Hammonasset Dam
Key Takeaway
Hammonasset Dam is classified as high hazard in Connecticut. It was completed in 1956 and is 70 years old. Its primary use is water supply. 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 | 63 ft (taller than 97.2% in CT) |
| Dam Length | 447 ft |
| Dam Type | Concrete |
| Normal Storage | 4.3K acre-ft |
| Surface Area | 280 acres |
| Drainage Area | 20 sq mi |
| Max Discharge | 14,385 cfs |
| Year Completed | 1956 (70 years old) |
| Year Modified | 1995 |
| NID ID | CT00400 |
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
South Central CT RWA
Public Utility
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What is the hazard classification of Hammonasset Dam?
Hammonasset 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 Hammonasset Dam?
Hammonasset Dam is owned by South Central CT RWA (Public Utility). The owner is responsible for maintenance, inspections, and compliance with dam safety regulations.
When was Hammonasset Dam built?
Hammonasset Dam was completed in 1956, making it 70 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 Hammonasset Dam?
Hammonasset Dam serves the following purposes: Water Supply. Many dams in the U.S. are multi-purpose, supporting flood control, water supply, recreation, and other uses.
How tall is Hammonasset Dam?
Hammonasset Dam has a dam height of 63 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 Hammonasset Dam last inspected?
Hammonasset Dam was last inspected on November 5, 2019. Inspection dates indicate when a formal review occurred, not the results of that inspection.