Longwood Lake Dam
Key Takeaway
Longwood Lake Dam is classified as high hazard in New Jersey. It was completed in 1898 and is 128 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 | 22 ft (taller than 79.5% in NJ) |
| Dam Length | 91 ft |
| Dam Type | Stone |
| Max Storage | 351 acre-ft |
| Normal Storage | 214 acre-ft |
| Surface Area | 43 acres |
| Drainage Area | 19 sq mi |
| Max Discharge | 813 cfs |
| Year Completed | 1898 (128 years old) |
| NID ID | NJ00333 |
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
Jersey City Municipal Utilities Authority
Local Government
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Low Hazard 12 ftFrequently Asked Questions
What is the hazard classification of Longwood Lake Dam?
Longwood 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 Longwood Lake Dam?
Longwood Lake Dam is owned by Jersey City Municipal Utilities Authority (Local Government). The owner is responsible for maintenance, inspections, and compliance with dam safety regulations.
When was Longwood Lake Dam built?
Longwood Lake Dam was completed in 1898, making it 128 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 Longwood Lake Dam?
Longwood 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 Longwood Lake Dam?
Longwood Lake Dam has a dam height of 22 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 Longwood Lake Dam last inspected?
Longwood Lake Dam was last inspected on July 14, 2021. Inspection dates indicate when a formal review occurred, not the results of that inspection.