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UNITED STATES OF AMERICA80 FERC 062, 166

FEDERAL ENERGY REGULATORY COMMISSION

Central Maine Power Company Proj ect No. 2552- 023

ORDER APPROVING DOWNSTREAM FISH PASSAGE

(August 21, 1997)

On May 30, 1997 , and supplemented on July 28, 1997, Central

Maine Power Company (licensee) filed a final report on the

results of its 1996 downstream fish passage study for the

Fort Halifax Project, pursuant to article 18 of the project

license. 1/ The licensee reports that the downstream passage

facility and operational procedures developed over the 1993- 1996

study period provide safe passage for most juvenile and adult

alewi ves migrating past the proj ect and that additional

downstream passage studies are unnecessary. The proj ect is

located on the Sebasticook River in Kennebec County, Maine.

Article 18 required the licensee to file a plan to monitor

the effectiveness of the downstream fish passage facility to be

installed at the project, and, based on the results of

monitoring, implement any necessary changes or additions to the facili ty, under a Commission-approved schedule.

BACKGROUND

The licensee completed the downstream fish passage facility

at the Fort Halifax Project in mid-August 1993. Fishway

effectiveness studies began in 1993 and continued through 1995.

As a result of the studies, the facility has undergone various

modifications over the study period. The facility consists of

a gate and flume at the existing trash sluice opening, in

combination with 12- foot-deep aluminum punched screens of

1/4-inch hole size over the existing trashracks with 1. inch

clear spacing.

On September 30, 1996, the Commission issued an order that

required the licensee to continue to provide for downstream

passage of adult and juvenile river herring at the project using

the methodology developed for effective downstream passage in

1995 and previous studies. 2/ The licensee was also required

to continue to observe for evaluation downstream fish passage

at the project during 1996 and document such in a report to the

U. S. Fish and Wildlife Service (FWS), the National Marine

Fisheries Service (NMFS), and the Maine Department of Marine

Resources (DMR) by March 31, 1997. The final report of fish

46 FERC 0 62, 078

76 FERC 0 62, 264

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proj ect No. 2552- 023

passage observations, including agency comments on the

observations and recommendations for further study, were required

to be filed with the Commission by May 30, 1997.

LICENSEE' S 1996 STUDY RESULTS AND RECOMMENDATIONS

The study during 1996 consisted of observing fish passage

with the aluminum trashrack overlays in place in combination with

3 foot and 2 foot fishway gate openings. The study was conducted

during the peak outmigration period for juvenile and adult

alewives.

The study found that extremely large numbers of juvenile

alewives emigrated safely past the project utilizing the 12 foot

deep trashrack overlay screens in combination with a 3 foot deep

gate opening at the fishway. The screens excluded juvenile

alewives from operational turbine pits during 95 percent of the

observation periods for Unit #1 and 62 percent of the observation

periods for Unit #2. The project is operated with Unit #2 first

on and last off. This maximizes attraction of fish to the

downstream Unit #2 trashrack screen and fishway.

Observations in 1996 found that the only significant fish

penetration of trashracks into the turbine pits involved Unit #1,

which is the unit farthest upstream from the fishway entrance.

Penetration was observed only when Unit #1 was operating at a

turbine gate setting of 100 percent. No penetration was observed

at gate settings of 40 to 60 percent. To minimize entrainment of

fish in the turbine pits into the turbine, the licensee developed

an operational procedure that includes reducing the gate setting

to 50 percent and then to 0 percent, with the trashrack overlay

screen removed for 1 to 2 hours to allow fish to escape into the

proj ect impoundment. 

With respect to adult alewives, the majority of adults were

found to pass the project utilizing the 12 foot deep screens in

combination with a 2 foot deep fishway gate opening.

