which provide different habitat than the original

flowing environments that they replace. There is

often a change in species composition favoring

fish species that prefer lake-like or pool-type

habitat. Such species include some sunfishes like

bluegill, largemouth bass, and crappie. Some of

these fish are generally structure oriented and

may not need to leave the reservoir to locate critical habitat.

PART 2: STUDY METHODS

❚ Entrainment and Turbine Mortality 

Studies

Entrainment studies quantify the numbers, sizes,

and species of fish that pass through the turbines

at hydropower facilities. Turbine mortality studies (which are often done in conjunction with the

entrainment studies) determine the risk of death

caused by passing through a given turbine for the

various species and sizes of fish. Prior to 1980,

nearly all of the research on entrainment and turbine mortality examined anadromous juvenile

salmon (17,19,199,224). Between 1980 and 1990

the experimental effort expanded somewhat to

include other anadromous species, especially

American shad and alewives (18,87,135,206,-

222).

Since 1990 there have been intensive efforts

to study entrainment and turbine mortality at

sites that primarily or solely support riverine fish.

Many of these studies were requested by state

and federal resource agencies during the Federal

Energy Regulatory Commission (FERC) relicensing process. The results of these studies are

used to determine what level of mitigation and

what kinds of mitigation are appropriate.

❚ Entrainment Study Methodology

Netting

Netting is the most common method used to

measure entrainment. Full tailrace nets (most

preferred netting technique) are anchored to the

exit of the draft tube and sample the entire discharge from one or several turbine units. Floating

mesh boxes of various sizes and types (i.e., “live

cars”) are often attached to the end of the net to

reduce mortality caused by fish scraping and

entangling in the net (i.e., net impingement). Partial tailrace netting may be used where full tailrace netting is impossible or prohibitively

expensive or even dangerous due to the physical

and hydraulic conditions of the tailrace. These

nets are usually anchored in the tailrace on a

metal frame held in place by guy-wires, or some

other anchors, and they sample some portion of

the discharge from one or several turbines. Nets

may also be deployed some distance downstream

of the tailrace and may cover the entire width of

the stream.7

The main problem with full and partial tailrace netting is contamination of the sample by

fish that did not pass through the turbine (i.e.,

residing in the draft tube or the surrounding areas

of the tailrace). This is particularly true for partial nets because they do not completely isolate

fish that reside in the tailrace from swimming

into them. In addition, fish may be able to escape

partial nets. This is the primary reason that full

tailrace nets are preferred. However, tailrace and

draft tube intrusions may also occur in full net

deployments, due to gaps between the draft tube

and net frame, gaps between the net frame and

the net itself, or ripped portions of the net. Obviously, gaps or rips may also allow entrained fish

to escape. These problems can be minimized by

careful net anchoring to avoid large gaps and frequent net inspections to locate rips which may

develop.

7 In general such deployments suffer from low recapture rates of entrained fish because the fish can reside in the tailrace upstream of the

net for considerable time, where they may suffer from other sources of injury or death (e.g., predation). There is also high incidence of capturing non-entrained fish that were naturally residing in the tailrace prior to the study.
46 | Fish Passage Technologies: Protection at Hydropower Facilities

Intrusions may also occur if the net is raised

allowing some fish to swim into the draft tube,

and later be captured when testing resumes. Most

studies guard against this type of intrusion by

running the turbine for a period of time without

the net in place so that the draft tube will be

flushed of fish when netting begins. However,

the effectiveness of this technique is unclear.

Nets may be deployed within the turbine

intake. Intake collection nets are relatively short

so as not to interfere with turbine function, and

usually several smaller nets are used rather than

one large net. This is accomplished by anchoring

the nets onto a frame which slides down into the

gatewell. Problems of intake netting include the

possibility that some of the fish that are sampled

in intake nets may not have been committed to

passing through the turbine, as well as the possibility of injury to collected fish because live cars

cannot be used. In addition, nets that come apart

from the frame may become lodged in the turbine, which could cause considerable damage.

Partial netting techniques, whether located in

the tailrace or intake, assume that there is equal

distribution of fish throughout the sampled area

and that fish cannot avoid the nets or netted

areas. These assumptions are not always, and

probably rarely, tested in the field or based on

any supporting evidence. Estimates of entrainment using partial netting techniques are only as

good as these assumptions.

If both tailrace and intake netting are ruled

out, nets may be deployed in the power canal

entrance. Fish that enter the canal are assumed to

be bound for turbine passage, but this may not

always be the case, as there are often resident

populations of fish within the power canals, or

groups of fish that frequently move between a

reservoir and its associated power canal. This

method may be acceptable for downstream

migrating anadromous fishes or when other

methods are ruled out.

One of the most critical features of netting

studies is “net efficiency.” Since sampling nets

are almost never 100 percent efficient, good

entrainment studies (even with full tailrace nets)

should include net efficiency tests. Testing is

typically done by introducing marked fish of various sizes and species into the turbine intake at a

point where they are committed to passage

through the unit. Good net efficiency studies

should test with both live and dead fish. In some

cases, it may not be possible to introduce fish at a

point in the intake where the fish are committed

to turbine passage. In such cases, fish may be

directly introduced into the collection nets. However, the distribution and behavior patterns of

specimens entering the net from the introduction

apparatus may be different than fish entering

from the draft tube.

There is some argument concerning the net

efficiency level that is acceptable for entrainment

studies. EPRI suggests that 85 to 100 percent net

efficiency is required to demonstrate the efficacy

of a full-flow recovery net (62). Low net efficiency may result from rips or gaps in the net

apparatus which allow fish to escape. In some

cases, strong-swimming fish may be able to

maintain positions within, or near, the draft tube,

thus avoiding capture. Finally, the net mesh size

may allow certain fish shapes and sizes to

escape.

Partial flow collection nets will have much

lower net efficiencies, the range of which may

depend on the fish size and behavior, net size and

location, and the flow conditions. Net efficiencies less than 10 percent are common. As previously discussed, net efficiency is assumed to be

proportional to flow (i.e., even distribution of

entrained fish) and often entrainment rates from

partial-flow nets are extrapolated to the full plant

flow. In these cases net efficiency testing should

be repeated to test the reliability of the estimates,

especially given the possibility of intrusions of

non-entrained fish and avoidance behavior of

entrained fish.

Hydroacoustic Technology (HAT)

Hydroacoustic technology (HAT), also known as

SONAR, has been widely used to estimate fish

entrainment at hydropower facilities, especially

on the West Coast. This technology involves

using a transducer to alternately transmit sound

waves of a known frequency, usually between 40
Chapter 2 Fish Passage and Entrainment Protection | 47

and 500 kHZ, into the water and then monitor for

any returning sound waves that may bounce off

of an object.8

 Most of the newer systems require

state of the art computers to decode the data and

may rely on various software packages or human

judgment to determine whether signals are from

debris or from fish.

For entrainment studies there are basically

three methods of HAT sampling: echo integration, echo counting, and target tracking. Echo

counting and target tracking count individual

fish, allowing a direct estimate of fish abundance. These methods are often preferred over

echo integration, which is used to get an estimate

of fish biomass over time. Echo integration is

usually used when fish are swimming in large,

tight schools, and individual fish cannot be recognized by the system. Echo integration is more

susceptible to background noise levels and errors

in estimates of target strength, especially when

schools are not of homogeneous species or size.

The major advantage to this technology is that

it is often cost effective over the long run as compared to netting. HAT sampling can operate 24

hours a day for months at a time with very little

labor cost. HAT counts all fish (within chosen

size limits) that swim into the ensonified region

without harming or delaying the animal. In comparison, nets may detain, injure, or kill fish and

are subject to avoidance behavior.

Recent HAT equipment, in addition to providing size and abundance of entrained fish, can also

determine the temporal distribution of entrainment and the spatial distribution of fish as they

enter a power canal, forebay, or intake. Information on important fish behaviors like swimming

velocity and trajectory is also available. These

data can help experimenters detect when, how,

and where fish enter turbine intakes and thus

may provide assistance in designing mitigation.

Real-time data analysis is available, which may

be used to alert plant operators when fish are

passing the plant in large numbers.

8 Typically, the technique involves a pulsed cycle of alternating “transmitting” and “listening” sequences that may be repeated as many as

50 or 60 times per second.

The major disadvantages include the initial

cost of the system, which is generally much

higher than nets. The technology is also very

complex and requires experienced personnel or

considerable training (months or years). By

design these systems collect a tremendous

amount of data, much of which may not be relevant to the study (detection of debris or entrained

air). In addition, fish that lie on the bottom or

swim very close to a boundary (like a retaining

wall, etc.) are very difficult, if not impossible, to

detect with HAT. HAT studies should not be

conducted in areas with electrical interference or

turbulent water flow with entrained air bubbles.

No (or little) information can be obtained concerning the species of the fish being detected,

and fish which are milling around rather than

actively migrating are likely to be counted more

than once.

HAT has been used to study entrainment on

the West Coast since about 1976. There have

been more than 100 HAT entrainment studies

(mainly targeting juvenile downstream migrating

salmonids) on the Columbia River alone. Several

sites have had multiple-year studies (e.g., Wells

Dam has had more than 10 consecutive years of

HAT entrainment sampling). In many cases, the

study objectives went beyond simply quantifying

the size and number of fish that were entrained.

Studies have been used to evaluate different

bypass alternatives (e.g., submerged spill orifices

v. surface sluiceways (191) and the efficacy of

vertical inclined traveling screens and other

structural devices) which have led in some cases

to increased bypass efficiencies (130).

HAT has also been applied at some sites in the

Midwest and on the East Coast, but has been far

more limited in scope. Early HAT studies in the

Midwest (especially Wisconsin and Michigan)

were not very successful, leading resource agencies in that area of the country to be very skeptical of the applicability of HAT to entrainment

studies. Many factors may have limited the

results of these early studies. HAT investigations
48 | Fish Passage Technologies: Protection at Hydropower Facilities

in the Columbia Basin are usually done with

state-of-the-art equipment and multiple transducers. This allows full coverage of intakes, etc., and

increases the likelihood of gathering statistically

useful data. The initial cost of these systems is

relatively high, as compared to older HAT technologies and to using fewer acoustic samplers.

Cost may not be a limiting factor at many

Columbia River sites where adequate budgets

allow state-of-the-art research. However, in the

Midwest there is generally less money available

to fund entrainment studies, and therefore HAT

studies tended to use cheaper technologies and

designs.

There are several substantial differences

between the Columbia River sites and the Midwest sites, including fish fauna (size range, species richness, behavioral diversity), hydropower

designs and operations, and overall scale. For

example, most studies on the Columbia River

have targeted juvenile downstream migrating

salmonids which are generally of uniform species, size, and behavior. Studies in the Midwest

must typically contend with numerous species

with a broad size and behavioral range. These

differences result in more complexity that must

be addressed in the early design phase of HAT

studies. However, these challenges can often be

met with the proper experimental design and

adequate technologies. The efficacy of HAT, like

other methods to study entrainment, is highly

site-specific. At some sites HAT may be impractical, while at others it may be highly feasible. If

budgets (or logistical constraints) do not allow

for adequate HAT equipment, then other study

methodology should be sought.

Netting studies are often used in concert with

HAT. This can be useful if species identification

is important. In addition, the entrainment rates

estimated from each method can be compared to

one another, which may give a good idea of

study accuracy. Comparisons of HAT and netcatch estimates of entrainment have been done at

several sites (e.g., Tower and Kleber dams in

Michigan (119); Ice Harbor, Rocky Reach,

Lower Granite, and Wanapum dams on the

Columbia River (192)) and have generally compared favorably.

Telemetry Tagging Technologies

Telemetry tagging technologies, including radio

tags, sonic tags and Passive Integrated Transponder (PIT) tags, can be used to study the behavior

of fish that are approaching or swimming in the

neighborhood of a dam. While these types of

studies cannot be used to quantify natural

entrainment, they can provide valuable information that can aid in the interpretation of the

potential for a problem. For instance, such studies can be used to estimate the percentage of fish

that use various routes past a dam (spill, log

sluice, bypass, turbine, etc.) or to estimate the

risk of entrainment for different species of riverine fishes that are caught, tagged, released and

then monitored in various parts of a reservoir.

Radio tags have been developed to transmit

both pulsed and continuous signals. Continuous

signals are easier to distinguish from background

noise and are perceptible from greater distances.

Pulsing systems use less energy, so batteries last

longer, and individual fish can be distinguished

by adjusting the length, rate or interval between

pulses.

Transmitters can be attached externally, or

placed in the stomach, or implanted surgically.

Thus the size of the fish will determine the size

of the transmitter. A small whip antenna sends

the signal. Prior to attachment, transmitters are

covered with a variety of substances to protect

them from corrosion during operation.

The signal is stronger when the tagged fish is

closer to the surface. Turbulent as well as saline

water may disturb the signal quality. Radio transmitters are best suited for surface-oriented fish

that are swimming in calm freshwater. Lower

frequencies are transmitted further than higher

frequencies, but require larger batteries and

receiving antennae.

The receiver unit must be able to detect the

bandwidth and exclude ambient noise. Wider

bandwidths are easier to detect, but will include

more background noise. Receivers may be

mounted on boats or airplanes, or may be porta-
Chapter 2 Fish Passage and Entrainment Protection | 49

ble. Radio tags are comparatively expensive,

often leading to relatively small sample sizes.

Sonic tags are used less frequently than radio

tags because they operate over a more limited

range, underwater hydrophones must be used,

and fewer unique signals can be simultaneously

monitored. The tags operate from 30 to 70 kHz,

and therefore do not work well in areas of high

background noise in overlapping frequency

range (e.g., waterfalls, spillways, underwater

movable machinery, etc.).

PIT tags have been developed over the past 10

years and allow billions of different codes. They

have no internal power source and are only activated in the presence of an electromagnetic field.

They are thus suited to monitor longer term

migrations of adult salmonids, because the

devices can be implanted during downstream

migration and still be functioning when the fish

return. Since the returning adults must pass

through confined areas to get past dams, PIT

monitors, when installed in a series of dams, can

provide information on many fish passage questions. These include rate of passage, mortality

during upstream migration and success rate of

individual bypass facilities. The principal drawback of the technology is the need for the fish to

be within a highly confined area to be detected.

Depending on the transponder, the range of

detection is 7 to 33 cm.

❚ Turbine Mortality Study Methodology

Turbine mortality may be assessed using three

basic types of studies: mark-recapture studies

(e.g., tailrace netting, balloon tags), observations

of net-caught naturally entrained fish, and telemetry techniques.

Mark-recapture studies are preferred because

they allow for the use of control groups. Currently there are several methods of marking and

recapturing the fish. The most common marking

techniques include one or a combination of mutilation (fin clipping, branding, etc.), painting,

external tags (physical items attached to the fish),

and internal tags (e.g., coded wire tags). Fish

may be recaptured in the tailrace with various net

designs, or in some cases for anadromous fish

they may be captured when they return as adults.

If the latter method is used, careful control

groups must be used and a very large sample size

is required. However, it does have the advantage

of taking predation on turbine-passed fish into

account. Another recapture method involves

attaching “balloon tags” to the fish that inflate

after a given time and cause the fish to be buoyed

to the surface where they can be captured by personnel working from a boat.

Observations of naturally entrained fish have

also been used. Fish that are captured in tailrace

nets (partial or full flow netting) can be retained

in a live car and observed over a given time

frame to check for mortality. Advantages of testing naturally entrained fish include sampling fish

species and sizes that actually are entrained at the

project, elimination of stresses associated with

handling, holding, tagging, and introducing fish,

and elimination of any potential bias associated

with the placement of the introduction pipe. Disadvantages include inability to control for the

number, size, and species of the fish, the occurrence of pre-existing injuries on fish, and the

unpredictable nature of the timing of fish turbine

passage. These problems often lead to meager

statistical analyses of turbine mortality risk and

therefore resource agencies do not recommend

them.

Mark-recapture—Tailrace Netting

Partial or full tailrace nets are the most frequently used system for estimating turbine mortality. Full tailrace netting is preferred where

feasible.9

 Experimentally introduced fish should

be released at a point where they cannot avoid

being entrained. This usually means using a section of pipe (usually PVC of four to six inches in

diameter) to introduce the fish. A funnel may be

attached to the top of the pipe and fish are usually flushed out with water, compressed air, or by

9 See section on entrainment netting methods for a critique of net designs.
50 | Fish Passage Technologies: Protection at Hydropower Facilities

a physical plunger. There is some possibility that

the introduction apparatus may bias the results if

it introduces fish in a non-optimal location

within the intake or if fish are disoriented when

they exit the pipe thus altering their behavior in

the turbine. It is also possible that the results

could be biased by the number of fish introduced

at one time. In other words, fish introduced in

sequence may suffer different mortality rates

than those that pass in large groups.

The most common problems with tailrace netting studies are intrusion of non-entrained tailrace fish into the net,10 escape of some entrained

fish causing less than 100 percent net efficiency,

and injury and/or stress caused by handling or

subsequent capturing and holding of entrained

fish.

The intrusion of non-entrained fish should not

typically be a problem for most mark-recapture

studies, because the non-entrained fish should be

unmarked. However, the escape of some

entrained fish can be a problem. If injured and

non-injured fish are caught at different rates,

mortality estimates will be compromised. To

alleviate this problem, experimenters try to maintain nets so that rips are not allowed to form. In

addition, net mesh size must be smaller than the

smallest target fish, and gaps between the net and

frame (and the frame and draft tube) should be

minimized.

The third problem—handling, holding and net

capture stress—is one of the most controversial

aspects of mark-recapture turbine mortality studies. Test fish typically must be transported to the

study site, held in various types of pens, cages,

and/or tanks, and physically handled while transferring, measuring, tagging, and finally injecting

them into the turbines. To counter the problem,

studies must include control groups that expose

fish to all of the associated stresses besides turbine passage. These control groups should theoretically be able to identify the expected

mortality due to handling, holding, or collecting

stresses, and this amount of mortality can then be

10 See section on entrainment netting methods for a critique of tailrace intrusions.

factored out of turbine mortality estimates of the

test groups.

However, some scientists have argued that

control groups may not be capable of factoring

out all of the mortality associated with handling

stress. The concept is that the stresses of handling and turbine passage are synergistic rather

than discrete, thus the mortality caused by the

combination is greater than the sum of the individual effects. In other words, test fish (passing

through turbines) that survive turbine passage

may be stressed to some degree and may be

killed by a level of handling stress that would not

kill a “normal” fish. In other words, control fish

are not previously stressed by turbine passage,

and may be more able to survive the handling.

Thus, the mortality rate calculated for the control

fish would not properly account for the synergistic effects on the test fish. In such cases, an overestimate of turbine mortality may result

(202,203,206).

Mark-recapture—Balloon Tags

The balloon tag technique involves attaching a

self-inflating tag to the test fish, introducing the

fish into the turbine, and recovering the fish in

the tailrace after the balloon inflates and forces

the fish to the surface. This method eliminates

the need for tailrace nets (which can be very

expensive at large projects) and thus eliminates

the stresses associated with net capture. However, recovery can be difficult as personnel must

use boats to locate and capture fish, and thus

radio tags are often used to help locate the floating fish. Fish recovery is typically better than 85

percent (62), and predation on floating fish and

evasion by floating fish have been identified as

contributing factors to the percentage of fish that

is not recovered. The treatment of these nonrecovered fish is one of the most controversial

issues concerning this recapture technology.

Presently, most studies simply include all nonrecaptured fish in the dead column, which might

slightly overestimate turbine mortality. How-
Chapter 2 Fish Passage and Entrainment Protection | 51

ever, professional judgment may sometimes be

used to determine whether non-recaptured fish

are “dead” or “alive” (29).

This method has been identified as useful for

frail species that are easily harmed or stressed by

net capture (e.g., shad, herring, and alewife). The

balloon tags themselves have not been found to

kill the fish. The main disadvantage of this technology is the cost of labor-intensive fish recovery. Therefore sample sizes are usually low (total

samples less than 200 are most common). If multiple species and size classes of fish need to be

tested at more than one operating scheme, netting

techniques are more practical.

Telemetry

Radio tagging has been used with limited success

to study turbine mortality, but is less common

than netting. This approach compares the movements of live and dead fish that are implanted

with radio transmitters after turbine passage. In

general, fish are counted as living if they move

beyond the point where dead fish typically settle

to the bottom. This technique assumes, among

other things, that any fish that moves beyond the

typical settling point of dead fish will survive

(i.e., no delayed mortality), fish that settle are

dead and not just stationary, fish that are counted

as having moved beyond the settling point have

not been ingested by another fish and taken

downstream, and no fish regurgitate tags. Results

may also be confounded by the loss of signals

related to fish moving to areas beyond the reach

of the transmitter device. In general, resource

agencies prefer netting or balloon tagging methods over telemetry for turbine mortality studies.
| 53

3

Upstream

Fish Passage

Technologies:

How Well Do

They Work?

ish ladders, fish elevators (lifts) and

locks, and trapping and trucking are the

three main methods of upstream passage

technology (see box 3-1) (36). Fish are

“passively” transported via lifts and trucks, but

must actively swim or leap up fish ladders. Ladders are the most frequently used means of transporting fish upstream past hydropower facilities.

Ladders of various types are distinguished by

hydraulic design and the degree to which they

are hydraulically self-regulating, the species and

numbers of fish they most readily accommodate,

and their operability over a range of flows. Fish

lifts can be automated and are best for high head

sites or for loading trucks. Trapping and trucking

fish is a labor-intensive measure, but may be

appropriate when fish need to be transported

long distances upstream or around a number of

obstacles (i.e., hydropower plants) (243).

A fishway can be defined as any artificial

flow passage that fish negotiate by swimming or

leaping (i.e., fish ladders) (243). In an engineering context, it is a waterway specifically

designed to afford fish passage around a particular obstruction (121). It may be any structure, or

modification to a natural or artificial structure,

for the purpose of fish passage. Fishway systems

often include attraction features, entrances, auxiliary water systems, collection and transport

channels, exits, and operating/maintenance standards (15). A fishway can be a simple culvert

under a country road or a complex bypass system

at a huge hydropower facility.

UPSTREAM FISH PASSAGE DESIGN

The success of a fish passage system (i.e., ladders, lifts, and trap and truck) at a hydropower

facility is dependent on many factors. Effectiveness is directly related to biology and behavior of

the target species, as well as hydrologic conditions both up- and downstream of the project.

Ultimately, a fishway must be designed to be

“fish friendly” by taking into consideration all of

the above. At some sites, two types of upstream

mitigation may be required to provide effective

fish passage.

The hydrologic conditions of the waterway

above and below the project will influence the

location of the fishway exit and entrance, and

influence conditions within the fishway itself.

The fishway should be designed to be effective

under a range of conditions while accommodating the swimming ability and behavior of the

F
54 | Fish Passage Technologies: Protection at Hydropower Facilities

target species and the targeted run size.1 In addition, physical and environmental conditions will

influence location and effectiveness of the fishway, especially under changing flow conditions

(133).

Hydraulic engineering plays a large role in

fishway design. An understanding of how to create, manipulate, and maintain appropriate flows

in a fishway is critical to success. If available,

historical flow data for the waterway can have

bearing on hydraulic decisions. There is a significant need for stream flow data from gauging stations to create databases to support good fishway

design. Alaska, for example, has an average of

one stream gauge per 7,600 square miles versus

the lower 48 states average of one gauge per 400

square miles (see box 3-2) (67). As a result,

hydropower project planning or development for

many of the ungauged rivers in the state must be

based on rough flow estimates generated from

hydrologic models, unless a project can be

delayed until adequate data collection can occur

(66). Flow data is important information for

determining the depth of the fishway entrance to

assure access, and for maintaining appropriate

flow in the fishway itself. Flow data will also

help site the fishway exit, which must be far

enough upstream to prohibit “fall back” while

1 In Washington, fish passage hydraulic criteria must be complied with 90 percent of the time during the migration season (12).

putting fish in a position to respond to instream

flows and continue in their migratory path.2

An understanding of fish swimming performance and behavior is also essential to fish passage success. It is difficult to determine the exact

performance of fish under natural conditions.

However, significant knowledge exists in this

area for some species, which can be applied to

design. Species of fish and individuals within

species behave and respond differently, requiring

various types of flows and conditions in waterways and subsequently in fishways. Fishway

design should consider and accommodate the life

stages and unique characteristics of the target

fish. Fish passage structures can be designed to

accommodate fishes that are bottom swimmers,

surface swimmers, or orifice swimmers; fishes

that prefer plunging or streaming flow; and weak

or strong swimmers (120).

Advances in fish passage will depend on fish

behaviorists and biologists working cooperatively with hydraulic engineers to design appropriate fishway environments (133). 

❚ Fish Ladders

The actual physical structure that allows fish to

climb or carries them to a higher elevation is the

ladder, which is part of the entire fishway system.

Ladders can be classified in categories based on

2 Fall back refers to fish that climb the length of a fishway or part of a fishway and drop back to a previous pool to rest. This can be a

response to fatigue, unfavorable hydraulic conditions, lighting, or other factors that influence behavior. Fall back also refers to fish that complete the passage of a fishway and exit successfully but are then swept back over the spillway or through the turbines. Shad tend to exhibit fall

back, thus limiting the types of fishways that can accommodate the species.

BOX 3-1: Chapter Findings—Upstream Technologies

■ There is no single solution for designing upstream fish passageways. Effective fish passage design

for a specific site requires good communication between engineers and biologists and a thorough

understanding of site characteristics.

■ Technologies for upstream passage are considered well-developed and understood for particular

species.

■ Upstream passage failure tends to result from less-than-optimal design criteria based on physical,

hydrologic, and behavioral information, or lack of adequate attention to operation and maintenance

of facilities.

SOURCE: Office of Technology Assessment, 1995.
Chapter 3 Upstream Fish Passage Technologies: How Well Do They Work? | 55

BOX 3-2: The Special Case of Alaska 

Alaska’s rivers, streams, and lakes represent 40 percent of the nation’s surface water (67) and support

over half of North America’s commercial salmon fisheries (109). Sport fisheries figure prominently in the

state’s economy, while Alaskan natives rely on subsistence fishing for economic and cultural reasons

(200). Water-based navigation and recreation further contribute to the state’s overall economy, as do

industrial and municipal water uses such as hydropower development, community water supplies, etc. (97).

Presently, the majority of Alaska’s water resources are high quality and unallocated (97). Alaska’s

stage of water development is equivalent to that of the western states approximately 150 years ago. During that time, the majority of water in the western states remained unappropriated and water was initially

diverted from the Colorado River in Colorado (66). Increases in private, government, and commercial

developments in Alaska, associated with increased population growth, urbanization, and resource development, can be detrimental to continued fish production if they impair or reduce fish habitat or result in

higher than desired fish harvests. Proposals to export and sell large quantities of Alaskan water to other

states and countries also have the potential to negatively affect fish production (67,68,97). Therefore, the

continued production of Alaska’s valuable fishery resources will be dependent upon maintaining the

quality and quantity of its fish-bearing waters and actively managing fish harvests.

Based on the abundance of undeveloped water sources in Alaska, it is therefore not surprising that

Alaska has more preliminary Federal Energy Regulatory Commission licenses in progress for developing

new hydropower projects than other states. Unlike the Pacific Northwest and other portions of the country

where flowing waters were impounded for hydropower development, Alaska has a unique opportunity to

approach hydropower development with fish protection in mind while a project is in the early planning

stages. For example, the Alaskan Department of Fish and Game attempts to work with developers to site

project facilities so they do not impede fish passage and destroy spawning and rearing habitat. State

statutes grant the Alaska Department of Fish and Game permitting authority to require that fish passage

flows and physical structures (upstream and downstream) be provided to prevent impairment of fish passage (Title 16, AS 16.05.840) for all fish species, and that the spawning, rearing and migration habitat of

13,000 waters, classified as sustaining anadromous fish species, be protected (AS 16.05.870). Had North

America’s largest thin arch dam complex been built on the Susitna River in the mid-1980s, it would have

been located upstream of a natural fish migration barrier in the Susitna.

Through its Title 16 permitting authority and recommendations to FERC, the Alaska Department of Fish

and Game requests mitigation provisions and monitoring be integrated into the project plan during the

early design phase. The Department may even require developers of large projects to deposit funds for

mitigation and monitoring into an escrow account before project construction begins. Front-end funding

insures that mitigation and monitoring can and will be executed, even if a project undergoes financial

hardship or is sold or transferred to another entity during and after construction. In the past, many hydropower projects in the lower 48 states were built without implementing previously agreed upon mitigation.

One constraint to better fish protection in the state is a lack of baseline data required for planning and

resource management decisions. One inch to a mile topographic maps for most of Alaska are outdated

and undigitized, preventing the use of GIS for planning and analysis. It is likely that thousands of bodies

of water that support anadromous and resident fish populations have yet to be identified. Further, many of

the state’s fish and wildlife personnel are unfamiliar with FERC processes and require basic training. The

dearth of hydrologic data further hampers Alaska’s ability to define water availability for instream flow and

other water uses with confidence. Alaska has an average of one stream gauge per 7,600 square miles

versus the lower 48 states average of one gauge per 400 square miles (67). Therefore, project planning

or development for many of the ungauged rivers in the state must be based on rough flow estimates generated from hydrologic models, unless a project can be delayed several years to allow for data collection.

(continued)
56 | Fish Passage Technologies: Protection at Hydropower Facilities

hydraulic design and function: pool and weir;

vertical slot; roughened channel; hybrid;

mechanical; and climbing passes (15). For simplicity, all are commonly referred to as “fishways.”

Pool and Weir

The pool and weir ladder has the longest history

of use. Pool and weir fish ladders are designed

primarily to provide plunging flow and ample

resting areas that provide leaping fish with

hydraulic assistance in moving upstream

(15,120) (see figure 3-1). In these fishways,

pools are arranged in a stepped pattern and are

separated by overflow weirs (121). Ladders of

the pool and weir type can be applied on any

scale; they generally require a great deal of

space, but little water (15).

Pool and weir ladders can operate under two

hydraulic regimes. The normal flow regime in

fish ladders is plunging flow; however, at higher

velocities plunging flow converts to streaming

flow at the water surface. In this instance, a continuous surface jet passes over the weir crests,

skimming the pool surfaces. Streaming flows are

difficult to manage and should be used with caution. Moreover, the transition between plunging

and streaming flow creates a hydraulic instability

that may delay some fish species (15). Streaming

flow does not provide the hydraulic boost needed

by jumping fish to successfully negotiate the ladder; however, streaming flow is often required

because some species cannot or refuse to leap

(12). Auxiliary water, beyond what flows down

the ladder itself, is almost always needed to

attract fish to the entranceway.

Design parameters for pool and weir ladders

include receiving pool volume, head differential

between pools, water depth in pools, and slope.

Values can be calculated for different fish, different sized runs, and different project scales. For

example, the recommended head differential

between pools is one foot for most salmon and

trout, which can leap from pool to pool, and

three-fourths of a foot for chum salmon and

American shad (15,121). Most pool and weir ladders have a slope of 10 percent and are sensitive

to changing water levels (headwater variations)

with a narrow range of operation if no other flow

control is provided (121). An upper flow limit for

effective passage is that at which energy cannot

be dissipated from pool to pool (121).

Some pool and weir fishways have submerged

orifices that allow fish to pass upstream without

cresting each weir (121). Weir and orifice/weir

fishways have been used successfully by anadromous salmonids, but not readily by alewife, shad

and other fish that rarely leap over obstacles or

swim through submerged orifices (121). 

Fishing restrictions aimed at protecting Columbia Basin salmon have been inappropriately applied to

Alaska’s commercial and sport fisheries. The precipitous declines in some salmon stocks stem from habitat degradation and hatchery introgression, not commercial fisheries. Yet, under the provisions of the

ESA and the Pacific Salmon Treaty signed by the United States and Canada, fishermen carry the regulatory burden for intensive development practices. Commercial fishermen, many of whom operate smallscale family-owned troll fisheries, question fishing restrictions that may cost them their livelihoods and

save a handful of fish when so many are killed at dams hundreds of miles away. Sport fishing-related

restrictions also negatively affect local economies. Restricting Alaska’s fisheries is especially ironic in that

chinook stocks harvested in Alaska are the healthiest on the coast (200). In that entire communities in

Southeast Alaska earn their income primarily through trolling, fishery restrictions pose a serious threat to

regional economies, while resulting in only marginal improvement in salmon resources.

SOURCE: C. Estes, Statewide Instream Flow Coordinator, Alaska Department of Fish and Game, August 1995.

BOX 3-2: The Special Case of Alaska (Cont’d.)
Chapter 3 Upstream Fish Passage Technologies: How Well Do They Work? 57

Fishway

Flow Centre Side over- Centre exit Flow pattern

\ weir flow weir overflow and

Fishway

entrance

Centre overflow and orifice

Plan view

SOURCE: C. Katopodis, 1992.

between long segments

■ Limited by large water depths

■ Greater discharge of water than the Flow

other fishways are, therefore, a greater

attraction capability.

Flow pattern

Plan view

SOURCE: C. Katopodis, 1992.

Denil created by the baffling controls flow for fish pasDenil fish ladders are rectangular chutes or flumes. sage. The Denil concept originated in the 1920s and

These relatively narrow chutes have baffles extend- was tested in Iowa in the 1940s. The ladders are

ing from the sides and bottoms which point widely used in the eastern part of the country, and

upstream (see figure 3-2). The internal roughness are typically not deployed in the Northwest.
58 | Fish Passage Technologies: Protection at Hydropower Facilities

Denil fishways accommodate more different

species of fish than other fishways and have been

successfully used with a wide variety of anadromous and riverine fish. In the East, Denil fishways are most commonly deployed in small

streams. The U.S. Fish and Wildlife Service

(FWS) has very specific design parameters relating to slope, water depth and volume of flow to

control turbulence and velocity for different species (197).

Flow through Denil fishways is very turbulent, with large momentum exchange and high

energy dissipation (121). Fish must swim constantly in the Denil chute so resting pools must

be provided in higher head situations. Pools are

recommended at 10 to 15 meter intervals for

adult salmon and at 5 to 10 m intervals for adult

riverine species (120). The U.S. Fish and Wildlife Service, Region 5, suggests a resting pool for

every six to nine feet of vertical lift in Denil fishways (186). The large, turbulent flows associated

with the Denil decrease fishway sedimentation

and provide good attraction capability (121,186).

However, auxiliary attraction flows are often

needed since flows are generally lower near the

bottom and faster at the top depending on the

specific fishway design and depth of the water

(15,120).

Denil fishways are typically two to four feet

wide and four to eight feet deep. Fish can ascend

the fishway at their preferred depth. Fish ascending a Denil face varying water velocities depending on their preferred swimming depth (121).

Fish generally move more quickly through Denil

fishways than through pool and weir fishways

(121), and the former can be more effective at

steeper slopes than most other fishways (186).

Operable slopes range up to 25 degrees for adult

salmon; lesser slopes of 10 to 15 percent are

more appropriate for adult freshwater fish. Denil

fishways also accommodate a wider range of

flow conditions than pool and weir ladders; thus,

flow control to maintain operable depths is not as

critical. However, forebay elevations generally

must be maintained within several feet to maintain good passage conditions. For greater headwater variations, a stacked Denil with an

intermediate bottom can be used to increase the

range of flows over which the fishway can operate (121). Finally, debris blockage is a common

problem associated with Denil fishways.

Alaska Steeppass

The Alaska steeppass is a prefabricated, modular

style of Denil fish ladder originally developed

for use in remote locales (see figure 3-3). The

steeppass is a relatively economical, lightweight

fishway, where one 10-foot aluminum unit

weighs only about 1,500 pounds.

The steeppass has a more complex configuration of baffles than the standard Denil, is more

efficient in controlling water velocity, and is

operable at steeper slopes (up to about 33 percent

for salmon and steelhead). The maximum slope,

and therefore the water velocity within the fishway, is a design criteria dependent on species

and size of fish to be passed (12). Less flow is

required for successful passage. However, due to

its smaller open dimensions, the steeppass has a

more limited operating range and is more susceptible to debris problems than the plain Denil.

Flow control is critical to successful operation of

the steeppass. Forebay water surfaces cannot

vary more than a foot without passage difficulties. Similarly, tailwater levels cannot fluctuate

significantly without problems either with plunging flow or backwatering.

As is true of the plain Denil, water velocities

vary with depth within the steeppass. At low

depths, velocity tends to be higher near the bottom and to decrease toward the surface. At

higher depths, flow divides into upper and lower

layers with maximum velocities at mid-depth

(15,121). The U.S. Fish and Wildlife Service

Region 5, however, does not allow the use of the

steeppass design at hydropower facilities

because it cannot function under a range of flows

(i.e., it is not hydraulically self-regulating) (186).

Vertical Slot

Like pool and weir ladders (and unlike Denil

chutes), vertical slot designs have distinct steps.

The basic design is a rectangular channel parti-
Chapter 3 Upstream Fish Passage Technologies: How Well Do They Work? 59

Fishway

Flow exit

Fishway

entrance

Flow

Steeppass baffles

Flow

Plan Front elevation

Baffle detail

SOURCE: C. Katopodis, 1992.

tioned by baffles into resting pools (see figure 3-

4). Water flows and fish swim from pool to pool

through slots oriented vertically (121). The vertical slot fishway was first developed for application at Hell’s Gate, a barrier created by highvelocity flow through a narrow gorge of the

Fraser River in Western Canada (15). The design

has been used successfully in many locales for a

wide variety of anadromous and riverine fish

(121).

Fish are assumed to move from slot to slot in a

nearly direct path (this has not, however, been

verified) while swimming at their preferred

depth (15). Fish use a “burst-rest” pattern to

move up the fishway from pool to pool (121).

Pools provide an opportunity to rest, but fish

must exert a burst of speed to move upstream

through the slots (186).

The dimensions of slots and pools are critical

to the stability of flow in vertical slot ladders.

Flow is a function of slot width and depth, water

depth and the head differential across slots. Sill

blocks can be installed in the bottom of the slot

to reduce turbulence by reducing slot depth (15).

Usually, a 300-mm and 200-mm water level differential between pools is appropriate for passage of adult salmon and riverine species,

respectively (121). Slot width generally is based

on the maximum size fish that is expected to use

the fishway. However, many variations in design

are possible by varying the slot arrangement,

spacing, positions, width and materials, without

significantly affecting flow patterns in the fishway (186).

Vertical slot fishways typically have a slope

of 10 percent (121). The change in elevation

from ladder top (exit) to bottom (entrance) is

nearly equally divided among all the fishway

steps; the number of steps is determined by the

maximum forebay to tailwater head differential,

whether this maximum differential is a feature of

low or high flow conditions (15).

The greatest advantage of the vertical slot

design is that it is hydraulically self-regulating

through a large range of tailwater and forebay

water surface elevations. Hydraulic control is

provided by the slots, which are the zones of

highest water velocity. Energy, in the form of

water jets at each slot, is dissipated as the jet is

cushioned and mixes with the pool water

between baffles. The jet discharge pattern and

drop between pools can be adjusted for a particu-
60 Fish Passage Technologies: Protection at Hydropower Facilities

Fishway

Flow exit

Fishway

entrance

■ variable water levels readily

accommodated. Flow

Flow pattern

Plan view

SOURCE: C. Katopodis, 1992.

lar target species. Water velocities are almost

constant along the entire ‘slot height (15,121),

and velocities are maintained for very large

water depths. As flows increase, pools deepen

and the appropriate level of energy dissipation is

maintained. As a result, these fishways can be

built to accommodate a large range of water levels (121). The only constraint to operable range

is the depth of the slots.

Within this constraint, any change in forebay

or tailwater surface is automatically compensated for and distributed throughout the fishway

(15). Thus, vertical slot fishways may be the

most effective design for localities where water

levels are expected to vary significantly during

periods of fish migration (121). Additional water

generally is needed for attraction flow at the

entrance of vertical slot fishways (187).

Vertical slot fishways have had considerable

application across the country with wide success.

These fishways seem to work well for a variety

of species. In the Pacific Northwest, vertical slot

fishways were constructed at 21 tributary sites in

the 1980s. Radio telemetry studies showed that

fish moved past these facilities in less than a day

(187).

Hybrid

The design features of several types of ladders

may also be combined in a single fishway design

to accommodate variations in flows (186) or

multiple target fish. Features of pool and weir,

vertical slot and roughened channel (Denil)

designs can be brought together (see figure 3-5).

For example, a “pool and chute” fishway may

be constructed to accommodate a wider range of

stream flows than pool and weir ladders without

additional flow controls. The fishway essentially

operates as a pool and weir facility at low flow

and as a Denil-type chute at higher flow (15).

Combination designs such as this have not yet

been thoroughly tested and therefore have not

been evaluated as to effectiveness in passing target fish.

■ Fish Lifts

Fish elevators and locks, which can be collectively referred to as fish lifts, are desirable in certain settings because they are not flow

dependent, nor are they species specific (105).

The strategy of the lift is to attract fish to a waterfilled chamber at the downstream side of the

project (i.e., tailrace area) and transport them
Chapter 3 Upstream Fish Passage Technologies: How Well Do They Work? 61

Dam crest

6 " , ,0, ,

1

2“ x 2“ orifices

SOURCE: C. Katopodis, 1992

passively to the top of the project (i.e., headpond

area) for release. This approach has advantages

over ladder-based mitigation technologies under

certain conditions where large numbers of fish

must be accommodated, or if the target species

are not well suited to ladders (including weak

swimmers, and others that might not successfully

negotiate ladders), or if the hydropower project is

too large for cost-effective fishway installation

(242). However, fish may experience crowding

during peak migratory periods.

Elevators have the potential to accommodate

large numbers of fish if operated with sufficient

frequency based on population and migratory

data (196). In order for elevators to be effective

there must be adequate attraction flow out of the

entrance gallery to guide fish. After attraction

into the gallery, upward movement is mechanical. This technology can be a labor-intensive

means of achieving mitigation; however, automation and the use of a bypass to get fish from

the lift exit back to the river channel upstream of

the project can help alleviate this drawback.

While similar to fishways in capital costs, elevators involve higher operation and management

expenses (243). Also, they may be susceptible to

mechanical failure much more than fishways,

which might cause significant problems for fish

if out of commission during the peak migration

period.

Like elevators, locks require a fish collection

facility at the downstream side of the hydropower project level, with a fish entrance, V trap,

and fish crowding device to force fish into a

water-filled hopper (220). Locks are vertical
62 | Fish Passage Technologies: Protection at Hydropower Facilities

chambers into which fish are crowded; they are

then filled with water which raises fish to a

higher level. The technology may require a substantial amount of water but is a less complicated

device than an elevator.

Elevators and locks are used to lift fish to the

forebay level where they may either exit into a

bypass, which eventually exits into the river

upstream of the project, or be transferred to

trucks for release further upstream. A chief disadvantage of utilizing elevators is that automated

operation may not be possible (220), and stress

and mortality due to handling may occur. Counting and sorting of unwanted species can take

place in the collection hopper or in the bypass, if

the fish are crowded before release. Also, most

lifts have an intermittent mode of operation

which can delay fish at the base of a project for

unacceptable periods of time (243). Multiple

hoppers can be employed to alleviate this problem. Depending on site conditions, lifts can be

much less expensive to construct than other fishways. The greatest advantage is for high head

sites where fishways would be very expensive.

❚ Trap and Truck (Transportation)

Trapping and then trucking adult migrants to

move them upstream has become highly controversial. The lack of a conventional fishway and

the cost of installing one are typical reasons for

using this alternative means of fish transport.

Some practitioners have concerns regarding the

effect that handling and transport have on fish

behavior and health. On the other hand, trap and

truck operations have been successfully used in

some cases to move adults upstream of long reservoirs, or multiple projects; fish can then be

released close to spawning grounds.

Transportation operations should be executed

under conservative conditions to minimize stress.

Possible adverse impacts of trapping and trucking fish include disorientation, disease and mortality, delay in migration, and interruption of the

homing instinct, which can lead to straying.3

Additionally, in the case of a proposed trap and

truck system for a proposed project on the

Penobscot River in Maine, transport of fish

would bypass traditional fishing grounds of the

Penobscot Indian Nation (21). Additional

adverse impacts include low capacity to move

the peak of the run without delay and injury, and

the cost of operation, leading to a reduction of

the operating season or overloading of hauling

trucks.

However, moving fish by truck can be a sound

method of transport. On the Susquehanna River

in Pennsylvania, fish lifts are in operation at the

downstream-most hydropower project. They

assist a trap and truck operation which supports

the restoration of American shad, blueback herring, and alewives. The fish are transported

upstream of the four projects on the river and

released in the highest headpond near to spawning grounds. There are two lifts in operation at

the Conowingo project, one on the west side of

the dam and one on the east. Several improvements were made to trap and transfer operations

in 1993, including development of new holding

facilities at the east lift.

The 10-year-old Conowingo program, supported by state and federal resource agencies, has

been quite a success. The transport survival of

American shad ranged from 65 to 100 percent

from the east lift, while the west lift transport

survival ranged from 94.9 to 100 percent in 1993

(252). Holding facilities at both lifts were utilized to reduce stress, maximize transport operations, and release larger schools of fish (177). In

addition, load size of fish transported was

reduced to prevent undue stress due to crowding.

A monitoring program was instituted to determine delayed mortality rates at the release sites.

The evaluation of the program at Conowingo has

led the agencies to investigate the installation of

3 Returning adults are driven to spawn by biological cues; an upset of the physiological response can be detrimental. Fish may become

disoriented and delay in the river near the release point rather than migrate upstream to spawning grounds. In instances where fish must spend

long periods of time in the transport tank, the spread of disease and ultimate pre- or post-release mortality becomes a concern.
Chapter 3 Upstream Fish Passage Technologies: How Well Do They Work? | 63

fish lifts at three upstream projects (177) and

once built, trapping and trucking will be used at a

minimum to move fish around the Conowingo

hydropower facility.

❚ Fish Pumps

The use of fish pumps to move adult fish

upstream of hydropower projects is not widely

accepted or used. The FWS Region 5 generally

does not support the use of fish pumps due to the

nature of the passage method which is completely facilitated and subjects fish to an artificial

environment. Fish are pumped to a bypass conduit which releases them upstream of the project.

Pumping fish has the potential to lead to injury

and de-scaling as a result of crowding in the

bypass pipe. This means of passage may also

result in disorientation upon release which could

potentially lead to problems with predation.

At the Edwards Dam (hydropower project) on

the Kennebec River in Augusta, Maine, negotiations between the project owner and the resource

agencies over how best to provide an economic

means of safely passing American shad, alewife,

and Atlantic salmon have been underway for

some time. The intent was to use a pump to

transport fish (mainly adult alewives) to a sorting

and holding facility for trucking upstream. A fish

pump4

 is being used as an interim measure,

though it has not been as effective as hoped in

passing fish upstream (41). In addition, there

were initial difficulties with injury and mortality.

The State of Maine favors removal of the

Edwards Dam in an effort to restore the river

above the project as a spawning and rearing area

for a variety of anadromous species which are

not known to utilize conventional fish passage

technologies.

EFFECTIVE FISHWAY DESIGN

An effective fish passage system must be “fish

friendly.” Fish use proximate cues from the

4 The pump in question is a Wemco-Hidrostal screw impeller pump. This is the most commonly employed fish pump at fish hatcheries

and thermal power plants.

physical environment to select a riverine space

for migration. Increased understanding of these

innate preferences could improve the ability of

fish passage experts to create suitable environments that attract and pass fish (133). The design

must accommodate the unique site conditions

and target fish. Achieving such a standard is reliant on obtaining sufficient knowledge of the

biology and behavior of the target fish population, and collecting the appropriate hydrological

and environmental information.

The basic design requirements of standard

upstream fish passage facilities are reasonably

well understood, and some conventional fishway

designs (e.g., ladders such as the Denil, Alaska

steeppass, pool and weir, vertical slot; and lifts

and locks) have been used long enough that the

design specifications are almost generic. In other

words, fishway practitioners understand form

and function well enough to make predictions

about how a particular fishway might function

and accommodate a particular species under

given conditions.

Information and data specific to the site must

still be obtained. Site data are the physical

description of the barrier, river channel, uplands,

and hydrology associated with the barrier location, which includes geologic, hydrologic, and

topographic descriptions. Stream gauge data is

essential and aerial and ground photos are useful.

