South Fork No.21
South Fork No.21 is an earth dam located in Pendleton County, West Virginia, built in 1966. It carries a High hazard potential classification and has a satisfactory condition assessment.
About South Fork No.21
The primary purpose of South Fork No.21 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 Potomac Valley Cd (local government). It impounds the Little Rough Rn near Moorefield.
The dam stands 97 feet tall and stretches 644 feet across, creates a reservoir covering 5 acres, has a maximum storage capacity of 788 acre-feet, and collects water from a drainage area of 2 square miles. Completed in 1966, 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. Its condition is rated satisfactory, indicating no existing or potential dam safety deficiencies are recognized. An emergency action plan is in place for this dam. The most recent inspection on record was 04/30/2024.
At 97 feet, this dam is taller than 98% 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 West Virginia 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 | West Virginia |
| County | Pendleton |
| Nearest City | Moorefield |
| River/Stream | Little Rough Rn |
| Coordinates | 38.70222, -79.14361 |
Physical Characteristics
| Dam Type | Earth |
| NID Height | 97 ft |
| Dam Height | 97 ft |
| Dam Length | 644 ft |
| Year Completed | 1966 (60 years old) |
Storage & Hydraulics
| NID Storage | 788 acre-ft |
| Max Storage | 788 acre-ft |
| Normal Storage | 56 acre-ft |
| Surface Area | 5 acres |
| Drainage Area | 2 sq mi |
| Max Discharge | 26,312 cfs |
| Spillway Type | Uncontrolled |
Ownership & Safety
| Purpose | Flood Risk Reduction |
| Owner | Potomac Valley CD |
| Owner Type | Local Government |
| Hazard Classification | High |
| Condition Assessment | Satisfactory |
| Last Inspection | 04/30/2024 |
| Emergency Action Plan | Yes |
Identifiers
| NID ID | WV07111 |
| Federal ID | WV07111 |
| More Info | State Dam Safety Program |