EVALUATION OF MITIGATION EFFECTIVENESS 

AT HYDROPOWER PROJECTS: FISH PASSAGE

Division of Hydropower Administration and Compliance 

Office of Energy Projects 

Federal Energy Regulatory Commission 

September 2004 

iii

CONTENTS 

Page

LIST OF FIGURES ............................................................................................................... v 

LIST OF TABLES................................................................................................................. v 

ACKNOWLEDGMENTS ..................................................................................................... vii 

EXECUTIVE SUMMARY ................................................................................................... ix 

1.0 INTRODUCTION ........................................................................................................... 1 

1.1 BACKGROUND ................................................................................................ 1 

1.1.1 Review of Previous Hydropower Mitigation Studies ........................ 1 

1.1.2 Overview of Licensing Process ......................................................... 3 

1.2 PURPOSE OF STUDY....................................................................................... 3 

1.2.1 Measures of Effectiveness ................................................................. 3 

1.2.1.1 Project-Specific Measures .................................................. 4 

1.2.1.2 River-Basin Goals for Fish Restoration.............................. 6 

1.2.2 Source of Information........................................................................ 7 

2.0 DATA ANALYSIS......................................................................................................... 9 

2.1 SUMMARY OF PROJECTS WITH FISH PASSAGE REQUIREMENTS...... 10 

2.1.1 Background........................................................................................ 10 

2.1.2 Project Characteristics ....................................................................... 10 

2.2 REGIONAL ASSESSMENT OF FISH PASSAGE FACILITIES..................... 13 

2.2.1 Upstream Fish Passage ...................................................................... 14 

2.2.2 Downstream Fish Passage.................................................................. 16 

2.3 EVALUATION OF FISH PASSAGE EFFECTIVENESS ................................ 18 

2.3.1 Upstream Fish Passage ...................................................................... 18 

2.3.1.1 Summary of Results............................................................ 19 

2.3.1.2 Assessment of Effectiveness............................................... 21 

2.3.2 Downstream Fish Passage.................................................................. 25 

2.3.2.1 Summary of Results............................................................ 25 

2.3.2.2 Assessment of Effectiveness............................................... 28 

3.0 SUMMARY AND CONCLUSIONS ............................................................................. 33 

3.1 MITIGATION EFFECTIVENESS..................................................................... 33 

3.1.1 Upstream Fish Passage ...................................................................... 33 

3.1.2 Downstream Fish Passage.................................................................. 34 

3.2 ADEQUACY OF EFFECTIVENESS STUDIES............................................... 34 

3.3 RECOMMENDATIONS TO IMPROVE EFFECTIVENESS........................... 36 

4.0 REFERENCES ............................................................................................................... 39 

5.0 LIST OF PREPARERS................................................................................................... 45 

APPENDIX A. LIST OF PROJECTS .................................................................................. 47 

APPENDIX B. FISH PASSAGE AT HYDROELECTRIC DAMS ON THE 

SUSQUEHANNA RIVER: A CASE STUDY......................................................... 57 

v

LIST OF FIGURES 

Figure Page

 2-1 Geographical distribution of 269 projects (=licenses) with at least one license 

article that addressed fish passage......................................................................... 9 

 2-2 Total number of licenses issued and the licensing years of the 269 hydropower 

projects with at least one article related to fish passage (shaded area) that were 

reviewed in this study............................................................................................ 11 

LIST OF TABLES 

Table Page

 2-1 Number of hydropower developments with fish passage requirements for each 

of five capacity categories included in an earlier DOE mitigation study and the 

present FERC study .............................................................................................. 12 

2-2 Regional summary of 147 developments with fish passage requirements ........... 12 

 2-3 Regional summary of upstream fish passage facilities for 147 hydropower 

developments (i.e., dams) that have fish passage requirements............................ 15 

 2-4 Regional summary of downstream fish passage facilities for 147 hydropower 

developments (i.e., dams) that have fish passage requirements............................ 17 

 2-5 Status of implementation of fish passage requirements at 304 hydropower 

developments categorized by region..................................................................... 19 

 2-6 Results of monitoring upstream fish passage at 8 hydropower developments ..... 20 

 2-7 Numbers of river herring and Atlantic salmon passed at dams on East 

Coast rivers (1983-2001) ...................................................................................... 22 

 2-8 Results of monitoring the effectiveness of downstream fish passage at 

12 hydropower developments ............................................................................... 26 

 A-1 List of projects (by state) that were included in this study because (1) they 

were licensed or relicensed between 1986 and 2002 and (2) they have at least 

one fish passage requirement ................................................................................ 49 

 B-1 Description of four hydroelectric dams on the lower Susquehanna River............ 60 

 B-2 Number of American shad counted and passage effectiveness (%) at four 

hydroelectric dams on the lower Susquehanna River (1997-2003) ...................... 62 

vii

ACKNOWLEDGMENTS 

The draft report was discussed at a workshop held in November 2003 at the Alden 

Research Laboratory in Holden, MA. Written comments were received from Enel North 

America, Inc., the Michigan Department of Natural Resources, the Pennsylvania Fish and Boat 

Commission, Putnam Hydro, Save Our Sebasticook, and the U.S. Fish and Wildlife Service. The 

authors thank those individuals and organizations who attended the workshop and/or submitted 

comments. 

ix

EXECUTIVE SUMMARY 

Hydroelectric dams can be barriers to upstream-migrating fish and a source of mortality 

from turbine passage to downstream migrants. To mitigate these impacts, many projects are 

required to install upstream and downstream fish passage facilities, as stipulated in the articles 

associated with the licenses that are issued by the Federal Energy Regulatory Commission. The 

present study was conducted to evaluate the effectiveness of this mitigation in achieving the goal 

of fishery resource protection. The evaluation was based on information from fish passage 

effectiveness monitoring plans and annual reports which are filed with FERC by licensees and 

stored in the eLibrary database. Fish passage is one of several mitigation areas (others include 

shoreline management, water quality, and recreation) that were reviewed as part of the FERC 

strategic plan for meeting the intent of the Government Performance and Results Act of 1993. 

The study reviewed 269 projects that had at least one license article related to fish 

passage and were licensed or relicensed during a 16-year period from 1987 through 2002. 

Projects that were exempted from licensing and those with licenses that were later amended to 

require fish passage mitigation were not included in this study. Consequently, the projects on the 

Columbia River, with one exception, were not included in this evaluation because they were 

licensed before 1987. The study included 157 projects that had only an article reserving 

authority under Section 18 of the Federal Power Act to prescribe facilities for fish passage at 

some time in the future. Because they did not have a specific requirement for fish passage, these 

157 projects were excluded from further analysis. The remaining 112 projects, which consisted 

of 147 developments, constituted the database that was used to assess the effectiveness of fish 

passage mitigation requirements. 

More than 60% of the 147 developments are located in the Northeast and 75% have a 

generating capacity of <10 MW. Sixty percent of the developments are required to submit 

effectiveness monitoring plans, which were reviewed to identify quantitative measures of 

performance (e.g., the percentage of fish passed). In addition to these site-specific measures, the 

fish management and restoration plans for several large river basins in the Northeast listed goals 

for the recovery of various anadromous fish stocks. However, criteria to assess the success of 

the fish passage mitigation were generally not available from these management and restoration 

plans. 

Adequate data on the number of fish using upstream passage facilities were available for 

eight developments, but only three had sufficient data to provide a quantitative estimate of 

effectiveness. These three developments had a fish lift or lock. For three species (Atlantic 

salmon, American shad, and river herring, primarily alewives), between 45 to 67% of the 

available fish used the lift or lock. These estimates, which were similar to those obtained in 

other studies, met the passage criterion of 40 to 60% that was proposed for American shad at 

each successive upstream barrier on the mainstem Connecticut River. No analysis of 

effectiveness was possible for other upstream fish passage designs due to insufficient data. 

Having sufficient attraction flows at the entrance of the upstream fish passage facility was an 

important factor affecting passage at several projects. 
x

The proportion of fish that utilized downstream fish passage facilities was estimated at 

11 developments. At seven of these, radiotagging or mark-recapture techniques were used to 

measure the effectiveness of downstream passage for Atlantic salmon smolts. The percentages 

of fish that utilized downstream passage facilities, including spill, were highly variable, ranging 

from 6 to 100% for anadromous species and 3 to 87% for resident species. The high variability 

seemed to be related to the variation in flow; passage effectiveness was lowest at higher flows, 

when spill occurred. Surface collection systems and those that employed angled trash racks with 

a downstream bypass facility were the most effective, although spill at one facility achieved 

100% passage. Ensuring suitable bypass flows and adequate attraction flows (relative to 

generating flow) are critical variables affecting downstream fish passage effectiveness. 

Monitoring of fish passage facilities to assess effectiveness is important not only for 

determining site-specific performance but also for evaluating potential applications to other sites. 

The technology available for upstream fish passage is more advanced than that available for 

downstream passage, especially of riverine species. Levels of effectiveness substantially 

exceeding 50% for the passage of downstream migrants may be difficult to achieve on a 

consistent, cost effective basis without also considering spill to pass fish below the dam. With 

no support from a major research program, advancement of the science of downstream fish 

passage must rely on site-specific applications and good effectiveness monitoring plans. Such 

plans should consider defining the duration of the monitoring period in all license articles 

requiring fish passage. Finally, it is the responsibility of all parties involved in a licensing action 

to ensure that the best technical information is used to evaluate various alternatives for fish 

passage, especially downstream fish passage. 
1

1.0 INTRODUCTION 

Mitigative measures are commonly implemented to reduce the adverse effects of 

construction and operation of energy production facilities on the environment. Licenses issued 

by the Federal Energy Regulatory Commission (FERC), which regulates nonfederal hydropower 

facilities, usually contain articles that condition project design or operation to protect, mitigate, 

and/or enhance environmental resources and to achieve nonpower benefits. The Government 

Performance and Results Act (GPRA) of 1993 defines how federal agencies manage their 

performance and requires the development of strategic plans that describe the goals and 

measures of progress and performance in achieving those goals. In response to GPRA, FERC 

implemented an initiative to evaluate the effectiveness of the environmental mitigation 

requirements incorporated in hydropower project licenses. 

One of the most common environmental impacts caused by hydropower projects is the 

barrier to upstream and downstream fish passage created by dams. This report presents the 

results of an evaluation of the effectiveness of fish passage mitigation measures implemented at 

nonfederal hydropower projects that were recently licensed or relicensed by FERC. Projects 

with exemption from licensing and those with licenses that were issued and later amended to 

require fish passage mitigation were not included in this evaluation. This report is not intended 

to be a comprehensive review of the alternatives for mitigating the impacts of hydropower dams 

as barriers to fish passage. Such reviews are provided by Sale et al. (1991) and more recently by 

Weigmann et al. (2003). Finally, this evaluation of fish passage effectiveness at FERC-licensed 

projects is one of several studies of the effectiveness of environmental mitigation requirements 

that were initiated in response to GPRA. Previous reports addressed shoreline management 

(FERC 2001a) and water quality (FERC 2003), and a draft report on recreation was issued in 

July 2004. 

1.1 BACKGROUND 

In the 1980’s, environmental protection conditions in FERC licenses were implemented 

based on relatively limited information that was typically collected early in the licensing process. 

The effects of these measures were rarely evaluated, so little was known about whether the 

measures provided the level of protection intended at license issuance (Cada and Sale 1993). By 

the early 1990’s, but especially after 1993, most FERC licenses included requirements to 

develop plans for assessing the effectiveness of mitigation measures, such as fish passage. These 

plans and the subsequent study results have been included in reports submitted to FERC by the 

licensees. Those reports and other compliance filings required under the various license articles 

and FERC orders were reviewed in this study. 

1.1.1 Review of Previous Hydropower Mitigation Studies 

Hydropower mitigation that provided for the maintenance of instream flows, dissolved 

oxygen (DO), and upstream and downstream fish passage was examined in a U.S. Department of 

Energy (DOE) study by Sale et al. (1991). The study used public information from FERC 

records and additional information obtained from a written survey of developers and state/federal 

resource and regulatory agencies, focusing on nonfederal hydropower projects that were licensed 
2

or exempted between January 1980 and July 1990. Some overlap of information exists between 

the 1991 study and this one because they probably included many of the same projects. 

Consequently, some similarities in results are to be expected. 

From a target population of 707 projects that were identified in the FERC Hydropower 

Licensing Compliance Tracking System as having mitigation requirements for instream flow, 

dissolved oxygen, and/or fish passage, specific information was obtained from the project 

developers of 280 projects. Of these projects, 30 (11%) and 66 (24%) had operating upstream 

and downstream fish passage facilities, respectively. Nationwide, of the 1825 operating 

nonfederal hydropower projects in the United States (FERC 1992), 10 and 13%, respectively, 

have installed upstream and downstream fish passage facilities (Pringle et al. 2000). Sale et al. 

(1991) reported that more than 70% of the upstream facilities were fish ladders. The angled bar 

rack, which was used at 38% of the projects with downstream passage facilities, was the most 

frequently required downstream passage device, especially in the Northeast. 

Relatively few of the projects with passage facilities were required to monitor the 

effectiveness of the facilities in moving adults upstream over the dam and in bypassing juveniles 

(and adults of some species) downstream around the dam. Indeed, 57% of the projects with 

operating upstream fish passage facilities and 79% of those with operating downstream passage 

facilities did not conduct any biological monitoring to assess the effectiveness of the facilities. 

Most projects had no performance monitoring requirements for fish passage (e.g., 82% of 

projects with downstream fish passage facilities). Although 60% of the projects with upstream 

passage facilities had performance monitoring requirements, the most common performance 

criterion was “no obvious barriers to upstream movement.” It was the only criterion used to 

assess effectiveness in 17 of the 30 projects that responded to the survey question related to 

performance objectives. 

The 1991 study concluded that the proportion of projects with environmental mitigation 

requirements had increased significantly during the 1980s, but little information was available on 

the effectiveness of that mitigation. This earlier study had to rely primarily on surveys of 

licensees to obtain information on the implementation of mitigation, because the availability of 

data to directly assess mitigation success was limited. The present study used the data from fish 

passage effectiveness studies that were stipulated in various articles associated with more recent 

FERC licenses to determine the success of fish passage measures implemented to mitigate the 

adverse impacts of dams as barriers to fish movement and as sources of mortality from turbine 

passage. 

Several other trends on fish passage mitigation were noted in the DOE study by Sale et 

al. (1991). Downstream fish passage facilities not only were more common than upstream 

passage facilities, but also were installed more frequently to protect riverine than anadromous 

fishes. Of the projects with a downstream passage requirement, 55% were designed to protect 

riverine species. Thirty-eight percent of the projects with an upstream fish passage requirement 

were targeting migratory riverine species, and 12% targeted only riverine species. Moreover, 

there was a trend of increasing downstream fish passage requirements in the target population 

over the 10-year period (1980 to 1990) included in the study. No increase in upstream passage 
3

requirements was observed over the same period. Finally, all fish passage requirements were 

more common in the West than in the East. 

1.1.2 Overview of Licensing Process 

When a license is issued for a project, the articles may contain provisions for the licensee 

to submit plans for the installation, operation, and maintenance of upstream and/or downstream 

fish passage facilities. In many cases, fish passage design drawings and effectiveness plans are 

required in the same or a separate article. Often, the requirement for fish passage facilities is not 

specified; instead, authority is reserved by the FERC under Section 18 of the Federal Power Act 

(FPA) to require such facilities as may be prescribed by either the Secretary of the Interior or the 

Secretary of Commerce, or both, at some time in the future. Moreover, the requirements for fish 

passage may be included in the mandatory conditioning authority under Section 4(e) or Section 

18 of the FPA or under Section 401 (Water Quality Certification) of the Clean Water Act 

(CWA). However, if the license article stipulates that a fish passage facility be designed and 

installed, and its effectiveness be determined, then the licensee consults with the resource 

agencies and develops the appropriate plans, which are reviewed by the agencies prior to their 

submittal to the FERC for review and approval. 

Once the plan is approved and the facility is installed, effectiveness monitoring begins. 

The type and frequency of monitoring is project-specific. Reports of the results with any 

recommendations developed in consultation with the resource agencies usually will be filed by 

the licensee with the resource agencies and the FERC. These reports assess the effectiveness of 

fish passage, identify problems encountered during the monitoring period, and propose measures 

to address any problems. The goal of the present study is to review these reports in order to 

evaluate the effectiveness of fish passage measures. 

