Black Canyon Hydro LLC on Dec. 1 filed with the Federal Energy Regulatory Commission Draft License Application (DLA) materials for stakeholder review on a 25-MW project planned in the Pacific Northwest.
Stakeholder review of these materials is intended to aid the applicant in developing a Final License Application (FLA) which is expected to be submitted on or before Sept. 30, 2016. Materials not filed now will be submitted with the Final License Application.
Black Canyon Hydro said it must make changes to the project due to subsequent findings of the groundwater study and after consultation with Puget Sound Energy with regard to the transmission route and location of interconnection. The primary project changes will include a revised design and construction methods for the underground powerhouse, vertical shaft and a revised transmission route. As a result meaningful design and cost revisions are now underway, but not ready for review.
Black Canyon Hydro plans the Black Canyon Hydroelectric Project, which would be located on the North Fork Snoqualmie River (North Fork), four miles northeast of North Bend in King County, Washington. The project as proposed would have an installed generating capacity of 25 MW and would be located predominantly on private lands. The run-of-river project would divert water from a 2.7-mile-section of the North Fork referred to as the “Bypassed Reach.”
The combined maximum hydraulic capacity of the project’s four turbines would be 900 cubic feet per second (cfs). The project’s estimated annual average electricity generation would be 110.7 Gigawatt hours (GWh).
Transmission would consist of a 34.5-kV underground transmission line 1.25 miles long. The transmission line would follow existing logging roads to an interconnection with an existing power line corridor. No switch or substation would be required transform the voltage as the transmission line is also 34.5 kV.
The project would operate as a run-of-river facility with an instream flow of 50 cfs with a spawning flow of 75 cfs during the April 16-through-July 31 period each year. No water would be diverted for power generation if stream flow to the intake dropped below the proposed instream flow. The project would divert up to 900 cfs from the river for power generation.
The currently proposed project schedule includes tunnel boring to begin in June 2018 and completed in January 2019. Vertical shaft drilling would begin in June 2019 and is expected to be completed in October 2019. The powerhouse would be built in the vertical shaft in May 2019.