Swift No.
Wind
Humidity
1 is a private hydroelectric dam located in Cougar, Washington, along the Lewis River. Completed in 1958, this earth dam stands at a height of 412 feet and has a maximum storage capacity of 755,500 acre-feet. With a surface area of 4,620 acres and a drainage area of 477 square miles, Swift No. 1 plays a crucial role in flood risk reduction, hydroelectric power generation, and recreational activities in the region.
Managed by the Federal Energy Regulatory Commission, Swift No. 1 has a controlled spillway with a width of 100 feet and two Tainter radial gates for regulated water discharge. The dam's hazard potential is rated as high, with a very high risk assessment score. While the condition assessment is not available, the emergency action plan was last revised in February 2021, highlighting the importance of preparedness and risk management for such critical infrastructure.
Overall, Swift No. 1 serves as a significant water resource and climate resilience asset in Skamania County, Washington. Its strategic location and design contribute to managing water resources efficiently, generating clean energy, and providing recreational opportunities while addressing potential hazards and risks associated with dam operations. For water resource and climate enthusiasts, Swift No. 1 offers a compelling case study of sustainable water infrastructure development and management in the Pacific Northwest.
Year Completed |
1958 |
Dam Length |
2100 |
Dam Height |
412 |
River Or Stream |
Lewis River |
Primary Dam Type |
Earth |
Surface Area |
4620 |
Hydraulic Height |
400 |
Drainage Area |
477 |
Nid Storage |
755500 |
Structural Height |
412 |
Outlet Gates |
Tainter (radial) - 2 |
Hazard Potential |
High |
Foundations |
Soil |
Nid Height |
412 |
Speelyai Creek Near Cougar
|
14cfs |
Muddy Creek Below Clear Creek Near Cougar
|
1620cfs |
Lewis River Above Muddy River Near Cougar
|
2440cfs |
Canyon Creek Near Amboy
|
666cfs |
Lewis River At Ariel
|
18700cfs |
East Fork Lewis River Near Heisson
|
1530cfs |
| Location | Reservations | Toilets |
|---|---|---|
Beaver bay
|
||
2-B
|
||
2-A
|
||
Lake Merrill- State Forest
|
||
Swift Forest Camp
|
||
Berry Camp
|
Nw1/4 Of Sec 9, T5N, R6E To Ne1/4 Of Sec 6, T5N, R5E
Gifford Pinchot Nf Boundary To Maximum Pool Of Swift Reservoir In Nw1/4 Of Sec 35, T7N, R6E
Confluence With Smith Creek To Confluence With Lewis River
Mt. Adams Wilderness Boundary To Gifford Pinchot Nf Boundary
Middle Of Sec 19, T8N, R7E To Confluence With Muddy River In Se1/4 Of Sec 1, T7N, R6E
(Upper Muddy Segment) Headwaters In Se1/4 Of Sec 10, T8N, R5E To Conflence With Smith Creek