1.2 PURPOSE OF STUDY 

The purpose of this study is to assess the effectiveness of fish passage facilities that are 

required by FERC licenses. This evaluation should assist FERC in determining whether the 

license requirements are achieving resource protection. Studies such as this and the other studies 

of shoreline management, water quality, and recreation mitigation will help guide FERC 

decisions regarding the need for future environmental mitigation. The findings of this study are 

intended to provide FERC staff and all stakeholders with information to cooperatively decide the 

best and most cost-effective method of meeting license objectives, thus ensuring that mitigation 

measures implemented at nonfederal hydropower projects are effective. 

1.2.1 Measures of Effectiveness 

Effectiveness refers to the adequacy to accomplish a purpose or produce an intended 

result, which, in this study, would be the passage of fish around dams. There are different 

approaches or measures that can be used to assess effectiveness in this context. For example, the 

effectiveness of fish passage facilities is often determined by counts of the number of fish using 

them. Such an evaluation of effectiveness is usually insufficient, because the number of fish that 
4

did not use the fishway is not known. Another expression of effectiveness is the proportion 

(percentage) of the population that use a fish passage facility. License articles can require the 

development of monitoring plans that specify how the effectiveness of the fish passage facility 

will be measured. The various measures of effectiveness are described in these sections. 

1.2.1.1 Project-Specific Measures 

The most frequent metric used to document the benefits of a fish passage facility is the 

number of fish utilizing it. For example, annual counts of 500,000 to 1,000,000 fish for the two 

lifts at Holyoke Dam (FERC No. 2004) are the basis for the statement that these lifts “are one of 

the most successful fish passage facilities on the Atlantic Coast” (Kynard 1998). Counts of 

adults migrating upstream to spawn and juveniles migrating downstream to the ocean provide a 

quantitative measure of fishway use but are not necessarily adequate measures of fishway 

effectiveness. These measures are not based on knowledge of the size of a source population 

from which the number of bypassed fish was drawn. Fishway counts are a necessary but 

sometimes not sufficient measure of effectiveness. 

A better measure of fish passage effectiveness is one that is based on the proportion of 

the target population(s) below (above) the dam that is passed upstream (downstream). So, for 

example, a fish ladder that passes 1,000 fish may appear to be effective, unless it is learned that 

another 9,000 fish reached the dam but could not find the entrance to the ladder, after accounting 

for those that spawned below the dam and did not pass upstream. Although the number of adult 

fish that move upstream past the dam can be determined from direct counts or estimated from 

video records of the fishway, the number of adults constituting the source population below the 

dam (i.e., the number of fish available for passage) is rarely known or estimated. However, if 

there are two sequential, mainstem dams and both have fish passage facilities, fishway counts at 

the lower dam can provide a reasonable estimate of the source population available for passage 

at the upper dam. Again, fish passage effectiveness at the upper dam would be expressed as the 

percentage of the upstream-migrating population counted at the lower fishway that was 

subsequently counted at the fishway on the upper dam. Such an approach was approved by 

FERC to assess the effectiveness of the upstream fishway at the Caribou Project (FERC No. 

2367) on the Aroostook River, Maine when the goal of 10% of the restored salmon run, as 

estimated by the Maine State Salmon Authority, is passed at the next dam downstream (Tinker 

Dam). 

This method of measuring the effectiveness of upstream fish passage facilities assumes 

that any spawning that occurs in the mainstem river or tributaries between the two sequential 

dams is negligible. Unfortunately, this assumption may not always be valid, and testing its 

validity may be difficult. How much spawning habitat exists between the two dams and how 

much is actually utilized are usually not known nor easily determined. Spawning by American 

shad in these interdam reaches is suspected to occur in the Connecticut, Merrimack, and 

Susquehanna rivers (Medford 2004). Because the amount of spawning that occurred between 

dams was unknown, the estimates presented in this report of upstream passage effectiveness are 

considered to be conservative (i.e., effectiveness actually may have been higher). 
5

Performance measures can be used to document the benefits of fish passage. For 

example, some river basin plans for the restoration of anadromous species in New England 

coastal rivers include species-specific targets for the number of upstream migrants passed at the 

lower dam(s). If the passage facility is ineffective, these goals may never be reached. On the 

other hand, an increase in passage that results in attainment of the goal may not be associated 

with more effective passage but with an increase in stock abundance that is due to other factors, 

such as higher ocean survival, lower harvest rates, etc. While these targets are important 

milestones to the assessment of the status and recovery of anadromous populations, they do not 

provide a measure of effectiveness that can be a basis for the application of the same passage 

technology to other projects and species. 

That the dam is not a barrier to fish movement is another performance objective that is 

difficult to quantify (Sale et al. 1991) and therefore, not an adequate measure of fish passage 

effectiveness. Upstream-migrating fish may be delayed for hours or days searching for passage 

at a dam before finding the fishway entrance. This delay could reduce the fitness of spawning 

adults or the upstream extent of their migration. Methods have been employed to minimize 

delays in upstream migration, such as tailrace barriers, and these are included in the present 

study. Even if the effectiveness of a tailrace barrier is known, that information is not sufficient 

to address the question of fishway effectiveness; upstream migrants may successfully avoid the 

tailrace yet still be delayed in their upstream migration by fishway design and operation (e.g., 

inadequate attraction flows). 

The effectiveness of downstream fish passage facilities is easier to quantify than 

upstream fish passage facilities because it can be measured using a relatively simple 

experimental approach. For example, marked, tagged, or radiotagged juvenile salmon (e.g., 

smolts) can be released above the dam and collected at the downstream bypass facility. The 

proportion of tagged fish that used the facility can be calculated, and if radiotagging is used, the 

proportion of released fish that utilized other passage routes can also be directly estimated. 

Juvenile salmon are reared in hatcheries for release in river basins with anadromous fish 

restoration programs, so they are readily available in large numbers. However, caution must be 

exercised in the use of hatchery stocks to ensure their fitness is satisfactory and would not 

compromise the results of the test. 

 Measuring downstream fish passage effectiveness for other life stages of salmon or other 

species is considerably more difficult than it is for smolts. The primary constraint with 

measuring the passage effectiveness of adult Atlantic salmon is their availability. Although the 

same experimental approach of radiotagging can be used to measure upstream passage 

effectiveness, obtaining an adequate number of adult Atlantic salmon that could provide a 

meaningful measure of effectiveness is usually not possible. Availability is not a constraint in 

testing the passage effectiveness for American shad and other clupeids, but their high 

susceptibility to stress from collection and handling make experimental testing with these species 

considerably more difficult than with salmonids. 
6

1.2.1.2 River-Basin Goals for Fish Restoration 

Successful fish passage at hydropower dams is necessary to achieve the goals for 

restoration of anadromous fish stocks, and some restoration plans include specific fish passage 

goals for hydropower projects in the basin. For example, the Greenville Project (FERC No. 

2441) on the Shetucket River, a tributary of the Thames River in Connecticut, has both upstream 

and downstream fish passage facilities, which were installed in 1996. The Thames River basin 

is included in the anadromous fish restoration program of the Connecticut Department of 

Environmental Protection (CDEP); the goal of the program is to develop and maintain a 

recreational fishery for American shad and river herring in the basin. The restoration plan 

requires that the upstream fish lift at the Greenville Dam be capable of passing 110,000 adult 

American shad and 165,000 adult alewives each season; basin-wide production is estimated by 

CDEP to be 110,000 adult shad and 217,000 river herring (Kleinschmidt Associates 1999). In 

this case, the passage and the restoration goals can be important design criteria for the Greenville 

fish lift, but they are not considered to be adequate measures of the effectiveness of the lift. 

Although important to fish restoration efforts in the Thames River basin, achievement of these 

goals does not imply that the lift is effective in passing upstream migrants, only that it is 

effective in meeting the goals of the restoration program. That is, the lift may satisfy the agency 

goal of passing 110,000 adult shad, yet this number may be only a small fraction of the available 

population. Of course, to regulatory and resource agencies, the latter measure may be sufficient 

and only fishway counts are needed. In the studies that are discussed in this report, however, 

effectiveness is based on site-specific studies that considered the size of the fish population 

available for passage in evaluating the effectiveness of fish passage facilities. 

Projects in river basins that have not developed restoration plans often have no specific 

fish passage requirements. For example, upstream fish passage will not be required at the 

Marcal Project (FERC No. 11482) until a comprehensive fisheries management plan is prepared 

for the Little Androscoggin River basin in Maine, and the Maine Atlantic Salmon Commission 

has no plans to restore Atlantic salmon in this river in the near future. Even when an upstream 

fishway is present, measuring its effectiveness can be linked to the status of restoration efforts in 

the basin. Because the Atlantic salmon restoration plan for the Aroostook River was 

discontinued by the Atlantic Sea Run Salmon Commission in 1991, assessment of the 

effectiveness of the pool-weir fishway at the Caribou Project has been delayed until the goal of 

300 salmon is reached at the next lower dam (FERC 1998). 

Finally, it is important to recognize the significance of modeling tools for assessing fish 

passage improvements at multiple projects in a river basin. Considering fish passage 

effectiveness from this level of analysis provides a meaningful approach because cumulative 

benefits of fish passage and all other restoration measures in the basin can be assessed. An 

excellent example of this approach is described in Kareiva et al. (2000). The authors described 

the use of an age-structured matrix model that was applied to long-term fish population data to 

test the effectiveness of various past management actions, including the transportation 

downstream of juvenile salmon, in the Columbia River basin. None of the projects included in 

this present study used a modeling approach to evaluate fish passage effectiveness. 
7

1.2.2 Source of Information 

The review of the effectiveness of fish passage mitigation measures utilized information 

contained in the public record for hydropower projects that were licensed or relicensed from 

1987 through 2002. Fish passage effectiveness plans and reports filed with the FERC by 

licensees, as well as the orders issued by the FERC based on these documents, constitute the key 

elements of the eLibrary database used in this study. The eLibrary database contains (1) an 

index to all documents issued or received by the FERC since November 1981, (2) microfilm of 

documents submitted to and issued by the FERC for 1981-1995, (3) images of paper documents 

for 1995-present, and (4) documents submitted electronically through the FERC’s web-enabled 

filing mechanism since November 2000. The eLibrary can be accessed from the FERC website 

(see www.ferc.gov). 

The results of the analyses presented in Section 2.0 are based primarily on data presented 

in effectiveness monitoring reports submitted by the licensee and included in eLibrary before 

March 2003. For some projects, reports were submitted to the FERC for several years following 

approval and implementation of monitoring, and these were included in the review. The large 

projects on the mainstem Columbia River in the Northwest were not included. 

9

2.0 DATA ANALYSIS 

The initial group consisted of 304 hydropower developments (=dams) that (1) were 

licensed or relicensed during the period 1987-2002 and (2) had a license article addressing fish 

passage. This group of developments represented 269 projects (=licenses), which were clustered 

in the Northeast and North Central regions of the United States (Figure 2-1). With one exception 

(Rock Island Project, FERC No. 943), the large projects on the mainstem Columbia River in the 

Northwest were not included because they were licensed prior to 1987. 

Figure 2-1. Geographical distribution of 269 projects (=licenses) 

with at least one license article that addressed fish passage. 

Of the 269 projects, 231 (86%) had a license article reserving the FERC’s authority under 

Section 18 of the FPA to require construction, operation, and maintenance of fishways as may be 

prescribed by the U.S. Department of the Interior (Fish and Wildlife Service or FWS) or the U.S. 

Department of Commerce (National Oceanic and Atmospheric Administration or NOAA 

Fisheries). Although fish passage may not be required by FWS or NOAA Fisheries at the time 

of project licensing, the agencies may recommend that reservation of authority be included in the 

license. 

A license article reserving authority under Section 18 of the FPA was the only fish 

passage requirement at 157 projects. After excluding these projects because they only reserved 

authority and did not specify the requirements for fish passage, the actual database included in 

the study consisted of 147 developments associated with 112 licensed projects. The greater 

number of developments (i.e., dams) than projects (i.e., licenses) is accounted for by 15 projects 
10

that had two or more developments under the same license. In addition to Section 18, other 

sources of fish passage requirements that may be included in the license are (1) Settlement 

Agreements between the licensee and state and federal resource agencies and NGO’s, (2) 401 

Water Quality Certification issued by the designated state agency, (3) FERC license articles, and 

(4) Section 4(e) of the FPA. 

2.1 SUMMARY OF PROJECTS WITH FISH PASSAGE REQUIREMENTS 

2.1.1 Background 

Fish passage requirements represent measures to mitigate adverse impacts of hydropower 

dams, which have been well documented (e.g., see reviews by Hildebrand 1980, Turback et al. 

1981, and Jungwirth et al. 1998). These dams are barriers to the upstream movement of 

migratory fishes, and passage by downstream migrants through the turbines or spillways can be a 

source of direct or delayed mortality (e.g., injuries that cause greater susceptibility to predation). 

The life cycle of anadromous fishes, which spend most of their adult life in the ocean but return 

to freshwater to spawn, is impacted in both the adult and juvenile stages; adults often must pass 

one or more dams in the upstream journey to their natal streams, and the progeny that migrate 

downstream after one or more years must pass those same dams. Several Pacific salmonid 

species have such a life cycle, including chinook (Oncorhynchus tshawytscha), coho (O. 

kisutch), and sockeye salmon (O. nerka). Unlike Pacific salmon which die after spawning, 

steelhead (O. mykiss), Atlantic salmon (Salmo salar), and several anadromous nonsalmonids, 

including American shad (Alosa sapidissima), alewife (A. pseudoharengus), and blueback 

herring (A. aestivalis), are repeat spawners, so the adults also encounter dams during their postspawning, downstream migration to the ocean. Because of its declining abundance, the 

American eel (Anguilla rostrata), a catadromous species that rears in freshwaters of Atlantic 

coastal river basins but spawns in the ocean, has received increased attention from resource 

agencies and hydropower developers (see review by EPRI 2001). Much less is known about the 

impact of dams on the more localized movements of riverine fishes. 

2.1.2 Project Characteristics 

The hydropower developments used in this study were characterized by the year the 

project was licensed, the generating capacity of the development, and its geographical location. 

These characteristics are summarized and discussed below. 

The initial database of 269 projects with a license article related to fish passage 

represented 75% of the total of 363 projects that were licensed or relicensed during the period 

1987-2002. Of these 269 projects, 73% were licensed after 1993, and 47% were licensed during 

the five-year period from 1994-1998 (Figure 2-2). 

Several trends were evident in the percentage of licenses with fish passage requirements 

over the 16-year period from 1987 to 2002. The number of licenses issued in any given year that 

had one or more fish passage requirements ranged from one (33%) in 1990 to 29 (91%) in 1996 

(Figure 2-2). Of the 72 licenses issued from 1987 through 1991, 32 (44%) had fish passage 
11

requirements. The volume of licenses granted per year increased almost threefold over the next 

11 years, averaging 28 licenses per year, and the percentage with one or more fish passage 

requirements increased to 77%. When the projects with license articles reserving authority under 

Section 18 of the FPA were excluded, only 112 of the 269 projects (42%) had specific 

requirements for fish passage and thus were available for review in this study. The analyses that 

follow are based on these 112 projects, which consisted of 147 developments. 

Figure 2-2. Total number of licenses issued and the licensing years of the 

269 hydropower projects with at least one article related to fish passage 

(shaded area) that were reviewed in this study. 

The generating capacities of these 147 developments were categorized and compared 

with the capacities of projects included in the earlier DOE mitigation study (Sale et al. 1991) 

(Table 2-1). The proportion of developments within each of the five capacity categories was 

generally similar in the two studies. For example, both studies included relatively few large 

projects (>50 MW). With one exception, about 75% of the developments with upstream and 

downstream fish passage requirements were associated with projects that had generating 

capacities of <10 MW. An equivalent proportion (74%) of the developments included in the 

water quality mitigation study were also <10 MW (FERC 2003). In the present study, 26% of 

the smallest developments (<1 MW) had an upstream fish passage requirement, an interesting 

finding considering the relatively high costs often associated with construction and operation of 

these facilities (e.g., Francfort et al. 1994). Although an analysis of the costs of fish passage 

mitigation was beyond the scope of this study, it is worth noting that funding for mitigation, 

including effectiveness monitoring, would be very limited at such small projects. 

