Allen
Key Takeaway
Allen is classified as high hazard in South Dakota. It was completed in 1961 and is 65 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 Length | 370 ft |
| Dam Type | Earth |
| Normal Storage | 140 acre-ft |
| Year Completed | 1961 (65 years old) |
| NID ID | SD00981 |
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
BIA
Federal Government
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High HazardFrequently Asked Questions
What is the hazard classification of Allen?
Allen 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 Allen?
Allen is owned by BIA (Federal Government). The owner is responsible for maintenance, inspections, and compliance with dam safety regulations.
When was Allen built?
Allen was completed in 1961, making it 65 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 Allen?
Allen serves the following purposes: Recreation. Many dams in the U.S. are multi-purpose, supporting flood control, water supply, recreation, and other uses.
When was Allen last inspected?
Allen was last inspected on August 9, 2012. Inspection dates indicate when a formal review occurred, not the results of that inspection.