Black Canyon : P-14110

[ Archived / decommissioned ]

Waterway: North Fork Snoqualmie

Authorized capacity: 25 mW

License issued: 10/14/2011
License expires:


The proposed project would consist of the following new features: (1) an approximately 35-foot-wide, 7-foot-tall inflatable dam; (2) a 90-foot-wide, 7-foot-tall diversion intake structure; (3) a 9-foot-wide, 7-foot-tall fish ladder; (4) a 7,300-foot-long, 12-foot-diameter penstock; (5) a 60-foot-long, 100-foot-wide metal powerhouse with two Francis turbine units, one rated at 16 megawatts (MW) and the other rated at 9 MW; (6) a 150-foot-long, 40-foot-wide tailrace; (7) a 0.75-mile extension of the existing logging road; (8) a 4.2-mile-long, 115-kilovolt transmission line; and (9) appurtenant facilities. The estimated annual generation of the project would be 90,000 megawatt-hours.

In Fall 2016 the developer for this project elected to discontinue their effort to construct a hydropower project on this river. The proceeding was formally terminated in October 2016.

The Black Canyon Hydroelectric Project as proposed would have involved a new dam on the North Fork Snoqualmie, diverting the river around Ernie’s Gorge to a powerhouse. Ernie’s Gorge is a unique whitewater gem located near Seattle. The river section proposed for development holds numerous local, state and federal protections, including being listed as a Protected Area by the Northwest Power and Conservation Council. The river also flows through the WA Department of Natural Resources’ Mt. Si Natural Resources Conservation Area. The project is also prohibited by King County Ordinances and a County Conservation Easement.