Lake Hopatcong Dam
Key Takeaway
Lake Hopatcong Dam is classified as high hazard in New Jersey. It was completed in 1925 and is 101 years old. Its primary use is flood risk reduction. 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 | 17 ft (taller than 63.3% in NJ) |
| Dam Length | 271 ft |
| Dam Type | Concrete |
| Normal Storage | 48.2K acre-ft |
| Surface Area | 2,474 acres |
| Drainage Area | 25 sq mi |
| Max Discharge | 0 cfs |
| Year Completed | 1925 (101 years old) |
| NID ID | NJ00327 |
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
Division of Parks and Forestry
State Government
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Low Hazard 33 ftKofferls Pond Dam
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Low Hazard 20 ftJefferson Lake Dam
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Low Hazard 15 ftFrequently Asked Questions
What is the hazard classification of Lake Hopatcong Dam?
Lake Hopatcong 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 Lake Hopatcong Dam?
Lake Hopatcong Dam is owned by Division of Parks and Forestry (State Government). The owner is responsible for maintenance, inspections, and compliance with dam safety regulations.
When was Lake Hopatcong Dam built?
Lake Hopatcong Dam was completed in 1925, making it 101 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 Lake Hopatcong Dam?
Lake Hopatcong Dam serves the following purposes: Flood Risk Reduction. Many dams in the U.S. are multi-purpose, supporting flood control, water supply, recreation, and other uses.
How tall is Lake Hopatcong Dam?
Lake Hopatcong Dam has a dam height of 17 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 Lake Hopatcong Dam last inspected?
Lake Hopatcong Dam was last inspected on October 21, 2021. Inspection dates indicate when a formal review occurred, not the results of that inspection.