Souhegan River Site 10a Dam

MILL BROOK· Hillsborough, New Hampshire· Built 1966· Earth· 59 ft tall
High Hazard Flood Risk Reduction State Government

Key Takeaway

Souhegan River Site 10a Dam is classified as high hazard in New Hampshire. It was completed in 1966 and is 60 years old. Its primary use is flood risk reduction. 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 59 ft (taller than 96.2% in NH)
Dam Length1,281 ft
Dam TypeEarth
Max Storage2.8K acre-ft
Normal Storage49 acre-ft
Surface Area8 acres
Drainage Area6 sq mi
Max Discharge5,600 cfs
Year Completed1966 (60 years old)
NID IDNH00264

Safety Information

High Hazard

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?

Emergency Action Plan: Yes
Last Inspection: May 5, 2021
State Regulated: Yes
Regulatory Agency: NH DES

Ownership

NH DES WATER DIVISION

State Government

Nearby Dams

Frequently Asked Questions

What is the hazard classification of Souhegan River Site 10a Dam?

Souhegan River Site 10a 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 Souhegan River Site 10a Dam?

Souhegan River Site 10a Dam is owned by NH DES WATER DIVISION (State Government). The owner is responsible for maintenance, inspections, and compliance with dam safety regulations.

When was Souhegan River Site 10a Dam built?

Souhegan River Site 10a Dam was completed in 1966, making it 60 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 Souhegan River Site 10a Dam?

Souhegan River Site 10a Dam serves the following purposes: Flood Risk Reduction. Many dams in the U.S. are multi-purpose, supporting flood control, water supply, recreation, and other uses.

How tall is Souhegan River Site 10a Dam?

Souhegan River Site 10a Dam has a dam height of 59 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 Souhegan River Site 10a Dam last inspected?

Souhegan River Site 10a Dam was last inspected on May 5, 2021. 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.