Little Seneca Dam
Key Takeaway
Little Seneca Dam is classified as high hazard in Maryland. It was completed in 1984 and is 42 years old. Its primary use is water supply. High hazard means loss of life is likely if the dam fails — it does not indicate the dam's current condition. Learn more.
Physical Details
| Dam Height | 99 ft (taller than 98.1% in MD) |
| Dam Length | 628 ft |
| Dam Type | Earth |
| Max Storage | 24.2K acre-ft |
| Normal Storage | 13.1K acre-ft |
| Surface Area | 505 acres |
| Drainage Area | 21 sq mi |
| Max Discharge | 73,292 cfs |
| Year Completed | 1984 (42 years old) |
| Year Modified | 1984 |
| NID ID | MD00271 |
Safety Information
Loss of human life is likely if the dam fails.
Hazard potential describes downstream consequences of failure, not the dam's current condition. What does this mean?
Ownership
Washington Suburban Sanitary Commission
Local Government
Nearby Dams
Manchester Farm Regional Swm Pond Dam
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Low Hazard 22 ftLake Churchill (Wynnfield Drive)
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Low Hazard 44 ftFairfield East Dam
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High Hazard 18 ftRailroad Branch Swm Pond
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High Hazard 25 ftRolling Hills Swm Pond
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High Hazard 15 ftCloppers Mill West Pond F (Cricket Hill Drive)
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Significant Hazard 26 ftSeneca Meadows Swm Dam (Seneca Meadows Pkwy)
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Low Hazard 17 ftFrequently Asked Questions
What is the hazard classification of Little Seneca Dam?
Little Seneca Dam is classified as High Hazard. Loss of human life is likely if the dam fails. This classification refers to the potential downstream consequences of a failure, not the dam's current structural condition.
Who owns and operates Little Seneca Dam?
Little Seneca Dam is owned by Washington Suburban Sanitary Commission (Local Government). The owner is responsible for maintenance, inspections, and compliance with dam safety regulations.
When was Little Seneca Dam built?
Little Seneca Dam was completed in 1984, making it 42 years old. Many U.S. dams were built between the 1930s and 1970s during a period of major infrastructure investment.
What is the primary purpose of Little Seneca Dam?
Little Seneca Dam serves the following purposes: Water Supply, Flood Risk Reduction. Many dams in the U.S. are multi-purpose, supporting flood control, water supply, recreation, and other uses.
How tall is Little Seneca Dam?
Little Seneca Dam has a dam height of 99 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 Little Seneca Dam last inspected?
Little Seneca Dam was last inspected on March 2, 2023. Inspection dates indicate when a formal review occurred, not the results of that inspection.