Gregg Falls
Key Takeaway
Gregg Falls is classified as high hazard in New Hampshire. It was completed in 1917 and is 109 years old. Its primary use is hydroelectric. 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 | 66 ft (taller than 97.3% in NH) |
| Dam Length | 1,360 ft |
| Dam Type | Concrete |
| Max Storage | 3.7K acre-ft |
| Normal Storage | 3.7K acre-ft |
| Surface Area | 138 acres |
| Drainage Area | 200 sq mi |
| Max Discharge | 40,000 cfs |
| Year Completed | 1917 (109 years old) |
| NID ID | NH00093 |
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
State Government
Nearby Dams
Hadley Falls
Hillsborough, NH
Significant Hazard 20 ftUncanoonuc Lake Dam
Hillsborough, NH
High Hazard 10 ftUncanoonuc Lake Dike
Hillsborough, NH
High Hazard 15 ftGoffstown Lower Reservoir Dam
Hillsborough, NH
High Hazard 30 ftGoffstown Upper Reservoir Dam
Hillsborough, NH
High Hazard 31 ftKimball Pond Dam
Merrimack, NH
Low Hazard 8 ftKelley'S Falls Dam
Hillsborough, NH
High Hazard 31 ftFlintlock Estates Fire Pond Dam
Merrimack, NH
Low Hazard 8 ftFrequently Asked Questions
What is the hazard classification of Gregg Falls?
Gregg Falls 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 Gregg Falls?
Gregg Falls is owned by information not available (State Government). The owner is responsible for maintenance, inspections, and compliance with dam safety regulations.
When was Gregg Falls built?
Gregg Falls was completed in 1917, making it 109 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 Gregg Falls?
Gregg Falls serves the following purposes: Hydroelectric, Fire Protection, Stock, Or Small Fish Pond, Recreation. Many dams in the U.S. are multi-purpose, supporting flood control, water supply, recreation, and other uses.
How tall is Gregg Falls?
Gregg Falls has a dam height of 66 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 Gregg Falls last inspected?
Gregg Falls was last inspected on May 25, 2022. Inspection dates indicate when a formal review occurred, not the results of that inspection.