Biological data are the fish passage design criteria which include species targeted for passage,

physical size, run size, other species that might

compete for space or that should be excluded,

and timing of passage needs, including both the

time of year and day when target fish are present

(i.e., seasonal and diurnal characteristics). In

addition, information related to swimming ability

(speed and endurance) and preference for flow

(orifices, streaming or plunging flow, surface or

bottom), and an understanding of what behaviors

can be accommodated to enhance passage success are all important to design and success.
64 | Fish Passage Technologies: Protection at Hydropower Facilities

Understanding and maintaining hydrology and

design flows is critical, although there are few

situations in which fish passage can be maintained during all possible flow regimes (15). It is

important to determine the highest and lowest

flows at which the fish passage criteria are satisfied as well as the “normal” operational flows.

Different species may or may not be able to

adapt to higher flows when hydraulic conditions

in the fishway diverge from design criteria (15).

Finally, keeping the fishway debris free and regularly checking operation are critical to optimizing and maintaining proper hydraulic conditions.

Without the appropriate information, an ineffective fishway will likely result. Practitioners

should do their homework and hydraulic modeling can assist the practitioner in developing the

appropriate design. The design should allow for

any potential changes in hydrologic and environmental conditions that might occur up- or downstream of the facility. These changes may occur

naturally or may be human-induced and can negatively influence fishway operation. For example, inadequate or excess flow in the fishway due

to alterations in instream flows could result in a

submerged or elevated entrance that is inaccessible to the target fish (186).

However, because river systems are dynamic

and variable, each site presents the possibility of

new challenges that must be addressed and

resolved through the cooperative efforts of the

project owner, the resource agencies, and consultants (220). In some cases, the full involvement of agency personnel with the experience

and expertise necessary for designing effective

fish passage systems may not be possible, due to

lack of sufficient staff and/or their time constraints. There may be a lack of necessary information at the state and local levels, and as a

result, fishways may be inappropriately

designed. A lack of expert staff and/or information needed for the design of fish passage typically results in the use of those technologies that

are better known and generally accepted by the

resource agencies.

A relatively small group of people from

resource agencies, and some experienced consultants, is recognized regionally and/or nationally to posses significant experience and

expertise in fish passage problem solving, and in

the determination of design criteria. These

experts have generally provided written standards and guidelines for their regions of the

country, and are in general agreement over what

data and information are needed to build a successful and effective fish passage system. In the

last several years, the FWS, as well as a couple

of state resource agencies, have hosted courses

on fish passage design and implementation for

those involved in fishway application, in an

effort to increase working knowledge and create

an open forum for discussion and information

exchange between practitioners and regulators. It

is the hope of these agencies that this type of

effort will help enhance fish passage results and

reduce the incidence of costly mistakes by

encouraging communication, dissemination of

information, and cooperation.

Effective design of a fishway system must

address the three basic components of all fishways: entrance, fishway, and exit. Key design

elements for each component are described

below.

❚ Fishway Entrance

The fishway entrance, the critical link to fishway

effectiveness, must be designed to attract fish in

a timely manner: “No fish in = No fish out”

(13,14,132). Adequate attraction flow is the most

important element of a successful passage system because it provides the means of getting fish

to the entrance and providing them access to the

fishway.

Entrances should be located where fish will

have good access. Considering which riverbank

most of the fish orient to during upstream migration, how instream and tailwater conditions may

affect fish movement and detection of attraction

flow are all critical to success.5 If fish are to be

attracted, the entrance cannot be located too far

5 In wide channel sites, fishway entrances are often required for both river banks and should be operational at all flows.
Chapter 3 Upstream Fish Passage Technologies: How Well Do They Work? | 65

downstream from the dam or powerhouse, or too

far from the main streamflow, or in a back eddy

(220).

The depth of the entrance is an important consideration, and is influenced by flows in the river

channel upstream of the fishway. If flows in the

system are erratic, the entrance should be situated low enough in the river to eliminate the risk

of its being exposed (i.e., elevated) and therefore

inaccessible to fish. Some sites may require that

fishways have multiple entrances. In these situations, tailrace flow conditions must be considered and understood (15). Should the entrance

become inaccessible, auxiliary water is needed.

The auxiliary water system is the source, control, and supply of supplementary water to the

lower end of the fishway (15). Auxiliary water

provides additional flow for attraction, especially

when the entrance is in competition with high

river flows, and helps maintain the desired flow

characteristics in the fishway and in transportation channels. This water can be introduced to

the fishway through diffusers (e.g., bar grating,

perforated plate, or wood racks) in the walls or

floors of the fishway. In general, diffusers must

introduce water at a relative velocity (perhaps as

low as 0.25 feet per second) that will not cause

delays by attracting fish (15). To mitigate against

this possibility, a steady stream of flow from the

fishway can be directed along the face of the diffuser (15).

❚ Fishway

Designing an effective fishway requires availability of the appropriate pre-design data including physical site and hydrologic data, and

biologic data (85). These data form the basis for

the technical design of the fishway which should

accommodate the weakest individual (in terms of

swimming performance) of the target fish population.

Excess flow in the fishway due to changes in

upstream conditions and flow characteristics

may be problematic, and mechanisms for controlling flow are essential. Such conditions typically require retrofitting to accommodate or

control the flow. Considerations of flow patterns

and hydraulics at all flows within the prescribed

fish passage design flow range must be given.

Extreme flows within the design flow range are

often not observable during the design process

and conditions should therefore be predicted by

hydraulic experts or physical modeling. Extra

baffling or other flow control methods may help

to alleviate this problem. Increased flows can

wash out the desired flow characteristics the fishway was designed to create, in the entrance, fishway, and exit.

❚ Fishway Exit

Fish tend to delay when exiting a fishway into a

forebay mainly due to disorientation and the

need to adjust to the new environment and flow

conditions (15). Proper placement of the fishway

exit can reduce this delay time but requires

understanding of a site’s forebay current. Exits

should be located away from spillways or powerhouses and placed in areas where there is a consistent downstream flow (15). Fish tend to orient

to the shoreline and into a consistent current during upstream migration. Exits may be extended

upstream of the facility in order to achieve correct current conditions. Accumulation of debris

around the fishway exit can be prevented by

placement of trash racks; however, regular maintenance is required to assure proper operation. A

rack or a boom may be placed to guide debris

away from the fishway exit to the spillway or

sluiceway.

WHY FISHWAYS FAIL

There are three major reasons why fishways do

not always work as expected: inadequate or

unclear goals, poor design, and inadequate operation and maintenance.

❚ Inadequate or Unclear Goals

The question of whether or not a fishway works

or how well it works can be answered in narrow

scope (Are fish using it? How many fish are

using it?) or in broad scope (What impact is the

movement of fish via the fishway having on the
66 | Fish Passage Technologies: Protection at Hydropower Facilities

larger population and ecosystem?) (189). Determining which approach to take is dictated by the

goal. Goals for establishing fishways vary from

site to site. Goals may be short or long term, they

may be directly measurable or more broad in

nature. If no goal is set, there can be no real measure of effectiveness.

If the goal of the fishway is protection, i.e., to

pass fish as a mitigative measure for whatever

blockage might be in place, then evaluating passage (through counts, telemetry, tag/mark and

recapture studies) will serve to determine how

well the fishway is functioning. However, if the

goal of establishing the fishway is much broader

than that, for example, to assist in the restoration

of a threatened species or the restoration of a species which has ceased to exist in the waterway,

then measurement of achievement and success

becomes more complex. This type of measurement would require knowledge of past conditions and population information as well as

management and population goals for the future.

❚ Poor Design

Upstream fish passage technologies, though relatively well understood, can still fail to pass fish

effectively. Some of the reasons include lack of

attraction flow, poorly designed entrances,

unsuitable hydraulic conditions within the fishway, ill-placed exits, improper operation, or

inadequate maintenance. Fish ladders are highly

flow- and velocity-dependent, not only to attract

but to move fish. Successful operation of fish

lifts is also dependent on attraction flow. Transportation operations are less dependent on flow.

Attraction flow can make the difference

between fish passage success and failure. Optimum attraction flow often requires multiple fishway entrances. In these situations, however,

tailrace and/or flow conditions can vary considerably. A lack of good attraction flow, or the

inability to maintain the appropriate flow, can

result in delays in migration as fish become confused or fatigued. The proper location and position of the fishway entrance will help move fish

past the obstruction more quickly.

Similarly, increased volume and velocity of

flow in the fishway over baffles and around

weirs could negate the roughness factor they create, and a submerged fishway entrance could

increase “delay time” for fish looking for a

means to move upstream (120). Current velocities that exceed the swimming capabilities of the

fish create a barrier to fish movement (14,133).

The capacity to add additional baffles helps to

mitigate increased flow by adding roughness.

Decreases in flow in the fishway can negate the

fishway hydraulics and expose the entrance,

making it inaccessible to fish. Also, decreased

flow in the fishway can significantly raise temperatures in turning pools and resting areas, causing fish to hold up (i.e., school or delay) in the

fishway. The addition of auxiliary flow can help

avoid these situations. In fact, improper flow

inside the fishway can negate any positive elements associated with the attraction flow and

fishway entrance.

In addition to hydraulic conditions and temperature, some species are also sensitive to light,

and in a lesser way to odor. Lighting conditions

in the fishway can discourage or encourage

movement (133). For example, adult American

shad tend to avoid shade, while adult alewives

avoid intense mid-day illumination during

migration (133). Light intensity affects the orientation ability of some fish. As light intensity

decreases below a threshold level, fish cannot

orient; this behavior is exacerbated in fast flow

(133). For example, adult American shad may

actively seek passage in high-flow tailraces during the daylight hours but tend to move more

slowly at night in those areas. In addition, some

fish may be caused to delay movement in

response to certain odors introduced via surface

runoff.

Good fishway design cannot occur without

consideration of fish behavior and swimming

ability. Understanding the behavior of target fish

species is necessary to optimally design, locate,

and operate upstream passage facilities (133).

Delays in migration can result if the hydraulic

conditions within the fishway itself are inappropriate for the species to be passed. Design must
Chapter 3 Upstream Fish Passage Technologies: How Well Do They Work? | 67

accommodate species preference for different

swimming behavior (e.g., surface, bottom, middle of water column), flow regimes (such as

plunging or streaming), and willingness to swim

through slots, orifices, etc. Appropriate flow conditions must be maintained under all river flow

conditions. The resting and turning pools and

baffle and weir configurations of the fishway

must be matched to biology, behavior, and swimming ability.

❚ Inadequate Operation and Maintenance

Consistent performance of any well-designed

fishway is largely based on maintenance and regular observation of operation. If a fishway

becomes clogged or blocked with debris, hydraulic conditions will be altered and the fishway

may be rendered ineffective. Some styles of fishways tend more easily to be blocked with debris.

The susceptibility to debris blockage often regulates minimum dimension of orifices and weirs

and fishway flow. In addition, physical changes

in the waterway that alter hydraulics above and

below the fishway can adversely impact fishway

performance. Debris loading and blockage

within the fishway can alter flow conditions and

slow or prohibit fish movement. Without proper

maintenance even perfectly designed fishways

can be rendered useless.

CONCLUSIONS

Upstream fish passages are necessary to move

fish around hydropower facilities so they can

reach necessary habitat and spawning grounds.

Most conventional fishways are accepted and

approved for use by the resource agencies. Fish

ladders (e.g., pool and weir, Denil, Alaska steeppass, vertical slot), and fish lifts are in use at a

number of FERC hydropower projects.6

Although few have been evaluated, these technologies are considered well developed and

understood for certain anadromous species,

including salmonids, American shad, alewives,

6 Resource agencies have many concerns about the use of fish pumps for upstream passage.

blueback herring, and eels; and somewhat for

riverine (so-called resident species) including

trout, walleye, bass, and lamprey. Site- and species-specific criteria, as well as economics, help

to determine which method is most appropriate.

Fish passage success is highly dependent on

creating a “fish friendly” environment. Some fish

ladders perform better than others because they

better accommodate fish behavior and responses

to particular hydraulic conditions. Attention to

ichthyomechanics is essential to fish passage

success. Although it is difficult to pinpoint the

range of responses that the target fish might

exhibit under natural conditions, available data

on fish behavior can be applied to fishway

design. An understanding of whether the target

fish(es) are bottom, surface, or orifice swimmers,

or whether plunging or streaming flow is preferred, helps to assure successful passage.

Attraction flow can make the difference

between fish passage success and failure. This is

true for fish ladders and lifts. A lack of good

attraction flow, or the inability to maintain the

appropriate flow, can result in delays in migration. Conversely, good attraction flow and a

properly located fishway entrance will help

enhance fishway effectiveness. This is true for

fish ladders and fish lifts.

The design of fishways must also accommodate a range of flow conditions up- and downstream of the structure and be self-regulating, to

the extent that it is possible. They should be

properly maintained and kept debris free, or even

the best designed structures will fail. Inadequate

operations and maintenance, inadequate coordination between design of fishway and hydropower generation, inadequate attraction flow

(e.g., difficulty or delay in finding entrance), illmaintained flow regime in the fishway, or excessive fishway length (e.g., fish become fatigued or

hold up in resting areas) are all potential contributors to fishway failure.

The use of trucks to move adult migrants

upstream is somewhat controversial, and some
68 | Fish Passage Technologies: Protection at Hydropower Facilities

practitioners have concerns regarding the effect

that handling and transport might have on fish

behavior and health. On the other hand, trap and

truck operations have been successful in moving

adults upstream of long reservoirs where they

might become lost or disoriented on their way to

habitat and spawning grounds. In some cases,

where hydropower plants occur in series and

fishway installation occurs as a staged process,

trucking is critical to species survival. At sites

where fishways are feasible, resource agencies

prefer the use of transport only as an interim

measure.

Because river systems are dynamic and variable, each project site has unique characteristics

and can present new challenges in fishway

design. They can be addressed through the cooperative efforts of the project owner, the resource

agencies, and consultants. The full involvement

of agency personnel with the experience and

expertise necessary for designing effective fish

passage systems is critical. The FWS and some

state resource agencies have provided courses on

fish passage design and implementation in an

effort to increase working knowledge of practitioners, and to promote an open forum for discussion and information exchange between

practitioners, FERC, and project operators. This

type of effort could help enhance fishway performance and reduce the incidence of costly mistakes by encouraging communication, cooperation, and commitment to doing good work.
| 69

4

Downstream

Fish Passage

Technologies:

How Well

Do They Work?

he implementation of downstream mitigation for fish passage at hydropower

facilities has three distinct goals: to

transport fish downstream; to prevent

fish from entrainment in turbine intakes; and to

move fish, in a timely and safe manner, through a

reservoir.1

A range of mitigation methods for downstream passage and for prevention of turbine

entrainment exist, and some have been applied

with more success than others. The so-called

“standard” or “conventional” technologies are

mainly structures meant to physically exclude or

“guide” fish to a sluiceway or bypass around the

project and away from turbine intakes by means

of manipulating hydraulic conditions. Other

“alternative” technologies attempt to “guide”

fish by either attracting or repelling them by

means of applying a stimulus (i.e., light, sound,

electric current). Many theories have been

applied to the design of downstream passage systems and further experimentation is underway in

some cases (see box 4-1).

1 The main difference between up- and downstream passage is that upstream moving fish may keep trying until they find a means of passage (i.e., a fishway). A downstream migrating juvenile has one chance to find the proper passage route, otherwise it becomes entrained.

For downstream migrating species, including

the juveniles of anadromous upstream spawners,

it is important that a safe route past hydropower

facilities be made available. For these fish, a

means of preventing turbine entrainment, via a

diversion and bypass system, is often needed

(242,243) (see box 4-2). For some resident fish,

downstream movement may not be critical or

desirable. Philosophies of protection vary across

the country depending on target fish, magnitude

of the river system, and complexity of the hydropower facility. For example, practitioners in the

Northwest tend to prefer exclusion devices that

physically prevent entrainment, while those in

the Northeast tend to recommend structural

devices that may alter flow and rely on fish

behavior for exclusion.2 Much of the variance in

protection philosophy may be linked to differences in target fish in these regions. The Northwest hosts a number of endangered or threatened

species (mainly salmonids), while the Northeast

does not have quite the same history of concern.

In the Northwest, fish protection is mainly

focused on salmonids. Downstream migrants

2 The mechanism that causes fish to be guided by angled bar racks is not well understood.

T
70 | Fish Passage Technologies: Protection at Hydropower Facilities

tend to be small and have limited swimming ability. In the Northeast, fish protection is focused on

a variety of species. In some cases downstream

migrants are of fairly good size and possess

fairly good swimming ability (e.g., American

shad).

Physical barriers are the most widely used

technology for fish protection. These technologies include many kinds of screens (positioned

across entrances to power canals or turbine

intakes) providing physical exclusion and protection from entrainment. In some parts of the country, behavioral guidance devices such as angled

bar racks (modified versions of conventional

trashracks) are used to protect fish from turbine

entrainment. For both categories of downstream

passage technologies, careful attention to dimensions, configurations and orientations relative to

flow is required to optimize fish guidance.3

In most cases, structural measures to exclude

or guide fish are preferred by resource agencies.

Screens and angled bar racks providing structural

measures for physical guidance are preferred by

resource agencies, however, the screens can be

expensive to construct and maintain. As a result,

3 Fish impingement on screens or trashracks can stress, descale and otherwise injure fish, particularly juveniles (168, 190).

the development of alternatives to these technologies, such as alternative behavioral guidance

devices (e.g., light, sound), continues to be

explored. These devices have not been proven to

perform successfully under a wide range of conditions as well as properly designed and maintained structural barriers. Thus, the resource

agencies consider them to be less reliable in the

field than physical barriers. In addition, other

methods for downstream passage are also being

explored. New turbine designs that will be not

only more efficient but more “friendly” to fish

are under proposal. And in the Columbia River

Basin, a surface collector system which intends

to guide fish past hydropower facilities by better

accommodating natural behavior is being experimented with at a number of sites.

DESIGN OF CONVENTIONAL 

STRUCTURAL MEASURES

Progress in developing effective downstream

fish passage and protection mechanisms has

occurred over the past 50 years (203,205,221).

Physical barrier screens and bar racks and louBOX 4-1: Chapter Findings—Downstream Technologies

■ There is no single solution for designing downstream fish passage. Effective fish passage design for a

specific site requires good communication between engineers and biologists and thorough understanding of site characteristics.

■ Physical barrier screens are often the only resource agency-approved technology to protect fish from turbine intake channels, yet they are perceived to be very expensive.

■ The ultimate goal of 100 percent passage effectiveness is most likely to be achieved with the use of physical barrier technologies, however site, technological, and biological constraints to passing fish around or

through hydropower projects may limit performance.

■ Structural guidance devices have shown to have a high level of performance at a few studied sites in the

Northeast. The mechanism by which they work is not well understood.

■ Alternative behavioral guidance devices have potential to elicit avoidance responses from some species

of fish. However, it has not yet been demonstrated that these responses can be directed reliably; behavioral guidance devices are site- and species-specific; it appears unlikely that behavioral methods will perform as well as conventional barriers over a range of hydraulic conditions and for a variety of species.

SOURCE: Office of Technology Assessment, 1995.
Chapter 4 Downstream Fish Passage Technologies: How Well Do They Work? | 71

BOX 4-2: Complements to Exclusion, Diversion, and Guidance Technologies

Once fish are diverted by physical screens, angled bar racks, or louvers, a means of passing them around

hydropower projects is needed. This is achieved through the use of bypasses and sluiceways. These measures

would also be required for any emerging behavioral guidance technologies.

Bypasses

Engineered bypass conduits are needed for downstream-migrating fish at hydropower facilities and are the

key to transporting fish from above to below a hydropower project. Most early downstream mitigation efforts

only marginally improved juvenile fish survival. Today, juvenile bypass structures are more efficient due to lessons learned and a better understanding of the interaction of hydraulics and fish behavior (190). In some

instances bypasses must provide efficient and safe passage for both juvenile and adult life stages (175).

Despite efforts at designing mitigation systems for specific sites, efforts may fail due to inadequately

designed fish bypasses (204). Bypass design should be based on the numbers, sizes, and behaviors of target

species (204). The entrance to such channels may be their most important feature. Smooth interior surfaces and

joints, adequate width, absence of bends and negative pressures, proper lighting, and appropriate hydraulic

gradients should be considered when designing an effective bypass system (239). High-density polyethylene,

PVC, or concrete cylinders are all appropriate bypass materials (175).

Bypass entrances and the velocity of the flow are critical to success. For example, fish may be less likely to

enter a bypass if met with extremely high flows. Typically, bypass entrances consist of a sharp-crested weir

configuration which causes an increase in velocity. The development of a new weir, which may be able to be

retrofitted at some applications, will result in gradual velocity acceleration intended to be more attractive to

fish.a

Bypass outfalls are also critical in achieving safe downstream passage of target fish. The potential for predation at bypass exits where fish are concentrated is a particular concern (204). Gulls, squawfish, otters, herons,

and other predators often congregate at these outfalls. Submerged outfalls may allow for avoidance of strong

currents, bottom injury, and predation by birds; but they may cause disorientation and have debris problems

(175,190). Elevated outfalls may greatly subject fish to predation and disorientation, but avoid problems with

debris. Injury and mortality associated with various bypass structures has rarely been studied, although in some

cases it has been high.

Sluiceways

Sluiceways are typically used to bypass ice and debris at hydropower projects, but they can also provide an

adequate and generally successful means of downstream passage provided fish are able to locate them. Small

hydropower projects often rely on sluiceways for passage. This type of passage may work well for surface or

near-surface oriented fish (i.e., clupeids, salmonids, and some riverine species) but may not work as well for

fish distributed elsewhere in the water column.

Entrance location, adequate flow, and thorough maintenance and debris removal are critical factors to

sluiceway success. The sluiceway should be located to one side of the powerhouse, generally at the most

downstream end, with its outfall located so as not to interfere with the attraction flow of the upstream fishway.

The greatest problem associated with sluiceways is the potential for predation at the entrance or exit.

aThe NU-Alden Weir was developed by Alden Research Laboratory with funding from Northeast Utilities, Inc. Testing of the

weir took place at the Conte Anadromous Fish Research Center during the spring of 1995. Results were promising.

SOURCE: Office of Technology Assessment, 1995.
72 | Fish Passage Technologies: Protection at Hydropower Facilities

vers have been used to exclude fishes from turbine intakes and are considered to be standard,

conventional technologies.4

 In cases where there

is a large forebay area, water velocities are high,

or site specifications are limiting, these types of

systems may not be feasible, or the costs may be

exceedingly high. Physical barrier screens may

provide nearly 100 percent protection for migrating (target) fish, but for the aforementioned reasons, the development of alternative behavioral

guidance techniques (e.g., sound and light) has

been, and continues to be, pursued in the public

and private sector.

The design of effective structural measures for

assisting in downstream passage of juvenile outmigrants and riverine species is dependent on

behavioral criteria, and the knowledge of physical, hydraulic, and biological information which

are critical to success (13,185). Lack of knowledge of fish behavior tends to lead to disagreement on what the best available method or

technology for a particular site might be. This

type of information is also necessary for the

design of alternative behavioral guidance

devices. For example, the limited swimming

ability exhibited at the juvenile stage is a critical

design concern. Flow data, species and population size, and where the target species tend to

exist within the water column will help determine location and type of passage system necessary.

Downstream passage design must take into

consideration the lack of or limited swimming

ability of outmigrating (anadromous) juvenile

and smolt fishes. Other catadromous and riverine

species may have limited swimming ability as

well, depending on age and size. Where larger

catadromous fishes and anadromous adult repeat

spawners are concerned, entrainment avoidance

might be more related to behavior than to physi4 Bar racks and louvers are considered standard technologies for application in the Northeast, but not in the Northwest.

cal swimming ability. Where hydropower

projects exist in series, a system of reservoirs

may be created where velocities are low and

water temperatures elevated. These conditions

may alter fish behavior and slow outmigration of

juveniles that are dependent on water flow to

assist their movement. The series of four dams

(McNary, The Dalles, John Day, Bonneville) on

the lower Columbia River, for example, can add

up to 20 to 30 days to the travel time for juvenile

fish due to alteration in flow conditions (230).

Screens as well as bar racks generally are

designed to work with site hydraulics to help or

encourage fish in moving past or away from turbine intakes. Well-designed screen facilities may

result in a guidance efficiency of over 95 percent

(see appendix B) (236,236A). The effectiveness

of bar racks is less conclusive. The size and cost

of screen and bar racks systems depends on the

site. However, water velocities in the forebay in

general, and the approach velocity5 in front of

the system in specific, are of primary concern.

The idea is to maintain approach velocities

within the cruising speed of all target fishes to be

screened in order to achieve protection (58).

❚ Physical Barriers

Screens

Outmigrating juvenile salmonids depend a great

deal on hydrology and hydraulics to guide their

movement. These fish have limited swimming

ability and orient themselves into the flow.6

Therefore, downstream protection devices must

take advantage of natural fish behavior. At many

hydropower projects a physical barrier is used in

conjunction with a bypass to facilitate passage.

The flow characteristics that are generated by the

particular placement of a screen and the physical

parameters of the screen itself help to guide fish

5 “Approach velocity” is the velocity component of flow normal to and approximately three inches in front of the screen face. Fisheries

agencies determine this value based on the swimming capabilities of the smallest and/or weakest fish present (239). 6 Some salmonid pre-smolts have good swimming ability (i.e., sockeye, coho, steelhead), while others (i.e., pink and chum) smolt shortly

after emergence and their swimming ability does not change significantly during smoltification. Not as much is known about how other

migratory species (e.g., American shad, blueback herring) behave during outmigration (187).
Chapter 4 Downstream Fish Passage Technologies: How Well Do They Work? | 73

to the bypass. The key to successful downstream

passage is to employ the fish’s behavior to guide

them to a safe bypass. The hydraulics of the

structure must be benign enough that the fish can

be guided to safety before they fatigue or are

injured.

Physical barrier screens can be made of various materials based on the application and type

of screen (i.e., perforated plate, metal bars,

wedgewire, or plastic mesh). Screens are

designed to slow velocities and reduce entrainment and impingement (78). Smooth flow transitions, uniform velocities, and eddy-free currents

just upstream of screens are desirable. Adequate

screen area must be provided to create a low flow

velocity that enables fish to swim away from the

screen.

The positioning of the screening device is critical. It must be in appropriate relationship to the

powerhouse to guide fish to the bypass by creating the appropriate hydraulic conditions. Fish

then enter a bypass which either deposits them in

a canal that eventually rejoins the main channel,

releases them into the main flow downstream of

the project via an outfall pipe or sluiceway, or

leads them to a holding facility for later transport. Outfall pipes typically release fish above

the water’s surface to avoid creation of a hydraulic jump or debris trap within the closed pipe.

Releasing fish above the water may also alleviate

disorientation and help to prevent schooling.

However, predation at the outfall can be a problem and there is no consensus on how to avoid

this, though multiple outfalls might alleviate the

situation in some cases (188).

The screen must be kept clean and clear of

debris or it will not function properly. Debris is

commonly the biggest problem at any screen and

bypass facility. Debris loading can disrupt flow

and create high-velocity hot spots, or cause

injury to fish (238). In addition, a partially

blocked bypass entrance can reduce the efficiency of fish passage and cause injury or mortality (190) (see box 4-2). Installation and

operation of a screen cleaning system and regular

inspections to ensure proper operation of screens

may be the most important activities to increase

effectiveness. Mechanical cleaning systems are

preferable over manual ones and often more reliable, provided they are functioning properly.

Very frequent cleaning may be needed where

there is a lot of debris. California screen criteria

require cleaning every five minutes. Ideally,

screens should be cleaned while in place, and

temporary removal of a screen for cleaning is

usually not acceptable (12).

A variety of physical barrier screens has been

developed to divert downstream migrants away

from turbine intakes.7 Years of design, experimentation, evaluation, and improvement have

alleviated some problems but others still remain,

and no physical barrier is 100 percent effective in

protecting juveniles. Few studies have been able

to demonstrate conclusively a guidance efficiency exceeding 90 percent; and although the

effectiveness of these facilities is probably close

to 100 percent at many sites, losses of fish may

occur due to predation or leakage of fish past

faulty or worn screen seals (59). However,

improvements in screen components have been

made and designs have begun to reflect new

knowledge about hydraulics. Some specifics of

design and function of a variety of low-velocity8

physical barrier screens are highlighted below.

The drum screen is often found to provide the

best fish protection at sites with high debris

loads. Comprehensive evaluation of large drum

screen facilities has demonstrated nearly 100

7 Between 1985 and 1989, a series of evaluation reports on the performance of diversion screens in use at irrigation and hydroelectric

diversions in the Yakima River Basin, Washington, were jointly produced by the U.S. Department of Energy, Bonneville Power Administration, and Batelle PNW Laboratory. The reports evaluate flow characteristics of the screening facilities. A discussion of these sites is not

included in OTA’s report; however, they were used by resource agencies in developing screen criteria in the Northwest and therefore the

reports deserve mention (244, 245, 246, 247, 248, 249, 250). 8 The physical barrier screens discussed in this section are considered to be low-velocity screens, meaning that they can function at velocities (perpendicular to the screen) between 0.33 to 0.5 feet per second (59).
74 | Fish Passage Technologies: Protection at Hydropower Facilities

percent overall efficiency and survival (12). The

drum rotates within a frame and is operated continuously for cleaning. Debris is carried over the

drum and passed down a channel or into a bypass

(175). Drum screens can be expensive to construct and install, but relatively economical to

operate; however, application criteria are site

specific. These screens have been proven to be

reliable at sites in California and the Pacific

Northwest (204). Relatively constant water levels in the forebay are necessary for operation,

and maintenance and repairs to seals can be

problematic and costly.

Simple fixed screens can be an economical

method of preventing fish entry into water

intakes at sites where suspended debris is minimal; however, costs are site specific. Though

fixed panel screens can and have been built in

areas with substantial debris, automatic screen

cleaners are required. These screens have demonstrated greater than 95 percent overall efficiency and survival at sites in the Columbia

River Basin (12). Several types of simple fixed

screen are available. The stationary panel screen

is a vertical or nearly vertical wall of mesh panels installed in a straight line or “V” configuration. Fish-tight seals are easily maintained

around this fixed screen, and the design accommodates a range of flows and forebay water elevations (175).

Inclined plane screens are also stationary, but

are tilted from the vertical to divert fish up or

down in the water column to a bypass. A conceivable problem with this design is the potential

for dewatering of the fish and debris bypass route

if water levels should fall below either end of the

tilted screen. Also, cleaning is a primary concern

for both stationary panel and inclined plane

screens (175). Manual brushing is usually

required to keep surfaces debris-free. The design

is practical for water intakes drawing up to 38

cubic meters per second (175,204); however,

application depends more on the site than on the

flow.

Submersible traveling screens (STSs) are

expensive to construct and install, and subject to

mechanical failures, although in some cases they

have been considered by the U.S. Army Corps of

Engineers to be the best available technology for

diverting downstream migrating fish in the

Columbia River Basin (204). STS configurations

operate continuously during the four- to ninemonth salmonid migration period in the Columbia River; they are capable of screening

extremely large flows in confined intakes but do

not screen the entire powerhouse flow (175,204).

At hydropower facilities where the fish are concentrated in the upper levels of the water column,

good recoveries have been achieved (65). However, intakes at projects in the Basin tend to be

very deep (i.e., greater than 90 feet) and flows

are high. Under these conditions, fish have been

seen to try to move away from STSs, especially

if they are deeper in the intake. Also, the potential for impingement is greater due to high

through-screen flow velocities (175). These

screens seem to work better for some species

than others.

Vertical traveling screens were originally

designed to exclude debris from water intakes

but were found to be effective at guiding or lifting fish past turbine intakes. The screen may

consist of a continuous belt of flexible screen

mesh or separate framed screen panels (baskets).

Vertical traveling screens are most effective for

sites where the intake channel is relatively deep.

If approach velocities are kept within the cruising speed of the target fish, impingement can be

greatly reduced (175,204). However, traveling

screens that lift fish are not recommended for

fish that are easily injured, such as smolting

salmonids.

❚ Structural Guidance Devices

Fish passage devices designed with the goal of

guiding fish by eliciting a response to specific

hydraulic conditions are described below.

Angled Bar or Trash Racks and Louvers

Angled bar racks and louvers are used to direct

juvenile fish toward bypasses and sluiceways at

hydropower plants. These structural guidance

systems are devices that do not physically
Chapter 4 Downstream Fish Passage Technologies: How Well Do They Work? | 75

exclude fish from intakes, but instead create

hydraulic conditions in front of the structures.

Theoretically, fish respond to this condition by

moving along the turbulence toward a bypass

system. The success of these systems is dependent on fish response to hydraulic conditions,

which means their performance can be poor

under changing hydraulic conditions and for different fishes of non-target sizes and species

(12,65).

Angled bar and trash racks have become one

of the most frequently prescribed fish protection

systems for hydropower projects, particularly in

the northeastern United States (59,243), to prevent turbine entrainment of down-migrating

juvenile anadromous species (e.g., alosids and

salmonids) (194,242). Most of the angled bar

racks installed to date consist of a single bank of

racks placed in front of the turbine intake at a 45-

degree angle to flow. Although design can vary

from site to site, most racks consist of 1-inch

spaced metal bars with a maximum approach

velocity of two feet per second (15,59).

The angled bar rack is set at an acute angle to

flow and with more closely spaced bars than conventional trashracks. It can divert small downstream migrating fish, and larger fish cannot

typically pass through the bars. However, the use

of close-spaced bar racks creates the potential for

impingement of fish. This is of greatest concern

for species with weak swimming ability and/or

compressed body shapes (59). Most of the angled

bar racks have been installed at small hydropower projects, the majority of which have not

been evaluated for their performance in effectively diverting fish.

Proper cleaning and maintenance of the bar

and trash rack systems on a regular basis is a critical element of operational success. Racks can be

equipped with mechanical cleaning systems or

can be pulled out of the water for manual cleaning; trash booms can also be helpful in mitigating

debris loading. The ideal trash boom is designed

to carry debris past the fishway exit to the spillway or falls and out of the forebay area (15).

A louver system consists of an array of evenly

spaced, vertical (hard plastic) slats aligned across

a channel at a specified angle and leading to a

bypass (59). The louver system, like the angled

bar rack, attempts to take advantage of the fact

that fish rely mainly on senses other than sight to

guide them around obstacles. Theoretically, as

fish approach louvers, the turbulence that is created by the system causes them to move laterally

away from it toward a bypass (59).

Louvers have been installed at a small number

of locations, but are not generally acceptable as a

mitigation technology for protecting fish from

turbine entrainment. If approach velocities do not

exceed their swimming ability, fish generally

assume a tail-first position and move parallel to

the line of louvers guided by streamflow and

hydraulics toward a bypass (204). However, louvers may be considered for sites with relatively

high approach velocities, large uniform flow and

relatively shallow depths (204), and for some

sites with species requiring lesser levels of protection. Louver efficiency in fish diversion,

although high for some species, is relatively low

on average compared to true physical barriers.

Passage of Atlantic salmon smolts at the Vernon and Bellows Falls hydropower projects on

the Connecticut River was evaluated during the

spring outmigration in 1995. A newly designed

angled louver system at the Vernon site, which

was based on hydraulic modeling, is in place to

guide fish to a primary bypass chute in the middle of the powerhouse. Smolts are spilled into the

tailwater of the project. Preliminary data indicate

that about half the smolts are being guided to the

primary bypass, while the remainder are either

sounding beneath the louvers and passing

through the turbines, or going through the secondary bypass, or are never making it into the

forebay due to downmigration behavior (94).

The system may not be as successful as hoped

due to the fact that the actual hydraulic conditions in the forebay of the project are not consistent with the modeling. This is mainly a result of

not replacing certain turbine units adjacent to the

primary bypass. This decision, which was made

based on economics, has led to a less than adequate flow regime in the forebay of the project.

Data and evaluation have yet to be finalized.
76 | Fish Passage Technologies: Protection at Hydropower Facilities

Despite efforts to monitor performance at any

of these hydropower sites on the Connecticut

River, information regarding effects of the

angled bar rack and louvers on the overall

salmon population in the Connecticut River has

yet to be generated. Though angled bar and trash

racks are frequently used to prevent turbine

entrainment, evaluations of performance and

effectiveness are rare. As of the writing of this

report, 36 trash racks have been installed at

projects in the Northeast (U.S. Fish and Wildlife

Service (FWS)–Region 5); however, few had

been evaluated prior to the spring of 1995.9

Louvers operate most efficiently when they

are designed for larger fish of a specific size

(175). Tests of a louver system at the J.E. Skinner Fish Protective Facility in Tracey, California,

showed good guidance for larger juveniles (i.e.,

greater than 70 percent) (100). However, this

same system operated poorly under high debris

conditions. Floating louver systems have shown

excellent promise for protecting fish which

migrate downstream near the water surface

(204). However, excessive entrainment on louvers of smaller, weaker fish, including juveniles,

has caused louvers to be rejected as a design concept at most new hydropower installations (190).

There is a great deal of variation in opinion

regarding how well, or why, louvers work. A better understanding of fish behavior could lead to

improved designs for these structural guidance

devices. Currently, they are recommended for

use by the FWS in the northeastern part of the

country. They are not in use in the Pacific Northwest because they have not been found to provide a high enough degree of effectiveness. The

degree of protection granted by a louver system

is directly related to the target fish, the degree of

protection being sought, the approach velocity,

and the extent that debris is present or is a problem.

9 The trash rack at the Wadhams Project on the Boquet River in northeastern New York, in place to guide down-migrating Atlantic

salmon smolts, has been evaluated. Others include Cabot Station and the Holyoke Canal Louver on the Connecticut River in Massachusetts,

and the Pine Valley Project on the Souhegan River in New Hampshire (195).

OTHER METHODS FOR PROVIDING 

DOWNSTREAM PASSAGE

Other methods for providing downstream fish

passage include pumps, spilling, turbine passage,

and transportation.

❚ Pumps

The hydropower industry is currently examining

the application of fish collection systems, or

pumps, to collect and divert fish at intakes (220).

There are air-lift, screw impeller, jet, and volute

pumping systems. These pumps could be used to

force fish into bypass pipes for downstream passage at hydropower projects. Pump size and

speed, however, may affect fish survival (223).

Fish pumps are not widely used because they

can lead to injury and de-scaling as a result of

crowding in the bypass pipe and to disorientation

once released back into the river environment,

and do not allow the fish to move on their own

(196). Historically, the conventional wisdom of

the resource agencies is to use bypass methods

which allow fish to move of their own volition.

However, a major research effort spearheaded by

the Bureau of Reclamation is underway at Red

Bluff Diversion Dam on the Sacramento River.

Tests are being done to evaluate the usefulness of

pumps to pass juvenile salmonids. Both the

Archimedes screw and the Hydrostal-Volute

pumps are being tested for the effective and safe

passage of fish.

❚ Spilling

Spill flows, or water releases independent of

power generation, are the simplest means of

transporting juvenile fish past (over) a hydropower project and away from turbines (36).

Increased spill to flush fish over a dam can be

especially cost-effective when the downstream

migration period of the target species is short,

when migration occurs during high river flows,
Chapter 4 Downstream Fish Passage Technologies: How Well Do They Work? | 77

or where spill flows are needed for other reasons

(e.g., to increase dissolved oxygen levels to

maintain minimal instream flows).

Care should be taken to ensure that spillway

mortality does not exceed turbine passage mortality (36,243). Consideration of forebay flow

patterns, location of spillway relative to turbine

intake, and positive flow to attract fish to spillways are all features of effective spillway passage (175).

Spilling is a particularly controversial issue in

the Columbia River Basin (see box 4-3). The

U.S. Army Corps of Engineers (COE) maintains

that spilling water to pass juvenile fish has been

demonstrated to be the safest, most effective, and

one of the lowest-mortality means of getting

juvenile anadromous fish past hydropower

projects in the Columbia River Basin. In addition, it is viewed as the only means of enhancing

survival without additional flow augmentation or

drawdown (229). However, spilling water to

assist fish in downstream passage means lost revenue for the hydropower operator. The COE recognizes that spill has its own associated risks

(231) and has modified some spillways and operations to reduce problems in the Columbia River

Basin (49). Passing juvenile fish by spilling

water can result in “gas bubble trauma,” or cause

pressure-induced injury. According to at least

one study, juvenile anadromous fish that pass a

hydropower project by means of spill have a significantly higher rate of survival (98 percent estimated) than do fish that pass through the turbines

(85 percent estimated) (229). However, this 85

percent turbine survival is through low-head

dams with Kaplan turbines; survival is much

lower for high-head dams with Francis turbines

(12).

Gas Bubble Trauma

As spill water plunges below the dam the hydrostatic pressure causes air, mostly nitrogen gas, to

be entrained in the flows. The pressure at the bottom of the stilling basins forces the gases into

solution, creating a supersaturated condition. The

slack water and low flow velocities below the

dam slow the escape of the gas back into the

atmosphere (23).10 When fish absorb this gas,

bubbles can form in the bloodstream. This effect,

coupled with the pressure changes experienced

when fish plunge with the flow and then return to

the surface, can cause traumatic effects and even

death. This situation is referred to as gas bubble

trauma.

Since the late 1960s, tests on exposure of adult

salmonids to supersaturated water have been

conducted to determine the effects of exposure.

The impact that dissolved gas may have on fish

at any given time cannot be simply determined

from gas saturation measurements. Thus, monitoring of migrants for signs of gas bubble trauma

is an important management tool for determining

if dissolved gas levels are having an impact on

populations (229).

In June of 1994 the National Marine Fisheries

Service (NMFS) Northwest regional office convened a panel of experts to review the biological

data concerning dissolved gas effects on fish.

Their findings indicate that a dissolved gas level

of 110 percent can protect fish on purely biological grounds, whereas levels above 110 percent

have the potential to be damaging (231,234).

COE policy calls for keeping gas supersaturation

levels at less than 110 percent in the Columbia

River Basin, the level set by Oregon and Washington State water quality standards (231). Some

laboratory research indicates that total dissolved

gas levels above 110 percent in shallow water

increases mortality observed in laboratory animals. Yet, field responses may be very different,

making it difficult to base in-river management

criteria on laboratory results.11 The NMFS

Northwest office and the Intertribal Fish Commission, which represents tribes in the Columbia

10 In the Columbia River Basin dams were built so that the reservoir of one project backs up on the tailwater of the next project upstream,

exacerbating the supersaturation problem. 11 For example, juveniles may dive to greater depths to avoid areas of high dissolved gas concentration.
78 | Fish Passage Technologies: Protection at Hydropower Facilities

BOX 4-3: Spilling to Facilitate Fish Passage:

Debate Over the Effects on Juvenile Salmonids

Spilling water to pass downmigrating fish is being used as an alternative method for protecting juveniles and

enhancing survival at mainstem dams in the Columbia River Basin.a Spilling would occur during high flow

periods when juvenile salmonids are in the midst of their downstream migration. However, there is still

debate over whether this method might do more harm than good.

A 1995 Spill and Risk Management report prepared for the Columbia River Basin notes that spill passage

and associated damage caused by dissolved gases should not generate greater mortality than that caused by

turbine passage. The report goes on to say that there is little doubt that increasing the total dissolved gas levels

in laboratory studies results in increasing the levels of mortality observed in laboratory animals in shallow water.

By the same token, the report recognizes that mortality levels experienced in the lab are in conflict with those

that would be observed in the natural environment where fish can sound to a safer depth to avoid injury.

The incidence of Gas Bubble Trauma (GBT) has been observed in juvenile anadromous fish during periods

of high flow and spill during the spring out-migration in the Columbia River Basin.b GBT occurs when gas bubbles or emboli develop in the circulatory systems and tissues of fishes as a result of supersaturated gaseous conditions in the tailrace waters of hydropower projects. GBT is considered a physical, not a

pathological, response to an environmental condition (117). The occurrence of GBT has been shown to be

dependent, in part, on water temperature, species, genetic composition, and physiological condition of

fish, as well as proximity and length of exposure to the total gas pressure (3,117).

The data which have been collected in situ as well as in the laboratory are in conflict with some observations

that have been made in the natural environment. Laboratory experiments have indicated that fish exhibit a high

level of mortality when exposed to constant supersaturated conditions, but in contrast, observations made in

the wild actually indicate that higher survival rates occur in populations migrating under higher spill/flow/TDG

conditions. In some of the laboratory situations fish were held at a constant depth and exposed to a constant

level of TDG. In the natural environment, fish would be sounding to different depths and therefore would probably exhibit a different response. As a result, the usefulness of these tests in the development of a spill management plan may be questionable.

The effect of supersaturated conditions on fish is dependent on the depths (i.e., spatial and temporal distribution) at which they swim and are present in the water column. Therefore, completing depth distribution studies

would generate helpful information. According to scientists, each meter of depth affords adults a 10-percent reduction in adverse impacts of gas supersaturation. In addition, the length of time it takes for a fish to travel through a

reach of the river, where nitrogen concentrations might be a concern, influences exposure to high levels of dissolved

gas. This is the major factor in determining the impacts a high-level exposure might have on the fish (44a).

These concerns, and mounting political pressure, have led the federal and state governments to set standards for limits on the allowable levels of gas supersaturation in the tailraces of mainstem dams in the Columbia

River Basin. Washington and Idaho have set water quality standards with maximum levels at 110 percent for the

Columbia and Snake Rivers, while Oregon has adopted a 105-percent standard. Some have contested that

these standards were set without adequate biological research and information regarding the effects of supersaturation on fish. In addition, there is concern over the lack of information regarding fish response to the combination of supersaturated conditions and reaction with other gases, varying water temperatures, exposure

time, and swimming depth.c In general, a 110-percent standard is considered conservative because this

level is typically observed, if not exceeded, in the Columbia River Basin with no discernible impacts on

fish. Therefore, scientists and resource managers argue that the impacts that supersaturated conditions

have on fish can only be determined by monitoring migrants for signs of trauma, and monitoring natural

environmental conditions.

(continued)
Chapter 4 Downstream Fish Passage Technologies: How Well Do They Work? | 79

River Basin, recently recommended that spilling

should be implemented on a broader scale to support juvenile downstream migration.

❚ Turbine Passage

An explicit assumption behind the design of

downstream bypass systems at hydropower facilities is that fish mortality associated with the

bypass will be significantly less than turbine

mortality (see figure 4-1; see chapter 2 for an indepth discussion of turbine entrainment and mortality). This assumption is reasonable for many

small-scale facilities, but is not always borne out

at hydropower plants with large, efficient turbines (243). For example, studies at Bonneville

Dam on the Columbia River indicate that subyearling Chinook salmon suffered more shortterm mortality in screen/bypass systems than

when passed through turbines, perhaps due to

predation at outfalls (242). In a review of studies

at 64 turbine installations, fish mortality ranged

from zero to more than 50 percent (204). Turbine-induced fish mortality may be greatly overestimated or underestimated (206), and can vary

considerably from site to site.

Turbine passage exposes outmigrating juveniles to blades, which can either de-scale or kill

them, and distinct pressure changes, which can

cause physical injury and/or death. Turbine mortality increases with fish size, suggesting that

physical impact is also important (51,87). At the

It is difficult to monitor the response of fish to supersaturated conditions because mortality may occur before

any physical characteristics are evident. After death, the external signs of GBT (i.e., large body blisters) may

disappear within 24 hours, leaving dissection the only option by which to make determinations regarding cause

of mortality (52). However, swimming performance, physical growth, and blood chemistry can be adversely

affected, leaving weaker fish more susceptible to predation, disease, and migration delay (47).

The National Biological Survey’s research lab in the Columbia River Basin has instituted a Smolt Monitoring

Program (SMP) to be implemented in 1995. The SMP will monitor biological parameters in both the tailwater and

the reservoir of a number of dams on the Lower Snake and Lower- and Mid-Columbia. Ideally, data resulting

from the SMP will give managers a sense of what the existing levels of supersaturation are so that an appropriate spill management plan can be developed.

Recently, a study of hatchery Chinook test fish (juvenile fall Chinook salmon) being in net-pens below Ice

Harbor Dam on the Snake River resulted in mortality during a study of the effects of high quantities of dissolved

nitrogen. While the exact cause of mortality was not known, an uncontrolled spill of heavy spring runoff was

occurring at the dam and all the dead fish had signs of GBT.

Events such as these have kept the debate over spilling to facilitate passage of juvenile outmigrants at a premium. And despite all past studies, there is still great disagreement and many unanswered questions that

remain regarding the level of dissolved gases that can be safely tolerated by juvenile salmonids.

aJuvenile salmon passed via spill as opposed to going through the turbines have a higher survival rate (98 percent) than those

exposed to turbine passage (85 percent) (Scientific Rationale for Implementing a Summer Program to Increase Juvenile Salmonid

Survival in the Snake and Columbia Rivers, by: Columbia Inter-Tribal Fish Commission, ID Dept. of F&G, OR Dept. of F&W, USFWS,

WA Dept. F&W).

b Spilling has been implemented at mainstem COE dams since 1989 under 1989 MOA (protection of juveniles until functional

bypasses are installed) and at Mid-Columbia PUD dams since 1983 under the Mid-Columbia FERC Proceedings. Studies have

shown mortality from turbine passage to be 8 to 32 percent compared to 0 to 4 percent for spillway passage.

c Some research has indicated that swimming stamina is affected at concentrations of 110 percent, growth is affected at 105

to 115 percent, and blood chemistry is affected at 115 percent.

