Wiswall Dam
Key Takeaway
Wiswall Dam is classified as significant hazard in New Hampshire. It was completed in 1911 and is 115 years old. Its primary use is recreation. Significant hazard means failure could cause economic or environmental damage. Learn more.
Physical Details
| Dam Height | 22 ft (taller than 76.5% in NH) |
| Dam Length | 400 ft |
| Dam Type | Concrete |
| Max Storage | 500 acre-ft |
| Normal Storage | 134 acre-ft |
| Surface Area | 27 acres |
| Drainage Area | 183 sq mi |
| Max Discharge | 12,630 cfs |
| Year Completed | 1911 (115 years old) |
| Year Modified | 2011 |
| NID ID | NH00441 |
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
TOWN OF DURHAM
Local Government
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What is the hazard classification of Wiswall Dam?
Wiswall 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 Wiswall Dam?
Wiswall Dam is owned by TOWN OF DURHAM (Local Government). The owner is responsible for maintenance, inspections, and compliance with dam safety regulations.
When was Wiswall Dam built?
Wiswall Dam was completed in 1911, making it 115 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 Wiswall Dam?
Wiswall 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 Wiswall Dam?
Wiswall 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 Wiswall Dam last inspected?
Wiswall Dam was last inspected on June 2, 2021. Inspection dates indicate when a formal review occurred, not the results of that inspection.