Hempstead Lake Dam
Key Takeaway
Hempstead Lake Dam is classified as high hazard in New York. It was completed in 1873 and is 153 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 | 24 ft (taller than 68.1% in NY) |
| Dam Length | 1,200 ft |
| Dam Type | Earth |
| Max Storage | 1.2K acre-ft |
| Normal Storage | 470 acre-ft |
| Surface Area | 149 acres |
| Drainage Area | 15 sq mi |
| Max Discharge | 323 cfs |
| Year Completed | 1873 (153 years old) |
| NID ID | NY00108 |
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
NYS OFFICE OF PARKS, RECREATION & HISTORIC PRESERVATION- LONG ISLAND REGION
State Government
Nearby Dams
Frequently Asked Questions
What is the hazard classification of Hempstead Lake Dam?
Hempstead 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 Hempstead Lake Dam?
Hempstead Lake Dam is owned by NYS OFFICE OF PARKS, RECREATION & HISTORIC PRESERVATION- LONG ISLAND REGION (State Government). The owner is responsible for maintenance, inspections, and compliance with dam safety regulations.
When was Hempstead Lake Dam built?
Hempstead Lake Dam was completed in 1873, making it 153 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 Hempstead Lake Dam?
Hempstead 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 Hempstead Lake Dam?
Hempstead Lake Dam has a dam height of 24 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 Hempstead Lake Dam last inspected?
Hempstead Lake Dam was last inspected on November 18, 2020. Inspection dates indicate when a formal review occurred, not the results of that inspection.