Fanchers Dam
Fanchers Dam is a concrete dam located in Okanogan County, Washington, built in 1926. It carries a High hazard potential classification and has a fair condition assessment.
About Fanchers Dam
The primary purpose of Fanchers Dam is irrigation. The dam stores and diverts water for agricultural irrigation, supporting farming operations in the surrounding area. The dam is owned by Colville Tribes (private). It impounds the Antoine Creek near Tonasket.
The dam stands 68 feet tall and stretches 450 feet across, creates a reservoir covering 28 acres, has a maximum storage capacity of 600 acre-feet, and collects water from a drainage area of 34 square miles. Completed in 1926, the structure is well-established, with more than 75 years of service.
This dam carries a high hazard potential classification, which means that a failure or uncontrolled release of water would likely cause loss of human life. This classification reflects the consequences of failure, not the likelihood — it indicates that people live or work in the area downstream. Its condition is rated fair — the dam has minor deficiencies that are being addressed or do not pose an immediate safety threat. An emergency action plan is in place for this dam. The most recent inspection on record was 10/19/2021.
At 68 feet, this dam is taller than 96% of all dams in the United States.
Living Downstream
If you live or work downstream of this dam, consider taking these steps: learn your local evacuation routes, check whether your county emergency management office has a dam failure inundation map, and sign up for local emergency alerts. The Washington dam safety program can provide more specific information about emergency planning for this structure.
Search for dams near your address to see all dams in your area with hazard classifications and safety data.
Location
| State | Washington |
| County | Okanogan |
| Nearest City | Tonasket |
| River/Stream | Antoine Creek |
| Coordinates | 48.82909, -119.26355 |
Physical Characteristics
| Dam Type | Concrete |
| NID Height | 68 ft |
| Dam Length | 450 ft |
| Year Completed | 1926 (100 years old) |
Storage & Hydraulics
| NID Storage | 600 acre-ft |
| Max Storage | 600 acre-ft |
| Normal Storage | 500 acre-ft |
| Surface Area | 28 acres |
| Drainage Area | 34 sq mi |
| Max Discharge | 330 cfs |
Ownership & Safety
| Purpose | Irrigation |
| Owner | Colville Tribes |
| Owner Type | Private |
| Hazard Classification | High |
| Condition Assessment | Fair |
| Last Inspection | 10/19/2021 |
| Emergency Action Plan | Yes |
Identifiers
| NID ID | WA00040 |
| Federal ID | WA00040 |
| More Info | State Dam Safety Program |