SOURCE: Office of Technology Assessment, 1995.

BOX 4-3: Spilling to Facilitate Fish Passage:

Debate Over the Effects on Juvenile Salmonids (Cont’d.)
80 Fish Passage Technologies: Protection at Hydropower Facilities

I

o I I I I I I 1 1 I I \

Dam Number

Simulation Assumption: Initial population size = 100,OOO

Turbine Mortality = 15 percent

Bypass Mortality = 5 percent per dam

Predation Mortality = 5 percent per dam

Turbine mortality is only assessed to that part of the group that does not use

the bypass. Bypass mortality is only assessed to that part of the group that uses

the bypass. Predation mortality is assessed to all surviving individuals that pass

through turbines and bypass.

Initial fish Fish surviving

population to next dam

100,000 83,885

SOURCE: Office of Technology Assessment, 1995.
Chapter 4 Downstream Fish Passage Technologies: How Well Do They Work? | 81

edge of the turbine blade are areas of negative

pressure that can be strong enough to pull molecules of metal from the turbine blades and likewise

can cause damage to fish in the same vicinity.

Various turbine designs have been found to be

linked to varying mortality rates for naturally and

experimentally entrained fish.12 Francis turbines

are designed with “fixed” blades to accommodate a given head, flow, and speed. Kaplan turbines have “adjustable” blades which are better

for low-head operations and seem to be better for

fish survivability (i.e., are more “fish friendly”).

To evaluate turbine mortality, fish must be

tagged and released in the intake and then captured in the tailrace. The mark, release, and

recapture technique has been found to be the

most effective method of evaluating resultant

turbine mortality for salmonid species; however,

it has not been proven to be as useful for alosids

(51) (see also chapter 2).

Operational factors can also affect turbine

mortality rates. Running turbines at maximum

overload during high power demands can result

in higher losses of juveniles (23). In 1967, Milo

Bell, a hydraulics engineer at the University of

Washington, suggested that the best way to

reduce mortality of smolts passing through the

turbines was to operate the turbines at maximum

efficiency. COE estimates that in most cases in

the Columbia River Basin the expectation for

turbine survival is 85 to 90 percent (230).

At Conowingo Dam (hydropower project) on

the Susquehanna River, two old, damaged turbines were replaced with new Kaplan-type

(mixed-flow) turbines.13 This technology has

been marked as more “fish friendly.” The passage of American shad juveniles through the tur12 Design changes to reduce turbine mortality include smoothing of conduit surfaces, increasing clearance spaces, decreasing speed of

rotation of turbine blades, reducing the height of the turbine above the tailwater, increasing the depth of the entrance to the penstock, and

decreasing turbine diameter (145). 13 Entrainment survival increased from about 80 percent with the old turbines, to 95 to 98 percent with the new turbines. There are plans

to replace the remaining turbines at some point in the future.

bines was evaluated to determine survival rate.

The new turbine design is based on a number of

concepts: it allows for shallow intakes, and a

smaller number of blades; it is capable of

increasing dissolved oxygen in the tailwater; it

has a wide flow range and is non-cavitating;14 it

also is greaseless and oil-free. These design considerations aim to increase survivability. Other

factors are equally important to successful passage, such as where the fish exist in the turbine,

what the blade strike range is, and what effect the

pressure gradient that occurs in the vortexes

between blades (gap flows) has on the juveniles.

Principals in the turbine industry predict that

technology is moving toward the use of these

variable speed units.

❚ Transportation

Transportation as a means of providing downstream passage of juvenile fish encompasses

both trap and truck operations and barging.

Transporting fish around hydropower facilities is

used for a variety of reasons: to mitigate the loss

of fish in long reservoirs behind dams; to avoid

the impacts of nitrogen supersaturation that may

be associated with spilling water; to decrease the

possibility of turbine entrainment; and to help

avoid predation problems associated with locating bypass entrances to downstream fish passageways and diversion systems.

The use of transportation to move juvenile

salmonids downstream in the Columbia River

Basin is to decrease the time it takes for outmigrants to move through the system.15 However,

transportation in the Basin is controversial. During high flow periods, the need for transport is

diminished, while during low flows the need for

14 Cavitation occurs when vapor masses collapse on or behind small localized areas of the turbine blade, creating intense negative pressure. This results in the loss of metal from the blade. This situation can result in injury to fish and/or oxygen depletion, nitrogen supersaturation, other physical stresses, and ultimately mortality. 15 Trucking requires approximately six to eight hours and barging, from the Lower Granite Dam to below Bonneville Dam, about a day

and a half (176).
82 | Fish Passage Technologies: Protection at Hydropower Facilities

transportation is favored, in part due to the length

of time required for the juveniles to move

through reservoirs (176). During high flows

juveniles may be bypassed by spilling and may

be able to pass relatively quickly through reservoirs. However, during times when flows range

somewhere in the middle, the use of transportation becomes controversial.

In the Columbia River System, juvenile

salmonids are screened from turbine intakes,

then loaded onto trucks or barges. After being

transported downstream, the fish are discharged

below the lowest dam, thereby avoiding turbine

entrainment and exposure to predators at intervening dams. However, juveniles may experience delay in their migration schedule as a result

of transportation, depending on flow rates, points

of collection, holding time, and points of release.

Delay may have a negative impact on physiological development (i.e., smolting) critical to the

survival of juvenile salmonids. Fish may also be

exposed to diseases, stress, and disorientation.

However, the effects of transportation on fish

development and behavior are virtually unknown

and little study has been done.

There is strong regional fish agency and tribal

support for trap and truck operations to move

juvenile fish in the Columbia River Basin, especially during low flow periods. Much work is

needed to improve facilities and operations further to reduce stress and injury (7).

Barging juvenile fish downstream has drawn

mixed reviews although it continues to be supported and promoted by the Army Corps of Engineers (230). More barges are scheduled for use

during 1997 in the Columbia River Basin. Barging juveniles has generated support over the use

of trucks by virtue of the fact that fish are left in

the water when barges are utilized. However,

some controversy remains.

In the Columbia River Basin the focus of the

transportation effort is on increasing smolt survival and improving the numbers of returning

adults in future years. Research results are not

conclusive regarding the link between transportation and adult returns to spawning grounds

(251). There is some evidence that transportation

from rearing to release site does affect salmon

homing, but the extent of the effect is dependent

on the status of the salmon (smolt, hatchery resident, or in-river migrant), the method of transportation, and the physical distance between

rearing and release sites (251). However, it has

been shown that salmon trucked long distances

do tend to return to their release site (i.e., below

lowest obstruction on the river), as opposed to

their rearing site (251). Juvenile salmon learn the

odors of their home stream, or hatchery, prior to

seaward migration and this olfactory memory is

essential for the freshwater stages of homing

(98). Salmon transplanted prior to smolt stage

tend to return to their release site, not their natal

(i.e., native) site. Smolts are more likely to return

to the reach of river where they were released

(251). Homing patterns may differ depending on

whether fish are transported by truck or barge.

The COE supports the transportation of fish in

the Columbia River Basin. However, due to the

lifecycle of salmonids, the length of time spent at

sea, and the various obstacles to survival any

given fish encounters, it is difficult to pinpoint

cause and effect relationships between the

impacts of either of these methods on population.

Although the desirability of transport is controversial, there is some agreement that barges are

preferable to trucks; that the release site should

not be an estuarine or marine one, but the river

itself; and that fish should be captured after some

period of migration rather than transported from

the point of origin; and finally, transportation

should be regarded as experimental (251).

EVOLVING DOWNSTREAM PASSAGE 

TECHNOLOGIES

A number of methods for providing downstream

fish passage are currently under development or

being experimented with.

❚ Advanced Hydropower Turbine System 

(AHTS)

The heritage of current hydropower turbine

designs dates from the late 19th and early 20th

centuries, when little was known about environ-
Chapter 4 Downstream Fish Passage Technologies: How Well Do They Work? | 83

mental conditions and requirements. DOE has

taken a new look at the “turbine system” in an

effort to identify innovative solutions to problems associated with the operation of turbines at

hydropower projects. DOE and the hydropower

industry have co-funded the AHTS program.

DOE has the lead role in developing and implementing the program (26). The hydropower

industry created a non-profit organization, the

Hydropower Research Foundation, Inc. (HRFI),

which includes 10 utilities that have contributed

funds for the conceptual design phase. HRFI will

represent and administer industry funds for the

program. Steering and technical committees consisting of representatives for industry, utilities,

and other federal agencies are in place to provide

program direction and technical evaluations.

The purpose of the program is to stimulate and

challenge the hydropower industry to design,

develop, build, and test one or more environmentally friendly advanced turbine(s). This would

involve the development of new concepts, application of cutting-edge technology, and exploration of innovative solutions (26). Also, the

AHTS program will function to develop, conduct, and coordinate research and development

with industry and other federal agencies in order

to improve the technical, societal, and environmental benefits of hydropower.

The first phase involves conceptual engineering designs submitted by the industry to a technical

review committee. The second phase involves

building and testing fully engineered models of the

most promising designs. The third phase will consist of building and testing prototypes of the most

promising models in actual operating hydropower

plants. Each phase will be independent of the others

and will follow in succession as the previous phase

is completed. The program will be subject to ongoing evaluation by HRFI and DOE.

The AHTS Program completed Phase I during

1995. Two firms, Voith Hydro, Inc., and Alden

Research Laboratory, Inc., have been selected for

negotiations toward possible contracts. Phase II

is scheduled to be initiated in the latter part of

1995.

The U.S. Army Corps of Engineers (COE) is

also working to develop an advanced turbine

design that would be more “fish-friendly” by

determining the mechanisms which affected fish

survival. Like the DOE effort, the COE is

attempting to come up with new turbine designs

to increase survival of downstream migrants

(34). The COE program is more oriented toward

relatively minor modifications of existing turbines in the Columbia River Basin; the DOE program is focused on developing new designs that

would be applicable across the United States.

❚ Eicher Screen

The Eicher Screen was developed in the late

1970s by biologist George Eicher in an effort to

develop a better means of bypassing fish safely

around a turbine. The elliptical screen design fits

inside the penstock at an angle and can function

in flow velocities up to 8 feet per second (fps)

(262).16 Non-penstock designs are also possible

(54). The screen’s ability to function at relatively

high velocities is what distinguishes it from conventional screens, which tend to operate at channel velocities of about 1-2 fps (262).

Eicher Screens are relatively less expensive

and have smaller space requirements than most

barrier screens (175). The system is about 50 percent cheaper to install than conventional, lowvelocity screening systems, and involves a

screened area about one-tenth that of conventional systems. The other benefits of employing

this screen are that it takes up no space in the

forebay area, has low operating costs, no risk of

icing, and is not dependent on forebay water levels. In addition, because the screen operates at

high velocities, there is less chance that it will

harbor predators (262)

The approach velocity into the screen violates

most state and federal screening criteria. EPRI

16 Both the Eicher Screen and the modular inclined screen are considered to be high-velocity screens. This type of screen is supposed to

function (i.e., safely pass fish) at 8 to 10 feet per second or up to 3 feet per second perpendicular to the screen (59).
84 | Fish Passage Technologies: Protection at Hydropower Facilities

supported the University of Washington test of

the screen’s efficiency. The studies were performed under the assumption that the swimming

ability and stamina of the fish were inconsequential to the functionality of the screen.17 Tests performed in the laboratory as well as in two

prototypes in the field have produced data to support this assumption. Prototype testing has been

performed at two hydroprojects, the Elwha

Hydropower Project near Port Angeles, Washington, and the Puntledge Project at B.C. Hydro

on Vancouver Island.

EPRI tested a refined screen design at the

Elwha Project with promising results. The Elwha

tests evaluated screen performance under a range

of velocity conditions. EPRI’s tests used hatchery-raised smolts which were marked and then

released into the forebay. After traveling into the

penstock and being guided by the screen, the fish

were bypassed to a collection tank where they

were measured, counted, and classified by

amount of de-scaling or injury they had suffered.

According to EPRI, the screen had nearly perfect

diversion efficiency (99 percent) for some species and life stages, indicating its potential for

protecting downstream migrating fish (263).

Diversion efficiency was lower and mortality

higher for fry of some species and the statistical

validity of this non-peer reviewed study has been

questioned (12). If the screen can pass different

sizes and species of fish it could have wide application in the hydropower industry. Additionally,

EPRI funded a series of hydraulic model tests

during 1992 to evaluate the applicability of

hydraulic data from Elwha to other sites and to

evaluate potential for further improvement of the

flow distribution via porosity control. To complete these tests, a model of the intake, penstock,

and Eicher Screen was constructed at Alden

Research Laboratory. The tests evaluated 1) the

possibility that hydraulic conditions at Elwha

were influenced by the bend in the penstock

17 These criteria are not applicable to this type of pressure screen, because the relative flat slope coupled with the high transportation

velocity over the smooth surface funneling into the bypass means that the fish are involuntarily swept into the bypass seconds after passing

over the screen (53).

leading up to the screen; and 2) the potential for

creating a more uniform velocity distribution

over the length of the screen (263).

The hydraulic model studies indicated that the

velocity distribution at Elwha was not significantly influenced by the upstream bend in the

penstock (263). The other tests showed that passage survival rates exceeding 95 percent can be

achieved for fish in the 1.5 to 2.0 inch range at

velocities up to 7 fps, while smaller fish can be

protected using lower design velocities and

closer bar spacing (263). At the Puntledge, British Columbia project, evaluations indicate 99.2

percent successful guidance of coho yearlings

through the new Eicher Screen (211).

In general, the Eicher Screen has multiple positive operating characteristics. For instance, it is

biologically effective for target fish; the total

costs of installation are usually less than for other

types of screen; it is unaffected by changes in the

forebay elevations; it takes up no critical space;

operation and maintenance costs are negligible;

the relatively high velocities at which it can be

used make it adaptable to almost all penstock situations (53).

Research and evaluation of the Eicher Screen

has led to approval at specific sites from agency

personnel who were not otherwise convinced in

the early stages. Agency approval of use at other

sites will depend on documentation that the

design performs well for target fish at velocities

present at the site.

❚ Modular Inclined Screen (MIS)

EPRI has developed and completed a biological

(laboratory) evaluation of a type of high velocity

fish diversion screen known as the Modular

Inclined Screen (MIS). This screen is designed to

operate at any type of water intake with water

velocities up to 10 fps (221). The MIS consists of

an entrance with trash rack, stop log slots, an

inclined wedgewire screen set at a 10- to 20-
Chapter 4 Downstream Fish Passage Technologies: How Well Do They Work? | 85

degree angle to flow, and a bypass for directing

diverted fish to a transport pipe.

This modular screening device is intended to

provide flexibility of application at any type of

water intake and under any type of flow conditions (221). Installation of multiple units at a specific site should provide fish protection at any

flow rate (220) Currently, no fish protection

technology has proven to be highly effective at

all types of water intakes, for all species, and at

all times (i.e., seasonal variability (65)).

To determine viability of the MIS, a testing

program to evaluate biological effectiveness was

undertaken by EPRI at the Alden Research Laboratory (ARL) in Holden, Massachusetts. Evaluations at ARL have focused on the design

configuration which yields the best hydraulic

conditions for safe passage and shows biologic

effectiveness for diverting selected species to the

bypass (58).

Mark, release, and recapture tests were undertaken with 11 species including walleye, trout,

alosid, and salmon smolts. These species were

chosen because they are representative of those

fish that are of greatest concern at water intakes

across the country, based on a review of turbine

entrainment and mortality studies that have been

conducted in recent years (62). The tests were

conducted with two screen conditions: clean

screen (i.e., no debris) and incremental levels of

debris accumulation. Three replicates were conducted at each of the five test velocities and control groups were used to determine mortality and

injury associated with testing procedures. Control fish were released directly into the net pen

and recovered simultaneously with the test fish.

To assess effectiveness, four passage parameters were calculated for each combination of species, module water velocity, and test condition

(i.e., clean screen and debris accumulation) that

was tested. Success was measured by determining percent of fish diverted live, adjusted latent

mortality, adjusted injury rate, and net passage

survival (221).

According to the 1992 EPRI report, the results

of the tests “clearly demonstrate that the MIS has

excellent potential to effectively and safely

divert a wide range of fish species at water

intakes.” The results showed that nearly 100 percent of the test fish were diverted live and that

the adjusted latent mortality was less than 1 percent, although this was variable depending on

species and velocity (58). Fish were safely

diverted over a range of velocities (e.g., 2 to 10

fps) with minimal impingement, injury, and

latent mortality; and debris accumulation did not

appear to affect fish passage up to certain levels

of debris-induced head loss (221). Also, EPRI

noted that it was possible that the testing procedures (i.e., transport, marking, fin clipping, netting from pen or bypass) may have contributed to

the observed mortality.

ARL has developed a prototype of the MIS

which will be field evaluated in the spillway

sluicegate at Niagara Mohawk’s Green Island

facility on the Hudson River in September of

1995. The prototype MIS test is important in the

development and acceptance of the technology.

However, resource agencies will be unlikely to

approve full-scale applications of the MIS without additional testing (12). Resource agencies are

particularly troubled by operational aspects of

high-velocity turbine screening. These screens

only collect fish when water is flowing over

them. Hydropower operational changes may be

necessary to ensure adequate flow to the screens,

especially during periods when many hydropower projects are filling reservoirs and not producing much power (12).

❚ Hydrocombine

A hydrocombine design of a hydropower facility

is one where the spillway is situated over the turbine intakes. This design was employed at Douglas County PUD’s Wells Dam (hydropower

project) on the Columbia River as a result of the

wide success of ice and trash (debris) sluiceways

in passing juvenile fish. Evaluations of the

hydrocombine design showed that it too was

effective in providing passage for juvenile

salmonids. As a result, Wells Dam became the

model for research on the “attraction flow” or

“surface collection” concept of downstream fish
86 | Fish Passage Technologies: Protection at Hydropower Facilities

passage and sparked investigation into the potential for use elsewhere.

The theory was that this combination system

could improve salmon survival by taking advantage of natural behavior and accommodating the

majority of juveniles that moved downstream in

the upper portion of the water column. Providing

a means of passage over a surface-level spillway

as opposed to forcing juvenile fish to dive to turbine intakes is more in line with natural behavior

of outmigrating juveniles. A bypass with vertical

slot barrier is placed in the spill intakes, which

creates an attraction flow for outmigrating juveniles. Once the fish are entrained in the flow,

they enter the bypass and are diverted past the

dam instead of passing through the turbines

(242). The hydrocombine was shown to produce

a 90 percent success rate for juvenile fish passing

through the Wells project (42).

The success of such a system might decrease

the need for spilling, as well as the possibility of

electricity rate increases. However, the results at

Wells Dam were not easily explained. As is the

case for many evolving fish passage technologies,

there is often a lack of information regarding why

they work. As a result, a prototype was installed at

Chelan County PUD’s Rocky Reach Dam and

Grant County’s Wanapum Dam. The configurations of the Wells, Rocky Reach, and Wanapum

projects are significantly different; however, the

surface collection concept is the same. Results are

not yet available on either of these evaluations, but

this research has sparked the development of the

COE’s Surface Collection Program.

❚ Surface Collector

Surface-oriented bypasses could prove to be

effective in improving juvenile salmon survival

in the Columbia River Basin (232).18 There is a

major effort underway in the Pacific Northwest

spearheaded by the COE to develop a surface

collector design (39,77). The thrust of the

research is to better understand the biological

and physical principles that are at work at the

18 For a more indepth discussion of the surface collector see appendix A.

Wells Dam, where a hydrocombine design is in

use, and apply them to the surface collector design

to provide a safer means of passage for juveniles.

This “attraction flow” concept may provide downstream-migrating juveniles with an alternate, more

passive route through hydropower facilities than is

possible with other methods (42).

Surface collector prototypes are being evaluated at The Dalles and Ice Harbor Dams by the

Portland and Walla Walla Districts of the COE,

respectively. Various configurations of the

design are being tested. The attraction flow prototype consists of a 12-foot-wide by 60-foot-high

steel channel attached to the forebay face of the

powerhouse (42) perpendicular to flow in the

forebay. The goal is to guide fish hydraulically

directly into the collectors, and then pump them

to a bypass which moves them around the dam.

Hydroacoustics will be used to monitor fish

movement and behavior in and near the collector.

An adaptation of the new surface collector

design is in operation at Bangor Hydro’s West

Enfield project on the Penobscot River and

Ellsworth project on the Union River, although

debris blockage has been a problem at both sites.

The results of the 1995 testing at Wanapum Dam

could potentially add much to what is known

about downstream fish passage and design at

hydropower facilities. Also, results of the prototype tests would hopefully be transferable to

other powerhouses at projects on the Columbia

and Snake Rivers (42).

❚ Barrier Nets

Most technologies proven to be effective in

downstream mitigation at hydropower intakes

rely on large screening structures designed to

provide a very low approach velocity. For many

projects, such technologies are not financially

feasible. For others, screens are inappropriate for

other reasons. In these cases, the use of barrier

nets may provide a cost-effective means of protecting fish from entrainment. In general, barrier

nets have not been utilized in situations where
Chapter 4 Downstream Fish Passage Technologies: How Well Do They Work? | 87

both downstream passage and protection from

entrainment are desirable.

Barrier nets of nylon mesh can provide fish

protection at various types of water intake,

including hydropower facilities and pumped

storage projects. Nets generally provide protection at a tenth the cost of most alternatives; however, they are not suitable for many sites. Their

success in excluding fish from water intakes

depends on local hydraulic conditions, fish size

and the type of mesh used. Barrier nets are not

considered to be appropriate at sites where the

concern is for entrainment of very small fish,

where passage is considered necessary, and/or

where there are problems with keeping the net

clear of ice and debris (213). It may not be practical to operate nets in winter due to icing and

other maintenance problems. Thus nets may not

offer entrainment protection in winter at some

sites.

Nets tend to be most effective in areas with

low approach velocities, minimal wave action

and light debris loads. Biofouling can reduce performance, but manual brushing and special coatings can help alleviate this problem. An

evaluation was underway during the spring of

1995 at the Northfield Pump Storage Project on

the Connecticut River in Massachusetts. The

study has yet to be completed. There have been

problems with debris loading and net inversion

when flow in the river is reversed due to pumpback at the project.

The Ludington Pumped Storage Plant, one of

the world’s largest pumped storage facilities,

located on the eastern shore of Lake Michigan,

has had a 13,000-foot-long barrier net installed

around the intake since 1989. Barrier net effectiveness, described as the percentage of fish prohibited from entering the barrier net enclosure,

was estimated at about 35 percent in 1989, but

substantially increased to about 84 percent in

1994 after significant improvements were made

(90). This seasonal barrier appears to be effective

for target fish (90).

ALTERNATIVE BEHAVIORAL GUIDANCE 

DEVICES19

Behavioral guidance technologies include any of

the various methods that employ sensory stimuli

to elicit behaviors that will result in downmigrating fish avoiding, or moving away from,

areas that potentially impair fish survival. In all

cases, the purpose is to get fish to leave a particular area (e.g., a turbine intake) and move somewhere else. The nature of the response may be

long-term swimming in response to a continuous

stimulus where the fish has to move some distance (e.g., a sound that is detected for an

extended period of time and from which the fish

continues to swim), or it may be a “startle

response” that gets a fish to turn away and then

continue in a different direction without further

stimulation. Any stimulus that produces a startle

response or frightens a fish from a particular

place (essentially exclusion) is not a suitable

deterrent unless there is a component to the

response that moves the fish in a specific direction that leads to safety as opposed to swimming

away from the stimulus in a random direction

(202).

Fishes, as well as other vertebrates, are capable of detecting a wide range of stimuli in the

external environment (76). The modalities most

often detected include sound, light, chemicals,

temperature, and pressure. Some fishes can

detect electric currents and possibly other stimuli

that fall outside of human detection capabilities.

For the most part, behavioral barriers have not

been approved of and accepted for use by the

resource agencies because they have not been

shown to achieve a high enough level of protection (220). In some cases, progress has been

made in developing technologies that can guide

fish, possibly at a lower cost than physical barriers. Some in the industry would like to see sub19 This section is drawn largely from A.N. Popper, “Fish Sensory Responses: Prospects for Developing Behavioral Guidance Technologies,” an unpublished contractor report prepared for the Office of Technology Assessment, U.S. Congress, June 1995.
88 | Fish Passage Technologies: Protection at Hydropower Facilities

stantial investment in developing these

technologies for use at sites where complete protection is not required, or as a means of improving the effectiveness of an existing physical

protection device (220).

Behavior-based technologies are touted as

being less expensive than physical screening

devices and easier to install than more conventional methods. Another presumed benefit is that

these technologies can be used with little disturbance to the physical plant or project operation.

Lastly, developers of these technologies claim

that although they have not yet achieved 100 percent effectiveness, they have shown that various

behavioral methods do guide fish, and that guidance can be improved upon with research and

experimental application.

❚ Lights

Many species of fish have well-developed visual

systems. Light has a high rate of transmission in

water and is not masked by noise. At the same

time, the usefulness of light depends upon the

clarity of the water as well as upon the contrast

between the artificial and ambient light.

The visual system of fishes is highly adapted

to enable different species to see in environments

that range from shallow waters of streams to

great ocean depths (142). These adaptations

include, for example, the shape of the lens, the

distance between lens and the photoreceptor

layer, the ability to adjust the eye to see objects

at different distances (“accommodate”), and

other aspects of the optics of the eye. As one

example, diurnal fish living in shallow waters

often have yellow corneas (and sometimes yellow lenses). This serves as an optical filter to

screen out some of the shortwave light which is

found in such waters, and which can scatter

around the eye and decrease visual acuity. Special adaptations may also be found in the setup of

the photoreceptors.

While most fish see reasonably well, problems

with use of light include transmission characteristics being very dependent on water turbidity,

and variable attenuation of different wavelengths. Also, the effectiveness of light is likely

to vary between day and night when the ratio

between the stimulus light (e.g., strobe) and

background illumination (e.g., daylight) differs

(152).

Two types of lighting are the most widely

used in experiments—mercury and strobe. Of the

two, experimental results suggest that strobe

lights (pulsing light) are the more successful in

affecting fish movements, although mercury illumination was useful in a number of instances

(61,101,163), including attracting and holding

blueback herring at the Richard B. Russell Dam

to keep them from entering undesirable areas

(165,178). At the same time, light may attract

some species and repel others living in the same

habitat (25,76).

One of the earliest studies on use of lights

(sealed beams) was by Brett and MacKinnon

who provided data on a limited number of animals moving down a canal away from a light

source (25). The fish were restrained in a particular region of the canal with nets. The results were

not extensive, but two findings are of interest.

First, some species swam away from the light

while others did not, suggesting different behaviors by different species. Second, flashing lights

were more effective at eliciting a response than

continuous light, a harbinger for the use of strobe

lights. Response differences to the same light

source between species have been documented

by others and are not surprising. These differences raise the issue, germane to all stimuli and

not just light, that the stimulus has to be closely

fit to the species being studied.

Strobe light has been extensively evaluated as

a fish deterrent in both laboratory and field situations (59). Deterrence has been shown with a

number of species, but the lights have worked

most extensively and effectively with American

shad juveniles (220). Successful fish deterrence

with strobe lights has often been site specific,

which indicates that hydraulic and environmental

conditions and project design and operation have

influence on the effect the lights have on species

(59). The lack of conclusive results may also be
Chapter 4 Downstream Fish Passage Technologies: How Well Do They Work? | 89

attributed to inadequate sampling methodology

and design.

Field tests conducted at the York Haven

project on the Susquehanna River demonstrated

a strong avoidance response to strobe lights by

juvenile American shad (62,63). The system was

designed to repel fish away from the turbine

intakes and through the sluiceway. The system

proved to be effective (94 percent). However, the

study pointed out the need for establishing relationships between behavioral fish bypass systems and site-specific hydraulics in an effort to

maximize bypass efficiency (59). Hydraulic and

environmental factors had primary influence

over the occurrence, distribution, and behavior of

shad (152). The influence of these factors has

definite bearing on the success of the system. As

a result, it was concluded that the proper combination of physical and hydraulic conditions must

exist in the area of the lights and the bypass system in order to achieve the desired level of effectiveness (152). Additional work is underway to

verify response of various species.

The use of mercury lights to attract or repel

various species including salmonids and clupeids

is reviewed by EPRI (57). The results suggest

that such illumination can be used with a number

of species to move fish away from intakes,

although the results are quite variable between

sites and species. Such illumination may be more

effective at night than during the day (not an

unreasonable situation considering the contrast

between the stimulus and ambient illumination

differs greatly at night). Incandescent illumination has been tried as a method to modify behavior (57), but with no clear success.

Studies conducted at the York Haven project

on the Susquehanna River indicate that mercury

lights can be highly effective in attracting gizzard shad, and several studies have successfully

improved bypass rates of salmonid species using

mercury or incandescent lighting (57). The relatively inexpensive nature of mercury lights is a

driving force of research. However, additional

research is necessary to determine the feasibility

of using sound as part of a directional bypass

system (57).

❚ Acoustics (Sound)

Sound has many characteristics that make it suitable for use in the possible modification of fish

movement, especially over longer distances or

when visibility is marginal. Sound travels at a

high rate of speed in water, attenuates slowly, is

highly directional, and is not impeded by low

light levels or water turbidity (201). Moreover,

many species of fish are able to detect sounds

(69). From the standpoint of directionality, attenuation characteristics (especially with depth), the

lack of effect of turbidity, and suitability during

the day and night, other potential signals are not

as versatile as sound. At the same time, high

noise levels, such as at turbine intakes, may prevent fish from hearing artificially generated

sounds in such environments, while high-intensity sounds (produced by any source) might have

deleterious effects on fish.

Many fish species are known to use sound as

part of their behavioral repertoire for intra-specific communication. Sounds produced by fish

for communication are generally low-frequency

(usually below 500 Hz) and broad-band

(159,181). More recently, it has become apparent

that fish are also likely to use sound to get a general “sense” of their environment, much as do

humans. These sounds may include those produced by surf, water moving against objects in

the environment, or wind action on the surface of

the water (207). In addition, there is some evidence that fishes may respond to sounds that are

produced in association with human-made structures, such as bypass screens and other signals

produced as a byproduct of hydropower projects

(6,164), although little is known about the actual

behavioral responses to these sounds.

It is important to understand that detection of

vibrational signals (which includes sounds) by

fishes involves two sensory systems, the ear and

the lateral line. Together, these are often referred

to as the octavolateralis system (182). Both systems use similar sensory hair cells as the transducing structure for signal detection and both

respond to similar types of signals. However,

from the perspective of modifying the behavior
90 | Fish Passage Technologies: Protection at Hydropower Facilities

of fish with sound, it is probably unimportant

which sensory system per se is involved with the

response; however, the distance over which stimuli can affect each sensory system differs.

A variety of different studies have been conducted using sound in attempts to affect movement patterns of fish. For the most part, these

studies have concentrated on various species of

salmonids and clupeids, although work has been

done with regard to a variety of other species.

The range of techniques used has also varied

quite widely, as have the sound sources and the

frequencies employed. Results are also quite

variable and range from totally unsuccessful in

controlling behavior to demonstrating potential

usefulness for a few species under certain conditions.

Various species of clupeids (herrings and their

relatives) have been studied by a number of

investigators. A major thrust of this work has

been to modify the swimming behavior of alewives and American shad so that they are kept

from entering turbine intakes at dams. Some

investigations have proven unsuccessful, while

others have achieved some success.

The most compelling studies to date on clupeids in the United States involve the use of

ultrasound to modify the swimming behavior of

American shad and other species at a variety of

sites. These transducers produce high-frequency

(approximately 120 kHz) signals that appear to

produce an avoidance response in juvenile

American shad, causing them to move away

from the sound source. Field studies have demonstrated that the effectiveness of sound can be

altered by environmental conditions such as

water temperature or site hydrology. Moreover,

sound may be more effective at certain times in

the life cycle of clupeids than at other times, and

at certain times of the day or night, possibly

depending upon the particular species being

studied.20

Early studies on controlling the migration of

salmonids with sound across a range of frequencies generated mixed and somewhat unclear

results (33,156,254). One study showed that animals in a lab setting would respond to certain

wavelengths, but there was no apparent response

in a river (254). In another study, attempting to

guide trout into a channel using plates set into

vibration at 270 Hz, there was some evidence of

success. However, there was no statistical analysis, and the limited amount of data does not suggest that results were replicated or that other

compounding factors were taken into consideration (254).

Hawkins and Johnstone found that Atlantic

salmon would respond to sounds from 32 to 270

Hz with best sensitivity from about 100 to 200

Hz (99).21 More recently, studies on Atlantic

salmon by Knudsen et al. (128) support the findings of Hawkins and Johnstone (99) that this species only detects very low-frequency sounds.

Using a behavioral paradigm, Knudsen and his

colleagues (126,128) measured the responses of

salmon to tones from 5-150 Hz. The best

responses were in the 5-10 Hz range. They also

determined that the juvenile salmon would show

an avoidance response (in a pool of water) to 10

Hz signals but not to 150 Hz signals, although

avoidance to the 10 Hz signal would only occur

if the fish were within 2 m of the sound

source.22,23

Knudsen et al. tested this hypothesis and demonstrated that low-frequency sounds could be

used to modify salmonid movements in a field

20 Blaxter and Batty (1987) show that the responses to sounds of clupeids changes in the light and in the dark (22). 21 Hawkins and Johnstone (1978) trained fish using classical conditioning so that they would show a decrease in heart rate whenever a

sound was presented (99). 22 Unconditioned startle responses were also investigated by Stober (217) on the cutthroat trout (Salmo clarki). Stober found that a number of specimens (but not all) would show an unconditioned startle response to sounds up to 443 Hz, although no response was found below

50 Hz. He also showed rapid habituation, as reported by Knudsen et al. (128). 23 While exact distances are different from those reported by VanDerwalker (254), the order of magnitude of the distance from the source

at which salmonids will respond to sound is the same. These results strongly support the suggestion that the response of salmonids to signals

is when they are close to the sound source and very far into the acoustic nearfield.
Chapter 4 Downstream Fish Passage Technologies: How Well Do They Work? | 91

experiment (126). They were successful in getting salmon to change direction and swim away

from a sound source. The stimulus was only

effective when the fish were within a few meters

of the source (within the acoustic nearfield). For

such a system to be fully effective in rivers or by

a dam, a large number of projectors would be

needed to insure that fish were properly ensonified.

A similar study reported effective, statistically

significant guidance (80-100 percent diversion

from the entrance to an intake canal for downmigrating steelhead trout smolts and Pacific Chinook salmon smolts) for a patented sound system

now available from the Energy Engineering Services Company (EESCO). Natural sounds of various salmonids were recorded, and modified

forms of the recorded sounds were played back

to affect fish movements (141). Results suggested that the fish could be as much as 70 feet

from the projector and the sound would still elicit

a response. These results have yet to be replicated and the study only provided minimal information as to the nature of the specific sounds

used to modify fish movements.

Results from preliminary tests of the EESCO

system on the Sacramento River in 1993 were

inconclusive (46,94a), largely due to the preliminary nature of the study and problems in experimental design. Studies are continuing at the

Georgiana Slough on the Sacramento (171). The

results of testing that took place during the spring

of 1994 at Georgiana Slough were encouraging

(50 percent overall) and statistically significant

(95 percent level) (100).

Infrasound testing is currently underway

within the Columbia River Basin as part of the

Columbia River Acoustic Program.24 Two types

of sources are being tested, both of which generate infrasound. They differ in one component of

the sound field they generate. The infrasound

source, patterned after that used in Norway, is

referred to as an “acoustic cannon” because it

24 Information on the Columbia River Acoustic Program taken from Tom Carlson, Pacific National Laboratory, comments to the Office

of Technology Assessment, August 1995 (39).

generates a sound field with large particle

motion. The acoustic cannon has a 19-cm-diameter piston with a displacement of 4 cm (39). Startle followed by avoidance has been shown under

controlled laboratory and field conditions for

Chinook and steelhead juveniles and smolt. The

other sound source, EESCO technology, generates a sound field with little particle motion. This

source has a moving coil with a diameter of

approximately 8 cm with a displacement of

approximately 0.08 cm (39). The Acoustic Program has not conducted nor do they know of any

controlled laboratory behavioral tests of fish

response to the EESCO technology source.

Experience to date indicates that large particle

motion is required to elicit avoidance responses

by salmonids.

Few other fish groups have been tested in a

systematic way to determine if they would avoid

low-frequency sounds (69,181). There are, however, remarks in the literature regarding avoidance responses of a number of species, and lack

of avoidance or any sort of responses by other

species. The Empire State Energy Electric

Research Corporation (ESEERCO) (65a)

reported laboratory studies of behavioral

responses to low frequencies by striped bass,

white perch, Atlantic tomcod, golden shiner, and

spottail shiner (51a, 201a, 201b). Despite some

limitations, the studies demonstrate that white

perch and striped bass would show an avoidance

response to broad-band sounds of below 1,000

Hz at sound levels of 148 and 160 dB (re: 1 μPa)

during the day, but they showed only a weak

response at night to sounds as high as 191 dB (re:

1 μPa). The other species only showed a weak

avoidance response during the day.

Considerable study and data are needed to elucidate the mechanisms through which certain

fish receive sound. No matter what the actual

stimulus, it is of considerable interest that sound

can affect the behavior of certain species either

by causing a startle response or actually causing
92 | Fish Passage Technologies: Protection at Hydropower Facilities

fish to swim away from the source of the sound.

It must be kept in mind that a startle response

alone is not sufficient for controlling movement

of a fish. Instead, whatever the stimulus, it must

elicit sustained movement of the fish in a specific

direction so the fish avoids the area of danger.

❚ Electric Fields

There are several recent reports in the gray literature that describe the use of electric fields to

guide fish behavior. To date, the results from

these experiments are equivocal as to their success in controlling downstream migration of several different species (20,106).25 A couple of

significant points, however, arise from consideration of these studies. First, electric fields are

potentially dangerous to other species that may

enter the water in the area of electric field. Second, the electric fields are restricted to regions

between electrodes. Thus, they are most effective

in shallow streams and relatively narrow regions

where sufficient field strength can be set up

between opposing electrodes.26

In general, evidence supporting the effectiveness of electrical barriers at supporting the downstream passage of fish is not available (220).

Effectiveness will vary depending on site-specific parameters and species/size-specific

responses. Several problems have been identified

with their application, including fish fatigue and

the relationship between fish size and susceptibility to electrical fields (59).

A combination electric screen and infrasound

system has been extensively tested by Simrad in

Scotland over the last two years (39). It is novel

in the sense that the electric portion of the behavioral barrier is used primarily to reinforce the

response to infrasound by migrating salmonids.

The infrasound sources used are large particle

motion sources.

25 The results of testing done during the spring of 1995, of an electrical barrier, at RD 108 (Wilkens Slough) on the Sacramento River

were inconclusive (100). 26 There is literature from the manufacturer of electrical guidance systems, Smith-Root, Inc., that their devices can also be used to protect

turbine intakes and in other environments than streams. However, this reviewer has seen no analysis, peer-reviewed or “gray” literature, that

evaluates the success of these systems beyond those described in the cited references.

❚ Bubble Curtains

Bubble barriers were used by Brett and MacKinnon in an attempt to guide fish, with no apparent

success (25). Other researchers suggested that

success with air bubbles may have been associated with the sound that they produce and not

necessarily with the bubbles (107,131). Ruggles

points out that air bubbles are effective for some

saltwater species and possibly for some species

in streams, but not in rivers. Patrick et al. report

that air bubbles were effective in producing

avoidance behavior in laboratory experiments

with gizzard shad, alewife, and smelt (172). They

also reported that avoidance increased when air

bubbles were combined with strobes. However,

these studies have apparently not been followed

up with field experiments. Patrick et al. found

that air bubbles were most effective when there

was some illumination. They also pointed out

that the basis for fish response was not known,

but may have been visual or sound-associated, as

suggested by Kuznetsov (131).

Air-bubble curtains have not proven to be

effective in blocking or diverting fish in a variety

of field applications, nor is there data available to

indicate potential effectiveness (220). There are

small-scale studies of water jet curtains in various field applications; however, mechanical and

reliability questions have prevented further

study. Hanging-chain curtains have shown some

success in preventing fish passage under laboratory conditions. Lab results have not been duplicated in the field and research has ceased (220).

❚ Hybrid Barriers

Some study has been done to evaluate the effectiveness of using behavioral barriers in various

combinations to increase overall effectiveness,

yet the results have been equivocal (220). Many

of the field evaluations have been conducted for
Chapter 4 Downstream Fish Passage Technologies: How Well Do They Work? | 93

application at hydropower projects, including a

test combining strobe lights and ultrasonics to

guide down-migrating juvenile American shad at

the York Haven Dam hydropower project on the

Susquehanna River.

PERSPECTIVES ON TECHNOLOGIES

In an effort to minimize expenditures while still

meeting protection goals, the hydropower industry is looking to implement low-cost fish protection. New behavioral guidance technologies may

be less expensive than conventional fish protection methods (for downstream passage); however, the agencies approach application of

behavioral technologies with caution and consider them to be “experimental.” Therefore, the

industry is reluctant to invest in these technologies for fear that they will simply have to replace

them with more conventional technologies. This

leads to frustration for the technology vendors.

❚ Resource Agencies

National Marine Fisheries Service

The NMFS national office seeks a high level of

effectiveness for new technologies before the

agency will approve application in the field, and

in some cases regional offices have released

position statements regarding fishery protection

and hydropower. These statements do not apply

on a national level, but they do have the potential

to be precedent-setting. The Northwest and

Southwest offices have specific guidelines for

developing, testing, and applying alternative fish

protection technologies (see appendix B). NMFS

regional offices in the Northwest and California

strongly prefer physical barrier screens, which

can completely exclude fish, for use at hydropower projects over other structural or behavioral guidance devices. In addition, the agency

requires that experiments evaluating a new technology should parallel the development of a conventional (technology) solution.

NMFS maintains that it is critical to require

technology developers and the hydropower

industry to abide by this high standard in order to

uphold the agency’s primary charge to protect

fish and because so many fish populations have

reached a “crisis” status (257). It is this argument

that forms the basis of NMFS support of the use

of physical barrier screens for fish protection

from turbine entrainment. The agency may be

more comfortable with the use of these barriers

because they physically block or physically

divert fish, but also because the technologies

have evolved over a fairly long period during

which much was learned about how to optimize

performance and make adjustments based on site

criteria and biological considerations. In addition

to NMFS’s Southwest and Northwest regional

offices, Washington State’s Department of Fisheries and Wildlife and the California Department

of Fish and Game have released statements

regarding screening criteria for salmonids

(237,238,239).

U.S. Fish and Wildlife Service

In the northeastern United States, FWS may be

willing to consider the application of “experimental” devices as an interim or complementary

measure, depending on the situation and the species. However, FWS has no formal policy or

position statement regarding the acceptability of

experimental fish passage technologies. The

agency accepted the use of these technologies in

certain limited circumstances, but these were

site-specific decisions based on professional

judgment, project specific characteristics, and

the significance of the resource at risk (150).

Determinations are a reflection of expert opinion and best professional judgment about what

might work best at a given site. The possibility of

achieving 100 percent efficiency with a passage

technology, or reducing entrainment to zero percent, is unlikely. However, given the status of an

increasing number of threatened and endangered

species, the agency may be willing to approve

the application of a technology that fails to reach

a 100 percent performance goal, but provides a

good level of protection, in situations where the

development of a physical barrier screen or

structural guidance device may take years to

achieve.
94 | Fish Passage Technologies: Protection at Hydropower Facilities

In the West, FWS is generally inactive on

screening, but is involved to a degree in experimenting with alternative guidance devices. The

agency has developed interim screen criteria for

one species, and supports the use of technologies

that provide the highest degree of protection possible for target fish at all intakes.

The agency prefers the use of physical barrier

and structural guidance devices over alternative

experimental guidance devices. However, there

is some concern within the agency that constant

pressure from vendors to utilize alternative

devices has led to concession in certain cases.

The agency is especially concerned that once an

experimental measure is in place at a site it will

remain as the long-term protection measure

regardless of whether performance is less than

what would be expected from a conventional

technology. Many agencies view experimentation as a delaying tactic. Although experimentation can be very costly over time (possibly

matching the cost of a conventional approach),

yearly expenditures are often much lower than

the capital outlay to install a conventional technology.

❚ Hydropower Industry

The industry’s goal is to provide effective fish

protection and to minimize costs, which can be a

challenge especially at large hydropower

projects. The industry claims to be facing difficult economic times, which may be exacerbated

by the possibility of deregulation. This mood has

forced the industry to come out against expenditures for what they refer to as seemingly “unnecessary” items such as fish passage and protection

mitigation technologies.

The possibility of deregulation has also

caused the industry to reassess its role in the

alternative energy market. NHA views hydropower to be the cleanest, most efficient, and most

developed renewable energy source. As a result,

some industry representatives balk at the federal

research and development investment to advance

and perpetuate other renewable energy sources

(i.e., wind, geothermal, solar, etc.), as opposed to

investing in the further improvement and efficiency of hydropower on a broad scale. The

industry claims that it cannot afford to bear the

costs associated with research and development

of fish passage technologies and that this support

should come from the federal government.

❚ Technology Vendors

Vendors of new behavioral and guidance technologies are frustrated by the reluctance of

resource agencies to approve their use despite

what some consider convincing results in the

field (27,50). Technology developers claim that

these alternatives to conventional fish protection

technologies will work for a fraction of the cost

of conventional screening mechanisms. The

agencies continue to question “how well” the

technologies work, and NMFS requires that

hydropower operators also pursue a parallel track

with an accepted technology (e.g., design a physical barrier or other interim measure technology

or method) while an alternative is being developed or tested at a site (174).

Though there is some discussion of allowing

the use of behavioral technologies to enhance

physical barriers or as interim protection devices,

the agencies are unwilling to allow these technologies to be utilized as the sole line of defense in

fish passage mitigation in the absence of scientifically rigorous demonstrations of effectiveness.

This frustrates the vendors who argue that no

such evaluation exists for physical barriers and

that behavioral and alternative guidance devices

are being held to a standard that other conventional technologies were not during previous

years.

CONCLUSIONS

Physical structures, including barrier screens,

angled bar racks, and louvers, that are designed

to suit fish swimming ability and behavior, as

well as site conditions, remain the primary downstream mitigation technologies at hydropower

facilities. There is general consensus among

practitioners that the conventional technologies

effectively protect downmigrating fish. Barrier
Chapter 4 Downstream Fish Passage Technologies: How Well Do They Work? | 95

screens have an appeal in that they are perceived

to be absolute in their operation. According to

some resource agencies, under certain conditions

they may be the only viable technology. However, the high costs associated with these technologies are often barriers to their use. As a

result, much of the fish passage research presently being done is focused on further developing behavioral guidance devices. Some of this

effort might be directed toward the installation of

physical structures because the resource agencies

have identified the need to provide protection

now while research on behavioral and alternative

guidance devices is taking place.

Extensive descriptions of downstream fish

passage mitigation measures are available

(16,59,65). Numerous and varied measures have

been used to reduce turbine entrainment, including fixed and traveling screens, bar rack and louver arrays, spill flows, and barrier nets, and

alternative behavioral devices. However no single fish protection system or device is universally effective, practical to install and operate,

and widely acceptable to regulatory agencies

(37).

With a few interesting exceptions, there is no

behaviorally-based technology that is operationally successful in guiding fish. There is potential

for use of strobe illumination with a number of

species, as well as use of infrasound with

salmonids (and possibly other species) and use of

ultrasound with clupeids and cod. These investigations need to be continued and include both

basic biology and investigation of field applications of these signals. Very little work is being

done with electrical stimuli and bubble barriers,

and these do not appear to have been broadly

successful in earlier studies. There is some evidence (165,178) that combinations of sensory

stimuli (e.g., light and sound) might be a productive possibility that needs further exploration.

