Cushman No.
Wind
Humidity
1 Spillway, located in Mason County, Washington, is a vital hydroelectric structure managed by a Public Utility. Designed by Harza Engineering Co., this concrete dam stands at a structural height of 54.8 feet and has a spillway width of 90 feet. Completed in 1990, it serves multiple purposes including hydroelectric power generation and recreation, with a storage capacity of 482,757 acre-feet and a maximum discharge capacity of 41,000 cubic feet per second.
The spillway, with a controlled design, is equipped with two Tainter (radial) gates for regulating water flow. Given its high hazard potential and very high risk assessment rating, the Federal Energy Regulatory Commission oversees its regulatory compliance. The dam's location on the North Fork Skokomish River, within the Skokomish Indian Reservation, further underscores the significance of its operation and maintenance to safeguard both the environment and surrounding communities.
Despite the lack of state regulation and inspections, the Cushman No. 1 Spillway's emergency action plan is essential for risk management and ensuring public safety in the event of emergencies. With its strategic location and critical role in water resource management, this dam stands as a testament to sustainable energy production and environmental stewardship in the Pacific Northwest region.
Year Completed |
1990 |
Dam Length |
340 |
Dam Height |
46 |
River Or Stream |
North Fork Skokomish River |
Primary Dam Type |
Concrete |
Surface Area |
4010 |
Hydraulic Height |
47.3 |
Drainage Area |
95 |
Nid Storage |
482757 |
Structural Height |
54.8 |
Outlet Gates |
Tainter (radial) - 2 |
Hazard Potential |
High |
Foundations |
Rock, Soil |
Nid Height |
55 |
| Location | Reservations | Toilets |
|---|---|---|
Camp Cushman
|
||
Oxbow Rustic
|
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Brown Creek Horse Campground
|
||
Brown Creek
|
||
Lebar Horse Camp
|
||
Le Bar Horse Camp
|
Headwaters To Confluence With North Fork Skokomish River
Headwaters- Includes All Tributaries To Confluence With North Fork Skokomish River
Headwaters- Includes All Tributaries Within Park To Olympic National Park Boundary
Headwaters- Includes All Tributaries And Excludes Flapjack Lakes To Confluence With North Fork Skokomish River
Headwaters- Includes All Tributaries Within Park To Confluence With North Fork Skokomish River