Based on 1996 observations, the licensee recommended the

following in its 1997 filing: 1) install 12- foot-deep aluminum

punched screens of 1/4- inch hole size over existing trashracks by

June 1, river conditions permitting; 2) open the fishway gate to

a depth of 2 feet by June 1 if river conditions allow and open

the gate to a depth of 3 feet by August 15; 3) operate Unit #2 on

a first on-last off basis; 4) reduce the output of the turbine (s)

to 50 percent or less if juvenile alewives enter the turbine pi t (s), then shut the units off and remove one screen to allow

fish to escape, if river conditions permit; 5) establish a daily

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screen cleaning schedule during any periods of debris loading;

and 6) if juvenile alewives congregate near the flashboards

during spill events, utilize the removable flashboard section to

allow fish to pass.

AGENCY COMMENTS

In letters dated April 29, May 23 and May 28, 1997 , the

NMFS, DMR and FWS, respectively, stated their concurrence with

the licensee that visual observations indicate the majority of

downstream migrants successfully use the passage facility. The

NMFS and DMR understand that the success rate is dependant on

proj ect operations and that the proj ect and passage facility

should be operated as required under the licensee s six

recommendations.

The FWS, in a letter dated July 17, 1997 recommends that

whenever juvenile alewives become entrained into the Unit # 

turbine pit, the licensee should either reduce the Unit #1 gate

setting to 60 percent or less and maintain operation at that

setting if river flows allow (i. e., if spill will not occur) or

shut the unit off. The screen should then be removed to allow

the fish to escape back into the impoundment (if spill will not occur). If river flows begin to exceed the capacity of Unit #2,

the licensee should then increase the Unit #1 gate setting

incrementally to handle the higher river flows. The FWS states

that this will minimize spill and flashboard failure.

Addi tionally, the FWS recommends the licensee maintain a log of

these events for potential future consultation with the resources

agencies (no formal year-end report required). The FWS concludes

that the licensee may be required to conduct additional studies

in the future regarding other species, including American shad,

Atlantic salmon, and American eel.

DISCUSSION AND CONCLUSION

The methodology developed by the licensee for effective

downstream fish passage from 1993 through 1996 should be applied

on an operational basis as the licensee recommends in its final

study report. The licensee s observations and results of studies

completed through 1996 indicate that the 12-foot-deep punched

metal sheet overlays and other additional measures used by the

licensee are very effective in preventing entrainment. We

concur, therefore, that additional downstream passage studies at

this time are unnecessary. The Commission should, however,

reserve the right to require downstream fish passage monitoring

studies for other anadromous fishes targeted for restoration in

the Sebasticook River when recommended by the licensee or the

resource agencies.

Project No. 2552- 023 -4-

Wi th respect to FWS' recommendations concerning fish

entrainment into the Unit #1 turbine pit, the licensee

methodology outlined in its 1996 report accommodates the FWS' s

recommendations and will provide similar safe passage. Further,

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the option to increase the gate setting on Unit #1 (during a fish

escapement event), if flows are too high for Unit #2 and excess

spillage and flashboard failure may occur, is appropriate to

prevent such an occurrence. The licensee should include this

recommendation in it operation methodology. The licensee should

also maintain a log of those events where juvenile alewives

become entrained into the turbine pits and of actions taken to

allow escapement to the impoundment. The log would provide

further evidence as to the effectiveness of the licensee

methods for preventing entrainment and would aid in development

of additional measures, if necessary, for other species needing

passage protection.

The Director orders:

(A) The licensee shall continue to provide for downstream

passage of adult and juvenile river herring at the Fort Halifax

proj ect using the methodology developed for effective downstream

fish passage through 1996 and recommendations presented in the

licensee s 1996 study report, filed on May 30, 1997, to include

recommendations of the U. S. Fish and Wildlife Service with

respect to fish escapement events. The licensee shall also

maintain a log of those events where juvenile alewives become

entrained into the turbine pits and actions taken to allow

escapement to the impoundment. The Commission reserves the right

to require additional monitoring or changes to project operation

or structures regarding other species requiring downstream

passage past the Fort Halifax proj ect.

(B) This order constitutes final agency action. Requests

for rehearing by the Commission may be filed within 30 days of

the date of issuance of this order, pursuant to 18 C. R. 0

385. 713.

Kevin P. Madden

Acting Director

Office of Hydropower Licensing

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