There are major discrepancies in the views of

resource agencies and technology vendors about

the potential value and performance of alternative behavioral guidance devices. Part of the discrepancy in interpreting performance data has

arisen from lack of a standard approach to testing

and evaluation of the technologies. Vendors will

work closely with clients and consultants but

rarely involve the agencies in the early stages

and the decisionmaking process. In addition,

though some behavioral guidance devices have

been shown to elicit an avoidance response in

fish at certain sites, there are inconsistencies in

subsequent years of testing. This type of result

has caused the resource agencies to question the

validity of the assumptions and criteria on which

the studies, and the evaluation, are based. It is

critical to keep in mind that results and methods

developed for large western hydropower facilities may not be applicable to much smaller facilities in the Northeast and Midwest. At the same

time, methods that do not work at the larger

facility may be very useful and appropriate for

much smaller facilities. In effect, it may be

important to have research programs directed at

different “classes” of sites—such as large hydropower projects, small hydropower projects,

bypasses, etc.

Most of the research on fish exclusion systems

has not been reported in the peer-reviewed scientific literature, but appears in progress reports for

funded installations, and may be overly optimistic. Often research is not described in sufficient

detail to allow thorough analysis of the results.

Thus, it becomes difficult, if not impossible, to

assess the effectiveness of many of the techniques described or the results reported. Some

experimental results seem at odds with others,

and care must be taken in interpreting this information (204). Conclusions reached should be

viewed as tentative.

Many of the earlier studies are weak with

regard to behavioral analysis. Methods of analyzing the behavioral responses of fish (e.g., methods of observation of fish in experimental pens)

have often been poorly described. Also, inappropriate methods have been used in some cases.

This has led some to believe that experimenters

did not use appropriate observational techniques

(e.g., “double-blind” experiments where the

observers were unaware of the presence of a

sound stimulus when reporting the behavior of a

fish). Moreover, the applicability of techniques
96 | Fish Passage Technologies: Protection at Hydropower Facilities

across species, or to the same species under different environmental or physical conditions (age

and size), is not well understood. Researchers for

the most part have failed to ask very basic questions about the general behavior of fishes under a

variety of conditions and information which

could be useful in developing bypass systems.

Statistical analyses of behavioral responses

are often inadequate and thus it is hard to assess

the effectiveness of a technique. An issue that

often arises appears to be differences in ways

that various investigators have used statistics to

interpret data. What may appear to be a positive

response in one statistical analysis may appear to

be nonsignificant in another.

Additional studies, with very specific directions, are needed to advance behavioral guidance

technologies. A key need is to develop a basic

understanding of the mechanism(s) by which

stimuli elicit responses. In particular, it is not

known how very high-frequency sounds are

detected by clupeids, and basic information to

answer that (and other) questions could help

markedly in the design of more suitable control

systems. Knowledge of the mechanisms of signals detection, the normal behavioral responses

to signals, and the range of signals to which a

fish will respond are critically important in helping design appropriate control mechanisms.27

Even basic information on the general behavior of fish is often lacking. Thus, it becomes

impossible to predict how a fish might alter its

behavior when it encounters a hydropower facility or water bypass, how it might respond to various sensory stimuli (e.g., light or sound),

including noxious stimuli, and whether certain

sensory stimuli are within the reception capabilities of a particular species. Without such basic

data it is very difficult to design a truly effective

means for controlling fish behavior.

An interdisciplinary approach to investigating

the potential for improving fish passage is

needed. Studies should be designed with close

collaboration between fisheries biologists having

interest and expertise in the needs for fish passage and basic scientists knowledgeable in the

behavior and sensory biology of fishes. Other

important specialists would likely include

hydraulic engineers and hydrologists, who would

bring special knowledge of currents and other

aspects of the problem to the discussion, and

engineers involved in designing and maintaining

barriers to fish movement. To date, there has

been little interaction along these lines.

27 An example of this is found in the work controlling the movement of Atlantic Salmon by Knudsen et al. (126,128). Their experimental

design for their field work was clearly based upon their first studies on hearing capabilities (128), as well as the earlier studies of Hawkins

and Johnstone (99).
| 97

5

The Federal

Role in Fish

Passage at

Hydropower

Facilities

ydroelectricity provides over 10 percent of the electricity in the United

States and is by far the largest developed renewable energy resource in the

nation (figure 5-1). At least 25 million Americans depend on hydropower for their electricity

needs. Conventional hydropower plants total

nearly 74,000 megawatts (MW) of capacity at

roughly 2,400 plants. Pumped storage provides

an additional 18,000 MW of capacity at about 40

plants. The undeveloped hydropower resource

potential in this country is significant. The Federal Energy Regulatory Commission estimates

that approximately 71,000 MW of conventional

capacity remains undeveloped (81,82).

History has shown that hydropower development can, and generally does result in changes in

the abundance and composition of migratory and

riverine fish populations. Dams impede fish

movements up and down rivers, delaying them,

blocking them altogether and sometimes killing

them directly (e.g., turbine mortality) or indirectly (e.g., predation at points of delay) (37).

However, specific data on population changes

attributable to hydropower development are difficult to come by and other factors also have had

adverse impacts (e.g., habitat destruction, water

pollution, over-harvest). To what degree each of

these factors contributes to the overall decline of

North American fisheries remains unclear.

This chapter examines the federal role in fish

passage and protection at hydropower facilities

(box 5-1). Federal involvement in managing nonfederal hydropower issues includes: licensing,

monitoring, and enforcement; identifying mitigation plans for hydropower facilities; and conducting research on and development of fish

protection technologies. The Federal Energy

Regulatory Commission (FERC) is responsible

for the licensing, monitoring, and enforcement of

license conditions for nonfederal hydropower

facilities. Explicit in FERC’s authority is the

responsibility for balancing the developmental

and nondevelopmental values of hydropower

development in the licensing process.

The National Marine Fisheries Service

(NMFS), the U.S. Fish and Wildlife Service

(FWS), and, in certain cases, U.S. federal land

management agencies prescribe mandatory fish

passage conditions for inclusion in hydropower

licenses. In addition, these agencies and state

resource agencies also may make nonbinding

recommendations for additional mitigation to

promote fish protection.

H
98 Fish Passage Technologies: Protection at

Biomass

Hydropower

SOURCE: “Renewable Resources in the U.S. Electric Supply, ” Table

4, February 1993,

Mitigation technologies to reduce the adverse

effect of hydropower on the nation’s fish

resources exist and have been employed,

although not uniformly, since the early part of

this century. These techniques can be costly and

their effectiveness is often poorly understood

(242). Yet, in a review of 16 case studies, the

majority demonstrated positive results stemming

from technology implementation (242). The high

cost of installing or retrofitting fish protection or

passage facilities relative to the perceived benefit

derived generates some tension between resource

agencies and the hydropower industry. Yet, few

studies have attempted to describe the full range

of benefits and costs of fish passage mitigation

over the long-term. 1

Hydropower Facilities

LICENSING OF NONFEDERAL

HYDROPOWER PLANTS

Federal licensing of nonfederal hydropower

plants on navigable waterways is the responsibility of the Federal Energy Regulatory Commission (previously the Federal Power Commission

(FPC) under the Federal Power Act of 1920).2 In

the 1930s, FPC’s role was expanded to include

rate regulation and other matters related to

wholesale, interstate sales of electricity and natural gas (1935 FPA and 1938 Natural Gas Act).

The 1977 Department of Energy Organization

Act created the Federal Energy Regulatory Commission (FERC) and transferred FPC’s energy

jurisdiction to the agency as well as jurisdiction

over oil pipeline transportation rates and practices. Today, FERC has exclusive authority to

license nonfederal hydropower facilities on navigable waterways and federal lands (approximately 1,825 dams); regulate the electric utility

and interstate natural gas pipeline industries at

the wholesale level (including reviewing electric

utility mergers and supervising/authorizing

hydropower and gas pipeline construction); and

regulate oil pipeline transportation (74).

The initial mandate of the agency was the regulation of energy production, distribution, and

availability; and the promotion of hydropower,

particularly for the Northeast and Northwest

regions of the United States. Environmental concerns were largely addressed through a number

of laws that were enacted to protect natural

resources and the environment, including: the

National Environmental Policy Act (NEPA),

Fish and Wildlife Coordination Act, National

Historic Preservation Act, Endangered Species

Act, Federal Water Pollution Control Act (Clean

Water Act), and the Wild and Scenic Rivers Act

(box 5-2).

1 Hydroelectric licenses run from 30 to 50 years. Economic comparisions of the costs of installing or retrofitting facilities and the revenue

flow from plant operation over the license period might clarify this debate, however, the information does not currently exist.

2 Under section 23(b) of the Federal Power Act, FERC has jurisdiction to license nonfederal hydroelectric projects that are on navigable

U.S. waters; are on non-navigable U.S. waters over which Congress has “Commerce Clause” jurisdiction, were constructed after 1935, and

affect interstate or foreign commerce; are on public lands or reservations; or use surplus water or water power from any federal dam (49).
Chapter 5 The Federal Role in Fish Passage at Hydropower Facilities | 99

In addition, section 18 of the FPA gave the

Secretaries of Commerce and Interior authority

to prescribe fishways at FERC-licensed hydropower projects. Section 4(e) allows federal land

management agencies to issue mandatory conditions to protect the purposes for which their lands

are held in trust. If the purposes of the lands

include fish and wildlife, then section 4(e) may

be used to issue mandatory fish protection conditions. Section 30 applies primarily to conduit

exemptions: projects that use the hydroelectric

potential of a conduit that is operated for the distribution of water for agricultural, municipal, or

industrial consumption and not primarily hydropower. In these cases, FERC must include in the

exemption the terms and conditions that NMFS,

BOX 5-1: Chapter Findings—Federal Role

■ The Federal Energy Regulatory Commission (FERC) has exclusive authority to license nonfederal hydroelectric facilities on navigable waterways and federal lands, which includes conditioning of licenses to

require operators’ adoption of fish protection measures.

■ Section 18 of the Federal Power Act (FPA) gives the federal resource agencies authority to prescribe

mandatory fish passage conditions to be included in FERC license orders. Section 10(j) recommendations relate to additional mitigation for rehabilitating damages resulting from hydropower development or

to address broader fish and wildlife needs (e.g., minimum flow requirements). Yet, these recommendations are subject to FERC approval.

■ FERC’s hydroelectric licensing process has been criticized as lengthy and can be costly for applicants

and participating government agencies. In some cases, the cost of implementing fish protection mitigations from the utility perspective may render a project uneconomical.

■ FERC uses benefit-cost analyses in its final hydroelectric licensing decisions; yet economic methods for

valuing habitat and/or natural resources are not well established and many economists feel that they fit

poorly in traditional benefit-cost analysis.

■ There is no comprehensive system for monitoring and enforcing resource agency fish passage prescriptions. FERC’s monitoring and enforcement authority has been used infrequently, and only recently, to fulfill

its mandate to adequately and equitably protect, mitigate damages to, and enhance fish and wildlife

(including related spawning grounds and habitat) affected by the development, operation, and management of hydroelectric projects.

■ Parties must perceive a need to negotiate in the FERC hydropower licensing process, beyond the regulatory requirements of applicants and agencies, in order to achieve success. FERC must be seen as a neutral party to motivate participants to find mutually acceptable agreements in accommodating the need for

power production and resource protection. If FERC is perceived to favor certain interests, the need to

negotiate is diminished or eliminated.

■ There are no clearly defined overall goals for North American fishery management and Congress has not

clearly articulated goals for management of fishery resources and/or priorities for resource allocation.

■ Fish protection and hydropower licensing issues return repeatedly to the congressional agenda. The

1920 FPA was designed to eliminate controversy between private hydropower developers and conservation groups opposed to unregulated use of the nation’s waterways. Greater consideration of fisheries and

other “nondevelopmental” values was called for in the Electric Consumers Protection Act of 1986 (ECPA)

and oversight on these issues continued with the passage of the Energy Policy Act of 1992. In the 104th

Congress, efforts continue to address power production (e.g., sale of PMA’s; BPA debt restructuring) and

developing sustainable fisheries (e.g., Magnuson Act amendments; Striped Bass Conservation Act).

SOURCE: Office of Technology Assessment, 1995.
100 | Fish Passage Technologies: Protection at Hydropower Facilities

FWS, and state resource agencies determine are

appropriate to prevent loss or damage of the

affected fish and wildlife resources. Under the

broad scope of section 30 language, fish passage

could be included, if appropriate. Sections 4(e),

18, and 30 have provided these specific authorities to protect fish and wildlife resources since

the inception of the FPA in 1920 (123,150).

In 1986, Congress passed the Electric Consumers Protection Act (ECPA)(PL 99-495), a

series of amendments to the FPA, which was

designed to alter FERC’s tendency to place

power over fish in licensing decisions. The FPA,

as amended by ECPA, establishes principles that

guide FERC in the issuance of hydropower

licenses. FERC is directed to give equal consideration3

 to the full range of purposes related to

the potential value of a stream or river, to

include: hydropower development; energy conservation; fish and wildlife resources, including

spawning grounds and habitat; recreational

opportunities; other aspects of environmental

quality; irrigation; flood control; and water supply (1,74,123).

Although mandatory fish passage authority

rested with the federal resource agencies since

the early part of this century,4 ECPA was instrumental in elevating the importance of nondevelopmental values in and increasing FERC’s

accountability for licensing decisions (1,240).

3 Equal consideration does not mean treating all potential purposes equally or requiring that an equal amount of money be spent on each

resource value, but it does mean that all values must be given the same level of reflection and thorough evaluation in determining that the

project licensed is best adapted. In balancing developmental and nondevelopmental objectives, FERC will consider the relative value of the

existing power generation, flood control, and other potential developmental objectives in relation to present and future needs for improved

water quality, recreation, fish, wildlife, and other aspects of environmental quality (74). 4 Since the early part of this century, the authority for issuing fishway prescriptions rested with the Department of Commerce and the

Department of the Interior (DOI). Prior to the passage of the Federal Power Act in 1920, the Secretary of Commerce held primary responsibility for fish passage facilities at federally licensed projects (An Act to Regulate the Construction of Dams Across Navigable Waters, 1906)

(P.L. 262). In 1939, DOI acquired concurrent authority. The Departments now share responsibility for developing fishway prescriptions

(257).

BOX 5-2: Environmental Laws Affecting the FERC Licensing Process

A number of laws beyond the FPA influence environmental protection in the FERC hydropower licensing process. These laws continue to affect the licensing process, although some of the intent contained in them has

been reiterated and directly applied to FERC through ECPA.

■ National Environmental Policy Act—requires preparation of an Environmental Assessment (EA) or an Environmental Impact Statement (EIS).

■ Fish and Wildlife Coordination Act—requires FERC to give full consideration to the recommendations of

the U.S. Fish and Wildlife Service (FWS), National Marine Fisheries Service (NMFS), and state resource

agencies on the wildlife aspects of a project.

■ National Historic Preservation Act—requires FERC to give the Advisory Council on Historic Preservation

reasonable opportunity to comment on a license issuance involving an historic resource.

■ Endangered Species Act—requires FERC to consult with FWS and NMFS to determine if action is likely to jeopardize the continued existence of any endangered or threatened species or adversely affect critical habitat.

■ Federal Water Pollution Control Act (Clean Water Act; CWA)—requires applicants to confer with the “certifying agency” (U.S. Army Corps of Engineers (COE) or the Environmental Protection Agency (EPA)) and

verify compliance with the CWA (National Pollutant Discharge Elimination System permit [NPDES], S401

water quality certificate, or S404 dredge and fill permit).

■ Wild and Scenic Rivers Act—FERC is prohibited from licensing projects on or directly affecting a wild and

scenic river as established by an act of Congress or State Legislatures.

SOURCE: Office of Technology Assessment, 1995.
Chapter 5 The Federal Role in Fish Passage at Hydropower Facilities | 101

Through the addition of section 10(j), federal and

state resource agencies may recommend conditions to protect, enhance, or mitigate for damages

to fish and wildlife resources under the FPA:

Section 10(j) (U.S.C.§803(j)) stipulates that: in

order to adequately and equitably protect, mitigate damages to, and enhance fish and wildlife

(including related spawning grounds and habitat) affected by the development, operation, and

management of the project, each license issued

under this subchapter [16 U.S.C. §§ 792-828c]

shall include conditions for such protection,

mitigation, and enhancement....[S]uch conditions shall be based on recommendations

received pursuant to the Fish and Wildlife

Coordination Act (16 U.S.C. 661 et. seq.) from

the National Marine Fisheries Service, the U.S.

Fish and Wildlife Service, and State fish and

wildlife agencies.

Whenever the Commission believes that any

recommendation referred to in paragraph (1)

may be inconsistent with the purposes and

requirements of this subchapter or other applicable law, the Commission and the agencies

referred to in paragraph (1) shall attempt to

resolve any such inconsistency, giving due

weight to the recommendations, expertise, and

statutory responsibilities of such agencies. If,

after such attempt, the Commission does not

adopt in whole or in part a recommendation of

any such agency, the Commission shall publish

each of the following findings (together with a

statement of the basis for each of the findings):

1) a finding that adoption of such recommendation is inconsistent with the purposes and

requirements of this Part or with other applicable provisions of the law, and 2) a finding that

the conditions selected by the Commission

comply with the requirements of paragraph (1).

The authority given to the resource agencies is

a little more restricted than it may appear. Section 4(e), which allows federal land management

agencies (e.g., Forest Service, Bureau of Land

Management, etc.) to issue mandatory terms and

conditions to protect the purposes for which their

lands are held in trust, including fish passage

where appropriate, applies to FERC-licensed

hydropower plants on federal reservation lands.5

Fish and wildlife recommendations made by federal and state resource agencies under section

10(j) are limited to those designed to protect,

mitigate damages to, or enhance fish and wildlife, including related breeding or spawning

grounds and habitats; but they are not mandatory.6 FERC must meet with the pertinent agencies to discuss alternatives and new information

or to demonstrate the recommendations’ inconsistency with other applicable legislation in order

to alter or decline section 10(j) recommendations. Nevertheless, this issue is at the core of

one of the larger “balancing” debates. Section 18

fishway prescriptions developed by the federal

resource agencies are mandatory, although of

narrower scope than recommendations allowed

under section 10(j).

FERC is not primarily an environmental

agency, yet has the ability to enforce environmental requirements through conditioning

authority, power to investigate, and penalty and

revocation authority (43). FERC can specify conditions for a license approval, such as minimum

flow, fishway requirements, etc. Once the conditioned license is accepted, the conditions become

enforceable by FERC. Indeed, FERC is able to

exact civil penalties of up to $10,000 per day in

enforcement. In one case, a hydropower licensee

that was found to have violated “run of the river”

and minimum stream flow requirements was

assessed a $19,000 civil penalty (43). Revocation

authority—whereby the agency can halt a project

found in non-compliance—is another important

FERC enforcement tool. Yet, revocation also

faces great constraints to use since it may not

result in correcting the damage. In one such

instance where revocation might have been

5 Federal reservation lands include national forests, wilderness areas, Indian reservations, and other federal public lands reserved for specific purposes and withdrawn from private disposition. 6 Additional recommendations related to broad-reaching efforts such as rehabilitation of damages, habitat, management considerations,

and general enhancements for fish and wildife populations may be made under section 10(a); also subject to FERC approval.
102 | Fish Passage Technologies: Protection at Hydropower Facilities

employed, FERC chose not to revoke the license,

but to examine possibilities for mitigation

requirements and penalties instead (43).

❚ Hydropower Licensing Procedure

The licensing (or re-licensing) procedure is a

seven-step process occurring in three stages and

culminating in a licensing decision (box 5-3)

(74). Prospective licensees must notify FERC of

the intent to relicense as early as five and a half

years, but no later than five years, prior to license

expiration. The application must be filed with

FERC at least two years prior to expiration. Prior

to application filing, prospective licensees must

confer with the appropriate resource agencies.

Pre-filing consultation stages include:

Stage 1: The applicant must provide the agencies with basic information about the project and

any proposed changes. The agencies respond

with recommendations for studies.

Stage 2: The applicant completes all reasonable and necessary studies, obtains all reasonable

and necessary information required by resource

agencies, and prepares the draft application.

Stage 3: The applicant provides the agencies with

a copy of the application, including agency correspondence regarding the project, and copies of relevant certifications (e.g., section 401 CWA permit).

FERC staff conduct the environmental analysis required for the project by the National Environmental Protection Act and produce an

Environmental Assessment or an Environmental

Impact Statement, as appropriate. Finally, the

Director of the Office of Hydropower Licensing

(by delegated authority) or the Commission

determines whether or not to issue the license

and includes the conditions recommended by the

agencies and found consistent by FERC, as well

as conditions recommended by FERC staff in the

environmental analysis.

A large number of FERC licenses have

recently expired and many more are due for

renewal by the year 2010. This situation provides a

significant opportunity to consider the adequacy of

fish passage at these sites. As of July 1995, FERC

had relicensed 65 of the 167 projects in the “class of

1993.” An additional 97 facilities will need relicensing between now and the year 2010 (49).

The Federal Resource Agencies

The Department of Commerce, acting through

the National Marine Fisheries Service (NMFS),

and the Department of the Interior, acting

through the Fish and Wildlife Service (FWS), are

the federal agencies primarily responsible for the

conservation and management of the nation’s

fish and wildlife resources. Together, these agencies share a mandate to conserve, protect,

enhance, and restore fish populations and habitat

for commercial, recreational, and tribal fisheries.

FWS has broad-delegated responsibilities to

protect and enhance fish and wildlife and related

public resources and interests under authorities

granted by the Fish and Wildlife Act of 1956; the

Fish and Wildlife Coordination Act (FWCA); the

National Environmental Policy Act (NEPA); the

Migratory Bird Treaty Act; and the Endangered

Species Act of 1973 (ESA). NMFS is entrusted

with federal jurisdiction over marine, estuarine,

and anadromous fishery resources under various

laws, including the FWCA, NEPA, ESA, and the

Magnuson Fishery Conservation and Management Act.

FWS and NMFS have expertise and responsibility for fishery resources which are germane to

FERC’s hydropower licensing decisions. Prior to

licensing, FERC has an affirmative duty to consult with FWS and NMFS pursuant to the FWCA

and the FPA to determine measures to protect,

mitigate damages to, and enhance fishery

resources, including related spawning grounds

and habitat. FWS and NMFS recommend license

conditions to achieve these goals and prescribe

mandatory conditions for the construction, operation, and maintenance of fishways (150).

Consultation with prospective hydropower licensees and development of fish passage mitigation plans are the responsibility of these federal

resource agencies and their state counterparts.

NMFS and FWS develop fish passage prescriptions under section 18 of FPA for inclusion in the

FERC license order. Broader mitigation recom-
Chapter 5 The Federal Role in Fish Passage at Hydropower Facilities | 103

mendations are made by the federal and state

resource agencies under section 10(j) of the FPA.

Federal land management agencies (e.g., U.S.

Forest Service, Bureau of Land Management,

Bureau of Reclamation) have authority to issue

section 4(e) conditions for hydropower facilities

on public lands under their jurisdiction. Facilities

on U.S. Forest Service lands represent nearly 15

percent of all FERC-licensed hydropower plants,

or at least 240 facilities. The Forest Service (FS)

currently is facing approximately 50 applications

for relicensing and another 60 applications for

new projects. In an effort to streamline its process and improve certainty for prospective licensees, the FS has recently outlined a proposed

policy with regard to issuing section 4(e) conditions.7

Although the FERC licensing process is not

integrated with the fishway prescription process,

it drives the latter. Resource agency prescriptions

and recommendations must be submitted when

FERC rules that the project is ready to undertake

the required environmental studies (EA or EIS).

In some instances, FERC makes this decision

before the resource agencies have the information they believe is needed to make meaningful

fish and wildlife recommendations that can be

supported by substantial evidence.

7 In the proposed policy, it is stated that 4(e) recommendations would not try to achieve “preconstruction” conditions. This harmonizes

with FERC’s approach to environmental assessment documents. A second alteration involves the relinquishing of FS’s unilateral “reopener”

for special-use permits. At present, FS may revise special-use authorization conditions at specified intervals to reflect changing environmental conditions if the terms of the authorization exceed 30 years. This enables FS to re-open the permit to ameliorate negative impacts at a site

without waiting up to 50 years for a license to expire.

BOX 5-3: Procedural Steps in Hydropower Licensing

■ Applicant submits an application to FERC along with the background information on the project, economic,

environmental, proposed benefits, etc. The background information may include as much as eight to nine

volumes of information.

■ FERC reviews the application and the supporting information and determines the need for additional studies

or information. FERC sends Deficiency Statements to the applicant describing the types of information or

studies that will be required to continue the application process.

■ Additional information requests may be submitted by FERC after reviewing the new information submitted by

the applicant in response to the Deficiency Statements.

■ Upon receipt of all of the required information, FERC identifies the project as “Ready for Environmental Analysis.” This is the starting point for the resource agencies, which have 45 days to develop and determine the

need for fish protection mitigation under sections 10(j) and 18 of the Federal Power Act. The agencies may

file for an extension if this cannot be completed within the 45-day period.

■ Based on the information provided by the applicant and resource agencies, FERC develops Scoping Document I that investigates whether to undertake an Environmental Assessment (EA) or an Environmental Impact

Statement (EIS) in compliance with the National Environmental Policy Act (NEPA).

■ Scoping Document I is submitted for general public comment. Based on the review comments, FERC produces Scoping Document II, which is in essence a blueprint for the EA or EIS.

■ The draft EA or EIS is produced and submitted for general public comment. Based on review, the final EA or

EIS is produced.

■ FERC develops a License Order for the project and submits this and the environmental document to the

Commission for final determination for licensing.

SOURCE: Office of Technology Assessment, 1995.
104 | Fish Passage Technologies: Protection at Hydropower Facilities

❚ Issues in Hydropower Licensing

The licensing and relicensing of hydropower

projects under the jurisdiction of FERC provides

a unique opportunity to restore, rehabilitate, and

protect river systems for the license term, often a

30- to 50-year time frame. However, relicensing

is a highly controversial issue among the many

stakeholders involved in the process. State and

federal resource agencies, the hydropower industry, special interest groups (e.g., environmental),

Native Americans, individual owner/operators,

and the public at large are all involved. Balancing of all of the competing interests in hydropower licensing is a complex process, generating

much dispute among the participants (112). Key

issues include: adequate balancing of developmental and nondevelopmental values; defining

the baseline goal for mitigation; process timeliness; reopening license orders; and dam decommissioning.

Adequate Balancing

The need for balance of developmental and nondevelopmental values in hydropower licensing

decisions was underscored by ECPA in 1986.

Yet, resource agencies contend that despite existing authority identifying their role and expertise

in the hydropower licensing process, insufficient

weight is given to their recommendations in final

balancing decisions. Some observers note that

FERC’s role in balancing competing interests in

hydropower licensing has become increasingly

difficult because of the many mandatory license

conditions possible in the licensing process (e.g.,

resource agencies, states) (112). Others point to

the need for this broad level of input to ensure all

factors are considered in FERC’s balancing role.

Federal and state resource agencies and environmental groups note that the nonbinding nature

of the section 10(j) recommendations is a significant problem. If FERC finds that 10(j) recommendations are inconsistent with other

applicable law, they may be altered or excluded.

FERC must meet with relevant agencies to alter

or decline section 10(j) recommendations and

section 10(j)(2) requires that FERC give “due

weight to the recommendations, expertise, and

statutory responsibilities” of federal and state

resource agencies. In some instances where disputes are settled on the basis of FERC professional judgment, the resource agencies feel that

their views and expertise have not been adequately considered or have been supplanted by

FERC expertise. Thus, FERC has been criticized

for rejecting or modifying recommendations—

in some cases nullifying the recommendations’

impacts (91). On the other hand, GAO found that

FERC accepts a higher proportion of environmental recommendations without modification

now than it did before ECPA, i.e., three-fourths

versus two-thirds in the cases studied

(123,240,241). However, given the nature of balancing, recommendations that are unlikely to

affect a hydropower project’s economic viability

may be more likely to be approved than those

that directly affect power production.

States may also enter into the balancing process in other venues. Where FERC’s jurisdiction

is exclusive it may preempt state environmental

requirements. For example, in California v.

FERC, 495 U.S. 490 (1990), FERC successfully

defeated a proposal by the California State Water

Resources Control Board to increase minimum

streamflow requirements for a previously

licensed hydropower plant. The licensee demonstrated to FERC that this increase would

adversely affect the economic viability of the

project (43).

Yet, FERC’s authority to preempt state

requirements recently was limited by the U.S.

Supreme Court in Jefferson County v. Washington Dept. of Ecology. The case clarified that

states could require minimum instream flows as

a condition of a federally issued permit, such as a

FERC license. Under the Clean Water Act’s section 401, all applications for a federally issued

permit must include a certification from the state

that the proposed permit is consistent with

achieving the state’s water quality goals. The

State’s Department of Ecology argued that minimum flows were necessary to maintain the quality of the riverine systems for fisheries

management, and refused to grant a certification
Chapter 5 The Federal Role in Fish Passage at Hydropower Facilities | 105

unless the permit required those flows. The

Supreme Court found that a state’s responsibility

for achieving water quality goals gave it the

authority to mandate release of flows by FERClicensed projects and to enforce other standards

(136).

Critics of the ruling in Jefferson County argue

that the intent of the Clean Water Act is to

restore and maintain water quality, not to interfere with water quantity issues (113). Proponents

of the decision say the Supreme Court was correct in saying that water quantity was an integral

part of the Clean Water Act’s intent to “restore

the chemical, physical and biological integrity of

the nation’s waters” (Clean Water Act §101(a),

33 U.S.C. §1251(a)). The Jefferson County decision has created substantial controversy within

the hydropower sector and is likely to be a continuing point of contention. In the 104th Congress, legislation has been introduced that would

alter the effect of the decision.

Defining Baseline for Mitigation

Defining the baseline to be used in determining

the goal for mitigation is perhaps one of the more

hotly disputed issues. This is particularly significant in re-licensing decisions since existing

hydropower plants may not have been previously

required to mitigate for environmental impacts.

Further, lack of historical baseline environmental

data hinders identification of pre-construction

conditions.8

 The question also arises as to the

potential for achieving pre-construction conditions, given that the alterations to the environment may have occurred decades ago.

Operators sometimes feel that they are being

asked to mitigate for conditions not of their making. Many view relicensing as a continuation of

the status quo, and thus, existing conditions

become the starting point for environmental

studies. On the other hand, critics state that relicensing is not just a continuation of the status

quo but a federal recommitment of public

resources for a lengthy period of time (30 to 50

8 Preconstruction conditions refers to the environmental conditions that existed prior to the placement of the hydroelectric facility.

years). The environmental community points to

the relative time sequence of past and present

decisionmaking criteria and the significant

advances made in environmental law and mitigation measures since the mid 1900s. Thus, efforts

to achieve pre-construction conditions in certain

riverine systems might be considered properly

managing the resource for the public interest. In

any event, there clearly is a need for close collaboration among FERC staff (or their surrogates)

and the state and federal resource agencies in the

development of the Environmental Impact Statement (EIS) and Environmental Assessment (EA)

for hydropower projects.

Process Timeliness

Relicensing has not been a timely process, creating uncertainty for prospective licensees and

resource managers. Licensees are concerned

about uncertainty and costs in increasingly competitive energy markets. Delays due to multiple

processes at both the state and federal levels may

expose licensees to the risks of duplicative study

efforts and inefficiency. Resource managers are

concerned about preserving and conserving

resources at risk. Delays in the licensing process

slow the implementation of mandatory fish passage prescriptions. In the current “class of ‘93”

situation, the process has been especially prolonged. Some blame licensing delays on the lack

of cooperation among stakeholders, resulting in

revisiting issues over the course of the process to

ensure that all sides are fairly heard.

Delay may also be perpetuated by the timetables set by FERC’s licensing regulations. For

some projects, especially those involving multiple developments, the timeframe may be unrealistically short. Resource agencies contend that

one to two years is inadequate to complete the

required studies to give decisionmakers reliable

information (150). Similarly, linking multiple

facilities in the licensing process may lead to

delays in implementing resource protection mitigation at several facilities due to difficulties at a
106 | Fish Passage Technologies: Protection at Hydropower Facilities

single site. For example, several Bangor Hydroelectric Company facilities on the Penobscot

River in Maine are linked in the licensing process. A single, controversial new project proposal has delayed the licensing process, leaving

the other existing projects operating under

annual licenses and delaying decisions on the

need for fish protection mitigation at these sites

(21).

Decommissioning and Dam Removal

Decommissioning and/or removal of existing

dam facilities as an alternative to relicensing has

been raised more frequently since the “class of

1993” and as part of the movement toward

greater scrutiny of the adverse impacts of hydropower plants on certain fish populations. Dam

removal options are faced by a number of very

real environmental, economic, and political constraints and, thus, are infrequently considered as

alternatives to fish passage development.

A recent FERC policy statement (RM93-23)

identifies the Commission’s authority to order

decommissioning of hydropower plants at licensee expense as an alternative to relicensing.

FERC would hear the cases individually rather

than developing a generic decommissioning program. If the policy is actively pursued, a need

exists to incorporate planning and budgeting for

decommissioning and dam removal in the licensing procedure so that applicants are aware from

the start of the costs and possibilities.

The Bureau of Reclamation is examining possibilities for removal of Savage Rapids Dam on

the Rogue River in Oregon; the operator asked

for removal rather than fishway installation.

Removal of the dam would eliminate salmon and

steelhead passage problems although recreational value would be curtailed. Demolition of

the dam and construction of the plants is estimated to take five years and cost $13.3 million.

To retain the dam and install fish protection has

been estimated to cost $21.3 million (115).

License Reopeners

Reopening of licenses prior to expiration has also

been the subject of much debate. FERC can use

reopeners to require projects to mitigate cumulative impacts in multi-project basins. Placeholder

clauses allow revisiting of license conditions

after a specified event occurs. For example, an

upstream facility license could contain a placeholder clause that would require development of

fish passage mitigation at such time as a facility

downstream completed relicensing to include

fish passage, e.g., when fish populations were

physically able to proceed to the upstream facility.

Resource agencies and other participants in

the process may request that FERC reopen a

license for various causes. However, this is not a

unilateral decision and must be accomplished

through a hearing process. Understandably,

industry may be less inclined to support reopening when the potential for additional mitigation

costs may result from the activity and thus affect

project economics. Consequently, the resource

agencies have been criticized for attempting to

solve larger fishery management problems

through the prescription process. The agencies

respond that the long license period and lack of

reopening authority means that they must

develop mitigation plans with a vision toward

meeting future as well as present needs through

their recommendations, terms and conditions,

and prescriptions.

❚ Improving Hydropower Licensing

Not surprisingly, the level of controversy generated by hydropower licensing has led to a number of efforts to improve the process and bring

adversarial parties together. Some of these

efforts show promise, although in certain cases

they have been bogged down by the very debate

they intended to address. Primarily, efforts have

attempted to make the process transparent and

improve discussion among the participants.

Settlement Agreements

The FERC licensing process requires that prospective licensees consult with resource agencies

and others in the first stage of licensing. Yet,

many licensees are learning that even earlier

coordination and outreach is needed. Agreements
Chapter 5 The Federal Role in Fish Passage at Hydropower Facilities | 107

between parties with opposing interests are commonly used in other resource protection venues,

and now appear more often than before in FERC

proceedings. For parties advocating fish protection, a settlement agreement involves negotiating

with the licensing party to obtain the protective

measures deemed necessary. Tradeoffs in the

usual fixed positions of the two parties can be

made to obtain better mitigation than is usually

attainable through the FERC process. Holistic

viewpoints can be developed and maintained,

and decisions can be reached at a local rather

than exclusively federal level.

Parties must perceive a need to negotiate in

the FERC hydropower licensing process, beyond

the regulatory requirements of applicants and

agencies, in order to achieve success. FERC

must be seen as a neutral party to motivate participants to find mutually acceptable agreements

in accommodating the need for power production

and resource protection. If FERC is perceived to

favor certain interests, the need to negotiate is

diminished or eliminated. Requirements for successful use of settlement agreements are: skilled

negotiators, technical specialists and lawyers

skilled in FERC issues; and a shared goal to

resolve differences. Commitment to conflict resolution on the part of negotiating parties is essential for success. Necessary tradeoffs can then be

made to resolve difficult negotiating points.

Conceptual agreements may be reached fairly

early in the process without involvement of legal

expertise, but this expertise may be essential

when it comes to drafting the actual language of

the agreement. Successful settlement agreements

also depend on consensus on a single position

among resource agencies outside the negotiating

room. Since different agencies have their own

agendas and missions, which sometimes clash,

this can be problematic. Significant agency concessions may be needed to satisfy the interests/

missions of each.

The Michigan Department of Natural

Resources has realized many of its goals for fish

protection through settlement agreements on relicensing projects with Consumers Power Company and a new license project with Wolverine

Supply Cooperative. Issues resolved in these

agreements were largely accepted by FERC and

incorporated in the licenses for these projects.

NMFS/FWS Advanced Notice of Proposed 

Rulemaking (ANOPR)

Some licensees feel the licensing process is

unpredictable because of the lack of universal

standards to be used in the fish passage prescription process. Neither NMFS nor FWS has published standards and criteria that a licensee can

use to judge if a fishway is likely to be prescribed, and if so, what sort. However, licensees

can expect that passage will be an issue if their

project has blocked or will block fish movement

and access to historic habitat.

In an effort to address this concern, FWS and

NMFS solicited comments on the benefits of a

proposed rule to harmonize and codify their

existing practices for prescribing fishways under

section 18 of the FPA (233). An extensive review

and comment period generated a number of

issues to be resolved, one of which is the need

for such a rule or if a policy statement is sufficient.

Hydropower Reform Coalition

The Hydropower Reform Coalition (HRC) is a

coalition of conservation groups with an interest

in river protection. In its review of the hydropower licensing process, HRC found FERC’s

existing hydropower regulatory structure to be

better than any of the suggested alternatives.9

However, HRC feels FERC regulation of hydropower’s effects on nonpower values of river systems is inadequate and suggests several options

to rectify the problem, including:

9 Some of the suggested alternatives included: 1) placing regulatory authority at the state level and 2) exempting small dams from FERC

authority. The first alternative was criticized for increasing the fragmentation of the licensing process and the latter was for failing to recognize that adverse environmental impact is not necessarily proportionate to facility size.
108 | Fish Passage Technologies: Protection at Hydropower Facilities

■ FERC should examine an entire river system

when evaluating and mitigating adverse environmental effects from hydropower development;

■ FERC should synchronize license expiration

dates so projects in a basin can be reviewed

simultaneously; and

■ FERC should include headwater storage reservoirs more consistently within regulatory control.

HRC supports FERC deference to state CWA

section 401 rulings and favors adopting resource

agency section 10(j) recommendations.

HRC and National Hydropower Association

(NHA) entered into negotiations to determine if

it would be possible to collaborate in developing

a proposal to resolve many of the difficulties in

the licensing process. Issues included ensuring

compensation for private use of public goods by

setting up decommissioning funds, establishing

mitigation and restoration funds, and requiring

licensees to reimburse resource agencies for

study of license recommendations (113). Negotiations broke off, however, and NHA developed

its own proposal and requested a FERC rulemaking proceeding. HRC opposed the rulemaking as

unnecessary and a distraction to the relicensing

process.

MITIGATION COSTS AND BENEFITS10

Quantifying fish passage system capital costs is

fairly simple and largely a question of accounting. Determining which costs are rightly attributable to fish protection or passage may pose the

largest difficulty. For example, damaged turbines

at the Conowingo Plants required replacement to

continue generating power at the facility. These

new turbines provided acceptable downstream

passage for juvenile American Shad as well as

reduced turbine mortality rates compared to the

older models (177). What, if any, part of the new

10 This section is drawn from J. Francfort, Idaho National Engineering Laboratory, “Synthesis of the Department of Energy’s Fish Passage and Protection Report, Vol.II,” unpublished contractor paper prepared for the Office of Technology Assessment, U.S. Congress, June

1995.

turbines and installation expenses should be

counted as fish protection costs, given that the

turbines were needed for power generation in

any event?

Quantifying operating costs related to fish

passage is more difficult since it frequently

involves costs related to revenue loss from lost

power generation potential due to spillflows or

other water management practices that are

required for proper fish passage operation. For

example, the high annual cost of downstream

protection at the Lower Monumental Plant (table

5-1) is largely costs for the power that will not be

produced.

Determining the benefits of fish protection

and passage is more difficult. As a first step, it is

imperative to examine the multiple values

assigned to the resource. Some of these values

are difficult if not impossible to describe economically (e.g., cultural, ecological) and thus fit

poorly into traditional benefit-cost analyses.

Nevertheless, they must be weighed in decisionmaking.

Costs and benefits are not directly proportionate. For example, “X” dollars for constructing

and operating a fish passage/protection system

does not necessarily result in an “X” amount

change in the number of fish passing a barrier.

Other life-cycle factors that affect a species also

affect passage rates. Availability and quantity of

spawning habitat, downstream passage success,

ocean catch levels, and drought may directly

affect population success.

Mitigation costs vary considerably depending

on the type and scale of the mitigation measure.

Scale is driven by a site’s physical features (e.g.,

water flow, dam size, and configuration) and

finding similarities between two plants can be

difficult (table 5-2). For example, the Wadhams

plant, with its 0.56 megawatt capacity and 214

cubic feet per second (cfs) average water flows,
Chapter 5 The Federal Role in Fish Passage at Hydropower Facilities | 109

TABLE 5-1: Downstream Fish Passage/Protection Mitigation Benefits Over 20 Years

(Levelized Annual Costs in 1993 Dollars)

Plant Mitigation type Agency objective Mitigation benefit

Annual costa

(20-year

average)

Arbuckle 

Mountain

Cylindrical, wedgewire 

screens

Prevent fish entrainment 

(chinook salmon, steelhead, 

rainbow trout)

No anadromous fish present. 

Drought restricted monitoring.

$7,900

Brunswick Steel bypass pipe Reduce mortality for 

downstream migrating fish 

(American shad, alewife)

No established monitoring 

program.

46,500

Jim Boyd Perforated steel

screen

“No induced mortality” 

standard

Reportedly achieves agency 

standard. Visual observations 

performed.

51,000

Kern River

No. 3

Fixed barrier screens Protect “put-and-take” 

rainbow trout fishery

No established monitoring 

program.

7,700

Leaburg “V” wire screens and 

bypass

“No net loss” standard Meets agency standards. 381,200

Little Falls Wire mesh screens

and bypass

Protect downstream 

migrating blueback herring

Less than 1% turbine 

entrainment (>100,000 passed 

each season).

123,400

Lowell Bypass sluice Pass American shad and 

Atlantic salmon

No established monitoring 

program but existing sluice is 

considered ineffective.

52,850

Lower 

Monumental

Submerged, traveling 

screens

Prevent turbine entrainment 

(salmon and steelhead)

Not yet monitored. 4,812,000

T.W. Sullivan Eicher screen and 

conduit

Decrease turbine

entrainment

Bypass efficiency between 77 

and 95%.

713,000

Twin Falls Inclined wedgewire 

screens

“No induced turbine 

mortality” standard

Reportedly effective. 75,850

Wadhams Angled trash racks

and bypass sluice

Protect downstream-moving 

Atlantic salmon from turbine 

mortality

1987 study; 8% entrainment. 2,420

Wells Hydrocombine

bypass

Goal: “no induced mortality”; 

present agency criteria: 

(passage efficiency):

spring – 80% efficiency

summer – 70% efficiency

Passage efficiency exceeds 

agency criteria.

1,756,000

West Enfield Steel bypass pipe Protect downstream 

migrating Atlantic salmon

and alewife

Efficiency:

1990—18%

1991—62% (with attraction 

lighting).

Mortality in bypass greater than 

in turbines.

61,000

a Some of these annual costs include costs due to loss of power generation capacity resulting from spillflows and other water management

practices.

SOURCE: U.S. Department of Energy, Environmental Mitigation at Hydroelectric Projects, Volume II: Benefits and Costs of Fish Passage and Protection, Idaho Field Office, DOE/ID-10360(V2), January 1994.
110 | Fish Passage Technologies: Protection at Hydropower Facilities

has annual downstream mitigation costs of

$2,420. The Lower Monumental plant, with 810

MW capacity and average flows of 48,950 cfs,

has an average annual cost of $2.4 million (table

5-1). Although these are poor summaries of both

plants’ costs, it illustrates the disparity despite

their identical objectives to safely pass downstream migrants. A summary based on averages

for such diverse costs would be, if not erroneous,

at least misleading.

Alternatively, costs could be summarized

based on a factor such as fish ladder construction

costs per foot of design head; the design head

implies the vertical elevation that a ladder must

pass adults. Yet, it can also be misleading to

assume that the hydraulic design head is approximately the same as the required height for a fish

ladder. For example, the Kern River No. 3 plant

has an 880-foot head, but the ladder is used at an

upstream diversion that is only 20 feet high.

In the same vein, quantifying the benefits of

fish passage mitigation is plagued with problems

stemming from the inadequacy of traditional

economic analyses in resource valuation. The

examination of the DOE case studies that have

implemented fish passage measures reveals that

several plants have been successful in increasing

the passage rates or survival of anadromous fish

(i.e., the Conowingo, Leaburg, Lower Monumental, Wells, Buchanan, and T. W. Sullivan

plants). Six other plants show encouraging preTABLE 5-2: Case Studies General Information

Plant name Capacity 

(MW)

Annual energy

production 

(MWh)

Diversion 

height (ft.)

Average 

site flow 

(cfs)

State Upstream 

mitigation

Downstream 

mitigation

Mitigation 

cost

(mils/kWh)a

Arbuckle 

Mountain

0.4 904 12 50 California Y Y 12.9

Brunswick 19.7 105,200 34 6,480 Maine Y Y 3.7

Buchanan 4.1 21,270 15 3,636 Michigan Y N 10.6

Conowingo 512 1,738,000 105 45,000 Maryland Y N 0.9

Jim Boyd 1.2 4,230 3.5 556 Oregon Y Y 21.1

Kern River 

No. 3

36.8 188,922 20 357 California Y Y 0.09

Leaburg 15 97,300 20 4,780 Oregon Y Y 5.2

Little Falls 13.6 49,400 6 n/a New York Nb Y 2.8

Lowell 15 84,500 15 6,450 Massachusetts Y Y 5.5

Lower 

Monumental

810 2,856,000 100 48,950 Washington Y Y 2.3

Potter Valley 9.2 57,700 63 331 California Y Y n/a

T.W. Sullivan 16.6 122,832 45 23,810 Oregon Nc Y 5.8

Twin Falls 24 80,000 10 325 Oregon N Y 0.9

Wadhams 0.56 2,000 7 214 New York N Y 1.2

Wells 840 4,097,851 185 80,000 Washington Y Y 1.0

West Enfield 13 96,000 45 12,000 Maine Y Y 3.9

aCosts are in 1993 dollars, per kilowatt-hour of generation, based on 20-year averages. All upstream and downstream mitigation-related

costs are included.

bUpstream passage occurs through New York Department of Transportation Barge Lock Number 17.

cUpstream passage occurs through Oregon Department of Fish and Wildlife maintained fish ladder at Willamette Falls.

KEY: n/a = not available.

SOURCE: U.S. Department of Energy, Environmental Mitigation at Hydroelectric Projects, Volume II: Benefits and Costs of Fish Passage and Protection, Idaho Field Office, DOE/ID-10360(V2), January 1994.
Chapter 5 The Federal Role in Fish Passage at Hydropower Facilities | 111

liminary results; they have not been adequately

studied to determine the long-term impacts on

fish populations (i.e., Brunswick, Jim Boyd, Little Falls, Lowell, Twin Falls, and Wadhams).

Only one of the case studies (West Enfield)

appears to have failed in the attempt to enhance

fish populations, but for some the benefits are

unclear. In some cases, benefits could be

expressed only in terms of the numbers of individual fish that were transported around the dam

or protected from entrainment. Missing, however, is the assessment of the long-term effects of

these mitigation measures on fish population levels.

“How much are additional fish worth?” In

some cases, the fish are commercially caught and

determining value may be simplified. It is

slightly more difficult to determine the revenue

stream from fish caught recreationally. It

becomes even more difficult to attach a price tag

to fish caught as part of a traditional cultural

activity. For example, Native American fishing

rights at usual and customary locations as guaranteed by U.S. treaty is recognized as a significant cultural event. If hydropower development

depletes historic stocks to the point where this

activity can no longer be pursued, then how

much is a fish worth? Clearly, fish have a variety

of values depending on their ultimate use and the

role that fishing plays in human activities.

