Foss Dam
Foss Dam is an earth dam located in Custer County, Oklahoma, built in 1961. It carries a High hazard potential classification.
About Foss Dam
The primary purpose of Foss Dam is flood risk reduction. The dam is designed to control downstream flooding by temporarily storing excess water during storms and releasing it at a controlled rate. The dam is owned by Bureau Of Reclamation (federal). It impounds the Washita River near Clinton.
The dam stands 142 feet tall and stretches 18,130 feet across, creates a reservoir covering 13,141 acres, has a maximum storage capacity of 816,900 acre-feet, and collects water from a drainage area of 1,473 square miles. Completed in 1961, the structure is well into its service life at over 50 years old.
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. An emergency action plan is in place for this dam. The most recent inspection on record was 04/28/2023.
At 142 feet, this dam is taller than 99% 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 Oklahoma 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 | Oklahoma |
| County | Custer |
| Nearest City | Clinton |
| River/Stream | Washita River |
| Coordinates | 35.54720, -99.18370 |
Physical Characteristics
| Dam Type | Earth |
| NID Height | 142 ft |
| Dam Height | 142 ft |
| Dam Length | 18,130 ft |
| Year Completed | 1961 (65 years old) |
Storage & Hydraulics
| NID Storage | 816,900 acre-ft |
| Max Storage | 816,900 acre-ft |
| Normal Storage | 168,732 acre-ft |
| Surface Area | 13,141 acres |
| Drainage Area | 1,473 sq mi |
| Max Discharge | 3,150 cfs |
| Spillway Type | Uncontrolled |
Ownership & Safety
| Purpose | Flood Risk Reduction |
| Owner | BUREAU OF RECLAMATION |
| Owner Type | Federal |
| Hazard Classification | High |
| Condition Assessment | Not Available |
| Last Inspection | 04/28/2023 |
| Emergency Action Plan | Yes |
Identifiers
| NID ID | OK02503 |
| Federal ID | OK02503 |
| More Info | State Dam Safety Program |