HomeMy WebLinkAboutCity of Angoon Ruth Flyer_rev03 11-09City of Angoon, Alaska
The proposed Project would be located in an
unincorporated area, 20 miles northeast of the
City of Petersburg, Alaska. The Project would
utilize the natural and raised impoundment of
Ruth Lake, a precipitation and glacial-fed body
of water.
Generation Features
Usable Stored Capacity 17,000 af
Operational Draw‐down 100 ft
Elevation Drop 1490 ft
Average Annual Flow 86 cfs
Power Conduit (diameter/length) 6‐10‐ft / 12,600‐ft
Installed Capacity 20 MW
Turbine Type / Number Impulse / 2
Estimated Average Annual Energy 70 GWh
Estimated Capital Cost $90 ‐ 100 million
FERC No. 13366-000
Ruth Lake Hydroelectric Project
Development of hydroelectric
power at the site would include:
Dam. A concrete arch dam of up to 170’ high
above the existing lake elevation would raise
Ruth Lake to the same elevation as Swan Lake.
Lake Tap or Siphon. The inlet works would
consist of a tunnel intake. Water would be with-
drawn through a screened intake into an approxi-
mately 12,600-foot long power conduit.
Spillway. A spillway in the existing bedrock would provide discharge from the storage reservoir around the
dam into Delta Creek.
Tunnel/Penstocks. The power conduit would be a combination of 10’ dia. bored unlined tunnel and 6’-8’ dia.
steel penstocks, either buried or surfaced, for a combined length of approximately 12,600 feet from Ruth Lake
to the powerhouse.
Powerhouse. The powerhouse would be located within 500 ft. of the mouth of Delta Creek. The powerhouse
would be exclusively for Ruth Lake/Delta Creek and would house two impulse turbines, each with a total rated
head of 1500 ft. The rated installed capacity of the powerhouse would be 20MW and the expected annual
energy output would be 70 GWh. Tailrace. Discharge from turbines would include
a tailrace channel of up to 600 ft. in length that
would discharge into Delta Creek or directly into
Thomas Bay.
Access Roads. The Project is separated from the
nearest town of Petersburg by Frederick Sound.
The only access for either construction or long-
term operation and maintenance of the Project
will be via boat or aircraft. An existing dock
located on Thomas Bay would be used for
loading and unloading personnel and supplies
from a boat. A new road would connect the
powerhouse to the existing road system in the
Patterson Delta.
Mayor Albert Howard
City of Angoon, Alaska
P.O. Box 189, Angoon, AK 99820
(907)788-3653
Ruth
Lake