If price tags are not available, how can the

value of fish be estimated? Resource economics

has developed two types of methods for estimating the values of natural resources, including recreational fish. The direct method is to ask people

their valuations of particular resources through

surveys constructed to eliminate a number of

potential biases. The indirect method relies on

the fact that to consume part of a natural

resource, which has no price tag, a fisherman

must spend some of his or her money (and time)

on goods which are sold in markets. Travel costs,

including the value of time as well as out-ofpocket costs and any entry fees at restricted fishing sites, amount to the effective, or implicit,

price which fishermen pay for their recreational

fish. This information can be used to construct a

demand curve to estimate the recreational value

of fish at a specific site and time—the marginal

value.

Use and nonuse values in natural resource valuation have become prominent in public, scientific debates in the past several years, however,

they are subject to theoretical and methodological concerns. The use value is the value someone

will pay to consume a natural resource, whether

that consumption act is catching a fish and eating

it, catching a fish and releasing it, or looking at a

mountain in a national park. The consumer of the

natural resource is actively involved in the act of

consumption and somewhere in the act of consumption pays out some real resources—money,

time, wear and tear on a vehicle—for that consumption.

Nonuse value is how much it is worth to a person simply to know that a natural resource exists,

even though he or she has no intention of ever

directly consuming it (e.g., hunting or catching

it, walking through it, or even viewing it). Nonuse value is more difficult—if not impossible—

to observe, and its measurement is restricted to

the direct method survey.

The estimated marginal values of recreational

fish vary considerably, even within a single state,

primarily according to the accessibility of the site

to a population of fishermen and, of course,

according to species. Fish at sites which are

accessible to larger numbers of fishermen will be

valued by more people, which drives up their

marginal values. Table 5-3, which shows marginal values for steelhead trout on 21 rivers in

Oregon in 1977 (in 1993 prices), reveals this

effect quite clearly. Table 5-4 shows marginal

values of trout and salmon (1978 values at 1993

prices) in 11 counties along the Lake Michigan

shoreline in Wisconsin, with a range of values

from $10.56 to $87.37, an eight-fold difference.

The values in these two tables clearly demonstrate variation in value between sites, and the

transfer of fish value estimates from one site to

another is a subject of active study. The principal

rule of thumb emerging so far is that values are

more transferable to nearby sites than to sites farther away, although measures of “near” and “far”

are still rough.

This brief review of the various methods used

in determining the value of a fish points out the
112 | Fish Passage Technologies: Protection at Hydropower Facilities

complex and subjective nature of this issue.

Determining the value of a natural resource such

as a fish is not an exact science. Research and

discussion continue in the attempt to develop a

methodology to determine natural resource values that would be universally acceptable. How

this ultimately will affect the development of

new hydropower sites, the relicensing of developed sites, and any affiliated mitigation requirements is unknown.

RESEARCH AND DEVELOPMENT: 

FEDERAL INVOLVEMENT

Many federal agencies are involved in research

and development efforts related to fish passage

and protection technologies. Below is an overview of certain institutions and activities relevant

to improving fish protection.

❚ Northwest Fisheries Science Center

The NMFS Northwest Fisheries Science Center

(NWFSC) is the research center serving the

Northwest Regional NMFS Office and provides

scientific and technical support for management,

conservation, and development of fishery

resources. Research is performed in conjunction

with federal, state, and local resource agencies,

universities, and other fishery groups. The mission of the NWFSC includes a focus on the following research areas:

■ understanding and mitigating the impacts of

hydropower dams on salmon and performing

ecological and genetic research on salmon in

support of the ESA;

■ evaluating the effects of marine pollutants on

coastal ecosystems in the United States;

■ enhancing the quality, safety, and value of

fishery products; and

■ developing methodologies for marine aquaculture and salmon enhancement.

Coastal Zone and Estuarine Studies

The Coastal Zone and Estuarine Studies (CZES)

Division of NMFS defines its scientific mission

as to develop information leading to conservation, enhancement, and balanced use of marine

and anadromous resources of the Pacific Northwest (235). Research of the CZES Division

focuses on the Columbia River Basin and Puget

Sound and the salmonid populations in these

regions. Four research programs exist in CZES:

Ecological Effects of Dams, Habitat Investigations, Fisheries Enhancement, and Conservation

Biology. Projects within these programs are

undertaken collaboratively with other appropriate agencies (e.g., COE, FWS). CZES maintains

TABLE 5-3: Marginal Values of Steelhead Trout in Oregon Rivers, 1977 (in 1993 prices)

River

Marginal value

(in $) River

Marginal value

(in $)

Alsea $31.48 Rogue $114.95

Chetco 30.11 Salmon 243.59

Clackamas 240.86 Sandy 157.38

Columbia 190.22 Santiam 253.17

Coquille 46.53 Siletz 87.58

Coos 24.63 Siuslaw 90.32

Descutes 109.48 Trask 184.75

Hood 168.33 Umpqua 134.11

John Day 56.11 Willamette 455.71

Nehalem 183.54 Wilson 172.43

Nestucca 143.69

SOURCE: Loomis, 1989, table 1, in U.S. Department of Energy, Environmental Mitigation at Hydroelectric Projects, Volume II: Benefits and Costs

of Fish Passage and Protection, Idaho Field Office, DOE/ID-10360(V2), January 1994.
Chapter 5 The Federal Role in Fish Passage at Hydropower Facilities | 113

two field stations for research on the Columbia

River at Pasco, Washington, and Hammond,

Oregon.

The Ecological Effects of Dams Program

engages in applied research relating to the migration of anadromous fish. Studies include: 1) the

adaptability of juvenile salmonids to changing

environments created by dams, 2) collection and

transportation of juvenile salmonids, 3) migrant

passage at dams, and 4) enhancement and redistribution of stocks. Habitat Investigation Program projects focus on the Columbia River

estuary and emphasize environmental background studies, impacts of dredging and dredgedisposal studies, impacts of discharged materials

or heat studies, and estuarine salmonid studies.

The Fisheries Enhancement Program provides

regional leadership in research on improving the

production of aquatic organisms for commercial

and recreational use and conservation of endangered populations. The Conservation Biology

Program has responsibility for providing scientific bases for decisions on listing anadromous

Pacific salmonids under the Endangered Species

Act.

❚ Conte Anadromous Fish Research 

Center

The National Biological Survey (NBS) operates

the Conte Anadromous Fish Research Center in

Turner’s Falls, Massachusetts, and conducts

cooperative research with a number of federal

agencies. Conte is the sole center for applied fish

passage research in the country. The lab is relatively new, having opened its doors in 1991, and

is staffed and funded by FWS and NBS. The

facility’s size, and financial and personnel

resources, limits the number of projects that can

be conducted at any one time, and often joint

efforts are forged with private research organizations or utilities that can provide an area of

expertise or funding. As a result, the Conte staff

tends to select studies that have the potential for

generic applicability in the field, as opposed to

those that might be more site- or project-specific.

Thus, research results have the potential to be

broadly applicable to practitioners in the field.

Conte’s laboratory resources are allocated to

projects that address questions concerning fish

passage from hydraulic, biological, and behavioral perspectives. Staff engage in a constant

exchange of data and results to help support

research in the complementary area. Below are

sketches of research areas the lab is currently

engaged in:

Hydraulic Lab: The Hydraulic Lab conducts

hydraulic modeling to answer specific research

questions. Current projects include evaluation of

a new passage technology, gathering basic data

on the operation of Denil and Alaska steeppass

fishways at various slopes and flows, and development of a fish passage design for Little Falls

Dam on the Potomac River. Some investigatory

work at Cabot Station on the Connecticut River

is also underway.

Fish Behavior Lab: The fish behavior lab at

Conte addresses fish passage research questions

from a biological perspective. The lab has developed cooperative relationships with universities

who share graduate students and funding. This

program is an extension of the Fish and Wildlife

Research Units that came into existence in the

1960s to enable university-supported fisheries

TABLE 5–4: Marginal Values of Trout and Salmon in Eleven Wisconsin Counties Bordering 

Lake Michigan, 1978

County 1 2 3 4 5 6 7 8 9 10 11

Marginal value of 

fish in dollars

12.42 18.37 11.50 36.52 86.37 10.56 12.01 15.17 87.37 16.23 42.63

NOTE: Unweighted averages in 1993 dollars.

SOURCE: Samples and Bishop, 1985, Table 2, p. 69, pp. 70–71, in U.S. Department of Energy, Environmental Mitigation at Hydroelectric

Projects, Volume II: Benefits and Costs of Fish Passage and Protection, Idaho Field Office, DOE/ID-10360(V2), January 1994.
114 | Fish Passage Technologies: Protection at Hydropower Facilities

research. The lab has also established relationships with state resource agencies and hydro

project operators interested in improving and

developing fish passage technologies for application at specific sites.

❚ Project Improvements for Endangered

Species

Under the direction and supervision of the Secretary of the Army, through the Assistant Secretary

of the Army (Civil Works), the Commander of

the Army Corps of Engineers (COE) has responsibility for investigating, developing and maintaining the nation’s water and related

environmental resources; constructing and operating projects for navigation, flood control,

major drainage, shore and beach restoration and

protection, related hydropower development,

water supply, water quality control, fish and

wildlife conservation and enhancement, and outdoor recreation; responding to emergency relief

activities directed by other federal agencies; and

administering laws for the protection and preservation of navigable waters, for emergency flood

control, and for shore protection.

The COE has coordinated with other agencies

and other regional interests in establishing programs to lessen the impacts of those projects on

fish. The Portland District has developed a program that covers 19 activities under one umbrella

called Project Improvements for Endangered

Species (PIES). PIES, and its mission to improve

salmon passage, has been endorsed by NMFS.

The projects cover a wide range of issues and

costs and are financed through Operations and

Maintenance funding to the tune of $14 million.

The COE also has a regionally funded research

program known as the Fish Passage Development and Evaluation Program (FPDEP) which

has numerous studies underway on juvenile

bypass and transportation, adult fish passage, and

related issues such as spill effectiveness and dissolved gas effects.

❚ Waterways Experiment Station

The Waterways Experiment Station (WES) in

Vicksburg, Mississippi, is a COE research compound complete with six laboratories: Hydraulics, Coastal Engineering, Geotechnical,

Structures, Environmental and Information

Technology. At WES, working models of dams

in the northwest are used to assist engineers and

biologists in finding ways to increase anadromous fish survival rates. The facility was established in 1929 with the mission of developing

flood control plans for the Mississippi River.

Today, its mission is a bit different.

In the Hydraulics Lab, most of the work is

focused on fish passage issues. Research techniques are used on models (built 1 ft to 80 ft, or 1

ft to 100 ft) of the Columbia and Snake River

projects (231). The models are used to analyze

flow conditions, and scientists can evaluate the

hydraulic conditions that salmon may encounter

as they pass various projects in an effort to determine the range of on-site tests that might be

needed when investigating passage needs. There

are also sectional models at WES which focus on

specific portions of projects and are generally

constructed at a larger scale (1 ft to 25 ft). The

sectional models are used to answer more localized and specific fish passage questions.11 The

models also help answer questions about drawdown operations by tracking changing flow patterns. WES personnel are also involved in

passage research to develop and evaluate alternative behavioral guidance methods. At the Richard B. Russell Pumped Storage Project, an

ultrasonic and light system have been tested for

many years (chapter 1).

❚ System Configuration Study

The COE’s System Configuration Study (SCS) is

examining various alternatives for physically

altering the lower Snake and Columbia River

dams to improve salmon passage conditions. The

focus is mainly on restoration of the Snake River.

11 Sectional models currently being used include three-bay turbine intake sections of Lower Granite, the Lower Granite Spillway,

McNary, Bonneville, and the Dalles.
Chapter 5 The Federal Role in Fish Passage at Hydropower Facilities | 115

Preliminary findings of the study indicate that

passage would only improve if the Snake River

were returned to its natural condition (232).

Other options under consideration in the study

include constructing bypasses to route the river

around the dams, creating a controlled breach

through each dam, or removing the four lower

dams.12 The study also concluded that a yearround river drawdown would adversely affect

power production, navigation, irrigation and recreation benefits, and would result in short-term

loss of fish and wildlife habitat during construction and re-establishment of habitat (232).

❚ Fish Passage Research Center

The Bonneville Power Administration (BPA) has

responsibility to mitigate for wildlife and wildlife habitat affected by federal hydropower dams

and reservoirs in the Columbia River Basin

under the 1980 Pacific Northwest Electric Power

Planning and Conservation Act.13 The Northwest Power Planning Council was established by

the 1980 Act and was charged with developing a

program to “protect, mitigate, and enhance fish

and wildlife” and their habitats. Under section

4(h)(10)(A) of the Act, Congress directed BPA to

use its funds and legal resources to implement

the program and to fund many of the program

measures to offset effects of development and

operation of hydropower projects in the Columbia River Basin. Many of the recommendations

for fish and wildlife protection, mitigation, and

enhancement come from resource agencies and

Tribes, utilities, and the public. The Fish Passage

Research Center in Portland was established in

large part to monitor the effectiveness of programs undertaken in response to the 1980 Act.

One of the Center’s main responsibilities is to

monitor smolt passage on the Snake and Columbia Rivers. Hydrologic and hydraulic data, as

12 The four dams on the lower Snake River are Lower Granite, Little Goose, Lower Monumental, and Ice Harbor. 13 COE owns and operates many of the dams in the Columbia River Basin, whereas BPA is responsible for generation and distribution of

the power generated at those dams. COE engages in its own research efforts; BPA and COE jointly fund and support research and development of fish passage mitigation methods and managing techniques.

well as temperature and gas concentration data,

are collected at all trap sites in the tailraces of the

lower Columbia and Snake River projects.14 The

smolt monitoring program provides data on the

passage of fish through the basin’s dams and reservoirs and also provides data about the physiological status of the fish. This information can be

helpful in making operational management decisions relative to flow and spill which correlates

to determinations and recommendations regarding the status of the smolt passage program and

what improvements might be made to increase

its success.

❚ Surface Collector

BPA and COE are jointly supporting the development of a surface collection system for transporting downmigrating salmonids around dams.

The idea behind surface collection is to present a

flow stimulus to downstream migrants that will

take advantage of their natural outmigration

behavior. Juvenile migrants, typically oriented in

the upper levels of a reservoir water column, are

drawn into the system by the attraction flow at

the surface and are collected for transport or

directed to a bypass around the dam (40). NMFS

and the Northwest Power Planning Council have

endorsed the research effort. Hydroacoustic techniques will be used to monitor and evaluate the

effectiveness of the system.

Research at the Wells Dam in the Douglas

County Public Utility District indicated that

juvenile passage could be improved using surface collection techniques. Hydrocombine units

used at Wells Dam are a unique design for

hydropower where the spill bays are located

directly over the turbine units. Between 1984 and

1993, modifications to the spill bays at Wells

Dam along with operational changes achieved at

least 90 percent passage of smolts. Wells Dam

14 Data are collected at trap sites at the four dams on the lower Columbia (Bonneville, The Dalles, John Day, McNary) and at two Snake

River dams (Lower Granite, Little Goose); data are then downloaded to the Fish Passage Center for analysis.
116 | Fish Passage Technologies: Protection at Hydropower Facilities

has become a model for downstream migrant

passage using the surface collection concept, and

an adaptation of this design, which is suitable for

conventional hydropower configuration, is in

place at Rocky Reach Dam (40).

COE hopes that the four-year $90-million-dollar program will provide a new means of passing

juvenile salmon and steelhead around hydro

projects at lower cost, and with improved efficiency over conventional fish passage. COE has

placed great emphasis on this effort, as it represents an attempt to link the sciences of fish

behavior and engineering (77). Plans call for system prototypes to be installed at a number of

dams on the Columbia over the next few years,

beginning with Lower Granite Dam in 1997.

Additional prototypes will be installed at The

Dalles and Bonneville dams in 1998.

❚ Bureau of Reclamation Research

Facility

The Bureau of Reclamation (BuRec) has been

the nation’s pre-eminent western water resource

development agency for decades. The agency has

increasingly focused on environment and water

resource management as the need for large construction projects decreased. Today, BuRec helps

to fund and participates in research and development of fish passage technologies to protect

anadromous species in California and the Pacific

Northwest.

BuRec’s research facility in Denver offers

technical support on fish passage issues to the

Northwest and California regional offices. The

facility is used in part to experiment with hydraulic models of parts of the Columbia River hydropower system, and various projects on the

Sacramento River in California. This capability

gives scientists the opportunity to laboratory test

fish passage technologies under a range of potential hydraulic conditions which reflect field possibilities. The facility also evaluates prototypes

of fish passage technologies (e.g., various

screening technologies, downstream surface collector system) and conducts research on monitoring downmigrating salmonids on the Sacramento

River.

❚ Central Valley Project

In 1992, the Central Valley Project Improvement

Act (CVPIA) directed BuRec to improve the

management practices of the Central Valley

Project (CVP) to address fish protection concerns.15 The CVP is a federally funded water

project on the Sacramento and San Joaquin Rivers and Delta in California and is essential to the

distribution of water in California. The CVPIA

expands the purposes of the CVP to mandate the

protection of fish, wildlife, and associated habitat, and to work toward achieving a balance

among competing demands for water.

The streams and rivers of the Central Valley

are host to a multitude of diverters—federal,

state, and private—which range in size and flow.

In all, there are 3,000 outlets, most of which

serve agricultural uses. More than 2,000 of the

CVP diversions are unscreened and implicated in

the decline of species in the river system.

Although part of the CVPIA budget is allocated

for fish protection through a diversion screening

program, BuRec is not required to install physical barrier screens at diversions along the rivers

and Delta. Whether it should is a point of considerable debate because of the high cost of the

screens.

The resource agencies, NMFS, FWS, and the

California Department of Fish and Game, favor

positive-exclusion devices over alternative

behavioral techniques that rely on sound, light,

15 The Central Valley Project Improvement Act was passed in 1992 as part of an extensive piece of legislation known as the Reclamation

Projects Authorization and Adjustment Act of 1992. Some of the Act’s titles authorized water projects; however, the CVPIA (title 34) took a

step toward conservation in mandating fish and wildlife protection.
Chapter 5 The Federal Role in Fish Passage at Hydropower Facilities | 117

and electric barriers.16,17 The presence of endangered and threatened species in the CVP has

heightened the concern over experimentation and

use of behavioral guidance technologies particularly at sites where positive-exclusion barriers

are feasible and where fish that are entrained in

irrigation diversions have no chance at survival.

CONCLUSIONS

The incomplete state of knowledge regarding

fish population dynamics; the impacts of hydropower development on fish; the need for mitigation in various contexts; and the protection/

passage effectiveness of available mitigation

technologies exacerbate the already adversarial

relationship between hydropower and environmental interests. This situation is unlikely to be

alleviated unless a solid, science-based process

for mutual understanding and rational decisionmaking can be developed (box 5-4).

A combination of academic, government, and

industry expertise is needed in a concerted effort

to focus science and technology resources on the

question of hydropower development effects on

fish population sustainability, and on the assessment of available and developing fish protection

technologies at dams.

❚ Technologies

Technologies for upstream passage are more

advanced than for downstream passage but both

need more work and evaluation. Upstream passage failure tends to result from less than optimal

design criteria based on physical, hydrologic,

and behavioral information, or lack of adequate

attention to operation and maintenance of facilities. Downstream fish passage technology is

complicated by the limited swimming ability of

many downmigrating juvenile species and unfavorable hydrologic conditions. There is no single

solution for designing up- and downstream pas16 A positive exclusion device is a barrier that physically blocks fish from entering diversions or water intakes; its effectiveness is not

dependent on the swimming ability of the fish. 17 NMFS supports research efforts on behavioral guidance technologies but guards against implementation prior to performance criteria

being met.

sageways. Effective fish passage design for a

specific site requires good communication

between engineers and biologists and thorough

understanding of site characteristics.

Downstream passage of fish and protective

measures to reduce turbine mortality are probably the areas most in need of research. The most

fundamental test of downstream mitigation

effectiveness—that the measure should yield better survival than downstream passage through

turbines—rarely has been rigorously examined.

When research and demonstration is carried out,

results can be dramatic.

Varied technical fish passage knowledge

among participants in the debate results in

unsubstantiated claims and arguments. Moreover, some experimental results contradict others. Ambiguous or equivocal results of many fish

passage studies have caused concern as to

whether certain technologies are effective or

generally useful. The variability of results may

reflect site variability; uncontrolled environmental conditions in field studies; or incomplete

knowledge of fish behavior. Thus, certain proposed solutions to the problem may be based on

incomplete assessments. Advocates on both sides

of the fish/power issue can select from a diverse

body of scientifically unproven information to

substantiate their points of view. Care must be

taken in interpreting much published information

on fish protection, arguments drawn from it, and

conclusions reached.

❚ Hydropower Licensing

Controversy abounds in the FERC hydropower

licensing process. In part, this may be a result of

the lack of clearly identified goals to be achieved

through mitigation. Although objectives exist in

the legislative language of the FPA, as amended,

these lend themselves more to a philosophy than

to hard goals that describe numbers, timeframes,
118 | Fish Passage Technologies: Protection at Hydropower Facilities

and methods for achieving and measuring the

stated goal. Clearly defined goals for protection

and restoration of fish resources might refer to

numbers or percentages of fish expected to successfully pass a barrier and/or projected population sizes. Since resource management goals are

rarely articulated, mitigation and enhancement

measures are judged on a case-by-case basis with

no means for assessment or comparison.

The lack of clear goals is, in part, reflected in

the disjunction between section 18 prescriptions

and section 10(j) recommendations of the FPA.

Section 18 fish passage prescriptions are mandatory; however, section 10(j) recommendations

may be altered based on consistency with other

applicable laws or the goals for the river (e.g.,

whitewater rafting/recreation, power production

needs). Yet, the recommendations made under

section 10(j) may be critical to maintaining habitat for fish populations or promoting timely

migrations for certain species. FERC, as the final

authority for balancing developmental and nondevelopmental values, is not specifically charged

with sustaining fish populations. Without clear

identification of the goal for mitigation, monitoring and evaluation become less meaningful and

fail to become critical to the process.

Monitoring and evaluation conditions for

hydropower licenses are infrequently enforced,

resulting in little information on how effective

available mitigation technologies are in improving fish passage and survival at hydropower

plants. Operation and maintenance failures have

been implicated in poor efficiency of fishways.

Forty percent of nonfederal hydropower projects

with upstream fish passage mitigation have no

BOX 5-4: Development of Fish Passage Technologies: Research Needs

There are no “sure things” in the world of fish passage technology. The technologies themselves, which are

based on hydraulic engineering and biological science, can be designed to accommodate a wide range of

environmental conditions and behavioral concerns, but in the real riverine world anything can happen.

Upstream and downstream fish passage problems differ considerably and both present a range of obstacles and challenges for researchers and practitioners. Despite these differences, common considerations in

design and application exist, including: hydraulics in the fishway, accommodating the biology and behavior of

the target fish, and considering the potential range of hydrologic conditions in the waterway that the passage

technology must accommodate. Engineers and biologists in the Northeast and Northwest are collaborating in a

number of research programs designed to improve understanding of the swimming ability and behavior of target fish. Understanding how fish respond to different stimuli, and why, is critical to improving passage methods.

Using a scientific approach to explore as many scenarios as possible, and collecting data in a careful manner, can improve researchers’ abilities to design improved technologies. In addition, producing information that

all parties can acknowledge as credible is key to the successful advancement of fish passage technologies. A

sound scientific approach to developing, executing, and evaluating a field study is critical to the successful

advancement of fish passage technologies. The elements of a good test include the establishment of clear

objectives, agreement among all parties to the study design, and a protocol that lends itself to repeatability. In

addition, there must be a proper accounting of environmental variability, documentation of all assumptions, and

sufficient replications to support findings. Regular communication among stakeholders and peer-reviewed

research results are key requirements.

Employing a process of this type could increase the potential for information transfer between sites. That

information might include data regarding the response of the device to hydraulic parameters (e.g., flow/acoustical response), fish response to stimuli under hydraulic parameters, and basic biological information within species. Agreement on performance criteria and standards prior to study will avoid lack of acceptance of data and

recommendations in the long term.

SOURCE: Office of Technology Assessment, 1995.
Chapter 5 The Federal Role in Fish Passage at Hydropower Facilities | 119

performance monitoring requirements (242).

Those that do generally only quantify passage

rates, without regard to how many fish arrive at

and fail to pass hydropower facilities. Moreover,

most monitoring has dealt with anadromous

salmonids or clupeids; much less is known about

the effectiveness of mitigation measures for

“less-valued” or riverine fish. Research is needed

to determine whether river blockage is even negatively affecting riverine species.

Relicensing decisions often are not based on

river-wide planning and cumulative analysis.

FERC is required to review existing river management plans to assure that the project will not

interfere with the stated goals (pursuant to section 10(a) of the FPA). Yet, comprehensive river

basin planning is fragmented. Synchronizing

license terms on river basins could improve the

relicensing process and promote cumulative

impact analyses. Terms could be adjusted to

meet the ecological needs of the basin and to provide timeliness and predictability for licensees.

Under such a plan, multiple sites could be relicensed simultaneously, although operators may

be unlikely to respond positively to undergoing

the relicensing process “early.” On the other

hand, consolidation could yield benefits, allowing licensees to develop integrated management

plans to maximize the energy and capacity values of their projects; making it easier for all

involved parties to view the projects and their

impacts in their totality; and facilitating understanding of cause and effect relationships.

There is a need for further research on cumulative fish passage impacts of multiple projects;

and for consideration of fish needs at the watershed level. In several northeastern states, cooperative agreements between resource agencies and

hydropower companies have generated successful approaches to basin-wide planning for fish

protection. Carefully planned sequential construction and operation of fish passages could

provide significant opportunities for restoring

historic fish runs. In the western states, watersheds in National Forests provide about one-half

of the remaining spawning and rearing habitat

for anadromous fish in the United States. Ecosystem or watershed management in these areas

could have immediate and long-term impacts on

fish populations (e.g., PACFISH).
| 121

A

Appendix A:

Overview of Fish

Passage and Protection

Technologies in the

Columbia River Basin

ABSTRACT1

ommercial exploitation of Columbia

River salmon and steelhead began in the

mid-1800s. Concurrent with commercial exploitation of adult fish was modification and destruction of spawning and rearing

habitat by various landuse practices. In addition,

survivorship of downstream migrants was negatively affected by unscreened irrigation diversions and entrainment of smolt in irrigation

water. By 1920, prior to construction of mainstem dams, it was clear that the salmonid stocks

of the Columbia River had been reduced significantly.

Construction of mainstem dams created additional challenges to the migration of adult and

juvenile fish in addition to causing additional

habitat degradation. The single most significant

impact to Columbia River salmon stocks was the

construction of Grand Coulee Dam, which was

built without fish ladders and eliminated all the

stocks originating above the dam site.

1 This appendix is derived from T.J. Carlson, “Overview of Aspects of the Development of Adult and Juvenile Migrating Fish Passage

and Protection Technologies Within the Columbia River Basin,” unpublished contractor report prepared for the Office of Technology

Assessment, U.S. Congress, Washington, DC, July 1995.

Fish passage research began with the study of

the Bonneville Dam fish ladders, which passed

adult migrants very successfully. During the

early stages of dam construction conventional

wisdom was that juvenile fish were not injured

during passage through hydro turbines so smolt

passage through dams was not a topic of

research. The U.S. Army Corps of Engineers

(COE) built a research laboratory at Bonneville

Dam that was used for 30 years to study the

behavioral response of adult migrants to elements of fish ladder design. The research conducted at the laboratory made major

contributions to the success of fish ladders at

other Columbia River Dams. Although adult

migration behavior research continues to the

present, its focus is on broader ecological questions.

Research of juvenile fish passage began with

development and evaluation of screens for irrigation diversions. Continued research in this area

for over half a century has resulted in irrigation

diversion screens that are effective in preventing

juvenile migrants from being entrained in irrigaC
122 | Fish Passage Technologies: Protection at Hydropower Facilities

tion water. Current research efforts are focused

on evaluation of behavioral barriers using infrasound that will reduce the movement of juveniles

past the headworks of irrigation diversions.

Juvenile fish passage research at mainstem

dams has been mostly concerned with prevention

of juveniles from passing through turbines. Since

the early 1960s turbine intake screens have been

in development to divert juveniles from turbine

intakes and into bypass facilities for return to the

river or transport. Most of the mainstem dams

have been equipped with intake screens, and a

major portion of the juveniles passing down the

Snake River are collected for transport.

Investigations conducted in the 1960s showed

that surface oriented flows were effective under

some conditions in attracting juvenile migrants

to alternative bypass routes prior to turbine passage. Subsequent research has further developed

surface collection of smolts. Surface collection

has been successfully developed at Wells Dam

on the upper Columbia River, where over 90 percent of smolts are passed by the dam through

modified spill bays utilizing less than 5 percent

of the hydraulic capacity of the dam’s powerhouse. Major surface collection research programs were initiated in 1995 by private utilities

and the COE. Preliminary results are very

encouraging and surface collection has become a

major focus for current smolt passage research.

INTRODUCTION

The Columbia River is the second largest river in

the continental United States in terms of volume,

with a total length of over 1,200 miles. Historically, flows in the lower Columbia often exceed

200,000 cubic feet per second, with wild fluctuations following snow melt and rains in the

spring. The Columbia drains 258,000 square

miles, an area larger than several states. The

watershed extends into four Northwest states:

Washington, Oregon, Montana, and Idaho.

Documented exploration of the Columbia

River by Europeans began in the late 1700s with

Capt. Robert Gray, who crossed the Columbia

River bar, a treacherous area of strong currents

and turbulent water, and explored parts of the

lower Columbia in the spring of 1792. It was

Capt. Gray who gave the river its European

name. Several years later, in 1805, Lewis and

Clark traveled down the Columbia, reaching the

Pacific Coast in November. The reports of Lewis

and Clark documented the many rapids and falls

in the Columbia River that initially were simply

hazards to navigation but later were exploited for

hydropower production. They also documented

the richness of the salmon and steelhead runs to

the river and their use by the native population

(21,43,45).

There has been considerable discussion of the

historical size of salmon and steelhead runs to

the Columbia River. Estimates range from highs

around 35 million to lows in the region of 6 to 7

million. For planning purposes, the Northwest

Power Planning Council (NPPC), created by act

of Congress in 1980 to develop and oversee

implementation of a program for restoration of

Columbia River stocks, estimated that the historical run sizes ranged between 12.5 to 13 million

fish (59). Current run sizes are on the order of 2.5

million fish, which amounts to a loss, on average,

of approximately 10 million fish (43). Research

continues to try to better understand the historical production of Columbia River Basin salmon

and steelhead. Discussion of the historical carrying capacity of the Columbia River Basin is of

more than academic interest as efforts to restore

habitat and recover stocks begin to focus on

identification of critical habitat for restoration

and targets for stocking levels. Of particular

interest are recent efforts at template analyses of

the many habitat features and climatic trends that

influence ecosystem carrying capacity and discussions of the recovery potential of discreet

stocks (38).

Although certainly exploited through aboriginal times, intensive commercial exploitation of

salmon and steelhead didn’t begin until the mid1800s. Early efforts at commercial exploitation

of salmon by salting and shipping to eastern U.S.

markets were unsuccessful because of poor product quality. However, the introduction of canning

in 1866 provided the means to preserve salmon
Appendix A: Fish Passage and Protection Technologies in the Columbia River Basin | 123

quality over the long periods required for shipping while delivering a desirable product at low

cost. With this innovation the commercial

exploitation of salmon and steelhead started in

earnest. Unlike today, the large quantities of

salmon available and low cost of production

made salmon a cheap food for the working class

(43).

Analysts partition the historical commercial

exploitation of Columbia River salmon and steelhead into several phases. The period from 1866

to present may be divided into four phases: initial

development of the fishery (1866-1888); a period

of sustained harvest with an average annual catch

of about 25 million pounds (1888-1922);

resource decline with an average annual harvest

of 15 million pounds (1923-1958); and maintenance at a depressed level of production of about

5 million pounds (1958 to present) (38). Additional declines recently may indicate a new lower

level of production and a fifth phase of exploitation. Another, similar analysis utilizes essentially

the same periods with the exception of dividing

the period of decline (1923-1958) into two segments bracketing the years prior to and following

mainstem dam construction (46).

Exploitation rates, the percentage of the total

run caught, at the height of commercial exploitation are estimated to have been in excess of 80

percent compared to estimated aboriginal exploitation rates of approximately 15 percent (19).

Beginning with commercial exploitation and

continuing in some cases until the mid-1940s, a

wide range of traps, nets, and other miscellaneous fishing gear were utilized to capture fish.

As late as the 1940s, gear such as large seines

were used to take up to 70,000 pounds of salmon

on single days. Such gear was not outlawed by

both Washington and Oregon until 1949 (21,43).

Coincident with commercial exploitation was

widespread settlement of the Columbia River

Basin with accompanying natural resource

exploitation in the form of mining, logging, and

agriculture. Use of the many tributaries to the

Columbia and Snake Rivers by anadromous fish

was very obvious to the early settlers, and the

potential damage to fish stocks by inappropriate

use of these rivers and streams was clear. As

early as 1848 the Oregon Territory had laws prohibiting obstruction of access to spawning and

rearing habitat by dams or other means. However, the laws were not rigorously enforced and

many dams were constructed that were barriers

to fish. By the early 1930s, prior to construction

of mainstem dams, it was reported that dams on

the Columbia River and its tributaries had eliminated access by fish to approximately 50 percent

of the most valuable salmon production areas. In

addition, because of the state of the art in design

and operation of fish ladders, many early

attempts at providing passage for adult migrants

were failures. An example was Sunbeam Dam,

constructed on a tributary to the Salmon River to

provide electric power for gold dredges. While

Idaho Fish and Game evaluated the dam’s fish

ladder as useless, the dam was permitted to operate for 20 years until 1934, earning the reputation

of perhaps being the primary reason for loss of

Redfish Lake sockeye salmon, now listed as an

endangered species (43).

Significant dangers also existed for downstream migrants beginning during the earliest

stages of settlement of the Columbia River

Basin. As early as the 1870s large losses of smolt

to irrigation diversions were observed. There

were hundreds of larger irrigation diversions and

perhaps thousands of smaller ones as farmers

withdrew water for crops. Most of these diversions were unscreened, and untold millions of

smolt and other juvenile fish were annually

drawn into the diversions, ultimately ending up

with the water on crops. In the early 1900s, laws

passed much earlier but not rigorously enforced

were amended, ordering irrigators and others

operating water diversions to comply with

screening laws. While many wanted to comply

with the law, screening devices to do the job

were not available. It wasn’t until 1911 that a

revolving drum screening device was invented

and in evaluation (21). There were myriad other

less obvious impacts to salmon populations from

agricultural practice. An example is the loss of

riparian vegetation by logging, the conduct of

farming, or destruction by cattle. Loss of riparian
124 | Fish Passage Technologies: Protection at Hydropower Facilities

cover probably caused heating of stream water,

negatively impacting adult migration and

degrading the rearing environment for juveniles.

Review of history shows that Columbia River

Basin salmon and steelhead stocks had been very

significantly reduced from historic levels prior to

construction of mainstem dams. The losses

resulted from a variety of land use practices common at the time. Nevertheless, the result was

wide-scale habitat modification and destruction

concurrent with dramatic reduction in adult

returns through commercial exploitation, sport

fishing, and high rates of juvenile mortality by

agricultural practice.

The first dam on the mainstem Columbia

River was Rock Island Dam, which was put into

service in 1933. Rock Island was a private dam,

constructed by the Washington Electric Company (21). The first federal dam on the Columbia

was Bonneville Dam, completed in 1938. Bonneville was followed by Grand Coulee Dam in

1941. Considerable thought was put into the

design of fish ladders for Bonneville Dam. It was

realized at the time that their success would

depend on their ability to attract adult migrants,

so the ladder entrances were supplied with water

in addition to that flowing through the ladders to

provide attraction flow. The Bonneville design

was successful and was studied and used as the

basis for the design of many other fish ladders

within the Columbia River Basin and elsewhere.

Grand Coulee Dam was another matter all

together. A high reservoir elevation was needed

to enable pumping of water for irrigation purposes, plus a high-head dam would have greater

power production potential. Therefore, in spite of

initial congressional intention for a low-head

dam, Grand Coulee was eventually built as a

high-head dam, almost 550 feet tall. The problem

for salmon with a dam as high as Grand Coulee

was that fish ladders were not considered feasible for dams over 100 feet high. As a result, fish

ladders were not built as part of Grand Coulee

Dam, and salmon runs to all of the upper Columbia River drainage, literally hundreds of miles of

rivers and streams and thousands of square miles

of habitat, were forever cut off from access.

During the three decades following construction of Grand Coulee, eight more large dams

were constructed on the mainstem Columbia and

four on the lower Snake River. All but four of

these dams were built by the federal government.

In 1937, near completion of construction of Bonneville Dam, the Bonneville Power Administration (BPA) was created to market the power of

Bonneville Dam and was later responsible for

marketing the power of the whole Columbia

River federal hydropower system. The role of

BPA was changed in a very marked way in 1980

when Congress, upon creation of the NPPC with

passage of the Pacific Northwest Electric Power

Planning and Conservation Act (Public Law 96-

501), charged BPA with implementation of the

Columbia River Basin Fish and Wildlife Program to be developed by NPPC for restoration of

Columbia River salmon and steelhead stocks.

The design of mainstem dams was driven by

several objectives: power production, irrigation,

flood control, recreation, and navigation. Other

uses were lower priority while the priority of the

major objectives changed from time to time. The

emphasis on power production for Bonneville

and Grand Coulee Dams may have been a decisive factor in the United States winning the Second World War. The large amount of power

available permitted high-volume production of

aluminum for airplanes and diversion of large

amounts of power to the Hanford Works, where

nuclear materials for the first atomic bombs were

manufactured. However, the sites selected and

aspects of the designs of dams did have additional negative impacts for fish. In the Snake

River, lobbying by the Inland Empire Waterways

Association resulted in locating the lower Snake

River dams on the mainstem Snake to enable

barge transport all the way to Lewiston, Idaho.

Mainstem sites were eventually selected even

though the economic return from navigation was

considerably lower than that from power production and the potential for power production was

greater at tributary sites, which would have

greatly reduced the impact to Columbia River

Chinook salmon stocks (43,62).
Appendix A: Fish Passage and Protection Technologies in the Columbia River Basin | 125

From the earliest days of fish harvest and natural resource utilization within the Columbia

River Basin, there were always advocates for fish

and investigators working to find ways to lessen

the impact of human activities on the fish. However, funding for fish passage research was very

scarce in the early years, partially because state

and federal agencies failed to appreciate the

value of systematic fish passage research. Most

progress in addressing fish passage issues was

through trial and error experimentation by a

small number of dedicated biologists. Fish passage research was also not given a higher priority

because there was widespread belief that artificial propagation of salmon and steelhead could

overcome habitat losses. It was common during

the dam-building decades for habitat lost through

dam construction to be mitigated by construction

and operation of fish hatcheries. It would not be

until the 1980s that the failings of this strategy

were better understood.

OVERVIEW OF COLUMBIA RIVER BASIN 

FISH PASSAGE RESEARCH: PAST TO 

PRESENT

Well-funded fish passage research did not really

begin in the Columbia River Basin prior to initiation of construction of large mainstem dams.

This came about because of an increasing realization in the 1930s by the public that the Columbia River fish stocks were in serious trouble.

Incentive for fish passage research came from

The Fish and Wildlife Coordination Act which

was passed in 1934 and amended in 1946 and

1958. Initially the act required the U.S. Army

Corps of Engineers (COE) and other water

development agencies to consult with the states

and the U.S. Fish and Wildlife Service about

damage to natural resources. The later amendments placed increasing emphasis on natural

resources, with the 1958 amendment requiring

water development agencies to give conservation

and enhancement of fish and wildlife equal consideration with other project objectives. Later in

the 1970s, further emphasis was placed on fish

and wildlife by the National Environmental Policy Act and the Endangered Species Act. Federal

legislation has been augmented up to the present

by the results of litigation such as the Boldt decision and the United States v. Oregon (21, 43).

❚ Adult Fish Passage

The early years of fish passage research were

focused on assisting upstream migration by

adults. The first products of this effort were the

successful fish ladders at Bonneville Dam (75).

A very important factor during the early years of

fish passage research was the existence of a fish

passage laboratory at Bonneville Dam. The initial focus of the laboratory was to understand the

apparent success of the Bonneville fish ladders,

their success being a surprise to almost everyone

involved. At the time of construction of the Bonneville ladders and, for that matter, a significant

period following, virtually nothing was known

about the design of fish ladders at the scales

required for large dams that migrants would react

favorably to and use. To meet these research

needs the COE built the Bonneville Fisheries

Engineering Research Laboratory in 1955. Significant amounts of fish passage research were

conducted at the laboratory until its demise in

1985. Almost all of this work was basic fish

behavioral research. Typical questions addressed

included: the rate at which fish ascend fishways;

maximum swimming velocities of fish; the optimum physical dimensions for fish ladders and

other facilities; etc. (20).

Work on aspects of the migration of adult fish

has been continuous over the intervening years

and continues to the present. There has been a

gradual transition from focus on issues related to

the design and operation of fish ladders to resolution of uncertainties existing within a broader

ecological context. Issues being addressed at

present at several locations within the Columbia

River Basin include habitat use, delays in passage at irrigation diversions, migration rates,

substock separation, spawner success and production, including causes of prespawning mortality, and response of adults to factors such as flow

manipulation for irrigation or power production,
126 | Fish Passage Technologies: Protection at Hydropower Facilities

increased turbidity, and general decreased water

quality due to irrigation (17,18,33,34,69). Adult

passage work has been greatly assisted by developments in radio telemetry and the global positioning system. Improved instrumentation and

deployment methods now permit adult migrants

to be tracked over long distances with high spatial and temporal resolution. This work is permitting identification of problems that are limiting

recovery of stocks as well as proving essential in

developing strategies for other aspects of stock

restoration. For example, an element of restoration of specific stocks may be hatchery supplementation. However, facilities for capture and

holding of adult migrants must be located so that

the stock of interest can be segregated from others. Fish tracking studies permit identification of

those places within a watershed where a particular stock might be isolated for such purposes.

A system where wide adult migrant radio

tracking study is to be performed beginning in

1996. The study will be funded by the COE and

performed primarily by the National Marine

Fisheries Services with cooperation by various

other state and federal agencies, universities, and

private utilities. The primary objective of the

study is to observe the migratory behavior of

adult salmon as they move through the hydropower system and onto their spawning grounds

(25). Of particular interest are the delay of

migrants at dams, fallback, straying, and

prespawning mortality. The scope of the study

includes the hydropower system as a whole, a

considerable expansion in scope over most previous studies which tended to be project-specific,

thereby very localized in comparison.

❚ Juvenile Fish Passage

Protection of juvenile fish during downstream

migration has historically focused in several

areas. The areas of major investment in juvenile

fish passage research have been: 1) protection

from entrainment in irrigation diversions, 2)

diversion from turbine intakes, 3) reduction in

mortality due to predation, 4) reduction in exposure to high levels of dissolved gas, and 5) reduction in delay during outmigration. While listed as

discreet juvenile fish passage concerns, there are

interdependencies in the basic biology and

behavior of juvenile fish between these elements.

These interdependencies make experimentation

to isolate an individual element quite difficult

and also have resulted in overlap between

research programs targeted on specific elements.

This overview will be restricted to elements 1)

and 2), with emphasis on diversion from turbine

passage by surface collection.

The volume of research conducted in these

areas, and others, to improve downstream passage for smolt has been huge. Literally hundreds

of studies, almost all field studies, have been

conducted within the last 40 years throughout the

Columbia River Basin. These studies have

greatly increased the knowledge base of the

behavior and factors influencing the survivorship

of smolt. The following sections will provide a

brief overview of this work. This is not intended

to be a synoptic review but rather an abbreviated

guide to provide context for discussion of

research currently in progress or planned for the

immediate future.

Irrigation Diversion Screening

As mentioned previously, it was apparent to all

who looked back to as early as the mid- to late1800s that juvenile migrants were being

entrained in irrigation diversions and killed on

farmers’ fields. Early records also show tension

between the states and the federal government

during this time. Although the states of Washington and Oregon had irrigation diversion screening laws as early as 1894, the federal government

was not required to comply with the laws. In

1911, Oregon petitioned the federal government

for compliance with Oregon state irrigation

diversion screening laws (21).

As an element of the Fish and Wildlife Program, NPPC has identified screening of irrigation diversions as a priority (58). Irrigation

diversions range from small, a few cubic feet per

second, to large, thousands of cubic feet per second. Irrigation diversion screens are typically

located downstream from the headworks for the
Appendix A: Fish Passage and Protection Technologies in the Columbia River Basin | 127

diversion, sometimes a considerable distance,

e.g., several hundreds of meters. Screening facilities for midsize and larger diversions typically

have capability at the screening facility for separation of smolt from irrigation water. Following

separation, smolt are returned to the mainstream

via a fish return conduit. The tolerances for the

mechanical and hydrodynamic elements of

screening facilities are quite tight and must be

kept in tolerance if the facility is to function

properly and protect migrants. Evaluations conducted to date indicate that screening facilities

kept in tolerance do provide high levels of protection to migrants (1,23,35,47,48,49,50,51).

Present research of irrigation diversion screening includes development and evaluation of

behavioral barriers to reduce the number of

migrants passing through headworks and into

diversion canals. The reason for wanting to

reduce the number of smolt entering the diversion canal is to reduce handling of migrants.

While screening facilities are effective, they do

require that smolt be passed through facilities to

separate them from irrigation flow, concentrated

into a smaller volume of water, and returned to

the mainstream. The effects on smolt behavior

and health of these actions are not clear, but the

general assessment is to avoid them if possible.

The Bonneville Power Administration, in cooperation with COE, has funded research beginning

in 1995 into behavioral barriers. An objective of

this research is to evaluate the use of infrasound

to divert smolt at the headworks of irrigation

diversion canals (52). Initial laboratory experiments recently completed have demonstrated

avoidance by juvenile Chinook salmon and steelhead of high-intensity, high-particle-displacement 10-Hz sound. In addition, limited

observations at a small irrigation diversion on the

Umatilla River during the 1995 smolt outmigration have shown repulsion of Chinook salmon

smolt from entering the irrigation canal (68).

Turbine Intake Passage and Diversion

At the time of construction of Bonneville Dam,

conventional wisdom was that there was little

danger of juvenile fish being injured during passage through hydro turbines. By the 1940s it was

clear that passage conditions for fish through turbines could range from good to awful. Initial

experiments indicated that direct mortalities

through turbines typical of the Columbia River

hydropower system were in the range of 15 percent (43). Subsequently, considerable research of

fish passage through turbines was conducted in

Europe and the United States (2,24,44). As a

consequence of this work, operating criteria for

Columbia River hydrosystem turbines was

developed, the most significant being the mandate for operation of turbines at peak efficiency

during periods of smolt passage.

There is currently a renewed interest in the

conditions fish face during passage through turbines. Both the federal government and private

utilities are performing studies to reassess injuries to smolt during passage through turbines.

Recent experiments indicate 90-96 percent survival of juvenile salmon during turbine passage

and that the majority of injuries observed are due

to mechanical strike (63,64,65). As a result of

study findings, the owners of Rocky Reach Dam

are having the runners of a turbine modified to

reduce the gap between the runner and the hub.

This gap has been identified as the probable

source for many, perhaps the majority, of

mechanic injuries to juvenile fish during passage

(22). In a comparable effort, COE is in the planning stage of a program to develop turbines that

minimize the mortality of juvenile fish (72).

Interest in providing a safer passage environment

for juvenile fish is due to the fact that turbine

bypass measures have not been and are unlikely

to prove 100 percent effective. This means that

some percentage of smolt will always pass

through turbines. Under some conditions and for

some species more so than others, a considerable

proportion of a species may pass through turbines even when turbine bypass measures are

fully implemented because of variation in migratory behavior between species and behavioral

responses to turbine bypass guidance mechanisms.

Upon discovery that hydro turbines could kill

and injure juvenile fish, considerable effort was
128 | Fish Passage Technologies: Protection at Hydropower Facilities

made to develop methods to divert fish from turbine intakes. Early studies of the vertical distribution of smolt entering turbine intakes showed

that many juvenile fish were located in the upper

third of turbine intakes (39), although it was clear

that smaller fish of all species and one or two

species in total tended to be more deeply distributed (30,37). Experience with irrigation diversion screens and other similar screens led to

development of a screen to be deployed in turbine intakes. Development continued through the

1960s, resulting in testing in 1969 of a prototype

turbine intake screen at Ice Harbor Dam (40).

