Union Street

Nubanusit Brook· Hillsborough, New Hampshire· Built 1916· Concrete· 15 ft tall
Significant Hazard Hydroelectric Private

Key Takeaway

Union Street is classified as significant hazard in New Hampshire. It was completed in 1916 and is 110 years old. Its primary use is hydroelectric. Significant hazard means failure could cause economic or environmental damage. Learn more.

Physical Details

Dam Height 15 ft (taller than 47.8% in NH)
Dam Length101 ft
Dam TypeConcrete
Max Storage9 acre-ft
Normal Storage9 acre-ft
Surface Area1 acres
Drainage Area44 sq mi
Max Discharge3,500 cfs
Year Completed1916 (110 years old)
NID IDNH83031

Safety Information

Significant Hazard

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?

Emergency Action Plan: Yes
Last Inspection: July 19, 2022
State Regulated: Yes
Regulatory Agency: NHDES DAM BUREAU

Ownership

American Hydro Power Company

Private

Nearby Dams

Frequently Asked Questions

What is the hazard classification of Union Street?

Union Street 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 Union Street?

Union Street is owned by American Hydro Power Company (Private). The owner is responsible for maintenance, inspections, and compliance with dam safety regulations.

When was Union Street built?

Union Street was completed in 1916, making it 110 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 Union Street?

Union Street 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 Union Street?

Union Street has a dam height of 15 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 Union Street last inspected?

Union Street was last inspected on July 19, 2022. Inspection dates indicate when a formal review occurred, not the results of that inspection.

Data from the National Inventory of Dams (NID) maintained by the US Army Corps of Engineers. Dam conditions may have changed since the last update. This site is not affiliated with USACE. Do not use for emergency planning — contact your local dam safety program.