Conconully is a historic earth dam located in Okanogan, Washington, built in 1909 by the Bureau of Reclamation for irrigation purposes.
Wind
Humidity
Standing at 72 feet tall with a hydraulic height of 63 feet, it harnesses the waters of Salmon Creek, providing a maximum storage capacity of 16,570 acre-feet and servicing a drainage area of 5 square miles. The dam covers a surface area of 450 acres and boasts a spillway width of 149 feet for uncontrolled discharge, with a maximum capacity of 11,580 cubic feet per second.
Managed by the Bureau of Reclamation, Conconully's hazard potential is classified as high, with a moderate risk assessment score of 3. The dam has not undergone a recent condition assessment, but emergency action plans have been prepared, last revised in September 2020. While the dam has not been modified in recent years, it remains a critical piece of infrastructure for the surrounding area, providing essential irrigation water to support agricultural activities. With its rich history and significant role in water resource management, Conconully stands as a testament to the importance of infrastructure in sustaining communities and ecosystems in Washington state.
Year Completed |
1909 |
Dam Length |
1075 |
Dam Height |
72 |
River Or Stream |
SALMON CREEK |
Primary Dam Type |
Earth |
Surface Area |
450 |
Hydraulic Height |
63 |
Drainage Area |
5 |
Nid Storage |
16570 |
Structural Height |
72 |
Hazard Potential |
High |
Foundations |
Rock |
Nid Height |
72 |
Okanogan River Near Tonasket
|
8640cfs |
Okanogan River At Malott
|
2420cfs |
Omak Creek Near Omak
|
8cfs |
Methow River At Winthrop
|
4510cfs |
Chewuch River At Winthrop
|
587cfs |
Methow River At Twisp
|
6560cfs |
| Location | Reservations | Toilets |
|---|---|---|
Conconully State Park
|
||
Cottonwood - Ton
|
||
Oriole Campground
|
||
Oriole
|
||
Kootenai Camp
|
||
Sugarloaf Campground
|