North Fork Skokomish River (Ho
|Current status||Active |
|Type of facility||Conventional Hydro|
|Mode of hydropower generation||Peaking|
|Type of permit||FERC License|
|FERC docket #||P-460|
|FERC project name||Cushman|
|Other projects with this FERC number|
Ownership and operation
|Owner||Tacoma City of|
|Owner type||Publicly Owned Utility|
|Year first online (conventional hydro)||1930|
|Transmission or distribution system owner||City of Tacoma - (WA)|
Power and generating capacity
|Number of units||5|
|Total capacity from hydraulic turbine-generator units within each plant||84.6 mW|
|Average annual net hydropower generation||198,073.2 mWH|
The Cushman Hydroelectric Project is located on the North Fork of the Skokomish River in Mason County, Washington, and occupies U.S. lands within the Olympic National Forest and the Skokomish Indian Reservation.
The project consists of two dams and impoundments on the North Fork of the Skokomish River with associated power tunnels and penstocks, powerhouses, and a 26.8- mile-long primary transmission system.
The Dam No. 1 development consists of a 260-foot-high concrete arch dam that impounds Lake Cushman, a 9.6-mile-long storage reservoir with a 4,058-acre surface area and a 453,350 acre-foot storage capacity at full pool.
The Dam No. 2 development consists of a 230-foot-high concrete arch dam approximately 2 miles downstream of Dam No. 1, which impounds Lake Kokanee, a 128-acre lake with a gross storage capacity of 7,300 acre-feet at full pool.
In January 2009, the City proposed to build a powerhouse which would contain two Francis turbine/generator units- 1.8MW each (for an additional 3.6MW). FERC approved the construction and the settlement and issued a renewed license for until 2048.