South Twin Lake Dam
Key Takeaway
South Twin Lake Dam is classified as significant hazard in Virginia. Its primary use is recreation. Significant hazard means failure could cause economic or environmental damage. Learn more.
Physical Details
| Dam Height | 14 ft (taller than 9.7% in VA) |
| Dam Length | 520 ft |
| Dam Type | Earth |
| Max Storage | 118 acre-ft |
| Normal Storage | 83 acre-ft |
| Drainage Area | 1 sq mi |
| NID ID | VA059011 |
Safety Information
No probable loss of human life, but can cause economic loss, environmental damage, or disruption of lifeline facilities.
Hazard potential describes downstream consequences of failure, not the dam's current condition. What does this mean?
Ownership
Fairfax County Park Authority;Fairfax County Park Authority
Local Government
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High Hazard 25 ftFrequently Asked Questions
What is the hazard classification of South Twin Lake Dam?
South Twin Lake Dam is classified as Significant Hazard. No probable loss of human life, but can cause economic loss, environmental damage, or disruption of lifeline facilities. This classification refers to the potential downstream consequences of a failure, not the dam's current structural condition.
Who owns and operates South Twin Lake Dam?
South Twin Lake Dam is owned by Fairfax County Park Authority;Fairfax County Park Authority (Local Government). The owner is responsible for maintenance, inspections, and compliance with dam safety regulations.
What is the primary purpose of South Twin Lake Dam?
South Twin Lake Dam serves the following purposes: Recreation. Many dams in the U.S. are multi-purpose, supporting flood control, water supply, recreation, and other uses.
How tall is South Twin Lake Dam?
South Twin Lake Dam has a dam height of 14 ft. Dam height is measured from the natural streambed at the downstream toe to the top of the dam, and may differ from the visible height.
When was South Twin Lake Dam last inspected?
South Twin Lake Dam was last inspected on April 28, 2022. Inspection dates indicate when a formal review occurred, not the results of that inspection.