The Federal Energy Regulatory Commission issued a 50-year relicense Nov. 6 for Chelan County Public Utility District’s 48-MW Lake Chelan hydroelectric project in Washington.
The 138-page document contains requirements expected to cost Chelan County $53 million over the 50 years. The order includes provisions for a year-round minimum flow in the Chelan River, maintenance of parks, regulating of lake levels, enhancements to fish habitat, and a new trail.
Chelan County said inflation and construction cost increases boosted original cost estimates, at one time projected to be $44 million.
The relicense (No. 637) is based on a 2003 settlement agreement between the district and communities, state and federal agencies, and environmental groups. Beginning in 1997, Chelan County employed FERC’s alternative licensing process to develop its relicense application. Since the original license expired in 2004, the PUD has operated the project under a temporary annual license.
Relicense offers slightly more flexibility
Under the relicense, Chelan County will have slightly greater flexibility to manage lake levels by establishing target elevations to be achieved between May 1 and Oct. 1, rather than a fixed elevation by a certain date.
The PUD plans to manage minimum lake elevations based on snow pack conditions, lake levels, predicted precipitation and runoff conditions, and operational objectives of maintaining minimum instream flows in the Chelan River. The plan is to reduce high flows in the river, provide useable lake levels for recreation, and ensure the project can pass the probable maximum flood. The project is to generate an average of 365 GWh annually.
Chelan County said its staff would study the relicense order to identify any significant changes from the settlement agreement. It has 30 days from the relicense date to appeal.
The district expects to award a contract in January for replacement or rehabilitation of the project’s two turbines, generators, and units controls. The PUD board of commissioners gave approval in October for the district to secure a contractor by negotiation.
The Lake Chelan project includes a 55-mile-long natural glacial lake that was raised 21 feet by construction of a 40-foot-tall, 490-foot-long concrete gravity dam; a 14-foot-diameter, 2.2-mile power tunnel; a powerhouse containing two vertical-shaft, Francis turbine-generators; and a tailrace adjacent to the confluence of the Chelan and Columbia rivers.