The 147 developments were reviewed to determine if there was any association between 

geographical location and (1) the type of fish passage requirements (e.g., upstream passage, 

downstream passage, and effectiveness monitoring) and (2) the number of Settlement 

Agreements, an important source of these requirements (Table 2-2). More than half of the 

developments (54%) were required to install both upstream and downstream fish passage 

facilities. This requirement for both facilities characterized all of the developments in the North 
12

Table 2-1. Number of hydropower developments with fish passage requirements for 

each of five capacity categories included in an earlier DOE mitigation study 

(Sale et al. 1991) and the present FERC study. The DOE study included projects 

that were licensed or exempted between January 1, 1980 and July 1, 1990. 

(Percentages of the total number of developments with upstream or downstream 

fish passage requirements are given in parentheses.) 

CAPACITY CATEGORY (MW) 

<1 1 to <10 10 to <50 50 to <100 >100 Total 

Upstream Fish Passage 

 DOE Studya 

 Present FERC Study 

5 

(17) 

23 

(26)

14 

(48) 

43 

(48) 

7 

(24) 

15 

(17) 

0 

(0) 

2 

(2) 

3 

(11) 

6 

(7) 

29 

 89 

Downstream Fish Passage 

 DOE Studya 

 Present FERC Study 

24 

(31) 

24 

(20)

38 

(48) 

65 

(56) 

16 

(20) 

22 

(19) 

0 

(0) 

1 

(1) 

1 

(1) 

5 

(4) 

79 

117b

a

SOURCE: Sale et al. (1991), Appendix C.

b

Excluded four projects with dams but no generating capacity.

Table 2-2. Regional summary of 147 hydropower developments 

with fish passage requirements. 

(SA = number of developments included in Settlement Agreements)

FISH PASSAGE REQUIREMENTS

Region No. of 

Developments SA Upstream 

Only 

Downstream 

Only 

Upstream 

and 

Downstream 

Effectiveness 

Monitoring 

Northeast 

(CT, MA, ME, NH, 

NY, VT) 

93 43 7 46 40 59a

North Centralb

(MI, WI) 

23 17 -- -- 23 8 

West/Northwestc

(AK, CA, CO, ID, 

OR, WA) 

25 6 6d 6 13 18 

Southeast 

(GA, SC, VA, WV) 

6 1 2 -- 4 4 

a

Includes monitoring the survival of fish in the downstream fish passage facility at two projects.

b

Includes downstream fish protection requirements at 11 of the 23 ‘Upstream/Downstream’ projects. c

Includes downstream fish protection requirements at 2 of the 4 ‘Downstream Only’ projects and 1 of the 13 

‘Upstream/Downstream’ projects.

d

Includes the closure of a fishway at one project.
13

Central United States. Upstream passage only was a requirement at just 10% of the 

developments and almost exclusively at those in the Northeast and West/Northwest where 

anadromous fish populations are the focus of major restoration efforts. Downstream fish passage 

was a more common requirement than upstream passage, a trend that was also noted by Sale et 

al. (1991) in a study of hydropower projects that were licensed between 1980 and 1990. Indeed, 

all 23 developments in the North Central region and 92% of those in the Northeast had a 

downstream fish passage requirement. 

Several factors may account for the high proportion of projects in the Northeast that had a 

downstream passage only requirement. In New York, for example, an upstream fish passage 

route is provided by a major network of navigational locks located on the Hudson, Mohawk, and 

Oswego rivers. In other regions of the state, hydroelectric projects were constructed on natural 

cataracts which served as barriers to upstream fish movements under most flow conditions. 

Consequently, only downstream fish passage was required at these sites. Finally, many upstream 

passage facilities in the Northeast were constructed and evaluated prior to 1987, and the time 

period of this study (1987-2002) represents a shift in emphasis to downstream fish passage. 

Most of the developments also had a requirement to monitor the effectiveness of fish 

passage (Table 2-2). Although 89 developments (61%) had this requirement, the regions with 

the highest proportion of developments requiring effectiveness monitoring were the Northeast 

(63%) and the West/Northwest (72%), where passage of anadromous fishes around dams is a 

significant issue. The emphasis on determining the effectiveness of fish passage facilities has 

only occurred within the past 10-15 years, because most of the hydropower projects that were 

reviewed by Sale et al. (1991) did not have such a requirement (see Section 1.1.1). 

This increasing importance of effectiveness monitoring coincided with a recent increase 

in the use of Settlement Agreements as a component of the FERC licensing process. Only four 

of the 19 Settlement Agreements that were associated with the hydropower developments 

reviewed in this study were negotiated before 1994. Fish passage requirements are included in 

many Settlement Agreements, and 65 of the 147 developments (44%), represented by 

53 individual licenses, are included in these 19 Agreements. That is, almost 50% of the 112 

licenses for projects reviewed in the present study are based on Settlement Agreements. Using 

this approach in the licensing process was especially favored in Michigan and Wisconsin, where 

74% of the 23 developments were included in just two Agreements. They are an increasingly 

popular tool for resolving issues in hydropower relicensing proceedings in a timely and 

consensus-based manner (FERC 2000). The use of Settlement Agreements, which the FERC 

encourages, provides a mechanism for ensuring that the effectiveness of fish passage mitigation 

is appropriately evaluated. 

2.2 REGIONAL ASSESSMENT OF FISH PASSAGE FACILITIES 

The fish passage facilities at the 147 developments included in this study were reviewed 

to identify common characteristics and to assess regional differences. This review included 

developments with planned facilities as well as those with operational facilities. 
14

2.2.1 Upstream Fish Passage 

Generally, there are three types of facilities for moving fish upstream: (1) fish ladders; 

(2) fish lifts (or elevators); and (3) fish locks (Bell 1980). The most common fish ladders include 

the pool and weir, Ice Harbor, vertical slot, Denil, and steeppass, all of which have fish 

swimming up a series of successively elevated pools. The steeppass is used to pass fish around 

natural barriers (e.g., waterfalls) and is not common at FERC-licensed projects. Both fish lifts 

and fish locks crowd fish into an enclosure for transport over the dam. With fish lifts, this 

enclosure is a water-filled mechanical hopper; for locks, it is a chamber that fills with water, 

raising the fish above the dam. An important advantage of lifts and locks over fishways is that 

they can pass most fish species, including those that are small and those with weak swimming 

capabilities. They are employed for species that cannot utilize ladders or where the height of the 

dam is great (Weigmann et al. 2003). Fish ladders, on the other hand, are species-specific, and 

passage via this type of fishway may be slower (Bell 1980). 

In addition to these methods of upstream passage, trap-and-truck can offer an interim 

option while other, more permanent alternatives are considered for passage, or in some cases, it 

can be a semi-permanent solution to the problem of upstream fish passage. Usually, a fish lift is 

used to collect fish at the dam, and a truck is used to haul them above the reservoir or above 

several dams farther upstream. Another method of upstream passage occurs via a breach in the 

dam (e.g., the Battersea Project, FERC No. 8535, on the Appomattox River in Virginia). Like 

the Alaska steeppass, however, it is not in common use at FERC-licensed projects. 

The types of upstream fish passage facilities at the developments included in the present 

study are summarized, by region, in Table 2-3. Most of the upstream passage facilities are 

located in the Northeast, and each type was about evenly represented. The targeted species at the 

Northeast projects are almost exclusively anadromous clupeids, Atlantic salmon, and the 

catadromous American eel. It is not surprising that anadromous fishes also constituted the 

majority of the targeted species at projects in the West/Northwest. 

A comparison among regions showed that lifts/locks and the Denil fishway are primarily 

used in the Northeast. Also, as a proportion of the total facilities in the region (both installed and 

planned), the pool-weir fishway was more common in the West/Northwest, as were tailrace 

barriers. Although they are not actually an upstream passage device, tailrace barriers are used to 

minimize delay of upstream migrants that are searching for the entrance to the fishway. The low 

number of facilities in the Southeast suggests that upstream fish passage may not be the 

significant issue it is in other regions. However, FERC expects to receive 137 relicense 

applications during the 10-year period from 2002 to 2012, and 26 of these projects, consisting of 

more than 50 developments, are located in the coastal states of North and South Carolina, 

Georgia, and Alabama (Hill and Murphy 2003). In Alabama and Georgia, dams operated by the 

U.S. Army Corps of Engineers are located downstream of many nonfederal dams, so the passage 

needs and fish management goals of the entire river basin could be addressed when the need for 

fish passage at these latter dams is considered. That is, the barriers downstream may already 

limit fish movements, thus requiring a basin-wide rather than site-specific approach (Bell 1980). 
Table 2-3. Regional summary of upstream fish passage facilities for 147 hydropower develo

(i.e., dams) that have fish passage requirements. 

(R = riverine species; A = anadromous species; and C = catadromous species (i.e., American eel); TBD = to be deter

TYPE OF FACILITY 

Region Fish Pr

No. of Facilities Lift Vertical Slot Pool- Weir Denil Trap -n- Truck Eel Ladder Other TBD Tai

Bar

Northeast  Installed  Planned 

27 22 

7a

-- 

1 

-- 

6 

-- 

3 4 

5 3 

2 

5c

2b 

-- 9 

North Central  Installed  Planned 

4 

23 

-- -- 

2 

-- 

1 

-- 

1 

-- 

-- -- 

-- -- 

-- -- 

-- 

23 

West/Northwest  Installed  Planned 

12 

6 

-- -- 

-- -- 

7d

2 

-- -- 

2 1 

-- -- 

1e 

-- 

-- -- 

Southeast  Installed  Planned 

1 4 

-- 

2f

-- 

1 

-- -- 

1 

-- 

-- -- 

-- -- 

-- -- 

-- 

1 

Total  Installed  Planned 

43 56 

aIncludes two locks at the Springs-Bradbury development (No. 2528) on the Saco River, ME.bProject shutdown.cIncludes three ladders at the Holyoke Project (No. 2004) on the Connecticut River, MA.dIncludes a fishway at the Kern River No. 3 development, CA (No. 2290) that was closed and three pool-weir fishways at the Rock Island ProjeeOpenings were created through the stoplogs in each of the five existing vertical slots through the dam.fIncludes a refurbished navigation lock at the Stevens Creek Project (No. 2535) on the Savannah River, GA.
16

For 56 of the 99 (57%) upstream fish passage facilities required by FERC licenses, the 

specific type of facility to be installed has not been determined (Table 2-3). Almost half of these 

facilities are located in Michigan and Wisconsin at developments that are included in Settlement 

Agreements (e.g., 17 of the 23 developments are included in only two Settlement Agreements). 

Unlike other regions of the country where the method of upstream fish passage has been 

determined for most of the planned facilities, the North Central region has not decided what type 

of facility should be installed. At some projects, the delay is related to the need for additional 

research to develop and test options for the upstream passage of lake sturgeon. Fish passage 

seems to be an emerging issue in the North Central region where more than 50% of the planned 

upstream passage facilities are targeting riverine species. The method of passage has been 

selected for almost 60% of the planned facilities in the Northeast, a region where fish passage is 

needed to support anadromous fish restoration programs. They have not been installed because 

requisite passage and/or restoration goals at the lower dams in the basins have not been met. 

2.2.2 Downstream Fish Passage 

A variety of fish passage facilities have been installed to divert downstream migrants 

away from turbine intakes and into a bypass system that transports them below the dam (Odeh 

and Orvis 1998, Weigmann et al. 2003). Physical barriers are designed to prevent entrainment or 

the passage of fish through the turbines where they are subjected to pressure and shear stresses as 

well as direct contact with the turbine itself. These barriers include several types of fixed and 

traveling screens in addition to barrier nets. Guidance devices are another group of downstream 

fish passage technologies that divert rather than exclude fish from the turbine intake area. This 

group includes (1) structural guidance devices, such as angled bar racks, louvers, and surface 

collectors; and (2) behavioral guidance devices, such as the use of sound and lights (Weigmann 

2003), and the use of chemical attractants (e.g., pheromones) for alosids (Young 2003). 

Research on alosids suggests that American shad use chemical cues to detect other individuals 

and that downstream-migrating river herring respond to ultrasound in forebays (Hendricks 2003). 

Spill is another option for downstream passage and is commonly used in the Columbia 

River basin. Odeh and Orvis (1998) also included guide walls and curtain walls in their review 

of downstream fish passage mechanisms, but none of the projects in this study utilized them. 

Only one project employed a trap-and-truck approach to transport fish below the dam. At the 

Cabinet Gorge development, which is included in the Clark Fork Project (FERC No. 2058) in 

Montana, this method is used to transport juvenile bull trout (Salvelinus confluentus) 

downstream of the Cabinet Gorge dam. This species is listed as threatened under the 

Endangered Species Act, and both the upstream and downstream transport of adults and 

juveniles, respectively, by trap-and-truck is designed to protect the genetic diversity of the 

populations and conserve the species (Epifano et al. 2003). In addition to trucks, barges have 

been used by the U.S. Army Corps of Engineers to haul downstream-migrating salmon smolts 

below Bonneville Dam, the lowermost dam on the Columbia River. 

The downstream fish passage facilities at the developments included in this study are 

summarized in Table 2-4. These data illustrate that fish passage mitigation measures are diverse, 

representing several different technologies. In both the Northeast and West/Northwest, ice or 

trash sluiceways are utilized for downstream fish passage. Screens that minimize entrainment in 
Table 2-4. Regional summary of downstream fish passage facilities for 147 hydropower develo

(i.e., dams) that have fish passage requirements. 

(R = riverine species; A = anadromous species; and C = catadromous species (i.e., American eel); TBD = to be determ

TYPE OF FACILITY

Fish Protection 

Region No. of Facilitiesa Sluice Spill Surface Collection Angled Bar Rack TBD Otherb Screen(s) Barrier Net 

Northeast  Installed  Planned 

47 31 

26 11 

5 3 

6 1 

6c

7 

-- 

9 

4 

-- 

-- -- 

-- -- 

North Central  Installed  Planned 

6 

27 

-- -- 

1 

-- 

-- -- 

-- -- 

-- 

27 

3 

-- 

-- -- 

2 

-- 

West/Northwest  Installed  Planned 

9 

11 

3 3 

1 

-- 

-- -- 

1c

-- 

-- 

3 

1 

-- 

3 5 

-- -- 

Southeast  Installed  Planned 

1 2 

1 1 

-- -- 

-- -- 

-- -- 

-- 

1 

-- -- 

-- -- 

-- -- 

Total  Installed  Planned 

63 71 

aThe number of facilities can exceed the number of developments, which may have more than one facility. For example, the Veazie Proje

Penobscot River, ME has both angled bar racks and a sluice and the Tule River Project (No. 1333 in CA, respectively) has screens and a sl

bIncludes project shutdown at 5 of the 8 developments listed.cIncludes louvers at the Holyoke Project (No. 2004) on the Connecticut River, MA and the Mayfield development (No. 2016) on the CowldIncludes landlocked Atlantic salmon at the Chace Mill (No. 2756) and Essex No. 19 (No. 2513) Projects on the Winooski River, VT and 

(No. 2458) on the Penobscot River, ME.
18

the turbines were used or are planned for use at several projects in the West/Northwest. 

Downstream fish passage is planned for hydropower projects in the North Central region, but the 

type of facility has not been determined for nearly all of the developments. 

Downstream fish passage facilities in the Northeast alone account for 75% of the total 

installed facilities that were reviewed in this study. When the facilities in the West/Northwest 

are included, the proportion approaches 90%. Such a trend reflects the importance of 

anadromous fish restoration and protection as a management goal in the major coastal river 

basins of the Northeast and West/Northwest. Consequently, much of what we know about 

methods for safe downstream passage at dams is based on studies conducted on anadromous 

species in these two regions of the country. 

Although the majority of the installed facilities in the Northeast region are used for 

passage of anadromous species (and catadromous eels), a substantial number are used for 

riverine species (e.g., 45% and 48% of the installed and planned facilities, respectively). The 

number of downstream passage facilities in the West/Northwest was considerably lower, but the 

trend was similar; 35% of the facilities included passage for riverine species. As was found with 

upstream passage at hydropower projects in the North Central region (Table 2-3), the facilities 

planned for this region of the country will be designed primarily for the passage of riverine 

species. 

