Pa-481
Pa-481 is an earth dam located in Washington County, Pennsylvania, built in 1984. It carries a High hazard potential classification and has a satisfactory condition assessment.
About Pa-481
The primary purpose of Pa-481 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 Washington County (local government). It impounds the Harmon Creek.
The dam stands 51 feet tall and stretches 560 feet across, creates a reservoir covering 11 acres, has a maximum storage capacity of 1,620 acre-feet, and collects water from a drainage area of 3 square miles. Completed in 1984, the structure is 42 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 11/02/2020.
At 51 feet, this dam is taller than 93% of dams nationwide.
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 Pennsylvania 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 | Pennsylvania |
| County | Washington |
| River/Stream | Harmon Creek |
| Coordinates | 40.39167, -80.43167 |
Physical Characteristics
| Dam Type | Earth |
| NID Height | 51 ft |
| Dam Height | 51 ft |
| Dam Length | 560 ft |
| Year Completed | 1984 (42 years old) |
Storage & Hydraulics
| NID Storage | 1,620 acre-ft |
| Max Storage | 1,620 acre-ft |
| Normal Storage | 59 acre-ft |
| Surface Area | 11 acres |
| Drainage Area | 3 sq mi |
Ownership & Safety
| Purpose | Flood Risk Reduction |
| Owner | WASHINGTON COUNTY |
| Owner Type | Local Government |
| Hazard Classification | High |
| Condition Assessment | Satisfactory |
| Last Inspection | 11/02/2020 |
| Emergency Action Plan | Yes |
Identifiers
| NID ID | PA01214 |
| Federal ID | PA01214 |
| More Info | State Dam Safety Program |