Prince William Parkway Regional Swm is an earth dam located in Prince William County, Virginia. It carries a High hazard potential classification and has a satisfactory condition assessment.
Dam profile
NID height · 48 ft48 ft tall and 470 ft long, taller than 92% of U.S. dams with a recorded height. Height is drawn to scale against a ten-story building, about 100 ft; the profile is a generic embankment section and the water level is illustrative.
About Prince William Parkway Regional Swm
The primary purpose of Prince William Parkway Regional Swm 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 Prince William County (local government). It impounds the Cow Branch.
The dam stands 48 feet tall and stretches 470 feet across, creates a reservoir covering 3 acres, has a maximum storage capacity of 316 acre-feet, and collects water from a drainage area of 0 square miles.
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 03/16/2022.
At 48 feet, this dam is taller than 92% 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 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 | Virginia |
| County | Prince William |
| River/Stream | Cow Branch |
| Coordinates | 38.65100, -77.29280 |
Physical Characteristics
| Dam Type | Earth |
| NID Height | 48 ft |
| Dam Height | 48 ft |
| Dam Length | 470 ft |
Storage & Hydraulics
| NID Storage | 316 acre-ft |
| Max Storage | 316 acre-ft |
| Normal Storage | 25 acre-ft |
| Surface Area | 3 acres |
| Drainage Area | 0 sq mi |
Ownership & Safety
| Purpose | Flood Risk Reduction |
| Owner | Prince William County |
| Owner Type | Local Government |
| Hazard Classification | High |
| Condition Assessment | Satisfactory |
| Last Inspection | 03/16/2022 |
| Emergency Action Plan | Yes |
Identifiers
| NID ID | VA153022 |
| Federal ID | VA153022 |
| More Info | State Dam Safety Program |