2.3 EVALUATION OF FISH PASSAGE EFFECTIVENESS 

Many of the 147 hydropower developments had no data available for assessing the 

effectiveness of the fish passage facilities (Table 2-5). Passage facilities have not been installed 

at 55% of these developments, and no effectiveness monitoring was required at another 16%. 

Even if the development had a monitoring requirement, data were not always available. For 

example, anadromous fish stocks may have been too low to meet the goals that would require the 

initiation of monitoring (e.g., Table 2-5, footnote ‘d’). In a few cases, an effectiveness 

monitoring plan was in preparation or monitoring was in progress and no report was available 

yet. 

Fish passage monitoring data were available at 22 developments, 77% of which were 

located in the Northeast. At some of these developments, data were limited (i.e., the data were 

qualitative, anecdotal, or in other ways, too limited for meaningful analysis). After reviewing the 

data from reports submitted by licensees to FERC in compliance with the license article(s), the 

monitoring results from effectiveness studies at eight upstream passage facilities and 

12 downstream facilities were analyzed in the sections that follow. 

2.3.1 Upstream Fish Passage 

Adequate data on the number of fish using the upstream passage facility were available 

for eight developments (seven projects), but only three of these had data that could be used to 

measure the effectiveness of the fish passage facility (Table 2-6). Two of these developments, 
19

Table 2-5. Status of implementation of fish passage requirements 

at 304 hydropower developments categorized by region.

NUMBER OF DEVELOPMENTS

Status Northeast North 

Central 

West/ 

Northwest Southeast Total 

Section 18, Reservation of Authoritya 41 85 4 27 157 

Construction not started/in progress 2 -- 7 -- 9 

Passage facilities not installed 42 19 6 5 72 

Passage facilities installed 

 — No effectiveness monitoring required 19b 3 1c -- 23 

 — Data not availabled 13e 1 7 -- 21 

 — Data available 17 -- 4 1 22 

 TOTAL 134 108 29 33 304 

a

Includes projects with only Section 18 authority. 

b

Includes four projects on the Passumpsic River in Vermont, each with an article requiring downstream fish passage 

effectiveness monitoring but none is required to conduct formal, quantitative studies. 

c

Kern River No. 3 Project (FERC No. 2290) in California where the fishway was closed. 

d

Data not available because (1) effectiveness monitoring plan not submitted, (2) monitoring is in progress, or (3) report of 

results is in preparation. 

e

Includes two developments (Caribou and Millinocket Lake) that will not conduct upstream fish passage effectiveness 

studies until specific goals are reached for Atlantic salmon returns to the lower dam on the Aroostook River in Maine 

(FERC No. 2367) and two projects (Bonny Eagle and West Buxton) that will not conduct downstream fish passage studies 

until sufficient numbers of river herring and Atlantic salmon are present in the Saco River in Maine (FERC No. 2529 and 

2531, respectively).

Springs-Bradbury (FERC No. 2528) and Skelton (FERC No. 2527), are located on the Saco 

River in Maine; they are the next dams upstream of the Cataract development (FERC No. 2528), 

which is the first dam encountered by upstream migrating anadromous fishes. In this case, 

effectiveness can be evaluated unambiguously, because the population available for passage at 

the upper dams is the number of fish passed at the Cataract dam, which is known. 

The third development (Greenville, FERC No. 2441) is located on the Shetucket River in 

Connecticut and utilized an alternative approach (mark-recapture study) to measure the 

effectiveness of the upstream passage facility. While the approach in this case may be different, 

this measure of effectiveness is sufficient, because the numbers of fish available for passage at 

the facility were estimated. 

A case study of upstream fish passage at four dams on the lower Susquehanna River is 

presented in Appendix B. Although the relicensing of these projects occurred before 1987, 

substantial efforts have been taken to evaluate fish passage in the Susquehanna River. The 

inclusion of these projects is intended to supplement the analyses presented here. 

2.3.1.1 Summary of Results 

The effectiveness of the three upstream fish passage facilities ranged from 45 to 67% 

(Table 2-6). Passage efficiencies were highest for river herring at the Springs-Bradbury 
Table 2-6. Results of monitoring upstream fish passage at eight hydropower developments. Fish passage 

 of fish passed at the downstream dam that were passed at the dam noted in the 

(ND = No data available; NA = Not applicable; NT = Not tested: TNT = Trap-and-truck) 

LOCATION FACILITY NUMBER OF FISH PASSED FISH PASSAGE EF

(%) 

Development 

(FERC No.) 

River State Dam Locationa Type Statusb Year of Initial Operation Year Atlantic Salmon American Shad River Herringc Atlantic Salmon Americ

Shad 

Ellsworth (2727) 

Union ME 1 TNT I 1974 2000

2001 2002 

Maximumd

8 2 

11 72 

ND ND ND ND 

362,610 446,850 666,967 666,967 

ND ND 

Cataracte

(2528) 

Saco ME 1 Lift/Denil/TNT P 1993 2000

2001 2002 

Maximumd

50 69 47 88 

ND ND ND 

4,629 

5,429 

44,839 20,198 44,839 

ND ND 

Springs Bradburye

(2528) 

Saco ME 2 Locks I 1997 2000

2001 2002 

Maximumd

ND ND ND ND 

ND ND 

557 

ND 

3,626 

27,271 

ND ND 

ND ND 

ND ND 

Skelton (2527) 

Saco ME 3 Lift/TNT P 2001f 2001 

2002 

Maximumd

31 26 31 

ND 

0 0 

ND 

11,582 11,582 

45 55 

ND 

0 

Greenville (2441) 

Shetucket CT 1 Lift P 1996g 1996 

1997 1998 

2 

10 16 

926 

2,860 5,577 

142 950 471 

NT 55h 

West Springfield (2608) 

Westfield MA 1 Denil P 1996 1996

1997 

21 39 

1,413 1,009 

ND ND 

ND ND 

Fort Halifax (2552) 

Sebasticook ME 1 Pump/TNT I 2000 2000

2001 2002 

Maximumd

0 0 0 0 

1 1 0 1 

128,741 145,067 153,103 153,103 

ND ND 

Harvell (8657) 

Appomattox VA 1 Denil P 1997 2001 NA 2 1,141j 

aFirst or lowermost dam on river = 1. bI = interim; P = permanent. cIncludes alewife (primarily) and blueback herring. dMaximum number of fish passed during 15-year period (1988-2002) or since year of initial operation. eDevelopment includes two upstream fish passage facilities. fFishway was not operational until August 2001. gMonitoring initiated on May 16 and conducted through June 27 in 1996 (31 d) and from March-June in 1997 (74 d) and 1998 (83 d).hEffectiveness was based on a mark-recapture study with 120 adult shad. iAnnual production goal for Kennebec River above Augusta. j98.7% blueback herring; 27 hickory shad, another anadromous clupeid, not included. 
21

development. The estimates of effectiveness at the Skelton project are somewhat lower, in part, 

because the counts there were compared to the first or lowermost dam on the river and not with 

the next dam downstream (i.e., Springs-Bradbury). The greater distance between dams 1 and 3 

than between dams 2 and 3, the preferred comparison, may have increased the probability for 

delays during passage at the Springs-Bradbury facilities. Estimates of fish passage effectiveness 

from the mark-recapture study with American shad at the Greenville project were remarkably 

similar to those that were based on direct counts of other species using the Skelton upstream fish 

passage facility. 

Effectiveness was not quantified at the other five developments, all of which were the 

lowermost dams on the river. Mark-recapture studies may represent the only quantitative 

method that can be used to estimate the effectiveness of upstream fish passage at dams such as 

these (i.e., the first dam in the basin). Nevertheless, these projects are included in this analysis 

because most (the exception is the Harvell Project, FERC No. 8657, in Virginia) are located in a 

river basin that has specific numeric goals for anadromous fish restoration (not percent passage), 

and the counts made at the upstream passage facility provide a measure of attainment of those 

goals. When the actual counts at those five developments are compared to the restoration goals 

for these lowermost dams, only the Ellsworth Project has passed enough fish to exceed 10% of 

the goal for the Union River (e.g., 14 and 33% of the goals for Atlantic salmon and alewives, 

respectively). 

The recovery of anadromous fish stocks, especially Atlantic salmon, has been slow in 

many coastal river basins of the Northeast (Table 2-7). Even stocks of river herring, primarily 

alewives, are well below relatively recent historical levels in the Connecticut and Merrimack 

rivers, while populations in the Union River in Maine are recovering well. The slow recovery 

elsewhere may explain why 45% of the required upstream passage facilities have not been 

installed (Table 2-3). For those developments with installed facilities, low anadromous fish 

abundance also may account for the absence of monitoring data at some projects (Table 2-5). 

2.3.1.2 Assessment of Effectiveness 

Although most of the facilities listed in Table 2-6 were successful in passing upstreammigrating anadromous fishes, their effectiveness (expressed as the numbers of fish passed as a 

percent of those available, for example) was adequately measured at only a relatively few 

developments. Moreover, all species were not passed upstream with equal effectiveness. 

Design and Species Considerations

Three of the eight upstream fish passage facilities in Table 2-6 were Denil fishways, the 

most common fishway in the Northeast because it can pass most migratory species and all 

alosids (Schaefer 2003). A plan to monitor the effectiveness of the fishway at the West 

Springfield Project (FERC No. 2608) was submitted and approved, and monitoring was 

conducted for two years. After the FWS and the Massachusetts Division of Fisheries and 

Wildlife (MDFW) concurred that the facility was functioning effectively, the MDFW assumed 

responsibility for day-to-day operations, as outlined in a Memorandum of Agreement with the 
Table 2-7. Numbers of river herring (RH) and Atlantic salmon (AS) passed at dams on East Coast riv

(N/A = data not available) 

Connecticut River 

Holyoke Dam 

(MA) 

Merrimack River 

Lawrence Dam 

(MA) 

Saco River 

Cataract Dam 

(ME) 

Androscoggin River 

Brunswick Dam 

(ME) 

Penobscot River 

Veazie Dama

(ME) 

Year 

RH AS RH AS RH AS RH AS AS 

1983 454,242 25 4,700 114 N/A 1 601 20 799 1984 480,000 86 1,800 115 N/A

2 2,650 94 1,451 

1985 630,000 285 23,000 213 N/A 80 23,895 25 3,020 1986 520,000 280 16,000 103 N/A 37 35,471 80 4,125 1987 380,000 208 77,000 139 N/A 40 63,523 27 2,341 1988 340,000 72 381,000 85 N/A 38 74,341 14 2,688 1989 290,000 80 388,000 84 N/A 19 100,895 19 2,752 1990 390,000 188 254,000 248 N/A 73 95,574 185 2,953 1991 410,000 152 379,000 332 N/A

4 77,511 21 1,578 

1992 310,000 370 102,000 199 N/A N/A 45,050 15 2,233 1993 103,000 169 14,000 61 831b 53b 5,202 44 1,650 1994 31,766 283 89,000 21 2,224 21 19,190 25 1,042 1995 112,136 151 33,425 34 9,820 34 31,329 16 1,342 1996 56,300 260 51 78 9,163 54 10,198 38 2,045 1997 63,945 199 403 71 2,130 28 5,540 1 1,355 1998 11,170 298 1,832 123 15,581 28 25,177

5 1,210 

1999 2,760 154 7,898 185 31,070 88 8,909

5 969 

2000 10,593 77 23,585 82 25,136 50 9,551

4 532 

2001 10,628 40 1,550 83 58,890 69 18,198

5 787 

aNo effective mechanism to count clupeids. bNew Saco River fishways began operating in 1993. The West Channel trap began operating in 1992. c666,967 river herring and 11 Atlantic salmon were passed in 2002. 

SOURCE: PPL Maine, LLC. 2002. Union River Fisheries Coordinating Committee Annual Report, 2000-2001. PPL Maine, LLC, 
23

licensee. Another Denil fishway is located at one of the two dams at the Cataract development 

(FERC No. 2528). Because the passage data from the two dams were not presented separately, 

no analysis of the Denil fishway effectiveness was possible. 

The Denil fishway at the Harvell Project in Virginia was evaluated in a 2001 study that 

showed the percentage of the target species, anadromous clupeids, using the fishway 

corresponded to the percentage observed from concurrent electrofishing surveys conducted 200 

m below the dam. FERC approved the combination of the two datasets as the basis for 

estimating passage efficiency. A Compliance Order issued by FERC on March 4, 2003 required 

submittal of a report on the monitoring results within 60 days of the date of the Order, but the 

issue of fish passage at the Harvell dam has not been resolved. A vertical-slot fishway installed 

at the Buchanan Project (FERC No. 2551) on the St. Joseph River in 1990 was reported by 

Francfort et al. (1994) to pass 92% of the chinook salmon and 69% of the steelhead that migrated 

upstream from Lake Michigan. 

A quantitative measure of fish passage effectiveness was obtained at three of the four 

developments with fish lifts or locks (Table 2-6). Estimates ranged from 45 to 67% across 

developments and species. These values are within the range of passage efficiencies given in the 

management plan for American shad in the Connecticut River basin (Connecticut River Atlantic 

Salmon Commission 1992). That plan stipulates an annual passage of 40 to 60% of the 

spawning run at each successive upstream barrier on the mainstem Connecticut River. Based on 

this comparison, the lifts/locks at these three developments (Table 2-6) can be judged successful, 

while recognizing that the Connecticut River criterion applies only to American shad, and the 

estimated effectiveness values in Table 2-6 are based on the passage of Atlantic salmon and river 

herring, in addition to American shad. The FWS and CDEP concur that the fish lift at the 

Greenville project is effective in passing the target species (shad and river herring) above the 

dam. 

Problems with the passage of American shad were noted at the Fort Halifax Project 

(FERC No. 2552) and the Springs-Bradbury development (FERC No. 2528), which actually 

consists of two dams, each with a fish lock. Studies to improve fish passage at the SpringsBradbury dams have been conducted since 1997, when the locks were installed. Many actions 

were tried, including altering flow through the deep gates and the position of the crowder gate, 

collecting extensive velocity measurements, installing underwater cameras, installing lighting, 

and other actions, which are continuing. In the interim, shad will be collected at the downstream 

Cataract development fish passage facilities and transported above the Springs and Bradbury 

dams. 

The pump at the Fort Halifax Project1

 on the Sebasticook River, a tributary of the 

Kennebec River in Maine, is an interim facility that was installed for the collection of alewives 

(e.g., average of 140,000 passed annually in 2000-2003). The low numbers of shad passed 

upstream in the pump may be due to low numbers of shad below the project, as the Licensee 

 1

 On January 23, 2004, the Commission issued “Order Approving Surrender of License and Partial 

Removal of Project Works and Dismissing Request for Rehearing.” This order granted an application filed by FPL 

Energy Maine Hydro, LLC for surrender of its license for the Fort Halifax Project. Further, this order authorized the 

partial removal of the Fort Halifax dam. 
24

postulates, rather than to other factors related to facility operation. Use of the pump to pass adult 

shad and salmon, however, was not intended initially. Whether the cause of the low passage of 

shad is due to a passage or pump-related problem is not known. 

The movement of radiotagged American shad was studied near the two fish lifts at 

Holyoke Dam (FERC No. 2004) on the Connecticut River in Massachusetts (Barry and Kynard 

1986). Passage efficiencies were 42 and 50% in 1980 and 1981, respectively, and the two lifts 

combined passed 350,000 or more shad upstream each year from 1976 to 1983. Another study 

of American shad passage was conducted at a navigation lock on the Cape Fear River, North 

Carolina (Moser et al. 2000). Passage efficiency for 86 radiotagged shad ranged from 18 to 61% 

during the three-year study, and the lowest efficiency coincided with a year of high river 

discharge. High flow was also observed to decrease fish passage effectiveness at the SpringsBradbury development. 

