Legion Lake Dam
Key Takeaway
Legion Lake Dam is classified as high hazard in South Dakota. It was completed in 1934 and is 92 years old. Its primary use is recreation. 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 | 38 ft (taller than 95.8% in SD) |
| Dam Length | 207 ft |
| Dam Type | Earth |
| Max Storage | 198 acre-ft |
| Normal Storage | 59 acre-ft |
| Surface Area | 12 acres |
| Drainage Area | 2 sq mi |
| Max Discharge | 5,944 cfs |
| Year Completed | 1934 (92 years old) |
| NID ID | SD02150 |
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
GF&P
State Government
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Significant Hazard 28 ftFrequently Asked Questions
What is the hazard classification of Legion Lake Dam?
Legion Lake 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 Legion Lake Dam?
Legion Lake Dam is owned by GF&P (State Government). The owner is responsible for maintenance, inspections, and compliance with dam safety regulations.
When was Legion Lake Dam built?
Legion Lake Dam was completed in 1934, making it 92 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 Legion Lake Dam?
Legion 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 Legion Lake Dam?
Legion Lake Dam has a dam height of 38 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 Legion Lake Dam last inspected?
Legion Lake Dam was last inspected on October 24, 2023. Inspection dates indicate when a formal review occurred, not the results of that inspection.