Studies of prototype screens demonstrated that

large numbers of juvenile fish could be diverted

by turbine intake screens. When it was found that

juvenile fish could be diverted and concentrated

into bypass facilities, studies were initiated to

evaluate the feasibility of transporting the juveniles to below Bonneville Dam, thereby eliminating their exposure to downstream dams. Initial

evaluations showed positive results, and in 1971

a prototype collection and transportation system

was evaluated at Little Goose Dam (43). At the

present time, collector dams on the Columbia

and Snake Rivers collect a significant portion of

the total outmigration for transportation by truck

and barge to below Bonneville Dam.

Development and evaluation of turbine intake

screens continues to the present as the operation

of those already installed is optimized and the

design of those to be installed is refined. While

most appear to be operating satisfactorily, not all

intake screens are as effective as the vertical distribution of juvenile fish would imply. In general, it appears that juvenile fish respond to the

modification of flow resulting from the presence

of the intake screens, which, in at least the case

of Rocky Reach Dam, rendered intake screening

ineffective as a turbine bypass option (31,32).

Visual observations of the behavior of smolt

upon encounter with turbine intake screens has

led to the hypothesis that the screens may act as

hydromechanical sources of infrasound, which is

detectable by salmonids and may be the stimulus

for avoidance response (53,54).

There is considerable contention about the

desirability of handling and transporting juvenile

fish. While development, evaluation, and installation of turbine intake screens continue, other

bypass alternatives are also being evaluated and,

in the case of spill, utilized on a wide scale. The

injury to fish during spill is thought to be significantly less than turbine passage and potentially

even less than for fish diverted by intake screens

and placed into bypass channels or otherwise

handled (67). However, comparisons of the

direct injury to smolt passing through turbines,

spillways, and bypass systems have not been

made at most dams. Assessment of smolt injury

passing through dams via these various routes is

an element of Phase II of the COE System Configuration Study Program which is at startup in

1995 (25).

Also an element of Phase II of the COE System Configuration Study is assessment of surface

collection as a means of passing juvenile

migrants past dams. The idea behind surface collection is to present a flow stimulus to downstream migrants that will take advantage of their

natural outmigration behavior and lead them into

a bypass leading around the dam or into collection facilities for transport. Surface collection is

not a new concept and has been extensively tested

with mediocre to poor success at scales considerably smaller than those required at mainstem

Columbia River dams (27,28,61,66,70,74,73).

The impetus for retaining surface collection as

a viable fish passage measure for mainstem

Columbia and Snake River dams has been observations over the years of the high effectiveness

and efficiency of ice and trash sluiceways,

present at many Columbia River dams, under

certain conditions as a means for bypassing

migrants. Early investigation of the ice and trash

sluiceway at Bonneville Dam indicated that during the day a large portion of total migrant passage was through the sluiceway, even through

sluiceway flows were less than 5 percent of

project total flow (41). This study lead to the recommendation that the ice and trash sluiceways at

other projects be evaluated for downstream fish

passage. In subsequent years similar studies were
Appendix A: Fish Passage and Protection Technologies in the Columbia River Basin | 129

performed at The Dalles and Ice Harbor Dams

(5,42,55,60). The findings in all these studies

were similar. The sluiceways were very effective

in passing migrants during the day, with effectiveness decreasing very markedly at night.

While up to 80 percent of migrants passing the

dam during the day might pass in sluiceway

flows, sluiceway passage would drop to 20 percent or less of total passage at night. It soon

became apparent that there were changes in the

vertical distribution of migrants day to night and

that there were probably other aspects of smolt

behavior as well that determined the proportion

of fish passing through sluiceways.

During the 1980s, in parallel with federally

funded research to evaluate ice and trash sluiceways, Douglas County Public Utility District was

evaluating modifications to its hydrocombine

units at Wells Dam that might serve as a means

to bypass smolt without using turbine intake

screens. A hydrocombine is a unique design for a

hydropower dam where the spill bays are located

directly over the turbine units. Early studies of

the distribution and passage behavior of smolt at

Wells Dam indicated that the fish might pass in

modified spill flows (3,4,5). Over the years

between 1984 and 1993, Douglas County was

able to develop a design for modification of spill

bays and operation of the modified bays to achieve in

excess of 90 percent passage of smolt in modified

spill using approximately 5 percent of powerhouse

hydraulic capacity (8,9,10,11,12,13,14,15,16,36).

Wells Dam has become the model for downstream migrant passage using surface collection

concepts. The characteristics of the modified

hydrocombine spill bays have become the basis

for other efforts. The combination that proved

successful was a slot 16 feet wide and approximately 70 feet deep, located at the face of the

dam upstream of the spill gate. The spill gate

downstream of the slot is operated so that velocities through the slot average approximately 2 feet

per second. As in the case of the successful Bonneville Dam fish ladder 50 years earlier, it is not

understood why the Wells Dam smolt bypass

system works. There are some clues, one of

which is the vertical distribution of smolt relative

to the depth of the bypass slots. It appears that

during both day and night periods at least 80 percent of the smolt approaching Wells Dam are

located at depths less than 70 feet (71).

During the smolt outmigration of 1995, Public

Utility District No. 1 of Chelan County tested a

surface collection prototype at its Rocky Reach

Dam. Characteristics of the operation of the

Rocky Reach prototype surface collector are

modeled after the Wells Dam bypass but utilize a

completely different approach since Rocky

Reach is a classical hydropower dam with separate powerhouse and spill. The evaluation of this

prototype is still underway at the writing of this

report, but initial evaluation appears favorable.

Preliminary data indicates that the surface collector prototype may have passed more than an

order of magnitude more smolt than the prototype bypass based on turbine intake screens evaluated in previous years (over 1 million smolt

compared to 75,000). Based on this favorable

performance, Chelan County expects to expand

the coverage of the powerhouse by the prototype

for the 1996 outmigration and continue evaluation (22).

Also during the 1995 smolt outmigration,

Public Utility District No. 2 of Grant County

evaluated a surface collection prototype at

Wanapum Dam on the mainstem Columbia

River. The design of this surface collector is different from both the Wells Dam bypass and the

Rocky Reach prototype but it still utilizes the

water velocities at the entrance to the collector

found effective for the Wells Dam bypass in

addition to other elements of the Wells bypass.

The evaluation of this prototype was just ending

at the time of writing this report and no preliminary estimates of effectiveness are available. It is

expected that Grant County will continue experimentation with surface collection next year since

the benefits to both fish and hydropower generation are well worth the effort and cost if a successful design and operating criteria can be

found.

The year 1995 is also the startup year for the

COE Surface Collection Program. As elements

of this program, surface collector prototypes are
130 | Fish Passage Technologies: Protection at Hydropower Facilities

being evaluated at The Dalles and Ice Harbor

Dams by the Portland and Walla Walla Districts

of COE, respectively. A variety of slot configurations and operation criteria is in evaluation.

Preliminary data about the effectiveness and efficiency of the various designs were not available

at the writing of this report. The Corps’ Surface

Collection Program is scheduled to continue

through fiscal year 1998 and to expand to include

other mainstem dams. Advanced planning for

engineering designs continues. Harza Northwest

recently submitted a report of general concepts

for surface bypass at Bonneville Dam (29).

The success of the Wells Dam bypass, the

apparent success of the Rocky Reach surface collector prototype, and the history of the high

effectiveness and efficiency of sluiceway bypass

during the day assures that testing of surface collection will continue well into the future. Surface

collection is a very attractive bypass option

because of the possibility of passing a high proportion of smolt using a relatively small amount

of water, leaving the rest for power production,

and working with, not against, the natural behavior of smolt. Within the group of biologists and

engineers working with surface collection in the

Columbia River Basin there is a desire to conduct controlled experiments under larger-scale

laboratory conditions, following the model of the

Bonneville Fisheries Engineering Laboratory. In

general, it is the feeling of most concerned that

some laboratory testing is needed to understand

why surface collection, or more precisely, flow

attraction, works. The challenge at this time is

that no facility exists within the Columbia River

Basin suitable for such work. In lieu of such

facilities, and the need to move forward aggressively with smolt passage improvements, the

needed observations of fish behavior are being

obtained at field scales using hydroacoustic,

radio tracking, and video monitoring technologies.

For successful surface collection at least two

things that depend upon the behavior of smolt

must occur. One of these is that the smolt must

be able to locate the collector, and the second is

that the physical characteristics of the collector

and the flow field its operations generate must

attract, or at least not repel, smolt. Considerable

effort has gone into review of available information about the behavior of smolt as they approach

the various mainstem dams. Such information is

critical to locating surface collectors so that the

opportunity for discovery by smolt of the flow

fields generated by their operation is maximized.

However, review of information provided by

previous studies of smolt behavior have been disappointing. Unambiguous models of smolt

behavior on approach to a dam cannot be developed, and information about the behavior of

smolt in accelerating flow fields is almost nonexistent (26). Large scale radio tracking studies are

being considered to provide the necessary smolt

behavior information.

REFERENCES

1. Abernethy, C.S., Neitzel, D.A. and Lusty,

E.W., Velocity Measurements at Six Fish

Screening Facilities in the Yakima River

Basin, Washington, Summer 1989 (Portland, OR: Bonneville Power Administration,

1989).

2. Bell, M.C., Revised Compendium on the

Success of Passage of Small Fish Through

Turbines (Portland, OR: North Pacific Division, U.S. Army Corps of Engineers, 1990).

3. BioSonics, Inc., Hydroacoustic Assessment

of Downstream Migrant Salmon and Steelhead at Wells Dam in 1981 (Wenatchee,

WA: Douglas County Public Utility District,

1982).

4. BioSonics, Inc., Hydroacoustic Assessment

of Downstream Migrant Salmon and Steelhead at Wells Dam in 1982 (Wenatchee,

WA: Douglas County Public Utility District,

1983).

5. BioSonics, Inc., Hydroacoustic Assessment

of Downstream Migrant Salmon and Steelhead at Wells Dam in 1983 (Wenatchee,

WA: Douglas County Public Utility District,

1984).

6. BioSonics, Inc., Hydroacoustic Evaluation

of the Efficiencies of the Ice and Trash
Appendix A: Fish Passage and Protection Technologies in the Columbia River Basin | 131

Sluiceway and Spillway at Ice Harbor Dam

for Passing Downstream Migrating Juvenile

Salmon and Steelhead, 1982 and 1983

(Walla Walla, WA: Walla Walla District,

U.S. Army Corps of Engineers, 1984).

7. BioSonics, Inc., Hydroacoustic Assessment

of Downstream Migrant Salmon and Steelhead at Wells Dam in 1983 (Wenatchee,

WA: Douglas County Public Utility District,

1984).

8. BioSonics, Inc., Hydroacoustic Assessment

of Downstream Migrant Salmon and Steelhead at Wells Dam in 1984 (Wenatchee,

WA: Douglas County Public Utility District,

1985).

9. BioSonics, Inc., Hydroacoustic Assessment

of Downstream Migrant Salmon and Steelhead at Wells Dam in 1985 (Wenatchee,

WA: Douglas County Public Utility District,

1986).

10. BioSonics, Inc., Hydroacoustic Assessment

of Downstream Migrant Salmon and Steelhead at Wells Dam in 1986 (Wenatchee,

WA: Douglas County Public Utility District,

1987).

11. BioSonics, Inc., Hydroacoustic Assessment

of Downstream Migrant Salmon and Steelhead at Wells Dam in 1987 (Wenatchee,

WA: Douglas County Public Utility District,

1987).

12. BioSonics, Inc., The Smolt Monitoring Program and Hydroacoustic Evaluation of

Characteristics of the Smolt Bypass System

at Wells Dam in 1988 (Wenatchee, WA:

Douglas County Public Utility District,

1988).

13. BioSonics, Inc., The Smolt Monitoring Programs at Wells and Zosel Dams in 1989

(Wenatchee, WA: Douglas County Public

Utility District, 1990).

14. BioSonics, Inc., Evaluation of the Smolt

Bypass System at Wells Dam in 1990

(Wenatchee, WA: Douglas County Public

Utility District, 1991).

15. BioSonics, Inc., Evaluation of the Smolt

Bypass System at Wells Dam in 1991

(Wenatchee, WA: Douglas County Public

Utility District, 1992).

16. BioSonics, Inc., Evaluation of the Smolt

Bypass System at Wells Dam in 1992

(Wenatchee, WA: Douglas County Public

Utility District, 1993).

17. Bjorn, T.C., and Perry, C.A., A Review of

Literature Related to Movements of Adult

Salmon and Steelhead Past Dams and

Through Reservoirs in the Lower Snake

River, U.S. Army Corps of Engineers, North

Pacific Division, Technical Report 92-1,

Portland, OR, 1992.

18. Bjorn, T.C., et al., Migration of Adult Chinook Salmon and Steelhead Past Dams and

Through Reservoirs in the Lower Snake

River and into Tributaries, U.S. Army Corps

of Engineers, North Pacific Division, Technical Report 94-1, Portland, OR, 1994.

19. Chapman, D., “Salmon and Steelhead Abundance in the Columbia River in the Nineteenth Century,” Transactions of the

American Fisheries Society, 115:662-670,

1986.

20. Collins, G.B. and Elling, C.H., “Fishway

Research at the Fisheries-Engineering

Research Laboratory,” U.S. Fish and Wildlife Service, Circular 98, 1956.

21. Costello, R.J., A Historical Perspective and

Information for Activities and Actions

Affecting the Pacific Salmon Species, Relative to Development and Management of

Land and Water Resources Within the

Columbia River Basin, During the Period of

1792-1967 (Portland, OR: Bonneville Power

Administration, 1995, draft report).

22. Christman, B., Hydraulic Engineer, Public

Utility District No. 1 of Chelan County,

Wenatchee, WA, personal communication,

July 7, 1995.

23. Easterbrooks, J.A., Juvenile Fish Screen

Design Criteria: A Review of the Objectives

and Scientific Data Base (Yakima, WA:

State of Washington Department of Fisheries, Habitat Management Division, 1984).

24. Eicher Assoicates, Inc., Turbine-Related

Fish Mortality: Review and Evaluation of
132 | Fish Passage Technologies: Protection at Hydropower Facilities

Studies (Palo Alto, CA: Electric Power

Research Institute, 1987).

25. Ferguson, J., Fish Passage Biologist, U.S.

Army Corps of Engineers, Portland, OR,

personal communication, June 29, 1995.

26. Giorgi, A.E., and Stevenson, J.R., “A

Review of Biological Investigations

Describing Smolt Behavior at Portland District Corps of Engineer Projects: Implications to Surface Collection Systems,” U.S.

Army Corps of Engineers, Portland, OR,

1995.

27. Graban, J.R., Evaluation of Fish Facilities at

Brownlee and Oxbow Dams (Boise, ID:

Idaho Fish and Game Department, 1964).

28. Haas, J.B., “Fishery Problems Associated

with Brownlee, Oxbow, and Hells Canyon

Dams on the Middle Snake River,” Investigational Report No.4, Fish Commission of

Oregon, Portland, OR, 1965.

29. Harza Northwest, Inc., ENSR, Consulting

and Engineering, and Fisheries Consultants,

“Surface Bypass at Bonneville First Powerhouse 30 Percent Submittal—General Concepts,” Portland District, U.S. Army Corps

of Engineers, Portland, OR, 1995.

30. Hays, S., “Determination of the Depth Distribution of Juvenile Salmonids in the Turbine Intakes at Rocky Reach and Rock

Island Dams,” (Wenatchee, WA: Chelan

County Public Utility District No.1, 1984).

31. Hays, S., “Developmental Testing of a Prototype Fish Guidance System for Turbine

Intakes at the Rocky Reach Hydroelectric

Project,” (Wenatchee, WA: Chelan County

Public Utility District No. l, 1986).

32. Hays, S., “Rocky Reach Prototype Fish

Guidance System—1986 Developmental

Testing,” (Wenatchee, WA: Chelan County

Public Utility District No.l, 1987).

33. Hockersmith, E., Vella, J., Stuehrenberg, L.,

Iwamoto, R.N., and Swan, G., Yakima River

Radio-Telemetry Study: Spring Chinook

Salmon, 1991-92 (Portland, OR: Bonneville

Power Administration, 1994).

34. Hockersmith, E., Vella, J., Stuehrenberg, L.,

Iwamoto, R.N., and Swan, G., Yakima River

Radio-Telemetry Study: Steelhead, 1989-93

(Portland, OR: Bonneville Power Administration, 1995).

35. Hosey and Associates, Easton Facility Evaluation: Evaluation of Effectiveness of Fish

Protection Facilities (Yakima, WA: U.S.

Bureau of Reclamation, 1990).

36. Johnson, G.E., Sullivan, C.M., and Erho,

M.W., “Hydroacoustic Studies for Developing a Smolt Bypass System at Wells Dam,”

Fisheries Research, Vol.14, 1992.

37. Krcma, R.F., Swan, G.A., and Ossiander,

F.J., Fish Guiding and Orifice Passage Efficiency Tests with Subyearling Chinook

Salmon, McNary Dam, 1984 (Seattle, WA:

National Marine Fisheries Service, Northwest and Alaska Fisheries Center, 1985).

38. Lichatowich, J.A. and Mobrand, L.E., Analysis of Chinook Salmon in the Columbia

River from an Ecosystem Perspective (Portland, OR: Bonneville Power Administration,

1995).

39. Long, C.W., “Diel Movement and Vertical

Distribution of Juvenile Anadromous Fish in

Turbine Intakes,” Fisheries Bulletin, 66:599-

609, 1968.

40. Long, C.W., et al., Further Research on a

Fingerling Bypass for Low Head Dams

(Seattle, WA: National Marine Fisheries

Service, Northwest and Alaska Fisheries

Center, 1970).

41. Michimoto, R.T., and Korn, L., A Study of

the Value of Using the Ice and Trash Sluiceway for Passing Downstream Migrant

Salmonids at Bonneville Dam (Portland,

OR: Fish Commission of Oregon, 1969).

42. Michimoto, R.T., Bonneville and The Dalles

Dams Ice and Trash Sluiceway Studies,

1971 (Portland, OR: Fish Commission of

Oregon, 1971).

43. Mighetto, L.M., and Ebel, W.J., Saving the

Salmon: A History of the U.S. Army Corps of

Engineers’ Role in the Protection of Anadromous Fish on the Columbia and Snake Rivers (Portland, OR: U.S. Army Corps of

Engineers, 1993).
Appendix A: Fish Passage and Protection Technologies in the Columbia River Basin | 133

44. Monten, E., Fish and Turbines: Fish Injuries

During Passage Through Power Station

Turbines (Stockholm, Sweden: Vattenfall,

1985).

45. Moulton, G.E. (ed.), The Journals of the

Lewis and Clark Expedition, 7 vols., (Lincoln, NE: University of Nebraska Press,

1988).

46. Mundy, P.R., “The Role of Harvest Management in Determining the Status and Future

of Pacific Salmon Populations: Controlling

Human Behavior to Enable the Persistence

of Salmon,” D. Stouder (ed.), Proceedings of

Pacific Salmon and Their Ecosystems (Seattle, WA: University of Washington Center

for Streamside Studies, College of Forest

Resources, College of Ocean and Fisheries

Sciences, in press).

47. Neitzel, D.A., et al., A Fisheries Evaluation

of the Sunnyside Canal Fish Screening

Facilities, Spring 1985 (Portland, OR: Bonneville Power Administration, 1985).

48. Neitzel, D.A., Abernethy, C.S., and Lusty,

E.W., “A Fisheries Evaluation of the Richland and Toppenish/Satus Canal Fish

Screening Facilities, Spring 1986,” (Portland, OR: Bonneville Power Administration,

1987).

49. Neitzel, D.A., et al., A Fisheries Evaluation

of the Richland and Wapato Canal Fish

Screening Facilities, Spring 1987 (Portland,

OR: Bonneville Power Administration,

1988).

50. Neitzel, D.A., Abernethy, C.S., and Lusty,

E.W., A Fisheries Evaluation of the Toppenish Creek, Wapato, and Sunnyside Fish

Screening Facilities, Spring 1988 (Portland,

OR: Bonneville Power Administration,

1990).

51. Neitzel, D.A., Abernethy, C.S., and Lusty,

E.W., A Fisheries Evaluation of the Westside Ditch and Wapato Canal Fish Screening Facilities, Spring 1990 (Portland, OR:

Bonneville Power Administration, 1990).

52. Nestler, J., et al., Developing Acoustic Technologies for Improving Fish Passage and

Protection in the Columbia River Basin:

Program Rationale (Vicksburg, MS: U.S.

Corps of Engineers, Waterways Experiment

Station, 1995).

53. Nestler, J. and Davidson, R., Imaging Smolt

Behavior on Screens, and a Vertical Barrier

Screen at McNary Dam in 1992 (Vicksburg,

MS: U.S. Corps of Engineers, Waterways

Experiment Station, 1995).

54. Nestler, J. and Davidson, R., Imaging Smolt

Behavior on an Extended-Length Submerged

Bar Screen and an Extended-Length Submerged Traveling Screen at The Dalles in

1993 (Vicksburg, MS: U.S. Corps of Engineers, Waterways Experiment Station,

1995).

55. Nichols, D.W., Young, F.R., and Junge,

C.O., Evaluation of The Dalles Dam Ice and

Trash Sluiceway as a Downstream Migrant

Bypass System During 1977 (Portland, OR:

Oregon Department of Fish and Wildlife,

1978).

56. Nichols, D.W., Passage Efficiency and Mortality Studies of Downstream Migrant

Salmonids Using The Dalles Ice and Trash

Sluiceway During 1978 (Portland, OR: Oregon Department of Fish and Wildlife, 1979).

57. Nichols, D.W., Development of Criteria for

Operating the Trash Sluiceway at The

Dalles Dam as a Bypass System for Juvenile

Salmonids, 1979 (Portland, OR: Oregon

Department of Fish and Wildlife, 1980).

58. Northwest Power Planning Council, Fish

and Wildlife Program (as amended) (Portland, OR: Northwest Power Planning Council, 1984).

59. Northwest Power Planning Council, Council

Staff Compilation of Information on Salmon

and Steelhead Losses in the Columbia River

Basin (Portland, OR: Northwest Power Planning Council, 1986).

60. Parametrix, Inc., Hydroacoustic Evaluation

of Downstream Migrating Salmonids at Ice

Harbor Dam in Spring 1986 (Walla Walla,

WA: Walla Walla District, U.S. Army Corps

of Engineers, 1986).
134 | Fish Passage Technologies: Protection at Hydropower Facilities

61. Quistorff, E. “Floating Salmon Smolt Collectors at Baker River Dams,” Washington

Department of Fisheries, 2(4):39-52, 1966.

62. Reisner, M., Cadillac Desert (New York,

NY: Penguin Books, 1993).

63. RMC Environmental Services, Inc., and

Skalski, J.R., Survival of Yearling Spring

Chinook Salmon Smolts (Oncorhychus

tshawytscha) in Passage Through a Kaplan

Turbine at the Rocky Reach Hydroelectric

Dam, Washington (Wenatchee, WA: Chelan

County Public Utility District No.1, 1994).

64. RMC Environmental Services, Inc., and

Skalski, J.R., Survival of Juvenile Fall Chinook Salmon Smolts (Oncorhychus tshawytscha) in Passage Through a Fixed Blade

Propeller Turbine at the Rocky Reach

Hydroelectric Dam (Wenatchee, WA:

Chelan County Public Utility District No.1,

1994).

65. RMC Environmental Services, Inc., MidColumbia Consulting, Inc., and Skalski,

J.R., Turbine Passage Survival of Spring

Migrant Chinook Salmon (Oncorhychus

tshawytscha) at Lower Granite Dam, Snake

River, Washington (Walla Walla, WA: U.S.

Army Corps of Engineers, Walla Walla District, 1994).

66. Rozenthal, F. and Rees, W.H., “The Passage

of Fish Through Mud Mountain Dam,”

Washington Dept. of Fisheries, Olympia,

WA, 1957.

67. Schoeneman, D.E., Pressey, R.T., and

Junge, Jr, C.O., “Mortalities of Downstream

Migrant Salmon at McNary Dam,” Transactions of the American Fisheries Society

90(1):58-72, 1961.

68. Schreck, C., Professor, Fisheries and Wildlife, Oregon State University, Corvallis, OR,

personal communication, June 29, 1995.

69. Schreck, C.B., et al., Migratory Behavior of

Adult Spring Chinook Salmon in the Willamette River and its Tributaries (Portland,

OR: Bonneville Power Administration,

1994).

70. Stockley, C., “Merwin Dam Downstream

Migrant Bypass Trap Experiments for

1957,” Washington Dept. of Fisheries,

Olympia, WA, 1959.

71. Sverdrup Corporation, A Review of the

1981 to 1992 Hydroacoustic Studies of the

Wells Dam Juvenile Fish Bypass System

(Ephrata, WA: Grant County Public Utility

District No. 2, 1995).

72. U.S. Army Corps of Engineers, Columbia

River Salmon Mitigation Analysis System

Configuration Study Phase 1. Appendix F:

System Improvements Technical Report

Lower Columbia River (Portland, OR: U.S.

Army Corps of Engineers, Portland District,

1994).

73. Wagner, E., and Ingram, P., Evaluation of

Fish Facilities and Passage at Foster and

Green Peter Dams on the South Santiam

River Drainage in Oregon (Portland, OR:

Fish Commission of Oregon, 1973).

74. Wayne, W.W., “Fish Handling Facilities for

Baker River Project,” Journal of The Power

Division, Proceedings of American Society

of Civil Engineers, 87:23-54, 1961.

75. Willinghan, W.F., Army Engineers and the

Development of Oregon: A History of the

Portland District U.S. Army Corps of Engineers (Washington, DC: U.S. Government

Printing Office, 1992).
| 135

B

Appendix B:

Experimental

Guidance Devices:

NMFS Position

Statements

EXPERIMENTAL FISH GUIDANCE 

DEVICES: POSITION STATEMENT OF 

NATIONAL MARINE FISHERIES SERVICE

NORTHWEST REGION

JANUARY 1995

❚ NMFS Northwest Region Position Paper 

on Experimental Technology for Managing 

Downstream Salmonid

Summary

NMFS believes that positive-exclusion barrier

screens, as described below, are appropriate for

utilization in the protection of downstream

migrant salmon at all intakes. However, the process described herein delineates an approach

whereby experimental behavioral guidance

devices can be evaluated and (if comparable performance is confirmed to the satisfaction of

NMFS) installed in lieu of screens.

Introduction

Numerous stocks of salmon and steelhead trout

in Pacific Northwest streams are at low levels

and many stocks continue to decline. Idaho sockeye salmon and Snake River spring, summer, and

fall chinook are listed as “endangered” under the

Endangered Species Act. Petitions for additional

listings are pending. It is essential to provide

maximum protection for all salmonid juveniles

to halt and reverse overall population declines.

The death and injury of juvenile fish at water

diversion intakes have long been identified as a

major source of fish mortality [Spencer, 1928;

Hatton, 1939; Hallock and Woert, 1959; Hallock,

1987]. Fish diverted into power turbines incur up

to 40 percent immediate mortality, while also

experiencing injury, disorientation and delay of

migration that may increase predation related

losses [Bell, 1991]. Fish entrained into agricultural and municipal water diversions experience

100 percent mortality. Diversion mortality is the

major cause of decline in some fish populations.

For the purposes of this document, diversion

losses include turbine, irrigation, municipal, and

all other potential fish losses related to the use of

water by man.

Positive-exclusion barrier screens which

screen the entire diversion flow have long been

used to prevent or reduce entrainment of juvenile

fish for diversions of up to 3,000 cfs. In recent

decades, design improvements have been implemented to increase the biological effectiveness of

positive-exclusion screen and bypass systems by

taking advantage of known behavioral responses
136 | Fish Passage Technologies: Protection at Hydropower Facilities

to hydraulic conditions. Recent evaluations have

consistently demonstrated high success rates

(typically greater than 98 percent) at moving

juvenile salmonids past intakes with a minimum

of delay, loss, or injury.

(For diversion flows over 3,000 cfs, such as at

Columbia River main-stem turbine intakes, submerged traveling screens or bar screens are commonly used. These are not considered positiveexclusion screens in the context of this position

statement.)

The past few decades have also seen considerable effort in developing “startle” systems to

elicit a taxis (response) by the fish, with an ultimate goal of reducing entrainment. This paper

addresses research performed to avoid losses at

intakes and presents a position statement reviewing and implementing future fish protection measures.

Juveniles at Intakes

Entrainment, impingement, and delay/predation

are the primary contributors to the mortality of

juvenile migrating salmonids. Entrainment

occurs when fish are drawn into the diversion

canal or turbine intake. Impingement occurs

when a fish is not able to avoid contact with a

screen surface, trashrack, or debris at the intake.

This can cause bruising, descaling, and other

injuries. Impingement, if prolonged, repeated, or

occurring at high velocities, also causes direct

mortality. Predation (which is the leading cause

of mortality at some diversion sites) occurs when

fish are preyed upon by aquatic or avian animals.

Delay at intakes increases predation by stressing

or disorienting fish and/or by providing habitat

for predators.

Positive-exclusion screen and bypass 

systems (PESBS)

Design criteria for PESBS have been developed,

tested, and proven to minimize adverse impacts

to fish at diversion sites. Screens with small

openings and fish-tight seals are positioned at a

slight angle to flow. This orientation allows fish

to be guided to safety at the downstream end of

the screen, while they resist being impinged on

the screen face. These screens are effective at

preventing entrainment [Pearce and Lee, 1991].

Carefully designed bypass systems minimize fish

exposure to screens and provide hydraulic conditions that safely return fish to the river, thereby

preventing impingement [Rainey, 1985]. The

PESBS are designed to minimize entrainment,

impingement, and delay/predation, from the

point of diversion through the facility to the

bypass outfall.

PESBS have been installed and evaluated at

numerous facilities [Abernethy, et al., 1989;

1990; Rainey, 1990; Johnson, 1988]. A variety of

screen types (e.g., fixed-vertical, drum, fixedinclined) and screen materials (e.g., woven cloth

[mesh], perforated plate, profile wire), have

proven effective, when used in the context of a

satisfactory design for the specific site. Facilities

designed to previously referenced criteria consistently resulted in a guidance efficiency of over

98 percent [Hosey, 1990; Neitzel, 1985; 1986;

1990a; 1990b; 1990c; 1990d; 1991].

The main detriment of PESBS is cost. At

diversions of several hundred cubic feet per second and greater, the low velocity requirement

and structural complexity can drive the cost of

fish passage to over $1 million. At the headworks, the need to clean the screen, remove

trash, control sediment, and provide regular

maintenance (e.g., seasonal installation, replacing seals, etc.) also increases costs.

Behavioral devices

Due to the high costs of PESBS, there has been

considerable effort since 1960 to develop less

expensive behavioral devices as a substitute for

positive fish protection [EPRI, 1986]. A behavioral device, as opposed to a conventional screen,

requires a volitional taxis on the part of the fish

to avoid entrainment. Some devices were investigated with the hope of attracting fish to a desired

area while others were designed to repel fish.

Most studies focused on soliciting a behavioral

response, usually noticeable agitation, from the

fish.

Investigations of prototype startle-response

devices document that fish guidance efficiencies
Appendix B: Experimental Guidance Devices: NMFS Position Statements | 137

are consistently much lower than for conventional screens. Experiments show that there may

be a large behavioral variation between individual fish of the same size and species to startle

responses. Therefore, it cannot be predicted that

a fish will always move toward or away from

that stimulus. Until shown conclusively in laboratory studies, it should not be assumed that fish

can discern where a signal is coming from and

what constitutes the clear path to safety.

If juvenile fish respond to a behavioral device,

limited size and swimming ability may preclude

small fish from avoiding entrainment (even if

they have the understanding of where to go and

have the desire to get there). Another concern is

repeated exposure; fish may no longer react to a

signal after an acclimation period. In addition to

vagaries in the response of individual fish,

behavioral variations due to species, life stage,

and water quality conditions can be expected.

Another observation is that past field tests of

behavioral devices have been deployed without

consideration of how controlled ambient hydraulic conditions (i.e., the use of a training wall to

create uniform flow conditions, while minimizing stagnant zones or eddies that can increase

exposure to predation) can optimize fish guidance and safe passage away from the intake. Failure to consider that hydraulic conditions can play

a big role in guiding fish away from the intake is

either the result of the desire to minimize costs or

the assumption that behavioral devices can overcome the tendency for poor guidance associated

with marginal hydraulic conditions. The provision of satisfactory hydraulic conditions is a key

element of PESBS designs.

The primary motivation for selection of

behavioral devices relates to costs. However,

much of the cost in PESBS is related to construction of physical structures to provide hydraulic

conditions which are known to optimize fish

guidance. Paradoxically, complementing the

behavioral device with hydraulic control structures needed to optimize juvenile passage will

compromise much of the cost advantage relative

to PESBS.

Skepticism about behavioral devices, at this

stage of their development, is supported by the

fact that few are currently being used in the field

and those that have been installed and evaluated

seldom show consistent guidance efficiencies

over 60 percent [Vogel, 1988; EPRI, 1986]. The

louver system is an example of a behavioral

device with a poor record. Entrainment rates

were high, even with favorable hydraulic conditions, due to the presence of smaller fish.

Entrainment can be high, particularly when operated over a wide range of hydraulic conditions

[Vogel, 1988; Cramer, 1973; Bates, 1961]. Due

to their poor performance, most of these systems

were eventually replaced by PESBS.

Experimentation Process

However, there is potential for future development of new and acceptable screening and

behavioral guidance devices that will safely pass

fish at a rate comparable with PESBS. These new

concepts are considered “experimental” until

they have been through the process described

herein and have been proven in a prototype evaluation validated by National Marine Fisheries

Service (NMFS). These prototype evaluations

should occur over the foreseeable range of

adverse hydraulic and water quality conditions

(e.g., temperature, dissolved oxygen). NMFS

encourages research and development on experimental fish protection devices, and stipulates that

the following elements should be addressed during the process of developing experimental juvenile passage protection concepts:

1) Consider earlier research. A thorough review

of similar methods used in the past should be

performed. Reasons for substandard performances should be clearly identified.

2) Study plan. A study plan should be developed

and presented to NMFS for review and concurrence. It is essential that tests occur over a

full range of possible hydraulic, biological,

and ecological conditions that the device is

expected to experience. Failure to receive
138 | Fish Passage Technologies: Protection at Hydropower Facilities

study plan endorsement from NMFS may

result in disputable results and conclusions.

3) Laboratory research. Laboratory experiments

under controlled conditions should be developed using species, size, and life stages

intended to be protected. For behavioral

devices, special attention must be directed at

providing favorable hydraulic conditions and

demonstrating that the device clearly induces

the planned behavioral response. Studies

should be repeated with the same test fish to

examine any acclimation to the guidance

device.

4) Prototype units. Once laboratory tests show

high potential to equal or exceed success rates

of state-of-the-art screening, it is appropriate

to further examine the new device as a prototype under real field conditions. Field sites

must be fully appropriate to (a) demonstrate

performance at all expected operational and

natural variables, (b) evaluate the species, or

an acceptable surrogate, that would be

exposed to the device under full operation,

and (c) avoid unacceptable risk to depressed

or listed stocks at the prototype locations.

5) Study results. Results of both laboratory tests

and field prototype evaluations must demonstrate a level of performance equal to or

exceeding that of PESBS before NMFS will

support permanent installations.

Conclusions

During the course of the past few decades, we

have seen an increase in the number of

unscreened stream diversions, and this trend is

likely to continue unless corrective measures are

implemented. Concurrently, anadromous fish

numbers have dwindled. Proven fish passage and

protection facilities, which have demonstrated

high guidance rates at other sites, can provide

successful passage at most diversion intakes.

Periodically, major initiatives have been

advanced to examine the feasibility of experimental guidance systems. Results were generally

poor or inconclusive, with low guidance efficiencies attributable to the particular device used.

Often results were based on a small sample size,

or varied with operational conditions. In addition, unforeseen operational and maintenance

problems (and safety hazards) were sometimes a

byproduct.

Nevertheless, some of these experiments show

potential. To further advance fish protection

technology, NMFS will not oppose tests that proceed in accordance with the tiered process outlined above. To ensure no further detriment to

any fish resource, including delays in implementation of acceptable passage facilities, experimental field testing should occur with the

simultaneous design and development of a

PESBS for that site. This conventional system

should be scheduled for installation in a reasonable time frame, independent of the experimental

efforts. In this manner, if the experimental guidance system once again does not prove to be as

effective as a PESBS, a proven screen and

bypass system can be implemented without additional delay and detriment to the resource.

Adopted January 6, 1995

WILLIAM STELLE, JR.

Regional Director

EXPERIMENTAL FISH GUIDANCE 

DEVICES: POSITION STATEMENT OF 

NATIONAL MARINE FISHERIES SERVICE

SOUTHWEST REGION

JANUARY 1994

❚ NMFS Southwest Region Position Paper 

on Experimental Technology for Managing 

Downstream Salmonid Passage

Introduction

Numerous stocks of salmon and steelhead trout

in California streams are at low levels and many

stocks continue to decline. The Sacramento

River winter-run chinook salmon is listed as

“endangered” under the Federal Endangered

Species Act. Petitions for additional listings are

pending. It is essential to provide maximum protection for juveniles to halt and reverse these

declines.
Appendix B: Experimental Guidance Devices: NMFS Position Statements | 139

The injury or death of juvenile fish at water

diversion intakes have long been identified as a

major source of fish mortality [Spencer, 1928;

Hatton, 1939; Hallock and Woert, 1959; Hallock,

1987]. Fish diverted into power turbines experience up to 40 percent mortality as well as injury,

disorientation, and delay of migration [Bell,

1991], while those entrained into agricultural and

municipal water diversions experience 100 percent mortality. Diversion mortality is the major

cause of decline in some fish populations.

Positive barrier screens have long been tested

and used to prevent or reduce the loss of fish.

Recent decades have seen an increase in the use

and effectiveness of these screens and bypass

systems; they take advantage carefully designed

hydraulic conditions and known fish behavior.

These positive systems are successful at moving

juvenile salmonids past intakes with a minimum

of delay, loss, or injury.

The past few decades have also seen much

effort in developing “startle” systems to elicit a

taxis (response) by the fish with an ultimate goal

of reducing entrainment. This Position Statement

addresses research designed to prevent fish

losses at diversions and presents a tiered process

for studying, reviewing, and implementing future

fish protection measures.

Juveniles at Intakes

The three main causes of delay, injury, and loss

of fish at water intakes are entrainment, impingement, and predation. Entrainment occurs when

the fish is pulled into the diversion and passes

into a canal or turbine. Impingement is where a

fish comes in contact with a screen, a trashrack,

or debris at the intake. This causes bruising, descaling, and other injuries. Impingement, if prolonged, repeated, or occurs at high velocities,

also causes direct mortality. Predation also

occurs. Intakes increase predation by stressing or

disorienting fish and/or by providing habitat for

fish and bird predators.

Positive barriers

Positive barrier screen systems and criteria for

their design have been developed, tested, and

proved to minimize harm caused at diversions.

Positive barriers do not rely on active fish behavior; they prevent physical entrainment with a

physical barrier. Screens with small openings

and good seals are designed to work with

hydraulic conditions at the site, providing velocities normal to the screen face and sufficient

sweeping velocities to move fish past the screen.

These screens are effective at preventing entrainment [Pearce and Lee, 1991]. Carefully designed

bypass systems minimize fish exposure to

screens and provide hydraulic conditions that

return fish to the river, preventing both entrainment and impingement [Rainey, 1985]. The positive screen and fish bypass systems are designed

to minimize predation, and to reduce mortality,

stress, and delay from the point of diversion,

through the bypass facility, and back to the river.

Carefully designed positive barrier screen and

bypass systems have been installed and evaluated at numerous facilities [Abernethy, et al.,

1989; 1990; Rainey, 1990; Johnson, 1988]. A

variety of screen types (e.g., flat plate, chevron,

drum) and screen materials (e.g., woven cloth,

perforated plate, profile wire), have proved

effective, taking into consideration their appropriateness for each site. Well-designed facilities

consistently result in a guidance efficiency of

over 95 percent [Hosey, 1990; Neitzel, 1985;

1986; 1990a; 1990b; 1990c; 1990d; 1991].

The main drawback to positive barrier screens

is cost. At diversions of several hundred cubic

feet per second or greater, the low velocity

requirements and structural complexity can drive

the cost for fish protection and the associated

civil works over a million dollars. At the headwork, the need to clean the screen, remove trash,

and provide regular maintenance (e.g., seasonal

installation, replacing seals, etc.) also increase

costs.

Behavioral devices

Due to higher costs of positive barrier screens,

there has been much experimentation since 1960

to develop behavioral devices as a substitute for

barrier screens [EPRI, 1986]. A behavioral

device, as opposed to a positive (physical) bar-
140 | Fish Passage Technologies: Protection at Hydropower Facilities

rier, requires a volitional taxis on the part of the

fish to avoid entrainment. Early efforts were

designed to either attract or repel fish. These

studies focus on soliciting a behavioral response

from the fish, usually noticeable agitation. Using

these startle investigations to develop effective

fish guidance systems has not been effective.

Experiments show that there is a large

response variation between individual fish of the

same size and species. Therefore, it cannot be

predicted that a fish will always move toward or

away from a certain stimulus. Even when such a

movement is desired by a fish, it often cannot

discern the source or direction of the signal and

choose a safe escape route.

Many behavioral devices do not incorporate

and use a controlled set of hydraulic conditions

to assure fish guidance, as does the positive

screen/bypass system. The devices can actually

encourage fish movement that contrasts with the

expected rheotactic response. Thus, the fish gets

mixed signals about what direction to move.

Another concern is repeated exposure; a fish may

no longer react to a signal that initially was an

attractant or repellent. In addition to the vagaries

in the response of an individual fish, behavior

variations are expected due to size, species, life

stage, and water quality conditions.

In strong or accelerating water velocity fields,

the swimming ability of a fish may prevent it

from responding to a stimulus even if it attempts

to do so. Other environmental cures (e.g., pursuing prey, avoiding predators, or attractive habitat) may cause a fish to ignore the signal.

A main motivation for opting to install behavioral devices is cost-savings. However, much of

the cost in conventional systems is for the physical structure needed to provide proper hydraulic

conditions. Paradoxically, complementing a

behavioral device with its own structural requirements may lessen much of its cost advantage.

Present skepticism over behavioral devices is

supported by the fact that few are currently being

used in the field and those that have been

installed and evaluated seldom exhibit consistent

guidance efficiencies above 60 percent [Vogel,

1988; EPRI, 1986]. The louver system is an

example of a behavioral device with a poor success record. In this case, even with the use of

favorable hydraulics, performance is poor especially for small fish. Entrainment can be high,

particularly when operated over a wide range of

hydraulic conditions [Vogel, 1988; Cramer,

12973; Bates, 1961]. Due to their poor performance, some of these systems are already

replaced by positive barriers.

Experimentation Process

However, there is potential for developing new

positive screens as well as behavioral guidance

devices for the future. Nonetheless, experimental

technology must achieve, over the foreseeable

range of adverse conditions, a consistent level of

success that equals or exceeds that of the best

available technology. It should be a deliberate,

logical process. NMFS will not discourage

research and development on experimental fish

protection devices if the following tiered study

process is incorporated:

1) Consider earlier research. A thorough review

should be performed of past methods similar

to that proposed. Reasons for substandard performances of these earlier methods should be

clearly identified.

2) Study plan. A study plan should be developed

and presented to NMFS for review and concurrence. It is essential that tests occur over a

full range of possible hydraulic, biological,

and ecological conditions that the device is

expected to experience.

3) Laboratory research. Controlled laboratory

experiments should be developed using species, size, and life stages intended to be protected (or acceptable surrogate species). For

behavioral devices, special attention must be

directed at providing favorable hydraulic conditions and demonstrating that the device

clearly causes the planned behavioral response.

Studies should be repeated with the same test

fish to examine and habituation to the stimulus.

4) Prototype units. Once laboratory tests show

high potential to equal or exceed success rates

of state-of-the-art screening, it is appropriate

to further examine the new device as a proto-
Appendix B: Experimental Guidance Devices: NMFS Position Statements | 141

type under real field conditions. Field sites

must be fully appropriate to 1) demonstrate all

operation and natural variables expected to

influence the device performance, 2) evaluate

the species, or an acceptable surrogate, that

would be exposed to the device under full

operation, and 3) avoid unacceptable risk to

resources at the prototype locations.

5) Study results. Results of both laboratory tests

and prototype devices examined in the field

must demonstrate a level of performance

equal to or exceeding that of conventional,

established technology before NMFS will support further installations.

Conclusions

In the course of the past few decades, we have seen

increased demand for water diversions. This trend

is likely to continue. Accompanying this demand is

a corresponding decline of fisheries. Therefore,

prudence dictates that fish protection facilities be

held to the highest practicable level of performance.

A major effort was made to examine experimental guidance systems over several decades by

a variety of funding agencies. The results were

generally poor or inconclusive, with low guidance

efficiencies attributable to the particular device

used. Often results were based on a small sample

size or varied with operation conditions. In addition, unforeseen operational and maintenance problems, including safety hazards, sometimes

developed.

Nevertheless, some of these experiments show

potential. To further improve fish protection

technology, NMFS will not oppose tests that proceed in the tiered process outlined above. Further, to ensure no further detriment to fish,

experimental field testing should be done with

the simultaneous design of a positive barrier and

bypass system for that site. This conventional

system should be scheduled for installation

immediately, if the experimental guidance system, once again, does not prove to be as effective

as a conventional system.

Adopted January 11, 1994

GARY C. MATLOCK, PH.D.

Acting Regional Director

REFERENCES FOR NORTHWEST AND 

SOUTHWEST REGIONS POSITION 

STATEMENTS

Abernethy, C.S., Neitzel, D.A., and Lusty, E.W.,

Velocity Measurements at Six Fish Screening Facilities in the Yakima Basin, Washington, Summer 1988, Annual report to the

Bonneville Power Administration, 1989.

Abernethy, C.S., Neitzel, D.A., and Lusty, E.W.,

Velocity Measurements at Three Fish

Screening Facilities in the Yakima River

Basin, Washington, Summer 1989, U.S.

Department of Energy Bonneville Power

Administration Division of Fish and Wildlife, 1990.

Bates, D.W. and Jewett, Jr., S.G., Louver Efficiency in Deflecting Downstream Migrant

Steelhead, transactions of the American

Fisheries Society, 90:3, 1961.

Bell, M.C., Revised Compendium on the Success

of Passage of Small Fish Through Turbines,

Report for U.S. Army Corps of Engineers,

North Pacific Division, Contract No.

DAWC-57-88-C-0070, Portland, OR, 1991.

Cramer, D.P., Evaluation of Downstream

Migrant Bypass System T.W. Sullivan Plant,

Willamette Falls, OR, progress report for fall

1981 and spring 1982, Oct. 11, 1982.

EPRI (Electric Power Research Institute),

Assessment of Downstream Migrant Fish

Protection Technologies for Hydroelectric

Application, EPRI, Palo Alto, CA, 1986.

Hallock, R.J., A Description of the California

Department of Fish and Game Management

Program and Goals for the Sacramento

River System Salmon Resource, California

Fish and Game, Anadromous Fisheries

Branch Administrative Report, 1977.

Hallock, R.J. and Van Woert, W.F., “A Survey

of Anadromous Fish Losses in Irrigation

Diversions from the Sacramento and San

Joaquin Rivers,” California Fish and Game

45(4):227-266, 1959.

Hatton, S., “Progress Report on Central Valley

Fish, 1939,” California Fish and Game,

26(3):334–373, 1940.
142 | Fish Passage Technologies: Protection at Hydropower Facilities

Hosey and Associates and Fish Management

Consultants, Evaluation of the Chandler,

Columbia, Roza and Easton Screening

Facilities, completion report prepared for

the Bureau of Reclamation, 1990.

Johnson, P.L., Hydraulic Design of Angled Drum

Fish Screens, In: Proceedings of the Electric

Power Research Institute Conference on

Fish Protection at Steam and Hydro Plants,

San Francisco, CA., Oct. 28-30, 1987, EPRI

CS/EA/AP-5663-SR.

Neitzel, D.A., et al., A Fisheries Evaluation of

the Sunnyside Canal Fish Screening Facilities, Spring 1985, Annual Report to the Bonneville Power Administration, 1985.

Neitzel, D.A., Abernethy, C.S., and Lusty, E.W.,

A Fisheries Evaluation of the Richland and

Toppenish/Satus Canal Fish Screening

Facilities, Spring 1986, Annual Report to

the Bonneville Power Administration, 1986.