The abundance of catadromous Anguillid eels has been declining throughout North 

America and worldwide (EPRI 2001), raising concerns about the passage of American eels at 

hydropower developments on coastal rivers and streams. Upstream eel passage facilities 

(eelways) were installed at two developments included in this study: the Millville Hydro Station 

(FERC No. 2343) on the Shenandoah River in West Virginia in 2002, and the Fort Halifax 

Project in 1999. The Millville Project had the first operating eelway in the Chesapeake Bay 

watershed. The estimated number of eels passed upstream at the Fort Halifax eelway ranged 

from 551,262 in 1999 to only 56,292 in 2002. An upstream eelway is planned for installation in 

2003 at the Weston Project (FERC No. 2325) on the lower Kennebec River, and three upstream 

eelways are planned at the Holyoke Project. Also, an upstream eelway has been proposed at 

another project, Medway (FERC No. 2666), on the West Branch Penobscot River in Maine. No 

information is available on the effectiveness of these eel passage facilities. 

Trap-and-truck has been employed at several other developments, usually as an interim 

measure until restoration goals are reached. At that time, permanent fish passage facilities would 

be installed. The Fort Halifax Project employs trap-and-truck but uses a Transvac fish pump to 

capture river herring. The pump has achieved interim passage goals for alewives, and the 

collection and transport of 153,103 river herring in 2002 was the largest number of fish collected 

since anadromous fish restoration efforts in the Kennebec River basin were initiated in 1986. 

Adequacy of Effectiveness Monitoring

One of the best measures of the effectiveness of upstream fish passage incorporates the 

number of fish available for passage, as well as the number that actually pass the dam, in the 

calculation of effectiveness. Mark-recapture or radiotagging studies are good examples of the 

types of effectiveness monitoring approaches that can be used at the lowermost dam on the river. 

Such studies were conducted at the Greenville dam on the Shetucket River, a tributary of the 

Thames River in Connecticut (Table 2-6) and at Holyoke Dam by Barry and Kynard (1986). 

Both studies focused on the upstream passage of American shad. For other dams that are farther 

upstream, a quantitative estimate of upstream passage effectiveness can be obtained from fish 

passage counts at the dam of interest and the next lower dam. In this case, effectiveness is 
25

expressed as a proportion of the number of fish available for passage (i.e., those that were passed 

above the lower dam). 

In this study, facilities were determined to be satisfactory and fish passage was judged 

successful by regulatory agencies based on substantially less information, such as direct 

observations of fish passage, conformance with design criteria, and a comparison of relative 

abundance of target species in fishway counts with relative abundance in the population below 

the dam. While the use of more rigorous, quantitative evaluations of facility performance may 

provide a more accurate measure of effectiveness, project economics often dictates the use of 

less rigorous and more qualitative measures. Fewer than half the developments in Table 2-6, all 

of which were required to develop effectiveness monitoring plans, utilized such an approach. 

2.3.2 Downstream Fish Passage 

The proportion of fish that utilized downstream fish passage facilities was estimated at 

11 developments, and actual counts of downstream migrants were made at one (Table 2-8). The 

larger number of developments that evaluated the effectiveness of downstream compared with 

upstream fish passage facilities reflects both the greater number of developments with 

downstream fish passage requirements (Table 2-2), and a more straightforward approach that can 

be used to measure downstream passage effectiveness (Section 1.2.1.1). 

2.3.2.1 Summary of Results 

At seven of the 12 developments (58%), radiotagging was used to measure the 

effectiveness of downstream passage for Atlantic salmon smolts. All of these developments are 

located in the Northeast. A different technique was utilized at each of the other five 

developments; these included radiotagging, acoustic tagging, marking (Floy tags), video 

monitoring, and complete census by draining the facility. 

The range in effectiveness of the 12 downstream fish passage facilities listed in Table 2-8 

was very broad. The percentage of radiotagged or marked fish that utilized downstream 

bypasses (compared to other passage routes) ranged from 6 to 100% for anadromous species and 

from 3 to 87% for resident species. This same degree of variability was evident when only the 

studies that utilized radiotagged Atlantic salmon smolts were considered. High variability in 

effectiveness also occurred among years for the same facility and species (e.g., Atlantic salmon 

smolts). For example, effectiveness ranged from 17 to 63% over a four-year period at the 

Cavendish Project (FERC No. 2489) on the Black River in Vermont and, similarly, from 17 to 

59% at the Mattaceunk Project (FERC No. 2520) on the Penobscot River in Maine. The high 

variability in downstream passage effectiveness between years that was observed at most of the 

projects may be associated with flow differences. Tests of effectiveness were generally 

scheduled to avoid periods of spill during high river flows. Recapture rates of marked Atlantic 

salmon smolts at the Cavendish Project on the Black River in Vermont were observed to be 

highest later in the migration season when river flows had subsided. Because of the 

configuration of the project, relatively low flows in the Black River can result in passage of some 

of the water over the spillway. The low effectiveness of the Essex 19 downstream fish bypass 

facility on the Winooski River in Vermont (FERC No. 2513) was attributed to unusually high 
Table 2-8. Results of monitoring the effectiveness of downstream fish passage at 12 hydro

LOCATION

FACILITY

RESULTS

Development 

(FERC No.) River State Dam Locationa Typeb Statusc Year of Initial Operation Speciesd Methode Effe

Deerfield No. 2f(2323) 

Deerfield MA 1 Sluice

P 1999 ATS RT 1999

2000 2002 2003 

Gardners Falls (2334) 

Deerfield MA 2 Sluice

(with 

louvers) 

I

g 1999 ATS RT 1999

2000 

Deerfield No. 3 f(2323) 

Deerfield MA 3 Surface

collection 

P 1999 ATS RT 1999

2000 2002 2003 

Deerfield No. 4 f(2323) 

Deerfield MA

4 Surface

collection 

P 1999 ATS RT 1999

2000 2002 2003 

Greenville (2441) 

Shetucket CT 1 Sluice

(with 

ABR) 

P 1996 JC

V 1997 

Cavendish (2489) 

Black VT 6 Surface

collection 

I 1996 ATS MR 1998 i

1999 2000 2001 

Essex 19 (2513) 

Winooski VT 3 Sluice

P 1996 ATSk RT 1996

1997 

Ayers Island (2456) 

Pemigewasset NH 2 Spill I 1992 ATS RT 1992

1993 1999 
LOCATION FACILITY RESULTS

Development 

(FERC No.) River State Dam Locationa Typeb Statusc Year of Initial Operation Speciesd Methode Effe

Mattaceunk (2520) 

Penobscot ME 5 Surface

collection 

P 1992 ATS RT 1993

1994 1995 1997 1998 1999 

Rock Island (0943) 

Columbia WA 7 Spill I 1996 JCS AC 2001 

Hudson Falls (5276) 

Hudson NY 2 Surface

collection 

(with 

ABR) 

P 1995 RES RT 1998

1999 (1) 1999 (2) 

Prospect No. 3 (2337) 

S. Fork 

Rogue 

OR 1 Sluice

(with 

inclined 

screen) 

P 1996 RBT CC 1999 

aFirst or lowermost dam on river = 1. bABR = angled bar rack. cI = interim; P = permanent. dATS = Atlantic salmon smolts; JC = juvenile clupeids; JCS = juvenile chinook salmon; RES = resident species (several); RBT = reRT = radio-tagging; V = video monitoring; MR = mark-recapture study; AC = acoustic tagging (internal); CC = complete census bfData for 2002 and 2003 from Ragonese (2003). gApproval to construct permanent downstream fish passage facilities issued on 7-25-01. hNumber of fish observed using downstream fish passage facility based on monitoring conducted from 6-8-97 to 7-1-97 and 9-8-97 

to 10-16-97). 

iResults of earlier studies not included due to extended periods of spill (1996) and the use of landlocked Atlantic salmon parr as surjMean value; number of tests in parentheses. kLandlocked Atlantic salmon smolts, which is the population inhabiting Lake Champlain and the Winooski River, a tributary. lValues represent the percentage of fish that utilized the fishway of those fish that moved downstream to the forebay; number in pa

that utilized the fishway of the total fish released. 
28

river flows and having to conduct tests during spills. Likewise, the effectiveness tests conducted 

at the Deerfield Project (FERC No. 2323) were scheduled to avoid spills over the dam. 

Moreover, these tests showed that the probability of downstream passage via the bypass facility 

increased with reduced intake flows (i.e., a higher bypass: intake flow ratio). Similarly, at the 

Gardner Falls Project (FERC No. 2334), which is located on the Deerfield River between the 

Deerfield No. 2 and Deerfield No. 3 developments, bypass effectiveness was higher at lower 

generating flows. Finally, reduced or no generation at one of the units of the Mattaceunk Project 

(FERC No. 2520) on the Penobscot River in Maine may be a major factor contributing to higher 

bypass efficiencies. 

2.3.2.2 Assessment of Effectiveness 

Substantially more data are available on the effectiveness of downstream fish passage 

facilities than on upstream passage facilities (Section 2.3.1.1). There were 28 studies of 

downstream fish passage effectiveness (Table 2-8) compared to only three quantitative studies of 

upstream passage effectiveness (Table 2-6). The former effectiveness tests, however, exhibited 

considerably more variability than the upstream effectiveness studies, even though the same 

method and species were used in 19 of the 28 downstream passage tests. 

Design and Species Considerations

Of the 34 tests to assess effectiveness, 18 were conducted on Atlantic salmon smolts at 

downstream fish passage facilities consisting of some method of surface collection and 

conveyance below the dam. At the Cavendish Project (FERC No. 2489), an uncovered ogee 

chute served as a sluiceway to transport fish from the entrance at the side of the dam to the 

plunge pool below. At the Mattaceunk Project (FERC No. 2520), fish were transported from 

surface inlets in two of the four turbine forebays (strobe lights were used to repel fish in the other 

two forebays) to a collection chamber and a 42-inch, stainless steel underground fish passage 

pipe. At the Deerfield Project (FERC No. 2323), which has a total of eight developments, a 

surface entrance to a downstream bypass channel characterized the facilities at both the Deerfield 

No. 3 and No. 4 developments. Despite the general similarities among the above four 

developments in the type of downstream passage facility and the use of the same species 

(Atlantic salmon smolts) and experimental approach to measure effectiveness, the results were 

highly variable (Table 2-8). The maximum effectiveness in passing Atlantic salmon smolts 

downstream for each of the four passage facilities ranged from 59 to 78%, and effectiveness 

exceeded 50% in 10 of the 18 tests. Studies conducted on existing surface bypass systems on the 

Columbia River suggest that they can be very effective in passing Pacific salmon smolts around 

mainstem dams (Ferguson et al. 1998). 

Sluices can be very similar in design to downstream passage facilities that utilize some 

method of surface collection. If fish tend to be oriented toward and concentrated in the upper 

portions of the water column, they may use surfaces or overflow areas that lead to existing ice 

and trash sluiceways to bypass the turbine intakes (Rainey 1985, as cited in Sale et al. 1991). 

Moreover, it is not uncommon to find sluiceways that incorporate a behavior guidance device, 

such as angled trash racks or louvers, in their design. They function to guide fish to a 

downstream bypass entrance. Although the data on sluice effectiveness in Table 2-8 are very 
29

limited, the project that utilized such a device (louvers at Gardner Falls, FERC No. 2334) 

achieved a substantially higher level of effectiveness (72%) than those two that did not 

(maximum = 27%). 

The effectiveness of angled trash racks and louvers in preventing fish passage through 

turbines has been evaluated in both laboratory and field studies. These devices have been 

installed or planned at hydroelectric projects with increasing frequency (EPRI 2003). Laboratory 

research suggests that 45° bar racks, most of which have targeted anadromous species, may have 

guidance efficiencies below 50% for riverine species and eels (Amaral 2003). However, flume 

experiments with 45° bar racks and yearling shortnose and pallid sturgeon resulted in guidance 

efficiencies of 58-80% (Kynard and Horgan 2001). Laboratory data on louvers, on the other 

hand, indicate that they could guide a wide range of species at efficiencies exceeding 80% 

(Amaral 2003). 

Trash racks placed at an angle to the intake flow with one-inch spacing between bars are 

commonly required in the Northeast (Sale et al. 1991). Effectiveness studies of this technology 

were conducted at the Wadhams Project (FERC No. 9691) on the Boquet River in New York 

(Nettles and Gloss 1987). More than 90% of the radiotagged Atlantic salmon smolts utilized the 

bypass (58%) or the spillway (33%), and none were entrained through the turbine penstocks 

when the angled trash rack was deployed. In another study of the Lower Saranac Hydroelectric 

Project (FERC No. 4114) located on the Saranac River in New York, the same experimental 

technique (radiotagged Atlantic salmon smolts) was used with similar results (Simmons 2000). 

Bypass effectiveness exceeded 95% for the salmon smolts and none passed through the turbine. 

Steelhead trout were also tested; most of the fish that were released in the two tests used the 

bypass (62%) or the spillway (6%) but 9% passed through the turbine. The same system of 

angled trash racks and bypass was recommended for installation at three other projects in New 

York (FERC 1996). 

Relatively few field studies of louver-bypass systems have been conducted. Two recent 

studies at Canadian hydroelectric projects assessed the guidance efficiencies of louvers on 

Atlantic salmon smolts. At a facility on the Exploits River in Newfoundland, fish guidance 

efficiencies increased from 25 to 65% following improvements to prevent fish losses through the 

louver (Scruton et al. 2002). Guidance efficiencies exceeding 85% were obtained in studies of 

downstream fish passage at a hydroelectric project on the LaHave River in Nova Scotia (Amiro 

and Jansen 2000). Finally, an important, two-year EPRI study of louvers at the Holyoke Project 

was initiated in 2003. The louver-bypass facility, which is one of only a few such facilities in the 

United States, consists of an existing 15° angled louver system and a temporary 25° structure 

that will be tested to determine their effectiveness in guiding riverine species and eels away from 

the turbine intakes and into a downstream bypass facility (EPRI 2003). 

Based again on limited data, the most effective downstream passage method was spill. 

Following several years of continuous design modifications, the Ayers Island project (FERC No. 

2456) achieved 100% effectiveness in passing radiotagged Atlantic salmon smolts downstream 

(Table 2-8). The project is located on the Pemigewasset River, a tributary of the Merrimack 

River, in New Hampshire and uses surface spill through a newly installed flashboard that was 

modified to pass downstream-migrating smolts. The length of the spillway section of the dam is 
30

267 feet (length of dam is 699 feet) with a maximum height of 72 feet. A bypass survival study 

involving 33 radiotagged smolts released into the bypass flow indicated that 29 fish (91%) had 

moved to a monitoring station 1.6 miles downstream; the other four fish remained in the plunge 

pool (two fish), the reach between the dam and monitoring station (one fish), or passed 

undetected (one fish). Spill is also the preferred method of passage at many of the dams on the 

Columbia River, including Rock Island (FERC No. 943). However, a new permanent 

downstream bypass facility was recently installed at the 1237-MW Rocky Reach Hydroelectric 

Project (FERC No. 2145), which was not included in the database used in this study, at a cost of 

$112 million (Anonymous 2003). Because it reduces the need for spill, the facility is expected to 

save $400 million over a 15-year period by generating electricity with water that would 

otherwise have been spilled. 

Another, alternative approach to mitigate the effects of dams on fish passage is 

modification of the turbines to reduce mortality during fish passage. The development and 

testing of new turbine technology is an important component of the DOE Hydropower Program 

(DOE 2004). Included in the Program’s large turbine field testing activity is the replacement of 

an existing Kaplan turbine with a minimum gap runner turbine at Wanapum Dam, a development 

that is part of the Priest Rapids Project (FERC No. 2114) on the Columbia River in Washington. 

Installation of this new, advanced-design turbine follows several years of DOE-funded research 

on turbine modifications to improve fish survival. An order was issued by FERC on April 30, 

2004 authorizing installation of the new turbine in Unit No. 8. A subsequent order issued on 

July 23, 2004 authorized the replacement of the ten turbines at Wanapum and operation of Unit 

No. 8, subject to conditions of the State of Washington’s Water Quality Certificate and the 

Biological Opinion issued by NOAA Fisheries. A passage survival study will be conducted at 

Unit No. 8, and the results will be used as a basis for proceeding with the replacement of the nine 

remaining units. 

