The Office of Energy Projects at the Federal Energy Regulatory Commission on Oct. 28 issued the final environmental assessment related to an application for an original license to construct the Old Harbor Hydroelectric Project in Alaska.
The proposed 525-kW project would be constructed on the East Fork of Mountain Creek and transfer water into a powerhouse on the Lagoon Creek Tributary, near the town of Old Harbor in Kodiak Island Borough, Alaska. The project intake and a portion of the penstock would be located on approximately 7.74 acres of federal land that is part of the Kodiak National Wildlife Refuge and approximately 3.24 acres of Old Harbor Native Corp. land that is subject to a conservation easement administered by the U.S. Fish and Wildlife Service and the State of Alaska.
The final EA contains commission staff’s analysis and response to comments filed on the draft EA issued on May 7. The final EA concludes that licensing the project, with appropriate environmental protective measures, would not constitute a major federal action that would significantly affect the quality of the human environment.
In November 2013, the Alaska Village Electric Cooperative (AVEC) applied to FERC for a license to construct, operate, and maintain this project.
The project would be constructed on the East Fork of Mountain Creek and transfer water into a powerhouse on Lagoon Creek Tributary, near the town of Old Harbor. AVEC proposes to install two Pelton 262-kW turbines, with the first turbine installation occurring at the time of initial construction and the second turbine being installed when “demand warrants an additional turbine.” In the EA, FERC staff is projecting that the first turbine should meet AVEC’s energy demands for the next 40 years. Because it could be 40 years before demand warrants the addition of the second turbine, this EA only examines the project with the installation of the first turbine. If and when there is an established need for additional power, AVEC could apply for a license amendment to increase power production.
The hydropower development would include: a new 100-foot-long, 4 to 8 foot diversion/cut off weir to be constructed on the East Fork of Mountain Creek with an integrated 3-foot-high spillway; a new 10,150-foot-long buried penstock that would transfer water from the Mountain Creek basin to the proposed project powerhouse in the Lagoon Creek basin; a flow control mechanism to be installed between the diversion and powerhouse to control the volume of flow diverted at the intake; a 30-foot by 35-foot by 16-foot-high powerhouse containing one 262-kW Pelton turbine; a water bypass system in the powerhouse to route flows to the tailrace during turbine maintenance to limit rapid changes in flow that could harm fish and aquatic invertebrates downstream of the project; a 2,300-foot-long tailrace to convey water from the powerhouse to a nearby Swimming Pond; and a 1,100-foot-long enhanced riverbed channel that would convey water from the Swimming Pond to the natural channel of the Lagoon Creek Tributary.
The project would also involve constructing and maintaining: an approximately 2.2-mile-long by 10-foot-wide project access trail between the intake and powerhouse; an approximately 5,720-foot-long by 24-foot-wide access road extending from the powerhouse to an existing road; and a 1.2-mile-long, 12.47-kV overhead transmission line from the powerhouse to the existing power distribution system in the City of Old Harbor. The project would have an annual generation of 2,300,000 kilowatt-hours.