Neitzel, D.A., Clune, T.J., and Abernethy, C.S.,

Evaluation of Rotary Drum Screens Used to

Protect Juvenile Salmonids in the Yakima

River Basin. In: Proceedings of the International Symposium on Fishways ‘90, Gifu,

Japan, 1990.

Neitzel, D.A., Abernethy, C.S., and Lusty, E.W.,

A Fisheries Evaluation of the Westside Ditch

and Wapato Canal Fish Screening Facilities, Spring 1989, Annual Report to the Bonneville Power Administration, 1990.

Neitzel, D.A., Abernethy, C.S., and Lusty, E.W.,

A Fisheries Evaluation of the Wapato, Sunnyside and Toppenish Creek Canal Fish

Screening Facilities, Spring 1988, 1990.

Neitzel, D.A., Abernethy, C.S., and Martenson,

G.A., A Fisheries Evaluation of the Westside

Ditch and Town Canal Fish Screening

Facilities, Spring 1990, Annual Report to

the Bonneville Power Administration, 1990.

Neitzel, D.A., Abernethy, C.S., and Lusty, E.W.,

Evaluation of Rotating Drum Screen Facilities in the Yakima River Basin, South-Central Washington State, In: Fisheries

Bioengineering Symposium, American Fisheries Society Symposium 10 (Bethesda,

MD: 1991).

Pearce, R.O. and Lee, R.T., Some Design Considerations for Approach Velocities at Juvenile Salmonid Screening Facilities, Fisheries

Bioengineering Symposium, American Fisheries Society Symposium 10 (Bethesda,

MD: 1991).

Rainey, W.S., Cylindrical Drum Screen Designs

for Juvenile Fish Protection at Two Large

Diversions, proceedings of the International

Symposium on Fishways ‘90 (Gifu, Japan:

1990).

Rainey, W.S., Considerations in the Design of

Juvenile Bypass Systems, In: F.W. Olson,

R.G. White and R.H. Hamre, proceedings of

the Symposium on Small Hydropower and

Fisheries (Aurora: 1995).

Skinner, J.E., A Functional Evaluation of a

Large Louver Screen Installation and Fish

Facilities Research on California Water

Diversion Projects, proceedings of the Second Workshop on Entrainment and Intake

Screening, Johns Hopkins University (Baltimore, MD: Feb. 5–9, 1973).

Spencer, J., “Fish Screens in California Irrigation

Ditches,” California Fish and Game

14(3):208–210, 1928.

Vogel, D.A., Marine, K.R., and Smith, J.G., A

Summary of Upstream and Downstream

Anadromous Salmonid Passage at Red Bluff

Diversion Dam on the Sacramento River,

California, U.S.A., proceedings of the International Symposium on Fishways ‘90, (Gifu,

Japan: 1990).
| 143

C

Appendix C:

Suggested

Reading

1. Abbott, R.R., “Induced Aggregation of

Pond-reared Rainbow Trout (Salmo gairdneri) Through Acoustic Conditioning,”

Transactions of the American Fisheries

Society 101:35–43, 1972.

2. American Fisheries Society, “Common and

Scientific Names of Fishes from the United

States and Canada,” 5th Ed. (Bethesda, MD:

American Fisheries Society, 1991).

3. Anderson, D.P., “Immunological Indicators:

Effects of Environmental Stress on Immune

Protection and Disease Outbreaks,” American Fisheries Symposium 8:35–50, 1990.

4. Anderson, J.J., “Diverting Migrating Fish

Past Turbines,” The Northwest Journal of

Fisheries Management 14:237–61, 1994.

5. Astrup, J., and Mhl, B., “Detection of

Intense Ultrasound by the Cod, Gadus

morhua,” Journal Experimental Biology

182:71–80, 1993.

6. Bakke, B.M., “Managing for Productivity: A

New Strategy for Pacific Salmon Recovery,”

Trout, The Journal of Coldwater Fisheries

Conservation summer 1993, pp.37–40, 68–

73.

7. Barnthouse, L.W., et al., (eds.), Science,

Law, and Hudson River Power Plants, A

Case Study in Environmental Impact Assessment American Fisheries Society, Monograph 4 (Bethesda, MD: American Fisheries

Society,1988).

8. Bell, M.C., “Fish Passage Through Turbines, Conduits, and Spillway Gates,” Proceedings of the Second Workshop on

Entrainment and Intake Screening Report

15, L.D. Jensen, (ed.) (Palo Alto, CA: Electric Power Research Institute, 1974) pp.251–

261.

9. Bell, M.C., Revised Compendium on the

Success of Passage of Small Fish Through

Turbines (Portland, OR: U.S. Army Corps of

Engineers, North Pacific Division, 1991).

10. Benke, A.C., “A Perspective on America’s

Vanishing Streams,” Journal of the North

American Benthological Society 9:77–88,

1990.

11. Bennett, D.H., et al., “Effects of Underwater

Sound Stimulating the Intermediate Scale

Measurement System on Fish and Zooplankton of Lake Pend Oreille, Idaho,” Research

Report #N00014-92-J-4106, College of Forestry, Wildlife and Range Sciences, University of Idaho, Moscow, ID, 1994.

12. Blaxter, J.H.S., Denton, E.J., and Gray,

J.A.B, “Acoustico-lateralis Systems in Clupeid Fishes,” Hearing and Sound Communi-
144 | Fish Passage Technologies: Protection at Hydropower Facilities

cation in Fishes, W.N. Tavolga, A.N.

Popper & R.R. Fay (eds.) (New York, NY:

Springer-Verlag,1981) pp. 39–59.

13. Blumm, M., and Simrin, A. “The Unraveling

of the Parity Promise: Hydropower, Salmon,

and Endangered Species in the Columbia

Basin,” Environmental Law, 21(3):657–

744, 1991.

14. Bonneville Power Administration, U.S.

Army Corp of Engineers, U.S. Department

of the Interior, Bureau of Reclamation,

Columbia River System Operation Review

Draft Environmental Impact Statement,

Main Report (Portland, OR: Bonneville

Power Administration, July 1994).

15. Bonneville Power Administration, U.S.

Army Corp of Engineers, U.S. Department

of the Interior, Bureau of Reclamation,

Columbia River System Operation Review

Draft Environmental Impact Statement,

Appendix C-1, Anadromous Fish (Portland,

OR: Bonneville Power Administation, July

1994).

16. Bonneville Power Administration, U.S.

Army Corp of Engineers, U.S. Department

of the Interior, Bureau of Reclamation,

Columbia River System Operation Review

Draft Environmental Impact Statement,

Appendix K, Resident Fish (Portland, OR:

Bonneville Power Administration, July

1994).

17. Bonneville Power Administration, U.S.

Army Corps of Engineers, U.S. Department

of the Interior, Bureau of Reclamation,

Columbia River System Operation Review

Screening Analysis, Volume 1, Description

and Conclusions (Portland, OR: Bonneville

Power Administration, August 1992).

18. Bregman, A.S., Auditory Scene Analysis

(Cambridge, MA: MIT Press, 1990).

19. Buck, E.H., “The Magnuson Fishery Conservation and Management Act: Reauthorization Issues,” CRS-ENR (Washington, DC:

January 25, 1993).

20. Buckendorf, R., “FERC Interaction With

Fish and Wildlife Agencies in Hydropower

Licensing Under the Federal Power Act Section 10(j) Consultation Process,” Tulsa Law

Journal, 27(1):433–452, spring 1992.

21. Buckley, J., and Kynard, B., “Habitat Use

and Behavior of Pre-Spawning and Spawning Shortnose Sturgeon, Acipenser brevirostrum, in the Connecticut River,” North

American Sturgeons, F.P. Binkowski and S.

Doroshov, (eds.) (Dordrecht, Netherlands:

Junk Publication, 1995).

22. Burnham, K.P., et al., “Design and Analysis

Methods for Fish Survival Experiments

Based on Release-Recapture,” Monograph 5

(Bethesda, MD: American Fisheries Society,

1987).

23. Butler, R.L., “Freshwater Drum, Aplodinotus grunniens, in the Navigational Impoundments of the Upper Missouri River,”

Transactions of the American Fisheries

Society 94:339–49, 1965.

24. Butschek, V., and Hofbauer, J., “Vercuche

uber die Schadigung von Aalen durch

Kaplanturbinen (Experiments on the Injury

of Eels by Kaplan Turbines),” Archiv fur

Fishereiwissen-schaft 7:178–84, 1956.

25. Burtlaw, D., and Frederick, K., Compensation Principles for the Idaho Drawdown

Plan ENR 93-17, (Washington, DC:

Resources for the Future, June, 1993).

26. Cada, G.F., and Hunsaker, C.T., “Cumulative Impacts of Hydropower Development:

Reaching a Watershed in Impact Assessment,” The Environmental Professional

12:2-8, 1990.

27. Calderwood, W.L., “Passage of Smolts

Through Turbines. Experiments at a Power

House,” Salmon and Trout Magazine

81:303-18, 1935.

28. Carlander, K.D., Handbook of Freshwater

Fishery Biology, Vol. 1, Life History Data

on Freshwater Fishes of the United States

and Canada, Exclusive of the Perciformes

(Ames, IA: Iowa State University

Press,1969).

29. Carlson, T.J., “Use of Sound for Fish Protection at Power Production Facilities: An Historical Perspective of the State of the Art,”

Pacific Northwest Laboratories Project 92-
Appendix C: Suggested Reading | 145

071, U. S. Dept. of Energy, Bonneville

Power Administration, Richland, WA, 1994.

30. Clay, C.H., “Design of Fishways and Other

Fish Facilities,” The Department of Fisheries of Canada, Ottawa, Canada,1961.

31. Colt, J., and White, R.J., (eds.), Fisheries

Bioengineering Symposium, Symposium 10

(Bethesda, MD: American Fisheries Society,1991).

32. ConEdison, “Evaluation of Underwater

Sound to Reduce Impingement at the Arthur

Kill Station,” Consolidated Edison Company of New York, Inc., Final Report, 1994.

33. Coombs, S., Görner, P., and Münz, H., (eds),

“The Mechanosensory Lateral Line, Neurobiology and Evolution (New York, NY:

Springer, 1989).

34. Coombs, S., Janssen, J., and Montgomery,

J., “Functional and Evolutionary Implications of Peripheral Diversity in Lateral Line

Systems,” Evolutionary Biology of Hearing,

D.B. Webster, R.R. Fay and A.N. Popper

(eds.) (New York, NY: Springer-Verlag,

1992).

35. Coutant, C.C., “Testing the Waters,” Electric Perspectives, July-August 1992, pp.32-

40.

36. Cox, M., et al., “Anatomical Effects of

Intense Tone Stimulation in the Goldfish

Ear: Dependence on Sound Pressure Level

and Frequency,” Journal Acoustic Society of

America 89:S100, 1987.

37. Cox, M., et al., “Frequency Regionalization

in the Fish Ear,” Journal Acoustic Society of

America 79:S80, 1986.

38. Cox, M., et al., “Anatomical effects of

Intense Tone Stimulation in the Ear of Bony

Fishes,” Journal Acoustic Society of America 80:S75, 1986.

39. Cramer, S.P. and Associates, Inc., “Evaluation of Sound and Electrical Fish Guidance

Systems at Wilkins Slough Diversion Operated by Reclamation District 108,” March

1994.

40. Denton, E.J. and Gray, J.A.B., “Stimulation

of the Acoustico-Lateralis System of Clupeid Fish by External Sources and their Own

Movements,” Phil. Transactions Royal Society London Series B(341):113-127, 1993.

41. Denton, E.J. and Gray, J.A.B., “Some

Observations on the Forces Acting on Neuromasts in Fish Lateral Line Canals,” The

Mechanosensory Lateral Line—Neurobiology and Evolution, S. Coombs, P. Görner

and H. Münz, (eds.) (New York, NY:

Springer–Verlag, 1989).

42. Devine, B., “The Salmon Dammed,” Audubon 94(1):83–89, 1992.

43. Dunning, D.J., et al., “Alewives Avoid

High-Frequency Sound,” North American

Journal Fisheries Management 12:407–16,

1992.

44. Eaton, R.C., DiDomenico, R., and Nissanov,

J., “Role of the Mauthner Cell in Sensorimotor Integration by the Brain Stem Escape

Network,” Brain, Behavioral Evolution

37:272–285, 1991.

45. Electric Power Research Institute (EPRI),

“Research Update on Fish Protection Technologies for Water Intakes,” Prepared by

Stone & Webster Environmental Technology and Services, Boston, MA, review draft,

August 1993.

46. Electric Power Research Institute (EPRI),

“Guidelines for Applying Fish Protection/

Passage Technologies at Hydroelectric

Projects and Other Water Intakes,” prepared

by Stone & Webster Environmental Technology and Services, Boston, MA, review

team draft, November 1993.

47. Electric Power Research Institute (EPRI),

“Lessons Learned in Hydro Relicensing

(1984–1989) Purpose: Trends, Costs, and

Recommendations,” prepared by Richard

Hunt Associates, Annapolis, MD, May

1991.

48. Enger, P.S., et al., “Detection and Reaction

of Fish to Infrasound,” ICES Marine Science

Symposium 196:108–112, 1993.

49. Enger, P.S., “Frequency Discrimination in

Teleosts-Central or Peripheral?” Hearing

and Sound Communication in Fishes, W. M.

Tavolga, A. N. Popper and R.R. Fay, (eds.)

(New York, NY: Springer–Verlag, 1981).
146 | Fish Passage Technologies: Protection at Hydropower Facilities

50. Enger, P.S., “Hearing in Herring,” Comparative Biochemical Physiology 22:527–538,

1967.

51. Engström, B., Borg, E., and Canlon, B.,

“Morphology of Stereocilia on Cochlear

Hair Cells After Noise Exposure,” Basic and

Applied Aspects of Noise-Induced Hearing

Loss, R. J. Salvi, et al., (eds.) (New York,

NY: Plenum, 1986).

52. Escheverria, J.D., Rivers at Risk: The Concerned Citizen’s Guide to Hydropower

(Washington, DC: Island Press, 1989).

53. Empire State Electric Energy Research Corporation (ESEERCO), “Responses of White

Perch, Striped Bass, Alewives, Spottail

Shiners, Golden Shiners, and Atlantic Tomcod in a Cage to High and Low Frequency

Underwater Sounds Generated by an Electronic Fish Startle System,” ESEERCO,

Project EP89-30, 1991.

54. Fay, R.R., Hearing in Vertebrates: A Psychophysics Data Book (Winnetka, IL: HillFay Assoc., 1988).

55. Federal Energy Regulation Commission

(FERC), “Draft Order Denying Requests For

Rehearing on Projects No. 2570-018,-019,

and -020,” Washington, DC, 1995.

56. Federal Energy Regulatory Commission

(FERC), “Revised List of Comprehensive

Plans,” FERC, Office of Hydropower

Licensing, Washington, DC, May 1994.

57. Federal Energy Regulatory Commission

(FERC), “DRAFT Environmental Impact

Statement, Lower Penobscot River Basin,

Maine,” FERC/DEIS-0082, FERC, Office of

Hydropower Licensing, Washington, DC,

November 1994.

58. Federal Energy Regulatory Commission

(FERC), “Identifying Transmission Facilities at FERC Hydroelectric Projects,” Paper

No. DPR-6, FERC, Office of Hydropower

Licensing, Washington, DC, January 1993.

59. Federal Energy Regulatory Commission

(FERC), “Hydropower Licensing and

Endangered Species, Procedures for Complying with the Endangered Species Act,”

Paper No. DRP-7, FERC, Office of Hydropower Licensing, Washington, DC, February 1993.

60. Federal Energy Regulatory Commission

(FERC), “Evaluating Geologic and Soild

Issues at the Federal Energy Regulatory

Commission,” Paper No. DPR-3, FERC,

Office of Hydropower Licensing, Washington, DC, March 1992.

61. Federal Energy Regulatory Commission

(FERC), “Manual of Standard Special Articles,” Paper No. DPR-4, FERC, Office of

Hydropower Licensing, Washington, DC,

April 1992.

62. Federal Energy Regulatory Commission

(FERC), “Report on Stream Ice Processes,

Physical and Biological Effects and Relationship to Hydroelectric Projects,” Paper

No. DPR-5, FERC, Office of Hydropower

Licensing, Washington, DC, July 1992.

63. Federal Energy Regulatory Commission

(FERC), “Evaluating Relicense Proposals at

the Federal Energy Regulatory Commission,” Paper No. DPR-2, FERC, Office of

Hydropower Licensing, Washington, DC,

April 1991.

64. Feist, B. E. and Anderson, J.J., “Review of

fish behavior relevant to fish guidance systems. Fisheries Research Unit,” Report FRIUW-9102, University of Washington, Seattle WA, 1991.

65. Fernald, R. D., “Aquatic Adaptations in Fish

Eyes,” Sensory Biology of Aquatic Animals,

J. Atema, et al., (eds.), (New York, NY:

Springer–Verlag, 1988).

66. Fulton, E., “Lessons Learned About Fish

Entrainment,” Hydro Review 14:16–25,

1995.

67. Gardner, J.A., and Woodall Jr., W.R.,

“Entrainment of Ichthyoplankton at Hatch

Nuclear Plant,” Proceedings of the First

Symposium on Freshwater Larval Fish.

Southeastern Electric Exchange, L.L. Olmsted (ed.) Atlanta, GA, 1977, pp. 94–116.

68. Geen, G.H., et al., “Life Histories of Two

Species of Catostomid Fishes in Sixteen

Mile Lake, British Columbia, with Particular

Reference to Inlet Spawning,” Journal of
Appendix C: Suggested Reading | 147

The Fisheries Research Board Of Canada

23:1761–88, 1966.

69. Gehrke, P.C., “Influence of Light Intensity

and Wavelength on Photoactive Behavior of

Larval Silver Perch Bidyanus bidyanus and

Golden Perch Macquaria ambigua and the

Effectiveness of Light Traps,” Journal of

Fish Biology 44:741–751, 1994.

70. Greenstreet, S.P.R., “Migration of Hatchery

Reared Juvenile Atlantic Salmon, Salmo

salar, Smolts Down a Release Ladder, Environmental Effects on Migratory Activity,”

Journal of Fish Biology 40(5):655–666,

1992.

71. Gresswell, R.E., Status and Management of

Interior Stocks of Cutthroat Trout, Symposium 4 (Bethesda, MD: American Fisheries

Society, 1988).

72. Gulliver, J. and Arndt, R.E.A., Hydropower

Engineering Handbook (New York, NY:

McGraw–Hill, Inc., 1991).

73. Hadderingh, R.H., and Kema, N.V., “Experimental Reduction of Fish Impingement by

Artificial Illumination at Bergum Power Station,” International Review Ges. Hydrobiology 67:887–90, 1982.

74. Hall, G.E., and Van Den Avyle, M.J., (eds.),

“Reservoir Fisheries Management: Strategies for the 80’s,” Proceedings of a Symposium held in Lexington, KY, June 13–16,

1983, Reservoir Committee, Southern Division, American Fisheries Society (Bethesda,

MD: American Fisheries Society, 1986).

75. Haymes, G.T. and Patrick, P.H., “Exclusion

of Adult Alewife, (Alosa pseudoharengus),

Using Low-frequency Sound for Application

at Water Intakes,” Canadian Journal Fisheries Aquatic Sciences 43:855–62, 1986.

76. Haymes, G.T., Patrick, P.H., and Onisto,

L.J., “Attraction of Fish to Mercury Vapour

Light and its Application in a Generating

Station Forebay,” International Review Ges.

Hydrobiolgy, 69:867–876, 1984.

77. Heisey, P., Mathur, D., and D’Allesandro,

L., “A New Technique for Assessing Fish

Passage Survival at Hydro Power Stations,”

Proceedings of the Workshop on Fish Passage at Hydroelectric Developments, U.P.

Williams, et al., (eds.) (St. John’s, Newfoundland: Canadian Technical Report on

Fish and Aquatic Sciences, 1993).

78. Helmstetter, F.J., and Bellgowan, P.S.,

“Hypoplasia in Response to Sensitization

During Acute Noise Stress,” Behavioral

Neuroscience 108:177–185, 1994.

79. Hilborn, R., “Hatcheries and the Future of

Salmon in the Northwest” in Fisheries

17(1):5–8, January–February 1992.

80. Hilgert, P.H., “Evaluation of a Graduated

Electric Field as a Fish Exclusion Device,”

Beak Consultants Inc. for Puget Sound

Power & Light Co, Bellevue, WA, 1992.

81. Hoar, W.S., Keenleyside, M.H.A., and

Goodall, R.G., “Reactions of Juvenile

Pacific Salmon to Light,” Journal Fisheries

Research Board Canada 14:815–830, 1957.

82. Hocutt, C.H., “Behavioral Barriers and

Guidance Systems,” Power Plants: Effects

on Fish and Shellfish Behavior, C.H. Hocutt,

et al., (eds.) (New York, NY: Academic

Press, 1980).

83. Hocutt, C.H., et al., (eds.), Power Plants,

Effects on Fish and Shellfish Behavior (New

York, NY: Academic Press, 1980).

84. Hoese, H.D., and Konikoff, M.A., “Cameron-Creole Watershed Management. Fisheries Study,” prepared for Coastal

Management Division, Louisiana Department of Natural Resources, SFP No. 21913-

89-16, 1990.

85. Holden, P.B., “Ecology of Riverine Fishes in

Regulated Stream Systems with Emphasis

on the Colorado River,” The Ecology of Regulated Streams, J.V. Ward and J.A. Stanford,

(eds.) (New York, NY: Plenum Press, 1979).

86. Hoyt, R.D., (ed.), “10th Annual Larval Fish

Conference,” Proceedings of a Conference

Held in Miami, FL, May 18–23, 1986,

American Fisheries Society Symposium 2,

Bethesda, MD, 1987.

87. Hunt, R.T., “The Status of Hydropower Regulation and Development—1989,” Richard

Hunt Associates, Annapolis, MD, December

1989.
148 | Fish Passage Technologies: Protection at Hydropower Facilities

88. Hunt, R., and Hunt, J.M., “Reinventing the

Process,” Independent Energy November

1994, pp. 75–77.

89. Huppert, D.D., and Fluharty, D.L., “Economics of Snake River Salmon Recovery, A

Report to the National Marine Fisheries Service,” School of Marine Affairs, College of

Ocean and Fishery Sciences, Seattle, WA,

February 1995.

90. Kalmijn, A.J., “Functional Evolution of Lateral Line and Inner Ear Systems,” in The

Mechanosensory Lateral Line—Neurobiology and Evolution, S. Coombs, P. Görner

and H. Münz, (eds.) (New York, NY:

Springer–Verlag,1989) pp.187–216.

91. Kalmijn, A.J. , “Hydrodynamic and Acoustic Field Detection,” Sensory Biology of

Aquatic Animals, J. Atema, et al., (eds)

(New York, NY: Springer, 1988).

92. Kalmijn, A.J., “Detection of Weak Electric

Fields,” Sensory Biology of Aquatic Animals, J. Atema, et al., (eds.) (New York,

NY: Springer, 1988).

93. Karlsen, H.E., “Infrasound Sensitivity in the

Plaice (Pleuronectes platessa),” Journal

Experimental Biology 171:173–187, 1992.

94. Karlsen, H.E., “The Inner Ear is Responsible

for Detection of Infrasound in the Perch

(Perca fluviatilis),” Journal Experimental

Biology 171:163–172, 1992.

95. Katopodis, C., et al., Assessment of Two

Denil Fishways for Passage of Freshwater

Species American Fisheries Society Symposium 10, Bethesda, MD, 1991.

96. Kelso, J.R.M., and J.K. Leslie, “Entrainment

of Larval Fish by the Douglas Point Generating Station, Lake Huron, in Relation to Seasonal Succession and Distribution,” Journal

of The Fisheries Research Board Of Canada

36:37–41, 1979.

97. Kerwin, J.G., Federal Water-Power Legislation (New York, NY: AMS Press, Inc.,

1926).

98. Kleinschmidt Associates, “Fish Entrainment and Mortality Study, Final Report,”

prepared for Niagara Mohawk Power Corporation, Syracuse, New York, 1995.

99. Kohler, C.C., and W.A. Hubert, (eds.),

Inland Fisheries Management in North

America (Bethesda, MD: American Fisheries Society, 1993).

100.Lee, K.N., “Rebuilding Confidence:

Salmon, Science, and Law in the Columbia

Basin,” Environmental Law 21(3):745–806,

1991.

101.Lombarte, A., et al., “Damage and Regeneration of Hair Cell Ciliary Bundles in a Fish

Ear Following Treatment with Gentamicin,”

Hearing Research 66:166–174, 1993.

102.Mallen-Cooper, M., “How High Can a Fish

Jump?” New Scientist 142:32–37, 1994.

103.Martin, P., et al., “A Demonstration of

Strobe Lights to Repel Fish,” American

Society Civil Engineers, Waterpower ‘91

Proceedings of the International Conference

on Hydropower (Portland, OR: American

Society of Civil Engineering, 1991).

104.Mayden, R.L., et al., “The Native Freshwater Fishes of North America,” Systematics,

Historical Ecology, and North American

Freshwater Fishes, R.L. Mayden (ed.)

(Stanford, CA: Stanford University Press,

1992).

105.Merriman, D., and L.M. Thorpe (ed.), “The

Connecticut River Ecological Study. The

Impact of a Nuclear Power Plant,” American

Fisheries Society, Monograph No.1

(Lawrence, KS: Allen Press, Inc., 1976).

106.Miller, D.R., and A.E. Giorgi, et al., “Effects

of Flow on the Migratory Behavior and Survival of Juvenile Fall and Summer Chinook

Salmon in John Day Reservoir,” Annual

Report of Research Financed by Bonneville

Power Administration, Seattle, WA, December 1985.

107.National Park Service, “Final Environmental

Impact Statement, Elwha River Ecosystem

Restoration, Olympic National Park, Washington,” June 1995.

108.National Research Council (NRC), “Lowfrequency Sound and Marine Mammals:

Current Knowledge and Research Needs,”

Committee on Low-Frequency Sound and

Marine Mammals, Ocean Studies Board,
Appendix C: Suggested Reading | 149

NRC, National Academy Press, Washington

DC, 1994.

109.Nehlsen, W., J.E. Williams, and J.A.

Lichatowich, “Pacific Salmon at the Crossroads: Stocks at Risk from California, Oregon, Idaho, and Washington,” Fisheries

16(2):4–21, 1991.

110.Nestler, J.M., et al., “Development of an

Operational, Full-Scale Fish Protection System at a Major Pumped-storage Hydropower

Dam,” American Society of Civil Engineers,

1995.

111.Nestler, J.M., et al.., “Responses of Blueback Herring to High-frequency Sound and

Implications for Reducing Entrainment at

Hydropower Dams,” North American Journal of Fisheries Management, 12:667–83,

1992.

112.New England Power Company (NEPCO),

RMC Environmental Services, Inc. and Sonalysts, Inc., “Effect of Ensonification on

Juvenile American Shad Movement and

Behavior at Vernon Hydroelectric Station,”

RMC Project No.4196, 1993.

113.Olsen, K., “Evidence for Localization of

Sound by Fish in Schools,” Sound Reception

in Fish,” A. Schuijf and A.D. Hawkins (eds.)

(Amsterdam: Elsevier, 1976).

114.Olson, F.W., R.G. White, and R.H. Hamre

(eds.) Proceedings of the Symposium on

Small Hydropower and Fisheries, Sponsored by the American Fisheries Society,

May 1–3, 1985, Aurora, CO.

115.Parker, J.A., “Migratory Patterns and

Exploitation of American Shad in the Farshore Ocean Waters of Southeastern North

Carolina,” North American Journal of Fisheries Management 12:752–59, 1992.

116.Patrick, P.H., R.W. Sheehan, and B. Sim,

“Effectiveness of a Strobe Light Eel Exclusion Scheme,” Hydrobiologica 94:269–277,

1982.

117.Platt, C., “The Peripheral Vestibular System

in Fishes,” Fish Neurobiology, R.G. Northcutt, R.E. Davis (eds.) (Ann Arbor, MI:

Univ. of Michigan Press, 1983) pp. 89–124.

118.Popper, A.N., and C. Platt, “Inner Ear and

Lateral Line of Bony Fishes,” The Physiology of Fish, D. H. Evans (ed.) (Boca Raton,

Fl: CRC Press, 1993).

119.Popper, A.N., and N.L. Clarke, “The Auditory System of the Goldfish (Carassius

auratus): Effects of Intense Acoustic Stimulation,” Compendium Biochemical Physiology 53:11–18, 1976.

120.Prendergast, J., “Hydropower’s Balancing

Act,” Civil Engineering 61(10):42–45, 1991.

121.Priegel, G.R. “Reproduction and Early Life

History of the Walleye in the Lake Winnebago region,” Technical Bulletin Wisconsin Department Natural Resources, 45:1–

105, 1970.

122.Radford, B.W., “Courts and Commissions:

Fish or Foul?” Fortnightly 131(19):62–63,

Oct. 15, 1993.

123.Railsback, S.F., Coutant, C.C., and Sale,

M.J., “Improving the Effectiveness of Fisheries Agencies in Developing Hydropower

Mitigation,” Fisheries 15(3):3–8, May–June

1990.

124.RMC Environmental Services, “Summary of

the Operations at the Conowingo Dam Fish

Passage Facilities in Spring 1993,” prepared

for Susquehana River Anadromous Fish

Restoration Committee, Part of the 1993

Annual Progress Report, Restoration of

American Shad to the Susquehanna River,

1994.

125.Rogers, P. “What Do Fish Listen To?” Journal Acoustic Society of America 79:S22,

1986.

126.Ruggles, C.P., “What’s New in Downstream

Fish Passage?” Salmon in the Sea and New

Enhancement Strategies, D. Mills, (ed.)

(Cambridge, MA: Blackwell Scientific Publications Ltd., Fishing News Books, 1993).

127.Satou, M., et al., “Characterization of Vibrational and Visual Signals Which Elicit

Spawning Behavior in the Male Himé

Salmon (landlocked red salmon, Oncorhynchus nerka),” Journal of Comparative Physiology A(174):527–537, 1994.
150 | Fish Passage Technologies: Protection at Hydropower Facilities

128.Satou, M., et al., “Behavioral and Electrophysiological Evidences that the Lateral

Line is Involved in the Inter-sexual Vibrational Communication of the Male Himé

Salmon (landlocked red salmon, Oncorhynchus nerka),” Journal of Comparative Physiology A(174):539–549, 1994.

129.Saunders, J.C., B. Canlon, and A. Flock,

“Mechanical Changes in Stereocilia Following Overstimulation: Observations and Possible Mechanisms,” Basic and Applied

Aspects of Noise-Induced Hearing Loss, R.

J. Salvi, et al., (eds.) (New York, NY: Plenum, 1986).

130.Schwarz, A.L., “The Behaviour of Fishes in

their Acoustic Environment,” Environmental Biology of Fishes 13:3–15, 1985.

131.Shabalin, V.N., “The Sensitivity of Fishes to

the High Frequency Hydroacoustic and

Electromagnetic Fields,” ICES C.M. (translation by author of Russian paper), 1991.

132.Skalski, J.R., and A. Hoffman, “Fixed-Location Hydroacoustic Monitoring Designs for

Estimating Fish Passage Using Stratified

Random and Systematic Sampling,” Canadian Journal of Fisheries and Aquatic Sciences 50(6):1208–1221, 1993.

133.Smallowitz, H., “Making Amends with

Nature,” Civil Engineering May 1989,

pp.56–59.

134.Stabell, O.B., “Homing and Olfactory

Responses in Salmonids: A Critical Review

with Special Reference to the Atlantic

Salmon,” Biological Review 59:333–388,

1994.

135.Swada, Y., “Reproducible Increases in

Blood Pressure During Intermittent Noise

Exposure: Underlying Hemodynamic Mechanisms Specific to Passive Coping,” European Journal Applied Physiological

Occupational Physiology 67:367–374, 1992.

136.Thomas, P., “Molecular and Biochemical

Responses of Fish to Stressors and their

Potential Use in Environmental Monitoring,” American Fisheries Society Symposium 8:9–28, 1990.

137.Tysus, H.M., “Effects of Altered River

Flows on Fishery Resources,” Fisheries

15(3):18–20, 1990.

138.Tysus, H.M., and B.D. Winter, “Hydropower Development,” Fisheries 17(1):30–

32, 1989.

139.U.S. Army Corps of Engineers, North

Pacific Division, “Columbia River and Tributaries Review Study, Report Number 49,

Books 1 and 2,” Portland, OR, July 1989.

140.U.S. Congress, General Accounting Office,

“Endangered Species, Potential Economic

Costs of Further Protection for Columbia

River Salmon,” Report to Congressional

Requesters, GAO/RCED-93-41, February

1993.

141.U.S. Congress, General Accounting Office,

“Hydroelectric Dams: Interior Favors

Removing Elwha River Dams, but Who

Should Pay is Undecided,” Report to the

Chairman, Subcommittee on Oversight and

Investigations, Committee on Energy and

Commerce, House of Representatives,

GAO/RCED-92-168, June 1992.

142.U.S. Congress, General Accounting Office,

“Endangered Species, Past Actions Taken to

Assist Columbia River Salmon,” Briefing

Report to Congressional Requesters, GAO/

RCED-92-173BR, July 1992.

143.U.S. Congress, General Accounting Office,

“Hydroelectric Dams: Costs and Alternatives for Restoring Fisheries in the Elwha

River,” Report to the Chairman, Subcommittee on Oversight and Investigations, Committee on Energy and Commerce, House of

Representatives, GAO/RCED-91-104,

March 1991.

144.U.S. Congress, General Accounting Office,

“Hydroelectric Dams, Issues Surrounding

Columbia River Basin Juvenile Fish

Bypasses,” Report to the Chariman, Subcommittee on Oversight and Investigations,

Committee on Energy and Commerce,

House of Representatives, GAO/RCED-90-

180, September 1990.

145.U.S. Congress, General Accounting Office,

“Energy Regulation: Opportunities for
Appendix C: Suggested Reading | 151

Strengthening Hydropower Cumulative

Impact Assessments,” Report to the Chairman, Committee on Energy and Commerce,

House of Representatives, GAO/RCED-88-

82, March 1988.

146.U.S. Congress, General Accounting Office,

“Energy Regulation: Hydropower Impacts

on Fish Should Be Adequately Considered,”

Report to the Chairman, Subcommittee on

Oversight and Investigations, Committee on

Energy and Commerce House of Representatives, Restricted Use, May 1986.

147.U.S. Department of Commerce, National

Oceanic and Atmospheric Adminstration,

National Marine Fisheries Service (NMFS),

“Proposed Recovery Plan for Snake River

Salmon,” NMFS, Northwest Region, Seattle,

WA, March 1995.

148.U.S. Department of Commerce, National

Oceanic and Atmospheric Administration,

National Marine Fisheries Service (NMFS),

“Fisheries of the United States, 1993, Current Fishery Statistics No. 9300,” NMFS,

Silver Spring, MD, May 1994.

149.U.S. Department of Energy (DOE), “DOE

Hydropower Program Biennial Report

1992–1993,” Idaho National Engineering

Laboratory, EG&G Idaho, Inc., Idaho Falls,

ID, July 1993.

150.U.S. Department of Energy, “Analysis of

Environmental Issues Related to Small Scale

Hydroelectric Development, II: Design Considerations for Passing Fish Upstream

Around Dams,” S.G. Hildebrand, M.C. Bell,

J.J. Anderson, E.P. Richey, Z.E. Parkhurst,

Environmental Sciences Division, Publication No. 1567, Oak Ridge National Laboratory, Oak Ridge, TN, August 1980.

151.U.S. Department of Energy, Bonneville

Power Administration, Integrated Hatchery

Operations Team, “Policies and Procedures

for Columbia Basin Anadromous Salmonid

Hatcheries,” Draft, July 1994.

152.U.S. Department of Energy, Bonneville

Power Administration, “1994 Snake River

Sockeye Salmon Sawtooth Valley Project

Conservation and Rebuilding Program,”

Final Environmental Assessment, DOE/EA0934, April 1994.

153.U.S. Department of Energy, Bonneville

Power Administration, Division of Fish and

Wildlife, “Recovery Planning for Endangered Salmon: A Multiple Attribute Analysis,” Prepared by C.M. Paulson, K.

Wernstedt, and J. B. Hyman, (Washington,

DC: Resources for the Future, December

1993).

154.U.S. Department of Energy, Bonneville

Power Administration, Division of Fish and

Wildlife, “Use of Artificial Propagation and

Supplementation for Rebuilding Salmon

Stocks Listed Under the Endangered Species

Act: Recovery Issues for Threatened and

Endangered Snake River Salmon: Technical

Report 5 of 11,” Project No. 93-013, Prepared by J. Lichatowich and B. Watson,

under subcontract to S.P. Cramer & Associates, Inc., Gresham, OR, June 1993.

155.U.S. Department of Energy, Bonneville

Power Administration, Division of Fish and

Wildlife, “Salmon Supplementation Studies

in Idaho Rivers, Experimental Design,” Prepared by E. Bowles, E. Leitzinger, Project

No. 89-098, Idaho Dept. of Fish and Game,

December 1991.

156.U.S. Department of Energy, Bonneville

Power Administration, Division of Fish &

Wildlife, “Analysis of Salmon and Steelhead

Supplementation, Part 1: Emphasis on

Unpublished Reports and Present Programs,

Part 2: Synthesis of Published Literature,

Part 3: Concepts for a Model to Evaluate

Supplementation, Technical Report 1990,”

Project No. 88-100, Prepared by W.H.

Miller, Dworshak Fisheries Assistance

Office, U.S. Fish and Wildlife Service, September 1990.

157.U.S. House of Representatives, “BPA at a

Crossroads,” Majority Staff Report, Committee on Natural Resources, BPA Task

Force, Washington, DC, May 1994.

158.van Bergeijk, W.A., “The Evolution of Vertebrate Hearing,” Contributions to Sensory
152 | Fish Passage Technologies: Protection at Hydropower Facilities

Physiology, W.D. Neff (ed.) (New York,

NY: Academic Press, 1967).

159.Vanicek, C.D., and R.H. Kramer, “Life History of the Colorado Sqawfish (Ptychocheilus lucius), and the Colorado Chub

(Gila robusta) in the Green River in Dinosaur National Monument, 1964–1966,”

Transactions of the American Fisheries

Society 98:193–208, 1969.

160.Warren, M.L., Jr., and B.M. Burr, “Status of

Freshwater Fishes of the United States:

Overview of an Imperiled Fauna,” Fisheries

19:6–18, 1994.

161.Washington State Department of Fisheries,

“Salmon 2000 Technical Report, Phase 2:

Puget Sound Washington Coast and Integrated Planning,” Seattle, WA, May 1992.

162.Williams, J.E., et al., “Fishes of North

America, Endangered, Threatened, or of

Special Concern,” Fisheries 14(6):2–20,

1989.

163.Yan, H.Y., et al., “Sensory Hair Cells of the

Fish Ear: Evidence of Multiple Types Based

on Ototoxicity Sensitivity,” Proceedings

Royal Society Series B(245):133–138, 1991.
| 153

References

1. Administrative Law Journal, “Regulatory

Intertia: FERC’s Failure to Consider Endangered Species’ Protection in the Issuance of

Hydroelectric Annual Licenses: Platter

River Whooping Crane Critical Habitat

Maintenance Trust v. FERC,” 4:321–360,

fall 1990.

2. Ahlstrom, E.H., “Distribution and Abundance of Egg and Larval Populations of the

Pacific Sardine,” U.S. Fish and Wildlife

Fishery Bulletin 56:83–140, 1954.

3. Alderdice, D.F., and Jensen, J.O.T.,

“Assessment of the Influence of Gas Supersaturation on Salmonids in the Nechako

River in Relation to Kemano Completion,”

Canadian Technical Report on Fish and

Aquatic Sciences, 1386:48, 1985.

4. Altufyev, Y.V., et al., “Analysis of the Beluga Sturgeon, Huso huso, Below the Vologograd Hydroelectric Power Station Dam

and in the Mashkina Kosa Overwintering

Depression,” Fishes of Wisconsin, G.C.

Becker (ed.), (Madison, WI: University of

Wisconsin Press, 1983).

5. American Fisheries Society, Handbook on

the Valuation of Fish Kills (Bethesda, MD:

American Fisheries Society, 1992).

6. Anderson, J., et al., “Measurement of the

Low Frequency Sound at Bonneville,

McNary, and Lower Granite Dams,” FRIUW-8906 (Seattle, WA: University of

Washington, Fish Research Institute, 1989).

7. Athearn, J.B., “Developments in Transportation from Dams to Improve Juvenile Salmonid Survival,” Fisheries Bioengineering

Symposium (Portland, OR: American Fisheries Society, 1991).

8. Auer, N.A., “Lake Sturgeon Studies–-Prickett Hydroelectric Project,” a report prepared

for Stone and Webster Engineering Corporation, Boston, MA, 1990.

9. Auer, N.A., “Addressing Critical Spawning

Needs of the Sturgeon River Lake Sturgeon,” a report prepared for the Upper Peninsula Power Company, Ann Arbor, MI,

1989.

10. Auer, N.A., “Survey of the Sturgeon River,

Michigan Lake Sturgeon Population,” Michigan Department of Natural Resources, Nongame Wildlife Fund and Living Resources

Small Grants Program Report, (Ann Arbor,

MI: 1988).

11. Auer, N.A., “Evaluation of a Lake Sturgeon

Population,” Michigan Department of Natural Resources, Nongame Wildlife Fund and

Living Resources Small Grants Program

Report, (Ann Arbor, MI: 1987).

12. Bates, K.M., Staff Engineer, Habitat Management Division, Department of Fisheries,

Olympia, WA, personal communication,

August 1995.

13. Bates, K.M., Staff Engineer, Habitat Management Division, Department of Fisheries,

Olympia, WA, personal communication,

November 1994.

14. Bates, K.M., “Fish Passage Policy and Technology,” Fisheries Bioengineering Symposium (Portland, OR: American Fisheries

Society, September 1993).

15. Bates, K.M., “Fishway Design Guidelines

for Pacific Salmon,” working paper (Olympia, WA: Washington Department of Fish

and Wildlife, March 1992).
154 | Fish Passage Technologies: Protection at Hydropower Facilities

15a.Becker, C.D., ed., Fisheries Laboratories of

North America, American Fisheries Society,

Bethesda, MD,1991.

16. Bell, M.C., Fisheries Handbook of Engineering Requirements and Biological Criteria, 3d Ed. (Portland, OR: U.S. Army Corps

of Engineers, North Pacific Division, 1991).

17. Bell, M.C., Updated Compendium on the

Success of Passage of Small Fish Through

Turbines (Portland, OR: U.S. Army Corps of

Engineers, 1981).

18. Bell, C.E. and Kynard, B., “Mortality of

Adult American Shad Passing Through a 17-

Megawatt Kaplan Turbine at a Low-Head

Hydroelectric Dam,” North American Journal of Fisheries Management 5:33–38, 1985.

19. Bell, M.C., DeLacy, A.C., and Paulik, G.C.,

A Compendium on the Success of Passage of

Small Fish Through Turbines (Portland, OR:

U.S. Army Corps of Engineers, 1967).

20. Bengeyfield, W., “Evaluation of an Electrical Field to Divert Coho Salmon Smolts

from the Penstock Intake at Puntledge Generating Station,” Global Fisheries Consultants Ltd., a report prepared for B.C. Hydro,

(Vancouver, BC, Canada: 1993).

21. Bisulca, P., Assistant to the Governor, Environmental Affairs, Penobscot Indian Nation,

Oxford, ME, personal communication,

August 1995.

22. Blaxter, J.H.S. and Batty, R.S., “Comparison

of Herring Behavior in the Light and Dark,

Changes in Activity and Responses to

Sound,” Journal of the Marine Biology

Association U.K., 67:849–860, 1987.

23. Bonneville Power Administration, U.S.

Army Corps of Engineers, U.S. Department

of the Interior, Bureau of Reclamation,

Columbia River System Operation Review

Draft Environmental Impact Statement,

Appendix C-2, Juvenile Fish Transportation

(Portland, OR: Bonneville Power Administration, July 1994).

24. Bouck, G.R., and Smith, S.D., “Mortality of

Experimentally Descaled Smolts of Coho

Salmon (Oncorhynchus kisutch I) in Fresh

and Salt Water,” Transactions of the American Fisheries Society 108: 67–69, 1979.

25. Brett, J.R., and Mackinnon, K.D., “Preliminary Experiments Using Lights and Bubbles

to Deflect Migrating Young Spring

Salmon,” Journal of the Fisheries Research

Board Canada 10:548–59, 1953.

26. Brookshire, P.A.M., Senior Project Manager, U.S. Department of Energy, personal

communication, October 1994.

27. Brown, R., Marketing/Sales Manager, Flash

Technology, personal communication,

March 1995.

28. Brousseau, C.S. and Goodchild, G.A., “Fisheries and Yields in the Moose River Basin,

Ontario,” Proceedings of the International

Large River Symposium, Canadian Special

Publication on Fish and Aquatic Science,

D.P. Dodge (ed.), 106:145–158, 1989.

29. Brush, T., Manager, Brattleboro Office,

Normandeau Associates, personal communication, August 1995.

30. Brush, T.D., Mathur, D., and Heisey, P.G.,

“Entrainment Survival of Fishes at Hydro

Projects,” paper presented at Hydro’s Leading Edge Technology Symposium, Phoenix,

AZ, Aug. 15–16, 1994.

31. Buckley, J., and Kynard, B., “Yearly Movements of Shortnose Sturgeons in the Connecticut River,” Transactions of the

American Fisheries Society 114:813–20,

1985.

32. Buerkett, C.G., “Passage and Behavior of

Adult American Shad in an Experimental

Louver Bypass System,” unpublished dissertation, University of Massachusetts, Boston,

MA, 1994.

33. Burner, C.J., and Moore, H.L., “Attempts to

Guide Small Fish With Underwater Sound,”

U.S. Fish and Wildlife Service, Special Science Report on Fisheries, 111:38, 1953.

34. Cada, G.F, Aquatic Ecologist, Oak Ridge

National Laboratory, personal communication, August 1995.

35. Cada, G.F., “A Review of Studies Relating

to Effects of Propeller-Type Turbine Passage on Fish Early Life Stages,” North
References | 155

American Journal of Fisheries Management

10:418–26, 1990.

36. Cada, G.F., and Sale, M.J., “Status of Fish

Passage Facilities at Nonfederal Hydropower Projects,” Fisheries 18(7):4–12, July

1993.

37. Cada, G.F., and Jones, D.W., “Benefits of

Fish Passage and Protection Measures at

Hydroelectric Projects,” Waterpower ‘93,

Proceedings of the International Conference

on Hydropower, Volume I, W.D. Hall (ed.)

(Nashville, TN: National Hydropower Association, 1993).

38. California Department of Fish and Game,

General Fish Screening Criteria, Sacramento, CA, February 1993.

39. Carlson, T., Lead Scientist, Aquatic Ecology

Group, Pacific Northwest Labs, Richland,

WA, personal communication, August 1995.

40. Carlson, T., “Overview of the Aspects of

Adult and Juvenile Migrating Fish Passage

and Protection Technologies Within the

Columbia River Basin,” unpublished contractor report prepared for the Office of

Technology Assessment, U.S. Congress,

Washington, DC, July 1995.

41. Central Maine Power Company, “Kennebec

River Developers Group 1991: Annual

Report in Support of Restoration of Anadromous Fish to the Kennebec River, Maine,”

Central Maine Power, Co., ME, Feb. 28,

1992.

42. Christensen, P.J., “Rerouting Fish Traffic in

the Columbia River Basin,” Hydro Review,

July 1995, pp. 96–102.

43. Cochran, C.H., “Environmental Enforcement at FERC–-A Bird’s-Eye View,” Natural Resources and Environment, spring

1994, pp. 14–16, 56–57.

44. Colle, D.E., Cailteux, R.L. and Shireman,

J.V., “Distribution of Florida Largemouth

Bass in a Lake after Elimination of all Submersed Aquatic Vegetation,” North American Journal of Fisheries Management

9:213–18, 1989.

44a. Columbia Basin Indian Tribes and the State

and Federal Fish and Wildlife Agencies,

“Scientific Rationale for Implementing a

Summer Program to Increase Juvenile

Salmonid Survival in the Snake and Columbia Rivers,” by the Columbia Inter-Tribal

Fish Commission, ID Dept. of Fish and

Game, OR Dept. of Fish and Wildlife, WA

Dept. of Fish and Wildlife, and U.S. Fish

and Wildlife Service, 1995.