Studies of the effectiveness of downstream fish passage have focused almost exclusively 

on salmonids, because they are the targets of major restoration programs in the Northeast and the 

West/Northwest. Downstream passage of other species, such as American shad, has not been 

addressed with equivalent experimental rigor. Effectiveness testing with juvenile clupeids, using 

the same experimental protocols as those used for salmon smolts, may not be feasible due to 

their sensitivity to stress. On the other hand, the preferred technique of counting juvenile 

clupeids utilizing downstream passage facilities by video monitoring does not provide a 

quantitative measure of effectiveness. Also, the behavioral response of fish to a guidance device 

is species-specific, so extrapolating the results from one species to another (e.g., Atlantic salmon 

smolts to juvenile shad) may not be appropriate, especially between different families of fishes, 

such as salmonids and clupeids. Additional research on nonsalmonids would contribute to 

selection of the most effective downstream fish passage facility for the targeted species. 

Likewise, little is known about the effectiveness of methods for diverting riverine species 

away from turbine intakes and into a downstream bypass facility. Quantitative techniques were 

used to estimate the effectiveness of the downstream passage of riverine species at the Hudson 

Falls Project (FERC No. 5276) on the upper Hudson River in New York. Studies were 

conducted with a total of 154 radiotagged fish, including four centrarchids and three percids, that 

were monitored for 30 days during each of three periods of testing (fall 1998, early spring 1999, 
31

and late spring 1999). Most of the fish (77%) did not pass downstream of the project, but of the 

35 fish that did move downstream, 51% used the fish passage facility and 31% used the spillway. 

These results suggest that evaluating downstream passage effectiveness for those species that are 

not migratory (i.e., most movements, at least for the centrarchids, are highly localized) is 

difficult and will require frequent interaction with resource and regulatory agencies to select the 

most appropriate methodology. 

Concern for the declining abundance of the catadromous American eel has resulted in the 

assessment of eel passage at hydropower dams. Utilization of downstream fish passage facilities 

by eels has been studied at the Medway Project (FERC No. 2666) on the West Branch Penobscot 

River in Maine. A video camera was used to monitor eel passage through the weir and flume 

located adjacent to the spillway. Difficulties were encountered with lighting and obscurance of 

the lens by insects and algal growth, so additional future monitoring is planned after resolving 

these problems. Plans to install an upstream eelway at the Medway project in 2004 have been 

developed by the licensee. 

Adequacy of Effectiveness Monitoring

Most of the studies of downstream fish passage reviewed in this study used an 

appropriate measure to determine effectiveness. The percentage of fish utilizing a downstream 

bypass facility from a sample of marked or radiotagged fish released above the dam is the best 

procedure. In this case, the problem is not with the measure of effectiveness that was used, as 

was the case in evaluating upstream fish passage effectiveness (Section 2.3.1.2), but with its 

limited application to nonsalmonid species. Most of the effectiveness monitoring of downstream 

fish passage has focused on salmonids, especially Atlantic salmon smolts, with highly variable 

results. Levels of effectiveness substantially exceeding 50% may be difficult to achieve on a 

consistent, cost-effective basis. High passage efficiency is dependent upon flow conditions, 

including the volume of flow for spills, power generation, and fish bypass as well as the 

apportioning of flow among these three uses. 

Spill was the most effective method of bypassing downstream migrants around dams in 

the Northeast. However, data on the effectiveness of spill, and the mortality associated with this 

route of passage, are limited, and the results may not be applicable to larger projects, such as 

those on the Columbia River. At many hydropower developments, the costs associated with spill 

for the purpose of downstream fish passage will be too high and this approach will not be 

feasible, but at some projects, it may be practical to make better use of this route of passage. 

33

3.0 SUMMARY AND CONCLUSIONS 

A total of 269 hydropower projects licensed between 1987 and 2002 were reviewed to 

assess the effectiveness of the mitigation that was implemented to pass fish upstream and 

downstream around dams. The review focused on 112 projects comprising 147 developments 

that had specific requirements for upstream and downstream fish passage. The other 157 

projects could not be evaluated for effectiveness because they had only a license article reserving 

authority under Section 18 of the FPA and no other fish passage requirements. 

3.1 MITIGATION EFFECTIVENESS 

Having well defined performance criteria would provide an unambiguous measure of the 

effectiveness of fish passage facilities. Such criteria were available in an earlier FERC study of 

the effectiveness of water quality mitigation at hydropower projects (FERC 2003). In that study, 

compliance with water quality criteria was used because states have established clearly defined 

criteria to protect aquatic ecosystems. Although no similar performance standards exist for fish 

passage, effectiveness can be assessed using the percentage of fish that are passed upstream or 

downstream. Nevertheless, the question remains regarding what passage percentage is 

acceptable. 

3.1.1 Upstream Fish Passage 

Of the 147 developments that had one or more license articles related to fish passage, 95 

developments (65%) required an upstream passage facility. More than 60% of the installed 

facilities are located in the Northeast where they are used to support efforts to restore 

anadromous fish stocks in coastal river basins. Upstream passage of riverine species was 

required at 6 of the 12 installed facilities in the West/Northwest and will be required at 12 of the 

23 upstream fish passage facilities planned at hydropower developments in the North Central 

United States. The technology for passing anadromous fishes upstream around dams is well 

developed, but its success can be difficult to measure at individual dams. Successful upstream 

passage of riverine fishes and catadromous eels, on the hand, will require additional research to 

identify the best approaches and those critical design and site-related factors that influence 

effectiveness. 

Eight hydropower developments had quantitative data available on upstream fish 

passage, but only three developments in the Northeast had data that could be used to directly 

assess the effectiveness of the upstream passage facilities. Using the counts of fish at two dams, 

the number of fish passed, when expressed as a percentage of the fish available for passage, 

provided an objective measure of effectiveness, assuming that spawning between dams is 

negligible. At the three developments, passage effectiveness for three anadromous species 

ranged from 45 to 67%, which met the performance guideline of 40 to 60% for annual passage of 

American shad at each successive upstream barrier on the Connecticut River (Connecticut River 

Atlantic Salmon Commission 1992). Only one study used radiotagging to assess effectiveness, 

and that value (55%) was similar to those obtained from the comparison of direct counts between 

dams. 
34

3.1.2 Downstream Fish Passage

Downstream fish passage was required at 132 of the 147 developments (90%) that had 

more than a license article reserving authority under Section 18 of the FPA. Most of these 

downstream passage facilities (53%), however, were not yet installed. Of the 63 facilities that 

have been installed, most (75%) are located in the Northeast, a trend similar to that observed 

with upstream fish passage. Nationwide, 55% of all the downstream passage facilities, both 

those in operation and those that are planned, must consider riverine fish passage. 

Because an experimental approach (i.e., mark-recapture or radiotagging studies) could be 

used to assess effectiveness and because downstream fish passage was a more common 

requirement in FERC licenses, more quantitative estimates of effectiveness were available for 

downstream than upstream passage. The results from 34 tests at 11 hydropower developments 

were highly variable even though the experimental approach and species tested (Atlantic salmon 

smolts) were similar in most of the tests. The percentage of radiotagged or marked fish that 

utilized downstream passage facilities ranged from 6 to 100% and from 3 to 87% for 

anadromous and riverine species, respectively. This variability decreased somewhat when the 

test method, species, and type of facility were similar. For example, 18 of the 34 tests were 

conducted on Atlantic salmon smolts at four facilities that employed surface collection with 

conveyance below the dam. At these developments, maximum effectiveness ranged from 59 to 

78% but exceeded 50% in only 10 of the 18 tests. 

A major cause of the variability observed in the effectiveness of downstream fish passage 

was testing during periods of high flow, resulting in spill. Avoidance of such periods during 

testing can be difficult; the time for the outmigration of smolts often overlaps with historical 

peaks in the hydrograph. Also important as a factor influencing bypass effectiveness is the 

volume of flow used to pass downstream migrants relative to that used for power generation. 

The technology that has been developed for downstream fish passage is not as effective 

as that for upstream fish passage. Except for spill, the variety of the physical and behavioral 

approaches to downstream passage has met with about the same degree of success. The 

technology for downstream passage of anadromous fishes is not well developed, and additional 

research is needed to identify suitable alternatives that have applicability across sites. Even 

though the data from the present study are limited, further research seems warranted to 

investigate the use of spill as an additional, secondary route of passage. There may be relatively 

minor, cost-effective modifications that can be made to enhance passage via spill whenever it 

occurs. Also needed are suitable measures to divert and bypass riverine species away from 

turbine intakes. Sixty-five percent of the planned downstream fish passage facilities will require 

effective passage of riverine fishes. 

3.2 ADEQUACY OF EFFECTIVENESS STUDIES 

Although data on effectiveness were available for less than 10% of the 269 projects 

(=304 developments) included in the database, enough studies of fish passage effectiveness were 
35

conducted to evaluate the methods and criteria that were used to determine effectiveness. A 

summary of this evaluation is presented below. 

Importance of Effectiveness Monitoring

The process of mitigating adverse environmental impacts should include an assessment 

of the effectiveness of the mitigation that is implemented. A license article requiring 

effectiveness monitoring was included in the license for 89 of the 147 developments (61%). This 

percentage represents a significant increase over the percentage of projects that were required to 

monitor fish passage effectiveness in a survey conducted almost 15 years ago (Sale et al. 1991). 

In that survey, only 43 and 21% of the operating projects had monitored the performance of 

upstream and downstream fish passage, respectively. 

The estimate of 61% of the licenses having an effectiveness monitoring requirement may 

be conservative. Even though a project may not have a license article that requires effectiveness 

monitoring, such monitoring may be required in the future when the fish passage facility plan is 

actually submitted. For example, effectiveness monitoring is not specifically addressed in the 

Settlement Agreement for 11 projects on the AuSable, Manistee, and Muskegon rivers in 

Michigan, but no plans for upstream or downstream fish passage have been submitted yet. These 

plans may include a requirement for monitoring. 

Monitoring of fish passage facilities could contribute not only to determining the sitespecific effectiveness of the facility but also to evaluating its potential use at other sites. Sale et 

al. (1991) noted the difficulty in transferring knowledge gained at one site to other sites without 

such monitoring. A systematic evaluation of fish passage facilities was recommended by 

Larinier (2001), who noted that the most significant progress in fish passage technology occurred 

in countries that conducted such systematic assessments of facility effectiveness. However, 

Cada and Sale (1993) observed that field studies to assess the effectiveness of fish passage 

facilities were limited. 

Although studies of fish passage effectiveness occur more frequently now than 15 years 

ago, there remains a need for more information on effectiveness, especially of new technologies. 

As noted by Sale et al. (1991) but still valid today, the designs of downstream fish passage 

facilities are varied, and some are relatively recent. Moreover, the operating experience with 

downstream passage facilities is less than that with their upstream counterparts. That many are 

actually demonstration projects is yet another reason why studies of their effectiveness must be 

considered part of the planning for such facilities. 

Selection of Suitable Methods and Criteria

Many of the methods used by licensees to evaluate the effectiveness of fish passage 

requirements are appropriate measures of facility performance. For upstream fish passage, these 

methods include counts of the number of fish passed at the dam of interest as a function of the 

number available for passage, which can be obtained from fish counts at the next dam 

downstream, assuming spawning between dams is negligible. If no data are available for the 
36

lower dam or one does not exist, then a radiotagging study to estimate the proportion of fish that 

are passed upstream can be an appropriate method of assessing effectiveness. 

Radiotagging is also an appropriate procedure for assessing the effectiveness of 

downstream passage. Effectiveness studies could benefit from the advances in fish monitoring 

technologies, such as balloon tags (e.g., Normandeau Associates 1996) and Passive Integrated 

Transponder (PIT) tags, which have been used since 1993 to estimate the survival of salmon 

smolts passing through the hydroelectric projects on the Snake River (Skalski et al. 2001). When 

necessary, mark-recapture studies can be used to determine effectiveness, too. Indeed, markrecapture techniques or hydroacoustic surveys may be the only feasible method for monitoring 

the downstream passage of juvenile clupeids. Counts or direct observation of the number of fish 

that utilize an upstream or downstream passage facility may be necessary but are usually not 

sufficient without some estimate of the size of the population available for passage. In addition, 

assuring that the facility was constructed properly and that all passage-related parameters, such 

as attraction flows and bypass flows, meet the design specifications is a necessary but not 

sufficient requirement for effective passage. 

Having obtained an estimate of passage effectiveness, it is important to be able to 

compare it with some criterion of acceptability. What does a passage efficiency of 50% for an 

anadromous species mean to the restoration of the stock in that river basin? Establishing criteria 

for passage efficiency or effectiveness seems necessary if anadromous fish restoration efforts are 

to be successful. Such criteria are expected to be specific for a given species and river basin. 

With the exception of the 40 to 60% passage criterion developed for American shad by the 

Connecticut River Atlantic Salmon Commission, such criteria have not been proposed. 

3.3 RECOMMENDATIONS TO IMPROVE EFFECTIVENESS 

The process established by the FERC to address the problem of dams as barriers to fish 

passage emphasizes the importance of early interactions between the licensee, resource agencies, 

and other stakeholders to assess the need for mitigation. Including a good, technically sound 

plan to assess the effectiveness of the proposed mitigation will provide the necessary quantitative 

data that can be used not only for a site-specific evaluation but also for the application of the 

same technology to other sites. In most cases, successful mitigation is dependent upon the 

development of such effectiveness monitoring plans. 

In addition to the recommendations included in Section 3.2, the following 

recommendations should be considered: 

1. If cost effective, consider having license articles requiring upstream or 

downstream fish passage also include an effectiveness monitoring plan as 

part of that requirement. 

2. Consider defining the duration of monitoring in the effectiveness 

monitoring plans. When radiotagging is used to assess the effectiveness of 

upstream and downstream fish passage, the duration of monitoring could 
37

be shorter than that for other methods that can produce results with 

inherently higher variability. Depending upon agency review and 

evaluation, testing, in these latter cases, may be necessary during the 

outmigration season for more than one year. Consideration should be 

given to discontinuing effectiveness monitoring if passage is judged to be 

satisfactory. However, the number of fish using the upstream facility 

should be routinely monitored and reported to FERC annually. 

Effectiveness should also be measured and included in these reports, if 

counts are available at the lower dam. 

3. Obtain additional information on the most effective downstream fish 

passage mitigation measures. Field applications of new technologies, 

including quantitative approaches to measure the success of the 

applications, are especially important. No existing national research 

program is available to develop and test innovative downstream passage 

technologies, so new knowledge must be gained from experience and the 

widespread exchange of information. It is important that the best technical 

information be used to evaluate various alternatives for fish passage. 

These recommendations and those identified in the previous section would contribute to 

the goal of implementing the most effective measures for fish passage mitigation. 

39

4.0 REFERENCES 

Amaral, S. 2003. The use of angled bar rocks and louvers for guiding fish at FERC-licensed 

projects. Presentation at FERC Fish Passage Workshop, Alden Research Laboratory, 

Holden, MA, November 13, 2003. 

Amiro, P. G., and H. Jansen. 2000. Impact of low-head hydropower generation at Morgan Falls, 

LaHave River on migrating Atlantic salmon (Salmo salar). Can. Tech. Rep. Fish. Aquat. 

Sci. No. 2323. Department of Fisheries and Oceans, Dartmouth, Nova Scotia. 

Anonymous. 2003. Tech Briefs: Rocky Reach’s new fish bypass produces promising results. 

Hydro Review 22(5):46. 

Barry, T., and B. Kynard. 1986. Attraction of adult American shad to fish lifts at Holyoke Dam, 

Connecticut River. N. Amer. J. Fish Manage. 6:233-241. 

Bell, M. C. 1980. General types of fish passage facilities. pp. 39-59. IN S. Hildebrand (ed.), 

Analysis of environmental issues related to small-scale hydroelectric development. II. 

Design considerations for passing fish upstream around dams. ORNL/TM-7396. Oak 

Ridge National Laboratory, Oak Ridge, TN. 

Cada, G. F., and M. J. Sale. 1993. Status of fish passage facilities at nonfederal hydropower 

projects. Fisheries 18(7):4-12. 

Cada, G. F., and J. E. Francfort. 1995. Chapter 14: Mitigation of environmental impacts at 

hydroelectric power plants in the United States. pp. 223-234. IN F. S. Sterrett (ed.), 

Alternative Fuels and the Environment. Lewis Publishers, Boca Raton, FL. 

Connecticut River Atlantic Salmon Commission. 1992. A management plan for American shad 

in the Connecticut River basin. 

