Before the FERC Application for New License for the Annex Creek ...

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DEPT. OF ENVIRONMENTAL (;ONSERV.4TION
R£~ST REGIONAL OFFICE
MAY 1 t \.~: .
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Mr. Willia. j. Corbus, Manager
Alaska Electric Light & Power
134 N. Franklin Street
Juneau, AK 99801
81LL SHEFFIEW, GOVERNOR
r.'.phon.: (907J
May 14, 1985
Add~u: 789-3151
P.O. Box 2420
Juneau, Alaska
CERTIFIED MAIL
RETURN RECEIPT
REQUESTED
99803
RE: Waiver, Annex Creek/Salmon Creek FERC Project No. 2307
~droelectric Project
You requested a water quality certification, pursuant to Section 401 of the
Clean Water Act of 19~J. Jor the existing developments at both Salmon and
Annex Creeks.
The Sal.an Creek facility consists of a 165-foot 'concrete arch dam which forms
a reservoir with a maximum.capacity of 19,000 arce-feet. Water from Salmon
Creek 01. is conveyed downstream to the Upper Powerhouse by a 4477-foot-long
steel pipe. Before reaching the powerhouse the penstock divides into a wye
branch which diverts the water either to the Upper Powerhouse or to another penstock
leading to the Lower Powerhouse. This flow is controlled by two butterfly
valves. The Upper Powerhouse contains two 2500-horsepower impulse wheels directly
connected to a 140O-kW geneator. The rehabilitation of the lower Salmon Creek
~droelectr1c Facility that was completed in December 1984 will provide an additiom.l
2.8 MWof capacity and an estimated 15,000,000 kWh annually.
The Annex Creek facility consists of a 20-foot timber crib dam located at Annex
Lake outlet. A 1420-foot-long tunnel has been driven into the lake, which provides
I drawdown of 150 feet and 22,000 acre-feet of storage. At the tunnel outlet a
34-incb pipe is used to control the water supply. The penstock is a riveted
steel pipe and is 7273 feet long. Annex Creek Powerhouse contains two units,
each cORsisting of a 2500-horsepower impulse wheel, connected to I 1750-kVA
generator. A 23-kY transmission line extends 12.4 miles between Annex Creek
and Thane.
The proposed activity is located on properties adjacent to Salmon Creek and
Annex Creek, Juneau, Alaska.
Water qaality certification is required for the proposed activity because
the actt.ity ~11be authorized by a Department of the Army Permit identified
as Annex Creek/Sal.on Creek ~droelectr1c Rel1censing, FERC Project No. 2307.
and a dtscharge '" res~lt from the proposed activity.
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