Hillsborough Mill
Key Takeaway
Hillsborough Mill is classified as significant hazard in New Hampshire. It was completed in 1925 and is 101 years old. Its primary use is hydroelectric. 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 | 200 ft |
| Dam Type | Concrete |
| Max Storage | 70 acre-ft |
| Normal Storage | 70 acre-ft |
| Surface Area | 7 acres |
| Drainage Area | 97 sq mi |
| Max Discharge | 13,100 cfs |
| Year Completed | 1925 (101 years old) |
| NID ID | NH00258 |
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
EEvergreen Electric
Private
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What is the hazard classification of Hillsborough Mill?
Hillsborough Mill 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 Hillsborough Mill?
Hillsborough Mill is owned by EEvergreen Electric (Private). The owner is responsible for maintenance, inspections, and compliance with dam safety regulations.
When was Hillsborough Mill built?
Hillsborough Mill 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 Hillsborough Mill?
Hillsborough Mill serves the following purposes: Hydroelectric. Many dams in the U.S. are multi-purpose, supporting flood control, water supply, recreation, and other uses.
How tall is Hillsborough Mill?
Hillsborough Mill 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 Hillsborough Mill last inspected?
Hillsborough Mill was last inspected on August 25, 2022. Inspection dates indicate when a formal review occurred, not the results of that inspection.