Happy Hollow Lake Dam
Key Takeaway
Happy Hollow Lake Dam is classified as significant hazard in Illinois. It was completed in 1940 and is 86 years old. Its primary use is recreation. Significant hazard means failure could cause economic or environmental damage. Learn more.
Physical Details
| Dam Height | 52 ft (taller than 92.7% in IL) |
| Dam Length | 260 ft |
| Dam Type | Earth |
| Max Storage | 232 acre-ft |
| Normal Storage | 63 acre-ft |
| Year Completed | 1940 (86 years old) |
| NID ID | IL00417 |
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
HAPPY HOLLOW LAKE ASSOCIATION
Private
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Low Hazard 40 ftFrequently Asked Questions
What is the hazard classification of Happy Hollow Lake Dam?
Happy Hollow 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 Happy Hollow Lake Dam?
Happy Hollow Lake Dam is owned by HAPPY HOLLOW LAKE ASSOCIATION (Private). The owner is responsible for maintenance, inspections, and compliance with dam safety regulations.
When was Happy Hollow Lake Dam built?
Happy Hollow Lake Dam was completed in 1940, making it 86 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 Happy Hollow Lake Dam?
Happy Hollow 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 Happy Hollow Lake Dam?
Happy Hollow Lake Dam has a dam height of 52 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 Happy Hollow Lake Dam last inspected?
Happy Hollow Lake Dam was last inspected on June 9, 2022. Inspection dates indicate when a formal review occurred, not the results of that inspection.