Sylvan Lake Dam
Key Takeaway
Sylvan Lake Dam is classified as high hazard in South Dakota. It was completed in 1906 and is 120 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 | 37 ft (taller than 95.4% in SD) |
| Dam Length | 57 ft |
| Dam Type | Arch |
| Max Storage | 240 acre-ft |
| Normal Storage | 214 acre-ft |
| Surface Area | 17 acres |
| Drainage Area | 1 sq mi |
| Max Discharge | 2,880 cfs |
| Year Completed | 1906 (120 years old) |
| NID ID | SD02151 |
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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High Hazard 56 ftFrequently Asked Questions
What is the hazard classification of Sylvan Lake Dam?
Sylvan 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 Sylvan Lake Dam?
Sylvan Lake Dam is owned by GF&P (State Government). The owner is responsible for maintenance, inspections, and compliance with dam safety regulations.
When was Sylvan Lake Dam built?
Sylvan Lake Dam was completed in 1906, making it 120 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 Sylvan Lake Dam?
Sylvan 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 Sylvan Lake Dam?
Sylvan Lake Dam has a dam height of 37 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 Sylvan Lake Dam last inspected?
Sylvan Lake Dam was last inspected on October 24, 2023. Inspection dates indicate when a formal review occurred, not the results of that inspection.