Electric Power Research Institute (EPRI). 2001. Review and documentation of research and 

technologies on passage and protection of downstream migrating catadromous eels at 

hydroelectric facilities. Final Report. Prepared for EPRI by Versar, Inc., EPRI Report 

No. 1000730. Electric Power Research Institute, Palo Alto, CA. 

Electric Power Research Institute (EPRI). 2003. Field evaluation of angled bar rack/louvers for 

fish protection at hydropower projects and cooling water intake structures. Project 

Opportunity Notice. Section 316 (a) and (b) Fish Protection Issues and Hydropower 

Environmental Issues, June 2003. Electric Power Research Institute, Palo Alto, CA. 

Epifanio, J., G. Haas, K. Pratt, B. Rieman, P. Spruell, C. Stockwell, F. Utter, and W. Young. 

2003. Integrating conservation genetic considerations into conservation planning: A 

case study of bull trout in the Lake Pend Oreille-lower Clark Fork River system. 

Fisheries 28(8):10-24. 
40

Federal Energy Regulatory Commission (FERC). 1990. Order approving functional design 

drawings and construction schedule. Conowingo Project (No. 405-027). 50 FERC 62, 

209. Federal Energy Regulatory Commission, Washington, DC. 

Federal Energy Regulatory Commission (FERC). 1992. Hydroelectric power resources of the 

United States: Developed and undeveloped. Federal Energy Regulatory Commission, 

Washington, DC. 

Federal Energy Regulatory Commission (FERC). 1996. Order approving trashrack/fish passage 

facilities drawings and construction and monitoring schedule. Watertown Hydroelectric 

Project (FERC No. 2442), December 19, 1996. 

Federal Energy Regulatory Commission (FERC). 1998. Order modifying and approving, in 

part, upstream fishway evaluation plan. Caribou Dam Development ( FERC No. 2367), 

March 23, 1998. 

Federal Energy Regulatory Commission (FERC). 2000. Interagency Task Force report on 

agency recommendations, conditions, and prescriptions under Part I of the Federal Power 

Act. Prepared by the Work Group on the Coordination of Federal Mandates, Federal 

Energy Regulatory Commission and five other agencies. December 8, 2000. 

Federal Energy Regulatory Commission (FERC). 2001a. Guidance for shoreline management 

planning at hydropower projects. Office of Energy Projects, Federal Energy Regulatory 

Commission, Washington, DC. 

Federal Energy Regulatory Commission (FERC). 2001b. Report on hydroelectric licensing 

policies, procedures, and regulations: comprehensive review and recommendations 

pursuant to Section 603 of the Energy Act of 2000. Submitted to the U.S. Congress, May 

8, 2001. Federal Energy Regulatory Commission, Washington, DC. 

Federal Energy Regulatory Commission (FERC). 2003. Evaluation of mitigation effectiveness 

at hydropower projects: Water quality. Office of Energy Projects, Federal Energy 

Regulatory Commission, Washington, DC. 

Foote, P. 2003. History of the development of fish passage facilities at FERC-licensed projects 

on the lower Susquehanna River. Presentation at FERC Fish Passage Workshop, Alden 

Research Laboratory, Holden, MA, November 13, 2003. 

Francfort, J. E., G. F. Cada, D. D. Dauble, R. T. Hunt, D. W. Jones, B. N. Rinehart, 

G. L. Sommers, and R. J. Costello. 1994. Environmental mitigation at hydroelectric 

projects, Volume II: Benefits and costs of fish passage and protection. DOE/ID10360(V2). Idaho National Engineering Laboratory, Idaho Falls, ID. 

Ferguson, J. W., T. P. Poe, and T. J. Carlson. 1998. Surface-oriented bypass systems for 

juvenile salmonids on the Columbia River, USA. pp. 281-299. IN M. Jungwirth, 
41

S. Schmutz, and S. Weiss (eds.). Fish Migration and Fish Bypasses. Blackwell Science 

Ltd., Oxford, UK. 

Hendricks, M. L. 2003. Email from M. L. Hendricks, Pennsylvania Fish and Boat Commission, 

State College, PA, to J. K. Novak, Federal Energy Regulatory Commission, Washington, 

DC, November 17, 2003. 

Hildebrand, S. G. (ed.). 1980. Analysis of environmental issues related to small-scale 

hydroelectric development. II. Design considerations for passing fish upstream around 

dams. ORNL/TM-7396. Oak Ridge National Laboratory, Oak Ridge, TN. 

Hill, J., and S. C. Murphy. 2003. A review of FERC hydropower licensing: what’s ahead? 

Hydro Review 2(8):32-45. 

Jungwirth, M., S. Schmutz, and S. Weiss (eds.). 1998. Fish Migration and Fish Bypasses. 

Blackwell Science, Ltd., Oxford, UK. 

Kleinschmidt Associates. 1999. 1996-1998 Evaluation of upstream and downstream fish 

passage facilities, Greenville Dam Project. Final Report to City of Norwich, Department 

of Public Utilities. Kleinschmidt Associates, Pittsfield, ME. 

Kareiva, P., M. Marvier, and M. McClure. 2000. Recovery and management options for 

spring/summer chinook salmon in the Columbia River basin. Science 290:977-979. 

Kynard, B. 1998. Twenty-two years of passing shortnose sturgeon in fish lifts on the 

Connecticut River: what has been learned? pp. 255-264. IN M. Jungwirth, S. Schmutz, 

and S. Weiss (eds.), Fish Migration and Fish Bypasses. Blackwell Science Ltd, Oxford. 

Kynard, B., and M. Horgan. 2001. Guidance of yearling shortnose and pallid sturgeon using 

vertical bar rack and louver arrays. N. Amer. J. Fish. Manage. 21: 561-570. 

Larinier, M. 2001. Dams, fish, and fisheries: opportunities, challenges, and conflict resolution. 

FAO Fisheries Technical Paper No. 419. Food and Agriculture Organization of the 

United Nations, Rome, Italy. 

Leggett, W. C., T. F. Savoy, and C. A. Tomichek. 2004. The impact of enhancement initiatives 

on the structure and dynamics of the Connecticut River population of American shad. IN 

P. M. Jacobson, D. A. Dixon, W. C. Leggett, B. C. Marcy, Jr., and R. R. Massengill 

(eds.). The Connecticut River Ecological Study (1965-1973) revisited: Ecology of the 

lower Connecticut River, 1973-2003. American Fisheries Society Monograph No. 9, 

Bethesda, MD. 

Medford, S. 2004. Comments on draft report: Evaluation of mitigation at hydropower projects: 

Fish passage. Attachment to email from S. Medford, Enel North America, Inc. to 

J. Novak, FERC, April 15, 2004. 
42

Moser, M. L., A. M. Darazsdi, and J. R. Hall. 2000. Improving passage efficiency of adult 

American shad at low-elevation dams with navigation locks. N. Amer. J. Fish. Manage. 

20:376-385. 

Nettles, D. C., and S. P. Gloss. 1987. Migration of landlocked Atlantic salmon smolts and 

effectiveness of a fish passage structure at a small-scale hydroelectric facility. N. Amer. 

J. Fish. Manage. 7:562-568. 

Normandeau Associates, Inc. 1996. Fish survival investigation relative to turbine rehabilitation 

at Wanapum Dam, Columbia River, Washington. Report prepared for Grant County 

Public Utility District No. 2, Ephrata, WA. 

Odeh, M., and C. Orvis. 1998. Downstream fish passage design considerations and 

developments at hydroelectric projects in the Northeast USA. pp. 267-280. IN 

M. Jungwirth, S. Schmutz, and S. Weiss (eds.). Fish Migration and Fish Bypasses. 

Blackwell Science Ltd., Oxford, UK. 

Pringle, C. M., M. C. Freeman, and B. J. Freeman. 2000. Regional effects of hydrologic 

alterations on riverine macrobiota in the New World: tropical-temperate comparisons. 

Bioscience 50:807-823. 

Ragonese, J. 2003. Fish passage effectiveness – it’s not just counting fish: Studies on the 

Deerfield River. Presentation at FERC Fish Passage Workshop, Alden Research 

Laboratory, Holden, MA, November 13, 2003. 

Rainey, W. S. 1985. Considerations in the design of juvenile bypass systems. pp. 261-268. IN 

Symposium on Small Hydropower and Fisheries, American Fisheries Society, Bethesda, 

MD. 

Sale, M. J., G. F. Cada, L. H. Chang, S. W. Christensen, J. E. Francfort, S. F. Railsback, 

B. N. Rinehart, and G. L. Sommers. 1991. Environmental mitigation at hydroelectric 

projects, Volume 1: Current practices for instream flow needs, dissolved oxygen, and 

fish passage. DOE/ID-10360. Idaho National Engineering and Environmental 

Laboratory, Idaho Falls, ID. 

Schaefer, S. 2003. Efficacy of a Denil fishway on a low-head dam on a small coastal river in 

central Virginia. Draft Report to Federal Energy Regulatory Commission. Virginia 

Commonwealth University, Richmond, VA. 

Scruton, D., R. McKinley, N. Kouwen, W. Eddy, and R. Booth. 2002. Use of telemetry and 

hydraulic modeling to evaluate and improve fish guidance efficiency at a louver and 

bypass system for downstream-migrating Atlantic salmon (Salmo solar) smolts and kelts. 

Hydrobiologia 483: 83-94. 

Simmons, R. A. 2000. Effectiveness of a fish bypass with an angled bar rack at passing Atlantic 

salmon and steelhead trout smolts at the Lower Saranac Hydroelectric Project. pp. 95-
43

102. IN M. Odeh (ed.). Advances in Fish Passage Technology: Engineering Design and 

Biological Evaluation. American Fisheries Society, Bethesda, MD. 

Skalski, J. R., R. L. Townsend, and R. D. McDonald. 2001. Estimation of Rock Island Project 

survival for yearling chinook salmon smolts in 2001 using PIT-tag release-recapture 

methods. Report prepared for Public Utility District No. 1 of Chelan County, Wenatchee, 

WA. 

Susquehanna River Anadromous Fish Restoration Committee (SRAFRC). 2004. Restoration of 

American Shad to the Susquehanna River. Annual Progress Report, 2003. U.S. Fish and 

Wildlife Service, Harrisburg, PA. 

Turbak, S. C., D. R. Reichle, and C. R. Shriner. 1981. Analysis of environmental issues related 

to small-scale hydroelectric development. IV. Fish mortality resulting from turbine 

passage. ORNL/TM-7521. Oak Ridge National Laboratory, Oak Ridge, TN. 

U.S. Department of Energy (DOE). 2004. DOE Hydropower Program Annual Report for 

FY 2003. DOE/NE-ID-1136. U.S. Department of Energy, Office of Energy Efficiency 

and Renewable Energy, Washington, DC. 

U.S. General Accounting Office (GAO). 2001. Licensing hydropower projects: better time and 

cost data needed to reach informed decisions about process reforms. GAO-01-499. U.S. 

General Accounting Office, Washington, DC. 

Weigmann, D., P. Johnson, J. Kubitschek, R. Tisdale-Hein, and R. Siegle. 2003. A roadmap for 

Public Interest Energy Research (PIER) research on fish passage at California 

hydropower facilities. Draft Report. California Energy Commission, Sacramento, CA. 

Young, L. M. 2003. Comments on “Evaluation of Mitigation Effectiveness at Hydropower 

Projects: Fish Passage Draft Report.” Letter from L. M. Young, Pennsylvania Boat and 

Fish Commission, to J. K. Novak, Federal Energy Regulatory Commission, Washington, 

DC, October 29, 2003. 

45

5.0 LIST OF PREPARERS 

Federal Energy Regulatory Commission 

 John Novak – FERC Task Monitor (Fisheries Biologist) 

Oak Ridge National Laboratory 

 James Loar – Lead Author (Aquatic Ecologist) 

 Glenn Cada – Co-author (Fisheries Biologist) 

47

APPENDIX A 

LIST OF PROJECTS 

49

Table A-1. List of projects (by state) that were included in this study because (1) they were 

licensed or relicensed between 1986 and 2002 and (2) they have at least one fish passage 

requirement. The total of 269 projects are shown in Figure 2-1. An asterisk designates 

those projects with only the reservation of authority requirement. 

State Project 

Number 

License 

Issued Project Name 

Alabama 2407 1994 Yates* 

Alaska 11480 2000 Reynolds Creek 

11690 2000 Old Harbor 

California 0137 2001 Mokelumne 

1061 1992 Phoenix* 

1333 1993 Tule River 

1962 2001 Rock Creek-Cresta* 

2290 1996 Kern River No. 3 

2661 2002 Hat Creek* 

Colorado 8914 1987 Taylor Draw 

Connecticut 2441 1993 Greenville Dam 

5062 1987 Quinebaug-Five Mile Pond 

10822 2001 Upper Collinsville 

10823 2001 Lower Collinsville 

11143 1992 Glen Falls* 

11168 1992 Dayville Pond* 

11217 1992 Still River* 

11547 1997 Hale 

11574 1999 Occum 

Georgia 1218 1999 Flint River* 

1951 1996 Sinclair* 

2354 1996 North Georgia* 

2535 1995 Stevens Creek 

Idaho 2058 2000 Cabinet Gorge 

2381 1987 Ashton-St. Anthony 

8436 1987 Smith Creek 

9907 1987 Sunshine 

11541 2002 Atlanta Power Station 

Illinois 2373 1993 Rockton Project* 

2446 1993 Dixon Project* 

Indiana 2579 1996 Twin Branch* 

11291 1997 Star Milling* 

Maine 2325 1997 Weston 

2329 1997 Wyman* 

2333 1994 Rumford Falls Hydro* 

2367 1993 Aroostook 
50

State Project 

Number 

License 

Issued Project Name 

2368 1991 Squa Pan* 

2375 1998 Riley-Jay-Livermore* 

2403 1998 Veazie 

2458 1996 Penobscot Mills 

2519 1993 North Gorham Project 

2520 1988 Mattaceunk 

2527 1998 Skelton 

2528 1989 Cataract 

2529 1998 Bonny Eagle 

2531 1988 West Buxton 

2534 1998 Milford 

2552 1997 Fort Halifax 

2555 1999 Automatic* 

2556 1999 Union Gas-Messalonskee* 

2557 1999 Rice Pips-Messalonskee* 

2559 1999 Oakland-Messalonskee* 

2572 1996 Ripogenus* 

2666 1999 Medway 

2671 1997 Moosehead 

2712 1998 Stillwater 

2727 1987 Ellsworth 

8277 1998 Otis* 

11132 1996 Eustis* 

11433 1997 Sandy River 

11482 1997 Marcal 

Massachusetts 2004 1999 Holyoke 

2323 1997 Deerfield River 

2334 1997 Gardner Falls 

2497 1989 Mt. Tom Mill* 

2608 1994 West Springfield 

2622 1990 Turner Falls 

2631 2002 Woronco 

2758 1989 Crocker Mill A/B* 

2766 1989 Albion Wheel-D Wheel* 

2768 1989 Albion Wheel-A Wheel* 

2770 1989 Crocker Mill-C Wheel* 

2771 1989 Nonotuck Mill* 

2772 1989 Gill Mill-A Wheel* 

2775 1989 Gill Mill-D Wheel* 

2927 2001 Aquamac 

2928 2001 Merrimac 

Michigan 1759 2001 Way Dam* 

2072 2001 Lower Paint* 
51

State Project 

Number 

License 

Issued Project Name 

2073 2001 Michigamme Falls Dam* 

2074 2001 Hemlock Falls* 

2402 1995 Prickett* 

2404 1998 Thunder Bay 

2433 1997 Grand Rapids* 

2436 1994 Foote 

2447 1994 Alcona 

2448 1994 Mio 

2449 1994 Loud 

2450 1994 Cooke 

2451 1994 Rogers 

2452 1994 Hardy 

2453 1994 Five Channels 

2468 1994 Croton 

2506 1995 Escanaba* 

2536 1997 Little Quinnescec Falls* 

2551 1996 Buchanan 

2566 2001 Webber 

2580 1994 Tippy 

2589 2002 Marquette* 

2599 1994 Hodenpyl 

10624 1991 French Paper 

10808 1998 Edenville* 

10809 1998 Secord* 

10810 1998 Smallwood* 

10854 1997 Cataract Hydroelectric* 

10855 2002 Dead River* 

10856 1997 Au Train* 

11120 2002 Middleville* 

11150 2001 Smithville and Mix* 

11300 2002 La Barge* 

11402 1995 Crystal Falls* 

11428 2001 425-KW Municipal Dam* 

11516 2002 Irving* 

11616 2001 375-KW Portland Municipal 

11730 2001 Alverno* 

11830 2001 Peavy* 

Minnesota 2360 1995 St. Louis River* 

2361 1993 Prairie River Project* 

2362 1993 Blandin* 

2363 1995 Cloquet* 

2454 1993 Sylvan* 

2532 1993 Little Falls* 
52

State Project 

Number 

License 

Issued Project Name 

2533 1993 Brainerd* 

11175 1999 Crown Mill* 

11546 1998 Municipal Power Project* 

Montana 2188 2000 Missouri-Madison* 

New Hampshire 2287 1994 J. Brodie Smith* 

2288 1994 Gorham P.S.N.H. 