45. Copeland, J.R. and Noble, R.L., “Movements by Young-of-Year and Yearling

Largemouth Bass and Their Implications for

Supplemental Stocking,” North American

Journal of Fisheries Management 14:119–

24, 1994.

46. Cramer, S.P. and Associates, Inc., “Evaluation of Sound and Electrical Fish Guidance

Systems at Wilkins Slough Diversion Operated by Reclamation District 108,” March

1994.

47. Dawley, E.M. and Ebel, W.J., “Effects of

Various Concentrations of Dissolved Atmospheric Gas on Juvenile Chinook Salmon

and Steelhead Trout,” Fisheries Bulletin

73(4):787–796, 1975.

48. Dewey, M.R., and Moen, T.E., “Entrainment

of Larval Fish from DeGray Lake, Arkansas,

During Epilimnial and Hypolimnial Discharges,” Proceedings of the DeGray Lake

Symposium, Technical Report E-87-4, R.H.

Kennedy and J. Nix (eds.) U.S. Army Corps

of Engineers, Waterways Experiment Station (Vicksburg, MS: 1987).

49. DeWitt, T., Office of Hydropower Licensing, Federal Energy Regulatory Commission, personal communication, August 1995.

50. Dolat, S., Vice President, Acoustic Systems,

Sonalysts, Inc., personal communication,

October 1994.

51. DuBois, R.B., and Gloss, S.P., “Mortality of

Juvenile American Shad and Striped Bass

Passed Through Ossberger Crossflow Turbines at a Small-scale Hydroelectric Site,”

North American Journal of Fisheries Management 13:178–85,1993.

51a. Dunning, et al., “Alewives avoid high-frequency sound,” North American Journal of

Fisheries Management 12:407–16, 1992.
156 | Fish Passage Technologies: Protection at Hydropower Facilities

52. Ebel, W.J., et al., “Effect of Atmospheric

Gas Supersaturation Caused by Dams on

Salmon and Steelhead Trout of the Snake

and Columbia Rivers,” National Oceanic

and Atmospheric Administration, National

Marine Fisheries Service, Northwest Fisheries Center report, 1975.

53. Eicher, G., President, Eicher Associates,

personal communication, April 1995.

54. Eicher, G., President, Eicher Associates,

personal communication, January 1995.

55. Eicher, G.C., “Turbine Related Fish Mortality,” Proceedings of the Workshop on Fish

Passage at Hydroelectric Developments,

D.A. Williams, et al., (eds.) (St. John’s,

Newfoundland: 1993).

56. Eicher, G.J., “Fish Passage,” A Century of

Fisheries in North America, N.G. Benson

(ed.) Special Publication 7 (Bethesda, MD:

American Fisheries Society, 1970).

57. Electric Power Research Institute (EPRI),

“Fish Protection/Passage Technologies

Evaluated by EPRI and Guidelines for Their

Application,” prepared by Stone and Webster Enginering Corporation, Boston, MA,

EPRI TR-104120, Project 2694-01, Final

Report, May 1994.

58. Electric Power Research Institute (EPRI),

“Biological Evaluation of a Modular

Inclined Screen for Protecting Fish at Water

Intakes,” prepared by Stone and Webster

Enginering Corporation, Boston, MA, EPRI

TR-104121, Project 2694-01, Final Report,

May 1994.

59. Electric Power Research Institute (EPRI),

“Research Update on Fish Protection Technologies for Water Intakes,” prepared by

Stone and Webster Enginering Corporation,

Boston, MA, EPRI TR-104122, Project

2694-01, Final Report, May 1994.

60. Electric Power Research Institute (EPRI),

“Guidelines for Applying Fish Protection/

Passage Technologies at Hydroelectric

Projects and Other Water Intakes,” Final

Report, May 1994.

61. Electric Power Research Institute (EPRI),

“Evaluation of Strobe Lights for Fish Diversion at the York Haven Hydroelectric

Project,” prepared by Stone & Webster

Environmental Services, Boston, MA, EPRI

TR-101703, Project 2694-01, Final Report,

November 1992.

62. Electric Power Research Institute (EPRI),

“Fish Entrainment and Turbine Mortality

Review and Guidelines,” prepared by Stone

& Webster Environmental Services, Boston,

MA, EPRI TR-101231, Project 2694-01,

Final Report, September 1992.

63. Electric Power Research Institute (EPRI),

“Fish Protection Systems for Hydro Plants,

Test Results,” prepared by Stone & Webster

Environmental Services, Boston, MA, EPRI

GS-6712, Project 2694-1, Interim Report,

February 1990.

64. Electric Power Research Institute (EPRI),

“Turbine Related Fish Mortality: Review

and Evaluation of Studies,” Prepared by

Eicher Associates, Portland, OR, EPRI AP5480, 1987.

65. Electric Power Research Institute (EPRI),

“Assessment of Downstream Migrant Fish

Protection Technologies for Hydroelectric

Application,” EPRI AP-4711, Project 2694-

1 Final Report, Prepared by Stone and Webster Engineering Corporation, Boston, MA,

EPRI AP-4711, Project 2694-1, Final

Report, September 1986.

65a.Empire State Electric Energy Research

Corp. (ESEERCO), “Responses of white

perch, striped bass, alewives, spottail shiners, golden shiners, and Atlantic tomcod in a

cage to high and low frequency underwater

sounds generated by an electronic fish startle

system,” Project EP89-30, ESEERCO, 1991.

66. Estes, C., Instream Flow Coordinator,

Alaska Department of Fish and Game, personal communication, August 1995.

67. Estes, C., “Annual Summary of Alaska

Department of Fish and Game Instream

Flow Reservation Applications,” Alaska

Department of Fish and Game, Fishery Data

Series No. 94-37, Anchorage, AK, 1994

68. Estes, C., “Annual Summary of Alaska

Department of Fish and Game Instream
References | 157

Flow Reservation Applications,” Alaska

Department of Fish and Game, Fishery Data

Series No. 92-45, Anchorage, AK, 1992.

69. Fay, R.R., Hearing in Vertebrates: A Psychophysics Data Book (Winnetka, IL: HillFaly Assoc., 1988).

70. Federal Emergency Management Agency

(FEMA), “Water Control and Infrastructure,

National Inventory of Dams,” FEMA, Dam

Safety Office (Washington, DC: 1994).

71. Federal Energy Regulatory Commission

(FERC), “Preliminary Assessment of Fish

Entrainment at Hydropower Projects. A

report on Studies and Protective Measures.”

DPR-10, Office of Hydropower Licensing

(Washington, DC: 1995).

72. Federal Energy Regulatory Commission

(FERC), “Hydropower Licensing and

Endangered Species, Procedures for Complying with the Endangered Species Act,”

DRP-7, FERC, Office of Hydropower

Licensing (Washington, DC: February

1993).

73. Federal Energy Regulatory Commission

(FERC), “Manual of Standard Special Articles,” DPR-4, FERC, Office of Hydropower

Licensing (Washington, DC: April 1992).

74. Federal Energy Regulatory Commission

(FERC), Hydroelectric Project Relicensing

Handbook, FERC, Office of Hydropower

Licensing (Washington, DC: April 1990).

75. Federal Energy Regulatory Commission

(FERC), “Evaluating the Economics of

Hydroelectric Projects at the Federal Energy

Regulatory Commission,” Paper No. DPR-1,

FERC, Office of Hydropower Licensing

(Washington, DC: September 1989).

76. Feist, B.E., and Anderson, J.J., “Review of

Fish Behavior Relevant to Fish Guidance

Systems,” Fisheries Research Unit, University of Washington, Report FRI-UW-9102

(Seattle, WA: 1991).

77. Ferguson, J., U.S. Army Corps of Engineers,

personal communication, April 1995.

78. Ferguson, J. “Relative Survival of Juvenile

Chinook Salmon (Oncorhynchus tshawytscha) Through a Bonneville Dam on the

Columbia River,” Proceedings of the Workshop on Fish Passage at Hydroelectric

Developments, U.P. Williams, et al., (eds.)

(St. John’s, Newfoundland: Canadian Technical Report on Fish and Aquatic Sciences,

1993).

79. Francfort, J.F., Senior Engineer/Economist,

Idaho National Engineering Laboratory, personal communication, August, 1995.

80. Francfort, J.F., Senior Engineer/Economist,

Idaho National Engineering Laboratory, personal communication, June 1995.

81. Francfort, J.F., Idaho National Engineering

Laboratory, “Synthesis of: U.S. Department

of Energy, Environmental Mitigation at

Hydroelectric Projects, Volume II. Benefits

and Costs of Fish Passage and Protection,

Idaho Field Office, DOE/ID-10360(V2),

January 1994,” paper prepared for the Office

of Technology Assessment study of Fish

Passage Technologies: Protection at Hydropower Facilities, June 1995.

82. Francfort, J., and B. Rinehart, “Protecting

Fish,” Independent Energy, October 1994,

pp. 72–76.

83. Funderburk, S.L., et al. (eds.), Habitat

Requirements For Chesapeake Bay Living

Resources (Annapolis, MD: Chesapeake Bay

Program, 1991).

84. Funk, J.L., “Movement of Stream Fishes in

Missouri,” Transactions of the American

Fisheries Society, 85: 39–57, 1955.

85. Gephard, S., Connecticut Department of

Environmental Protection, personal communication, June 1994.

86. Gerking, S.D., “The Restricted Movement of

Fish Populations,” Biological Review

34:221–42, 1959.

87. Gloss, S., Wahl, J., and Dubois, R., “Potential effects of Ossberger turbines on Atlantic

Salmon Smolts, Striped Bass, and American

Shad,” Potential Effects of Kaplan, Ossberger, and Bulb Turbines on the Anadromous Fishes of the Northeast United States,

W.E. Knapp, B. Kynard, and S.P. Gloss

(eds.) FWS/OBS-82/62 (Newton Corner,

MA: U.S. Fish and Wildlife Service, 1982).
158 | Fish Passage Technologies: Protection at Hydropower Facilities

88. Goodyear, C.P., “Assessing the Impact of

Power Plant Mortality on the Compensatory

Reserve of Fish Populations with Demersal

Eggs,” Assessing the Effects of Power-Plant

Induced Mortality on Fish Populations, J.H.

Blaxter (ed.) (New York, NY: Pergamon

Press, 1977).

89. Gowan, C., M.K.Young, K.D. Fausch, and

S.C. Riley, “Restricted Movement in Resident Stream Salmonids: A Paradigm Lost?”

Canadian Journal of Fisheries and Aquatic

Sciences 51:2626–37, 1994.

90. Guilfoos, S., “Six Years of Monitoring the

Effectiveness of a Barrier Net at the Ludington Pumped Storage Plant on Lake Michigan,” Waterpower ‘95, Proceedings of the

International Conference on Hydropower,

J.J. Cassidy (ed.) (San Francisco, CA: American Society of Civil Engineers, 1995).

91. Grimm, L.T., “Fishery Protection and FERC

Hydropower Relicensing Under ECPA:

Maintaining A Deadly Status Quo,” Environmental Law, Vol. 20, No. 4, 1990, pp.

929–974.

92. Hadderingh, R.H., Koops, F.B.J., and van

der Stoep, J.W., “Research on Fish Protection at Dutch Thermal and Hydropower Stations,” Kema Scientific and Technical

Reports 6:57–68, 1988.

93. Hall, J.W., T.I.J. Smith, and S.D. Lamprecht, “Movements and Habitats of Shortnose

Sturgeon, Acipenser brevirostrum, in the

Savannah River,” Copeia 991(3):695–702,

1991.

94. Hanson, B., RMC Environmental Services,

Inc., personal communication, May 1995.

94a. Hanson Environmental Inc., “Demonstration Projects To Evaluate The Effectiveness

Of An Acoustic (Underwater Sound) Behavioral Barrier In Guiding Chinook Salmon At

Georgiana Slough,” Results of 1993 Phase I

Field Tests, December 1993.

95. Harcup, M.F., R. Williams, and D.M. Ellis,

“Movements of Brown Trout, Salmo trutta

L., in the River Gwyddon, South Wales,”

Journal of Fish Biology 24:415–26, 1984.

96. Harkness, W.J.K., and J.R. Dymond, “The

Lake Sturgeon,” Ontario Department of

Lands and Forests, Toronto, Ontario, Canada, 1961, 121p.

97. Harle, M.L., and C.C. Estes, “Alaska’s

Instream Flow Program,” Instream Flow

Chronicle Colorado State University, Ft.

Collins, CO, 4(1):1–2, 1987.

98. Hasler, A.D., and A.T. Scholz, Olfactory

Imprinting and Homing in Salmon (Berlin:

Springer–Verlag, 1983).

99. Hawkins, A.D., and A.D.F. Johnstone, “The

Hearing of the Atlantic Salmon, Salmo

salar,” Journal of Fisheries Biology 13:655–

673, 1978.

100.Hayes, D., California Department of Water

Resources, personal communication, August

1995.

101.Haymes, G.T., Patrick, P.H., and Onisto,

L.J., “Attraction of Fish to Mercury Vapour

Light and its Application in a Generating

Station Forebay,” International Review of

Hydrobiology 69:867–876, 1984.

102.Heggenes, J., Northcote, T.G., and Peter, A.,

“Spatial Stability of Cutthroat Trout, Oncorhynchus clarkii, in a Small Coastal

Stream,” Canadian Journal of Fisheries and

Aquatic Sciences 48:757–62, 1991.

103.Heisey, P.G., D. Mathur, and T. Rineer, “A

Reliable Tag-Recapture Technique for Estimating Turbine Passage Survival: Application of Young-of-the-Year American Shad

(Alosa sapidissima),” Canadian Journal of

Fisheries and Aquatic Sciences 49:1826–

34, 1992.

104.Hesthagen, T.,"Movements of Brown Trout,

Salmo trutta, and Juvenile Atlantic Salmon,

Salmo salar, in a Coastal Stream in Northern

Norway,” Journal of Fish Biology 32: 639–

53, 1988.

105.Hildebrand, S.G., (ed.) “Analysis of Environmental Issues Related to Small Scale

Hydroelectric Development, II: Design Considerations for Passage Fish Upstream

Around Dams,” Oak Ridge National Laboratory, Environmental Sciences Division, Pub-
References | 159

lication No.1567, ORNL/TM-7396, August

1980.

106.Hilgert, P.H., “Evaluation of a Graduated

Electric Field as a Fish Exclusion Device,”

Beak Consultants Inc., a Report prepared for

Puget Sound Power and Light Co., Bellevue,

WA, 1992.

107.Hocutt, C.H., “Behavioral Barriers and

Guidance Systems,” Power Plants: Effects

on Fish and Shellfish Behavior, C.H. Hocutt,

J.R. Stauffer, J. Edinger, L. Hall and R. Morgan, (eds.) (New York, NY: Academic

Press, 1980) pp. 183–205.

108.Holden, P.B., “Ecology of Riverine Fishes in

Regulated Stream Systems with Emphasis

on the Colorado River,” The Ecology of Regulated Streams, J.V. Ward and J.A. Stanford,

(eds.) (New York, NY: Plenum Press, 1979).

109.Holliday, M. C. and B. K. O’Bannon, Fisheries of the United States, 1992, Current

Fishery Statistics No.9200 (Washington,

DC: U.S. Department of Commerce, NOAA,

NMFS, 1993).

110.Houston, J.J., “Status of the Lake Sturgeon,

Acipenser fulvescens, in Canada,” Canadian

Field-Naturalist 101(2):1171–185, 1987.

111.Humbles, G., “Evaluation of Smith-Root

Type Electric Fish Barrier,” Memorandum

to the Yakima Project, Yakima, WA, Jan.

28, 1993.

112.Hunt, R., and J.M. Hunt, “Reinventing the

Process,” Independent Energy, November

1994, pp. 75–77.

113."Hydro Industry: Change Clean Water Act

to Restore FERC Power,” Hydrowire

16(5):4–5, March 13, 1995.

114.Hydrowire, “Bailey: Congress Might Have

to Restore FERC Oversight Power,”

16(3):3–4, February 13, 1995.

115.Hydrowire, “BuRec Draft Environmental

Statement Calls for Dam Removal,”

16(1):1–2, January 17, 1995.

116.Jensen, A.L., “Estimation of Recruitment

Foregone Resulting from Larval Fish

Entrainment,” Journal of Great Lakes

Research 16:241–44, 1990.

117.Jensen, J.O.T., J. Schute, and D.F. Alderdice, “Assessing Juvenile Salmonid

Response to Gas Supersaturation Using a

General Multivariate Dose-response

Model,” Canadian Journal of Fisheries and

Aquatic Sciences 43:1694–1709, 1986.

118.Johnson, J. E., Protected Fishes of The

United States and Canada (Bethesda, MD:

American Fisheries Society, 1987).

119.Johnston, S.V., B.H. Ransom, and J.R. Bohr,

“Comparison of Hydroacoustic and Net

Catch Estimates of Fish Entrainment at

Tower and Kleber Dams, Black River,

Michigan,” Waterpower ‘95, Proceedings of

the International Conference on Hydropower, J.J. Cassidy (ed.) (San Francisco,

CA: American Society of Civil Engineers,

1995).

120.Katopodis, C., Engineer, Freshwater Institute, personal communication, December

1994.

121.Katopodis, C., “Introduction to Fishway

Design,” working document, Freshwater

Institute, Department of Fisheries and

Oceans, Winnipeg, Manitoba, Canada, 1992.

122.Kempinger, J.J., “Spawning and Early Life

History of Lake Sturgeon in the Lake Winnebago System, Wisconsin,” American Fisheries Society Symposium 5:110–122, 1988.

123.Kerwin, C.M., “Transforming Regulation: A

Case Study of Hydropower Licensing,” Public Administration Review 50(1):91–100,

January 1990.

124.Khoroshko, P.N., “The Amount of Water in

the Volga Basin and its Effect on the Reproduction of Sturgeons (Acipenseridae) Under

Conditions of Normal and Regulated Discharge,” Journal of Ichthyology 12:608–616,

1972.

125.Kieffer, M., and B. Kynard, “Annual Movements of Shortnose and Atlantic Sturgeons

in the Merrimack River, Massachusetts,”

Transactions of the American Fisheries

Society 122:1088–103, 1993.

126.Knudsen, F.R., P.S. Enger, and O. Sand,

“Avoidance Responses to Low Frequency

Sound in Downstream Migrating Atlantic
160 | Fish Passage Technologies: Protection at Hydropower Facilities

Salmon Smolt, Salmo salar,” Journal of

Fish Biology 45:227–33, 1994.

128.Knudsen, F.R., P.S. Enger, and O. Sand,

Awareness Reactions and Avoidance

Responses to Sound in Juvenile Atlantic

Salmon, salmo salar, L.,” Journal of Fish

Biology 40:523–534, 1992

129.Kramer, R.H., and L.L. Smith Jr., “Formation of Year Classes in Largemouth Bass,”

Transactions of the American Fisheries

Society 91:29–41, 1962.

130.Kudera, E.A., C.M. Sullivan, and G.E.

Johnson, “Evaluation of the Smolt Bypass

System at Wells Dam in 1990,” Report for

Douglas Co. PUD, East Wenatchee, WA,

1991.

131.Kuznetsov, Y.A., “The Behavior of Fish in

the Zone Affected by a Curtain of Air Bubbles,” Fish Behavior and Fishing Techniques, A.P. Alekeseeu (ed.) NTIS 71-50010

(Washington, DC: National Marine Fisheries Service, NOAA, 1971).

132.Kynard, B., Behavior/Ecology Section

Leader, National Biological Service, personal communication, June 1994.

133.Kynard, B., “Fish Behavior Important for

Fish Passage,” Fisheries Bioengineering

Symposium (Portland, OR: American Fisheries Society, September 1993).

134.Kynard, B., and J. O’Leary, “Evaluation of a

Bypass System for Spent American Shad at

Holyoke Dam, Massachusetts North American Journal of Fisheries Management,

13:782–789, 1993.

135.Kynard, B., et al., “Potential effects of

Kaplan Turbines on Atlantic Salmon Smolts,

American Shad and Blueback Herring,”

Potential Effects of Kaplan, Ossberger, and

Bulb Turbines on the Anadromous Fishes of

the Northeast United States, W.E. Knapp, B.

Kynard, and S.P. Gloss (eds.) FWS/OBS-82/

62. (Newton Corner, MA: U.S. Fish and

Wildlife Service, 1982).

136.Lagassa, G.K., “When FERC and States

Collide,” Independent Energy, October

1994, pp. 67–70.

137.Langhurst, R.W., and D.L. Schoenike, “Seasonal Migration of Smallmouth Bass in the

Embarrass and Wolf Rivers, Wisconsin,”

North American Journal of Fisheries Management 10:224–27, 1990.

138.Le Cren, E.D., “The Efficiency of Reproduction and Recruitment in Freshwater Fish,”

The Exploitation of Natural Animal Populations, E.D. Le Cren and M.W. Holdgate

(eds.) (New York, NY: Wiley, 1962) pp.

283–296.

139.Lewis, W.M., and S. Flickinger, “Home

Range Tendency of the Largemouth Bass,

Micropterus salmoides,” Ecology 48:1020–

23, 1967.

140.Li, H.W., et al., “Factors Influencing

Changes in Fish Assemblages of Pacific

Northwest Streams,” Community and Evolutionary Ecology of North American Stream

Fishes, W.J. Matthews and D.C. Heins (eds.)

(Norman, OK: University of Oklahoma

Press, 1987).

141.Loeffelman, P.H., J.H. Van Hassell, and

D.A. Klinect, “Using Sound to Divert Fish

From Turbine Intakes,” Hydro Review October 1991.

142.Lythgoe, J.N., “Light and Vision in the

Aquatic Environment,” in J.Atema, R.R.Fay,

A.N.Popper, and W.N. Tavolga, Sensory

Biology of Aquatic Animals (New York, NY:

Springer–Verlag, 1988).

143.Marcy, B.C., Jr., “Fishes of the Lower Connecticut River and the Effects of the Connecticut Yankee Plant,” The Connecticut

River Ecological Study. The Impact of a

Nuclear Power Plant. American Fisheries

Society, Monograph Number One, D. Merriman and L.M. Thorpe (eds.) (Lawrence, KS:

Allen Press, Inc, 1976).

144.Mathur, D., P.G. Heisey, and D.A. Robinson, “Turbine-passage Mortality of Juvenile

American Shad at a Low-head Hydroelectric

Dam,” Transactions of the American Fisheries Society 123:108–11, 1994.

145.Mattice, J., “Ecological Effects of Hydropower Facilities,” Hydropower Engineering

Handbook, Gulliver, J. and R.E.A. Arndt
References | 161

(eds.) (New York, NY: McGraw–Hill, Inc.,

1991).

146.Mattice, J., Senior Project Manager, Electric

Power Research Institute, personal communication, August 1995.

147.McAda, C.W., and L.R. Kaeding, “Movements of Adult Colorado Squawfish During

the Spawning Season in the Upper Colorado

River,” Transactions of the American Fisheries Society 120:339–45, 1991.

148.McBride, N., “Smallmouth Bass Population

Assessment in Three Lower Mohawk River

Lock Pools,” Watershed file No. 625, New

York Department of Environmental Conservation, Region 4 Fisheries Office (Stamford,

New York: 1993).

149.McDowall, R.M., “Evolution and Importance of Diadromy. The Occurrence and

Distribution of Diadromy among Fishes,”

American Fisheries Society Symposium 1:1–

13, 1987.

150.Mead, E., Biologist, U.S. Fish and Wildlife

Service, personal communication, August

1995.

151.Mesing, C.L., A.M.Wicker, “Home Range,

Spawning Migrations, and Homing of

Radio-tagged Florida Largemouth Bass in

Two Central Florida Lakes,” Transactions of

the American Fisheries Society 115:286–95,

1986.

152.Metropolitan Edison Company, “1993 Evaluation of Behavioral Fish Protection Technologies at the York Haven Hydroelectric

Project,” Final Report, prepared by Stone

and Webster Environmental Technology &

Services, Boston, MA, February 1994.

153.Mills, D., Ecology and Management of

Atlantic Salmon (London: Chapman and

Hall, 1989).

154.Mills, D. (ed.) Salmon In The Sea and New

Enhancement Strategies (Cambridge, MA:

Blackwell Scientific Publications, Inc., Fishing News Books, 1993).

155.Moffitt, C.M., B. Kynard, and S.G. Rideout,

“Fish Passage Facilities and Anadromous

Fish Restoration in the Connecticut River

Basin,” Fisheries, 7(6):2–11, 1982.

156.Moore, H.L., and H.W. Newman, “Effects

of Sound Waves on Young Salmon,” Special

Scientific Report on Fisheries No.172, U.S.

Fish and Wildlife Service, Washington, DC,

1956.

157.Moyle, P.B., “The Decline of Anadromous

Fishes in California,” Conservation Biology

8:869–70, 1994.

158.Moyle, P.B., and J.J. Cech, Jr., Fishes: An

Introduction to Ichthyology (Englewood

Cliffs, NJ: Prentice-Hall, Inc., 1982).

159.Myrberg, A.A. Jr., “Sound Communication

and Interception in Fishes,” Hearing and

Sound Communication in Fishes, W.N.

Tavolga, A.N. Popper and R.R. Fay (eds.)

(New York, NY: Springer, 1981).

160.Naslund, I., et al., “Importance in Habitat

Productivity Differences, Competition, and

Predation for the Migratory Behavior of

Arctic Charr,” OIKOS 66:538–46, 1993.

161.Naslund, I., “The Development of Regular

Seasonal Habitat Shifts in a Landlocked

Arctic Charr, Salvelinus alpinus L., Population,” Journal of Fish Biology 36:401–14,

1990.

162.Nehlsen, W., J.E. Williams, and J.A.

Lichatowich, “Pacific Salmon at the Crossroads: Stocks at Risk from California, Oregon, Idaho, and Washington,” Fisheries

16(2):4–21, 1991.

163.Nemeth, R.S., J.J. Anderson, “Responsing of

Juvenile Coho and Chinook Salmon to

Strobe and Mercury Vapor Lights,” North

American Journal of Fisheries Management,

12:684–92, 1992.

164.Nestler, J., and R. Davidson, “Imaging

Smolt Behavior on an Extended-Length

Submerged Bar Screen and an ExtendedLength Submerged Traveling Screen at the

Dalles Dam in 1993,” Technical Report EL95-13 (Vicksburg, MS: U.S. Army Engineer

Waterways Experiment Station, 1995).

165.Nestler, J., et al., “Developing Acoustic

Technologies for Improving Fish Passage

and Protection in the Columbia River Basin:

Program Evaluation,” Technical Report EL95-8 (Vicksburg, MS: U.S. Army Engineer
162 | Fish Passage Technologies: Protection at Hydropower Facilities

Waterways Experiment Station, February

1995).

166.Netboy, A., The Atlantic Salmon, a Vanishing Species? (Boston, MA: Houghton Mifflin, 1968).

167.Nettles, D.C., and Gloss, S.P., Migration of

Landlocked Atlantic Salmon Smolts and

Effectiveness of a Fish Bypass Structure at a

Small-Scale Hydroelectric Facility, North

American Journal of Fisheries Management,

7:562–68, 1987.

168.Nordlund, B., “Fish Screening and Guidance

at Water Diversions,” presentation at Fish

Passageways and Diversion Structures, U.S.

Fish and Wildlife Service, November 28–

December 2, 1994, Richland, WA.

169.Northcote, T.G., “Migratory Strategies and

Production in Freshwater Fishes,” Ecology

of Freshwater Fish Production, S.D. Gerking (ed.) (New York, NY: Halsted Press,

1978).

170.Novakovic, P., CEO, Energy Electric Services Corporation, personal communication,

August 1995.

171.Odenweller, D., California Department of

Fish and Game, personal communication,

June 1995.

172.Patrick, P.H., A.E. Christie, D. Sager, C.

Hocutt, and J. Stauffer, Jr., “Responses of

Fish to a Strobe Light/air-bubble Barrier,”

Fisheries Research 3:157–172, 1985.

173.Payne, D.A., “Biology and Population

Dynamics of Lake Sturgeon (Acipenser fulvescens) from the Frederick House, Abitibi,

and Mattagami Rivers, Ontario,” Proceedings of a Workshop on the Lake Sturgeon

(Acipenser fulvescens), C.H. Olver (ed.)

Ontario Fisheries Technical Report No.23,

1987.

174.Pearce, R., National Marine Fisheries Service, personal communication, January

1995.

175.Pearce, R., “Design Considerations for Fish

Protection at Water Diversions,” Portland,

OR, National Marine Fisheries Service,

unpublished data, November,1993.

176.Peters, R., U.S. Army Corps of Engineers,

personal communication, August 1995.

177.Pierson,W., Susquehanna Electric Company,

personal communication, May 1995.

178.Ploskey, G., et al., “Evaluation of an Integrated Fish-Protection System,” American

Society of Civil Engineers, in press.

179.Popper, A.N., Professor, University of

Maryland, personal communication, January

1995.

180.Popper, A.N., “Fish Sensory Responses:

Prospects for Developing Behavioral Guidance Technologies,” unpublished contractor

report prepared for the Office of Technology

Assessment, U.S. Congress, Washington,

DC, June 1995.

181.Popper, A.N., and R.R. Fay, “Sound Detection and Processing by Fish: Critical Review

and Major Research Questions,” Behavioral

Evolution 41:14–38, 1993.

182.Popper, A.N., C.Platt, and P. Edds, “Evolution of the Vertebrate Inner Ear: An Overview of Ideas,” Evolutionary Biology of

Hearing, D.B. Webster, R.R. Fay and A.N.

Popper (eds.) (New York, NY: Springer–

Verlag, 1992) pp. 49–57.

183.Porcher, J.P., “Fishways for Eels,” French

Journal of Fishing and Fish Breeding, E.

Vigneux (ed.) 3d-4th quarters:125–

133,1992.

184.Prince, E.D., and L. Mengel, “Entrainment

of Ichthyoplankton at Jocassee Pumped

Storage Station,” U.S. Fish and Wildlife Service FWS/OBS-80/ 28:26–39, 1980.

185.Quinn, D., Hydraulic Engineer, U.S. Fish

and Wildlife Service, Newton Corner, MA,

personal communication, February 1995.

186.Quinn, D., Hydraulic Engineer, U.S. Fish

and Wildlife Service, Newton Corner, MA,

personal communication, November 1994.

187.Rainey, W.S., Environmental and Technical

Services Division, National Marine Fisheries Service, Portland, OR, personal communication, August 1995.

188.Rainey, W.S., Environmental and Technical

Services Division, National Marine Fisher-
References | 163

ies Service, Portland, OR, personal communication, December 1994.

189.Rainey, W.S., Environmental and Technical

Services Division, National Marine Fisheries Service, Portland, OR, personal communication, October 1994.

190.Rainey, W.S., “Considerations in the Design

of Juvenile Bypass Systems,” paper presented at the Symposium on Small Hydropower and Fisheries, Denver, CO, May 1–3,

1985.

191.Ransom, B.H., and T.W. Steig, “Comparison of the Effectiveness of Surface Flow and

Deep Spill for Bypassing Pacific Salmon

Smolts, Oncorhynchus spp. at Columbia

River Basin Hydropower Dams,” Waterpower ‘95, Proceedings of the International

Conference on Hydropower, J.J. Cassidy

(ed.) (San Francisco, CA: American Society

of Civil Engineers, 1995).

192.Ransom, B.H., T.W. Steig, and P.A. Nealson, “Comparison of Hydroacoustic and Net

Catch Estimates of Pacific Salmon Smolt,

Oncohynchus spp., passage at Hydropower

Dams in the Columbia River Basin,” International Symposium on Fisheries and Plankton Acoustics MS No. 54 (Portland, OR:

International Civil Engineering Society,

1995).

193.Raymond, H.L., “Effects of Dams and

Impoundments on Migrations of Juvenile

Chinook Salmon and Steelhead from the

Snake River, 1966 to 1975,” Transactions of

the American Fisheries Society 108:505–29,

1979.

194.Rizzo, B., Engineering Field Office, U.S.

Fish and Wildlife Service, Newton Corner,

MA, personal communication, May 1995.

195.Rizzo, B., Engineering Field Office, U.S.

Fish and Wildlife Service, Newton Corner,

MA, personal communication, April 1995.

196.Rizzo, B., Engineering Field Office, U.S.

Fish and Wildlife Service, Newton Corner,

MA, personal communication, February

1995.

197.Rizzo, B., Engineering Field Office, U.S.

Fish and Wildlife Service, Newton Corner,

MA, personal communication, November

1994.

198.Rizzo, B., Bypass Efficiency Studies at

Hydroprojects with Angled Bar Racks in

Region 5, National Biological Service Memorandum to Alex Hoar, December 2, 1994.

199.Rochester, H., Jr., T. Lloyd, and M. Farr,

“Physical Impacts of Small-Scale Hydroelectric Facilities and Their Effects on Fish

and Wildlife,” FWS/OBS; 84/19WR 196,

U.S. Fish Wildlife Service Biological Service Program,1984, 119p.

200.Rogers, D.E., Estimates of Annual Salmon

Runs from the North Pacific, 1951–1994,

(Seattle, WA: Fisheries Research Institute,

University of Washington, 1995).

201.Rogers, P.H., and M. Cox, “Underwater

Sound as a Biological Stimulus,” Sensory

Biology of Aquatic Animals, J. Atema, et al.,

(eds.) (New York, NY: Springer, 1988).

201a.Ross, Q.E., et al., “Responses Of Alewives

to High-Frequency Sound at a Power Plant

on Lake Ontario,” North American Journal

of Fisheries Management, 13:291–303,

1993.

202b.Ross, Q.E., et al., “Reducing Impingement

of Alewives with High-Frequency Sound at

a Power Plant Intake on Lake Ontario,”

North American Journal of Fisheries Management, 1995.

202.Ruggles, C.P., “Effect of Stress on Turbine

Fish Passage Mortality Estimates,” Proceedings of the Workshop on Fish Passage at

Hydroelectric Developments, U.P. Williams,

et al., (eds.) (St. John’s, Newfoundland:

Canadian Technical Report on Fish and

Aquatic Sciences, 1993).

203.Ruggles, C.P., “Effect of Stress on Turbine

Fish Passage Mortality Estimates,” Canadian Technical Report on Fish and Aquatic

Sciences, 1992.

204.Ruggles, C.P., “A Critical Review of Fish

Exclusion and Diversion from Hydroelectric

Turbine Intakes, with Special Reference to

the Turner’s Falls Project on the Connecticut

River,” Report to the Northeast Utilities Service Company, Hartford, CT, January 1991.
164 | Fish Passage Technologies: Protection at Hydropower Facilities

205.Ruggles, C.P., “A Review of the Downstream Migration of Atlantic Salmon,”

Canadian Technical Report on Fish and

Aquatic Sciences 952:39, 1980.

206.Ruggles, C.P., T.H. Palmeter, and K.D.

Stokesbury, “A Critical Examination of Turbine Passage Fish Mortality Estimates,”

Monenco Maritimes limited Canadian Electrical Association, Project No. 801 G. 658,

1989.

207.Schellart, N.A.M., and A.N. Popper, “Functional Aspects of the Evolution of the Auditory System of Actinopterydian Fish,”

Comparative Evolutionary Biology of Hearing, D.B. Webster, R.R. Fay, and A.N. Popper (eds.) (New York, NY: Springer, 1992).

208.Scott, W.B., and E.J. Crossman, “Freshwater

Fishes of Canada,” Fisheries (Bethesda,

MD: American Fisheries Society, 1973).

209.Smith, D.V., President, Smith-Root, Inc.,

personal communication, April 1995.

210.Smith, G.J.C., “Innovative Technologies for

Fish Passage: Aspects of Development and

Implementation,” unpublished contractor

report prepared for the Office of Technology

Assessment, U.S. Congress, Washington,

DC, May 1995.

211.Smith, H., Development of Fish Passage

Technologies at Puntledge (Portland, OR:

American Fisheries Society, 1993).

212.Smith, M.W., and J.W. Saunders, “The

American Eel in Certain Fresh Waters of the

Maritime Provinces of Canada,” Journal of

The Fisheries Research Board of Canada

12:238–69, 1955.

213.Smith, J., Field Supervisor, U.S. Fish and

Wildlife Service, Green Bay, WI, personal

communication, August 1995.

214.Snyder, D.E., “Passage of Fish Eggs and

Young Through a Pumped Storage Generating Station,” Journal of The Fisheries

Research Board Of Canada 32:1259–66,

1975.

215.Soast, A., and H. King, “Dam Owners Have

to Coddle Fish,” ENR July 19:22–25, 1993.

216.Solomon, D.J., and R.G. Templeton, “Movements of Brown Trout, Salmo trutta L., in a

Chalk Stream,” Journal of Fish Biology

9:411–23, 1976.

216a. State of Washington, Department of Fisheries and Wildlife, Screening Requirements

for Water Diversions, May 19, 1993.

217.Stober, Q.J., “Underwater Noise Spectra,

Fish Sounds and Response to Low Frequencies of Cutthroat Trout, Salmo clarki, With

Reference to Orientation and Homing in

Yellowstone Lake,” Transactions of the

American Fisheries Society 98:652–63,

1969.

218.Stott, B., “The Movements and Population

Densities of Roach, Rutilus rutilis L., and

Gudgeon, Gobio gobio L., in the River

Mole,” Journal of Animal Ecology 36:407–

23, 1967.

219.Taft, E., Vice President, Program Manager

Environmental Services, Alden Research

Laboratory, personal communication,

August 1995.

220.Taft, E., “Fish Passage at Hydroelectric

Projects,” presented at Hydro’s Leading

Edge Technology Symposium, Phoenix, AZ,

August 1994.

221.Taft, E., “Biological Evaluation of a New

Modular Fish Diversion Screen,” Fish Passage Policy and Technology, Portland, OR,

1993.

222.Taylor, R.E., and B. Kynard, “Mortality of

Juvenile American Shad and Blueback Herring Passed through a Low Head Kaplan

Hydroelectric Turbine,” Transactions of the

American Fisheries Society 114:430–35,

1985.

222a. Toner, M.A. and E.M. Dawley, “Evaluation of the Effects of Dissolved Gas Supersaturation on Fish and Invertebrates

Downstream from Bonneville Dam,” funded

by U.S. Army Corps of Engineers, North

Pacific Division, and Coastal Zone and Estuarine Studies Division Northwest Fisheries

Science Center, January 1995.

223.Truebe, J., “Introduction to Fishways–-Their

Purpose and Methods of Analysis,” Lakeside Engineering, U.S. Fish and Wildlife
References | 165

Service, Fish Passage Training Course, Lecture Notes, April 28, 1992.

224.Turbak, S.C., D.R. Reichle, and C.R. Shriner, “Analysis of Environmental Issues

Related to Small-scale Hydroelectric Development. IV: Fish Mortality Resulting from

Turbine Passage,” ORNL/TM-7521 (Oak

Ridge, TN: Oak Ridge National Laboratory,

1981).

225.Tysus, H.M., “Life Strategies in the Evolution of the Colorado Squawfish, Ptychochelius lucius,” Great Basin Naturalist 46:656–

61, 1986.

226.Tysus, H.M., “Homing Behavior Noted for

Colorado Squawfish,” Copeia 1985:213–

15, 1985.

227.Tysus, H.M., R.L. Jones, and L.A. Trinca,

“Green River Rare and Endangered Fish

Studies, 1982–1985,” Final Report, Colorado River Fishes Monitoring Project, U.S.

Fish and Wildlife Service (Vernal, UT:

1987).

228.Tysus, H.M., and C.W. McAda, “Migration

Movements and Habitat Preferences of Colorado Squawfish, Ptychocheilus lucius, in

the Green, White, and Yampa Rivers, Colorado and Utah,” Southwestern Naturalist

29:289–299, 1984.

229.U.S. Army Corps of Engineers, North

Pacific Division, Fish Passage Center, “Spill

and 1995 Risk Management,” Portland, OR,

unpublished draft, 1995.

230.U.S. Army Corps of Engineers, North

Pacific Division, Salmon Passage Notes,

newsletter, January,1994.

231.U.S. Army Corps of Engineers, North

Pacific Division, Salmon Passage Notes,

newsletter, July,1994.

232.U.S. Army Corps of Engineers, North

Pacific Division, Salmon Passage Notes,

newsletter, November, 1994.

233.U.S. Department of Commerce, National

Marine Fisheries Service and U.S. Department of Interior, Fish and Wildlife Service,

“Notice of Proposed Policy and Procedures

on Hydropower Applications,” Congressional Record 60(98):S27154, May 22,

1995.

234.U.S. Department of Commerce, National

Marine Fisheries Service (NMFS), “Second

Working Group Meeting Panel on Gas Bubble Disease, Report and Recommendations”

(Seattle, WA: NMFS, Northwest Fisheries

Science Center, Seattle, 1995).

235.U.S. Department of Commerce, National

Marine Fisheries Service (NMFS), Coastal

Zone and Estuarine Studies Division, Activities and Organization (Seattle, WA: Northwest Fisheries Science Center, National

Marine Fisheries Service, April 1994).

236.U.S. Department of Commerce, National

Marine Fisheries Service (NMFS), Experimental Fish Guidance Devices, Position

Statement of National Marine Fisheries Service, Southwest Region, Santa Rosa, CA,

January 1994.

236a. U.S. Department of Commerce, National

Marine Fisheries Service (NMFS), Experimental Fish Guidance Devices, Position

Statement of National Marine Fisheries Service, Northwest Region, Portland, OR, January 1995.

237.U.S. Department of Commerce, National

Marine Fisheries Service (NMFS), Fish

Screening Criteria for Anadromous Salmonids, National Marine Fisheries Service,

Southwest Region, (Santa Rosa, CA: April

1992).

238.U.S. Department of Commerce, National

Marine Fisheries Service (NMFS), Fish Passage Facilities Functional Design Guidelines and Supplemental Criteria,

Environmental and Technical Services Division (Portland, OR: Nov. 16, 1990).

239.U.S. Department of Commerce, National

Marine Fisheries Service (NMFS), Fish

Screening Criteria, Environmental and

Technical Services Division (Portland, OR:

August 21, 1989).

240.U.S. Congress, General Accounting Office,

“Electricity Regulation: FERC’s Efforts to

Monitor and Enforce Hydroelectric Require-
166 | Fish Passage Technologies: Protection at Hydropower Facilities

ments,” GAO/RCED-94-162 (Washington,

DC: May 1994).

241.U.S. Congress, General Accounting Office,

“Electricity Regulation: Electric Consumers

Protection Act’s Effects on Licensing

Hydroelectric Dams,” GAO/RCED-92-246

(Washington, DC: September 1992).

242.U.S. Department of Energy, Environmental

Mitigation at Hydroelectric Projects, Volume II. Benefits and Costs of Fish Passage

and Protection, DOE/ID-10360 (Idaho Falls,

ID: U.S. Department of Energy, January

1994).

243.U.S. Department of Energy, Environmental

Mitigation at Hydroelectric Projects, Volume I. Current Practices for Instream Flow

Needs, Dissolved Oxygen, and Fish Passage, DOE/ID-10360 (Idaho Falls, ID: U.S.

Department of Energy, December 1991).

244.U.S. Department of Energy, Bonneville

Power Administration, Division of Fish &

Wildlife, and Pacific Northwest Laboratory,

Velocity Measurements at Six Fish Screening Facilities in the Yakima River Basin,

Annual Report 1988 (Yakima, WA: Bonneville Power Administration, 1989).

245.U.S. Department of Energy, Bonneville

Power Administration, Division of Fish &

Wildlife, and Pacific Northwest Laboratory,

A Fisheries Evaluation of the Richland and

Wapato Canal Fish Screening Facilities,

Spring 1987, Annual Report (Richland, WA:

Bonneville Power Administration, 1988).

246.U.S. Department of Energy, Bonneville

Power Administration, Division of Fish &

Wildlife, and Pacific Northwest Laboratory,

Velocity Measurements at Three Fish

Screening Facilities in the Yakima River

Basin, Annual Report 1989 (Yakima, WA:

Bonneville Power Administration, 1990).

247.U.S. Department of Energy, Bonneville

Power Administration, Division of Fish &

Wildlife, and Pacific Northwest Laboratory,

A Fisheries Evaluation of the Wapato, Sunnyside, and Toppenish Creek Canal Fish

Screening Facilities, Annual Report 1988

(Yakima, WA: Bonneville Power Administration, 1989).

248.U.S. Department of Energy, Bonneville

Power Administration, Division of Fish &

Wildlife, and Pacific Northwest Laboratory,

A Fisheries Evaluation of the Westside Ditch

and Wapato Canal Fish Screening Facilities, Spring 1989, Annual Report (Yakima,

WA: Bonneville Power Administration,

1990).

249.U.S. Department of Energy, Bonneville

Power Administration, Division of Fish &

Wildlife, and Pacific Northwest Laboratory,

A Fisheries Evaluation of the Westside Ditch

and Town Canal Fish Screening Facilities,

Annual Report 1989 (Yakima, WA: Bonneville Power Administration, 1990).

250.U.S. Department of Energy, Bonneville

Power Administration, Division of Fish &

Wildlife, and Pacific Northwest Laboratory,

Evaluation of Juvenile Fish Bypass and

Adult Fish Passage Facilities at Three Mile

Falls Dam, Umatilla River, Annual Progress

Report 1989 (Portland, OR: Bonneville

Power Administration, 1990).

251.U.S. Department of the Interior, U.S. Fish

and Wildlife Service, Transportation of

Juvenile Salmonids from Hydroelectric

Projects in the Columbia River Basin, prepared by Phillip R. Mundy, Fisheries and

Aquatic Sciences (Washington, DC: U.S.

Fish and Wildlife Service, May 1994).

252.U.S. Department of the Interior, U.S. Fish

and Wildlife Service, Restoration of American Shad to the Susquehanna River, Annual

Progress Report, 1993 (Harrisburg, PA:

Susquehanna River Anadromous Fish Restoration Committee, February 1994).

253.U.S. Department of the Interior, Fish and

Wildlife Service, Mitigation Policy; Notice

of Final Policy, Federal Register, Vol. 46,

No. 15, Friday, January 23, 1981, pp. 7644–

63.

254.VanDerwalker, J.G., “Response of Salmonids to Low Frequency Sound,” Marine Bioacoustics II, W.N. Tavolga (ed.) (New York,

NY: Pergamon Press, 1967) pp. 45–54.
References | 167

255.Voltinov, N.P. and V.P. Kasyanov, “The

Ecology and Reproductive Efficiency of the

Siberian Sturgeon, Acipenser baeri, in the

Ob as Affected by Hydraulic Engineering

Works,” Journal of Ichthyology 18:20–29,

1978.

256.Walburg, C.H., “Loss of Young Fish in Reservoir Discharge and Year-Class Survival,

Lewis and Clark Lake,” Missouri River.

American Fisheries Society Special Publication 8: 441–48, 1971.

257.Waste, S., Habitat Policy Coordinator,

National Marine Fisheries Service, Office of

Habitat, personal communication, January

1995.

258.Weber, J.L., and B.L. Les, “Spawning and

Early Life History of Yellow Perch in the

Lake Winnebago System,” Technical Bulletin No. 130, Wisconsin Department of Natural Resources, Madison WI, 1982.

259.Whelan, G., FERC Project Coordinator,

Michigan Department of Natural Resources,

personal communication, August 1995.

260.Wick, E.J., D.L. Stoneburner, and J.A.

Hawkins, “Observations on the Ecology of

Colorado Squawfish, Ptychocheilus lucius,

in the Yampa river, Colorado,” Technical

Report 83-7 (Fort Collins, CO: United States

Park Service, Water Resources Field Support Laboratory, 1983).

261.Willson, M.F., and Halupka, K.C., “Anadromous Fish as Keystone Species in Vertebrate

Communities,” Conservation Biology

9:489–97, 1995.

262.Winchell, R.C., “A New Technology for

Diverting Fish Past Turbines,” Hydro

Review December 1990, pp. 32–42.

263.Winchell, R.C., and Sullivan, C.W., “Evaluation of an Eicher Fish Diversion Screen at

Elwha Dam,” Waterpower ‘91 Proceedings

of the International Conference on Hydropower (Portland, OR: American Society of

Civil Engineering, 1991).

264.Wisconsin Department of Natural

Resources, U.S. Fish and Wildlife Service

and Great Lakes Indian Fish and Wildlife

Commission, Guidelines for Fish Entrainment and Mortality Mitigation at Federal

Energy Regulatory Commission Licensed

Hydropower Projects (Madison, WI: Wisconsin Department of Natural Resources,

1994).