2300 1994 Shelburne* 

2311 1994 Gorham J.R. 

2326 1994 Cross* 

2327 1994 Cascade of New Hampshire* 

2422 1994 Sawmill* 

2423 1992 Riverside Project* 

2456 1996 Ayers Island 

2457 1987 Eastman Falls 

11163 1997 South Berwick 

11313 1995 Apthorp 

New York 2047 2002 Stewart’s Bridge 

2060 2002 Carry Falls* 

2084 2002 Upper Raquette River* 

2318 2002 E.J. West* 

2320 2002 Middle Raquette River* 

2330 2002 Lower Raquette River* 

2385 2001 Glens Falls 

2438 1997 Waterloo and Seneca Falls 

2442 1995 Watertown 

2482 2002 Hudson River Project 

2487 2000 Hoosick Falls 

2538 1996 Beebee Island 

2554 2002 Feeder Dam 

2569 1996 Black River 

2582 1996 Station 2 

2583 1996 Station 5 

2584 1997 Station 26 Project 

2609 2000 Curtis/Palmer Falls* 

2616 2002 Hoosic 

2645 1996 Beaver River 

4114 1987 Lower Saranac 

5276 1992 Hudson Falls 

5461 1992 South Glen Falls 

6058 2002 Hailesboro No. 4 

6059 2002 Fowler No. 7 

10461 2002 West Br. St. Regis River* 

10522 1991 Whittelesy 
53

State Project 

Number 

License 

Issued Project Name 

11408 1996 Salmon River* 

North Carolina 2541 1994 Cascade* 

2694 2002 Queens Creek* 

11169 1992 Avalon* 

11219 1993 Mayo* 

11264 1995 South Yadkin* 

11392 1994 Ramseur* 

11437 1997 B. Everett Jordan* 

Oregon 2337 1989 Prospect No. 3 

2496 1997 Leaburg-Walterville 

11509 1998 City of Albany, Oregon Hydroelectric 

11512 2000 McKenzie 

South Carolina 1267 1995 Buzzards Roost* 

1895 2002 Columbia 

2315 1996 Neal Shoals* 

2331 1996 99 Islands* 

2332 1996 Gaston Shoals* 

2416 2002 Ware Shoals* 

2620 1999 Lockhart* 

10881 1993 Whitney Mill* 

11286 1997 Abbeville* 

Tennessee 11351 1994 Old Columbia* 

Vermont 2077 2002 Fifteen Mile Falls 

2392 1994 Gilman* 

2396 1994 Pierce Mills 

2397 1994 Gage 

2399 1994 Arnold Falls 

2400 1994 Passumpsic 

2445 1993 Center Rutland* 

2489 1994 Cavendish 

2490 1994 Taftsville* 

2513 1995 Essex No. 19 

2731 2001 Weybridge* 

2737 2001 Middlebury Lower* 

2756 1988 Chase Mill 

11090 1994 Turnbridge Mill 

Virginia 2391 1993 Warren* 

2411 1994 Schoolfield* 

2425 1993 Luray Newport* 

2509 1993 Shenandoah* 

2514 1994 Byllesby-Buck* 

2901 2001 Holcomb Rock* 

2902 2001 Big Island* 
54

State Project 

Number 

License 

Issued Project Name 

8535 1987 Battersea 

8657 1987 Harvell 

9840 1988 Appomattox 

Washington 0460 1998 Cushman 

0943 1989 Rock Island 

2016 2002 Cowlitz River 

2705 1997 Newhalem Creek 

8864 1993 Calligan Creek 

9025 1993 Hancock Creek 

West Virginia 2343 1987 Millville 

Wisconsin 0710 1997 Shawano* 

1953 1991 DuBay* 

1957 1989 Otter Rapids* 

1980 2001 Big Quinnesec Falls* 

1982 2002 Holcombe* 

1984 2001 Petenwell and Castle Rock* 

1999 1996 Wausau* 

2113 1996 Wisconsin River Headwaters* 

2131 2001 Kingsford* 

2212 1996 Rothschild* 

2239 1996 Kings Dam* 

2255 1996 Centralia* 

2256 1996 Wisconsin Rapids* 

2291 1996 Port Edwards* 

2292 1996 Nekoosa Papers, Inc.* 

2347 1994 Janesville Project* 

2348 1994 Beloit Blackhawk* 

2357 1997 White Rapids 

2390 1997 Big Falls Project* 

2394 1997 Chalk Hill 

2395 1997 Pixley* 

2417 1995 Hayward* 

2421 1997 Lower Project* 

2431 1995 Brule* 

2440 1994 Chippewa Falls* 

2444 1995 White River* 

2473 1997 Crowley Project* 

2475 1997 Thornapple* 

2476 1996 Jersey* 

2486 1995 Pine Hydroelectric Project* 

2522 1997 Johnson Falls* 

2523 1997 Oconto Falls* 

2525 1997 Caldron Falls* 
55

State Project 

Number 

License 

Issued Project Name 

2546 1997 Sandstone Rapids* 

2550 1996 Weyauwega* 

2560 1997 Potato Rapids* 

2567 2002 Wissota* 

2581 1997 Peshtigo* 

2587 1995 Superior Falls Project* 

2588 2000 Little Chute* 

2590 1996 Wisconsin River Drainage Project* 

2595 1997 High Falls* 

2640 1997 Upper Project* 

2663 1998 Pillager* 

2670 2002 Dells* 

2689 1994 Oconto Falls* 

2711 1994 Trego* 

3052 2002 Black River Falls* 

10805 1997 Hatfield* 

11162 2002 Prairie du Sac* 

11831 2001 Twin Falls* 

57

APPENDIX B 

FISH PASSAGE AT HYDROELECTRIC DAMS ON THE SUSQUEHANNA RIVER: 

A CASE STUDY 

59

Appendix B 

Fish Passage at Hydroelectric Dams on the Susquehanna River: 

A Case Study 

 The efforts to ensure passage of American shad at four hydroelectric dams on the lower 

Susquehanna River provides a unique dataset for assessing the effectiveness of upstream fish 

passage and the recovery of the population. Fish counts from all four dams are available since 

2000 and for the three lower dams since 1997. In addition, both fish passage counts and 

estimates of the shad population in the tailrace of the lowermost dam are available since 1984. 

The primary sources of information that were used in the discussion that follows include a 

review by Foote (2003), annual progress reports of the restoration program (e.g., SRAFRC 

2004), and the Pennsylvania Boat and Fish Commission and other websites. 

Background

The Susquehanna River basin consists of a 27,510-mi2

 area in New York, Pennsylvania, 

and Maryland that drains into the upper Chesapeake Bay. The river is 444 mi in length from the 

headwaters in Otsego Lake near Cooperstown, NewYork, to its mouth at Havre de Grace, 

Maryland. The Susquehanna River watershed comprises 43% of the drainage area of the 

Chesapeake Bay, and the river provides more than 50% of the freshwater inflow to the bay. 

Major tributaries include the Chemung River in New York (watershed area = 2,604 mi2

), and the 

West Branch Susquehanna River (6,992 mi2

) and Juniata River (3,406 mi2) in Pennsylvania. 

Based on the CWA Section 305(b) report issued in 2002 for the Susquehanna River basin, 3% of 

the assessed stream miles (which represented 3.8% of the 31,193 named stream miles in the 

basin) did not support the designated uses. The primary causes of stream impairment were 

nutrient enrichment, siltation, and habitat destruction from agricultural runoff, acid mine 

drainage, and habitat alteration. Degradation of basin streams due to low pH and high metals 

concentrations caused by acid mine drainage from past coal mining activities is one of the most 

prevalent water quality problems, affecting primarily streams in the West Branch and Middle 

Susquehanna subbasins. 

Historically, the distribution of American shad in the Susquehanna River included more 

than 300 miles of river north to Binghamton, New York, as well as the larger tributaries, such as 

the Juniata River. The commercial fishery in Pennsylvania was an estimated 2 million pounds 

(670,000 fish) prior to the construction in the 1830s of feeder dams for the new Pennsylvania 

canal system. Although fishways and shad hatcheries were constructed as mitigation for the 

dams, they were unsuccessful. Abandonment of the feeder dams 60 years later resulted in higher 

landings, which increased by about 50% to 312,000 pounds in 1908. 

The recovery of the shad population was impacted during the first quarter of the 

20th century by the development of hydroelectricity on the lower Susquehanna River. Four dams 

were constructed, beginning in 1904 (Table B-1). Mitigation included two fishways at the 

Holtwood Project (FERC No. 1881) and “in lieu of” payments for the Safe Harbor (FERC 
60

No. 1025) and Conowingo (FERC No. 405) projects. The York Haven dam of FERC No. 1888 

may have been partially passable. After conducting several studies between 1952 and 1966 on 

the feasibility of fish passage and the suitability of the Susquehanna River for shad restoration, 

the West fish lift was installed at Conowingo Dam in 1972, accompanied by the transport by 

truck of shad above the York Haven dam. New licenses were issued to each of the four dams in 

1980, the same year that the state of Maryland closed all Chesapeake Bay fisheries for American 

shad. The Maryland harvest had stabilized at 1-2 million pounds for a 50-year period up to the 

mid-1970s when a substantial decline prompted closure of the fishery. Only 945 shad were 

collected at the Conowingo lift from 1972 through 1980. 

Table B-1. Description of four hydroelectric dams on the lower Susquehanna River. 

Conowingo Holtwood Safe Harbor York Haven 

Construction completion 1928 1910 1930 1904 

Generating capacity (MW) 548 107 417 19 

Height of dam (ft) 95 55 55 6-22 

Location (RM)a 10.0 24.6 32.2 56.1 

Fish passage facilities 

 Type Westb

lift 

East 

lift 

Lift (2) Lift Vertical slot 

 Design capability 

 (millions of adult shad) -- 1.5c 2.7c 2.5d 0.5 

 Cost (millions) -- 12 20 18 9 

 Year of operation 1972 1991 1997 1997 2000 

a

River Mile; RM 0.0 is located at the mouth of the river.

b

Temporary facility only for the trapping and sorting of shad for transport upstream (FERC 1990). c

Also, 10 million river herring.

d

Also, 5 million river herring.

The Susquehanna River Anadromous Fish Restoration Committee (SRAFRC) established 

restoration goals for the basin in 1979 of two million American shad and 10 million river herring 

within 25 years of fish passage development. A Settlement Agreement was reached in 1988 that 

provided for a permanent fish passage facility at Conowingo, and the East lift was completed in 

1991. Fish passage at the other three upstream dams was addressed in a 1993 Settlement 

Agreement that provided for lifts at Holtwood and Safe Harbor, which were installed in 1997, 

and a vertical slot fishway at York Haven, which was completed in 2000. The upstream 

transport of shad collected by the East lift was terminated after 1996 with the completion of fish 

passage facilities upstream. Fish are collected at the West lift for offsite tank spawning, onsite 

egg collection, and age analyses; no fish were transported from the West lift for release upstream 

in 2003. 

Shad restoration in the Susquehanna River basin is coordinated by the SRAFRC and 

consists of three primary approaches: (1) trapping pre-spawn adults at Conowingo Dam and 

transfer to upstream areas (1972-1999), (2) direct fish passage (1997-present), and (3) stocking 

hatchery-reared fry and fingerlings (1976-present). An average of more than 10.5 million shad 

fry have been stocked annually over the past 20 years, ranging from 2.5 million in 2002 to 22.3 
61

million in 1989. Eggs are collected from adult shad in the Hudson, Delaware, and lower 

Susquehanna rivers. Shad of hatchery origin have comprised 61% of the fish that were collected 

at Conowingo Dam since 1989 and examined by otolith analysis with tetracycline marking. 

Variability among years in the percentage of fish that were of hatchery origin was high, ranging 

from 22 to 82% over the past 15 years. 

Fish Passage Effectiveness

The population of American shad in the lower Susquehanna River is growing, as 

evidenced by the increase in the fish counts at the Conowingo fish passage facility (East lift) 

(Table B-2). For example, the mean number of shad counted in the past four years (2000-2003) 

at Conowingo Dam was more than double that of the preceding three years. The effectiveness of 

the passage facilities varies substantially among the four dams and also among years at the same 

dam. Effectiveness is highest at Safe Harbor Dam, which is located only 7.6 miles upstream of 

Holtwood Dam. Passage effectiveness is lowest at York Haven Dam, which is located 

23.9 miles above Safe Harbor Dam. The inverse relationship between effectiveness and distance 

between dams might suggest that some shad are not available for passage at the next dam 

upstream, possibly due to mortality in the reservoirs, the presence of suitable spawning habitat in 

the reach between dams (both tributaries and mainstem), and/or fallback through the turbines or 

over the spillway. 

Based on the estimates of passage effectiveness (Table B-2), to reach the SRAFRC goal 

of two million fish above York Haven would require the passage of 50 million shad at 

Conowingo Dam. More than 210 miles of riverine habitat are available above the dam, yet, on 

average, only 4% of the fish counted in the Conowingo East lift reach this dam. If, however, a 

60% passage efficiency could be achieved at Holtwood and York Haven dams, a self-sustaining 

population in the Susquehanna River could be established (Young 2003). 

Finally, the case study provides an interesting contrast with American shad restoration 

efforts in the Connecticut River basin (Leggett et al. 2004). The population below Holyoke 

Dam, where the capacity of the lift was expanded in 1976 and will be doubled in 2004, has not 

increased in size even though fishways at Turner Falls and Vernon Falls were installed in 1980 

and 1981, respectively, providing American shad access to the upper 94 miles of their historical 

range in the Connecticut River. Further, after 1985, more than 40% of the total population 

routinely migrated beyond Holyoke Dam. Leggett et al. (2004) hypothesize that the increased 

energetic demands required for fish to reach these upstream areas results in higher adult 

mortality, a reduction in the number of repeat spawners, and a decrease in the mean size and age 

of adults, and therefore, mean population fecundity. Also, the successful recovery of striped bass 

populations may also contribute to the problem because of their predation on adult shad. 
Table B-2. Number of American shad counted and passage effectiveness (%)a at four hydroele

on the lower Susquehanna River (1997-2003). 

Source: SRAFRC (2004) 

CONOWINGO-EASTb HOLTWOOD

SAFE 

HARBOR

Estimated 

Population 

of Tailrace 

Number 

Counted 

Passage 

Effectiveness

Number 

Counted

Passage 

Effectiveness

Number 

Counted

Passage 

Effectiveness

N

C

1997 423,324 90,971 21.5 28,063 30.8 20,828 74.2 1998 314,904 39,904 12.7 8,235 20.6 6,054 73.5 1999 583,198 69,712 12.0 34,702 49.8 34,150 98.4 2000 957,249 153,546 16.0 29,421 19.2 21,079 71.6 2001 560,912 193,574 34.5 109,976 56.8 89,816 81.7 2002 555,597 108,001 19.4 17,522 16.2 11,705 66.8 2003 487,073 125,135 25.7 25,254 20.2 16,646 65.9 aPassage effectiveness (%) was estimated by dividing the number of fish passed at a dam by the number available, either estimated in th

Conowingo Dam or counted at the nearest fish passage facility.

bDuring the first six years of operation, the average number of American shad passed in the East lift was 24,293, ranging from 8,203 fis

1995. 

cNA = no data available; fishway not installed until 2000. 
63