Somersworth

Salmon Falls River· Strafford, New Hampshire· Built 1929· Masonry· 17 ft tall

Key Takeaway

Somersworth is classified as significant hazard in New Hampshire. It was completed in 1929 and is 97 years old. Its primary use is hydroelectric. Significant hazard means failure could cause economic or environmental damage. Learn more.

Physical Details

Dam Height 17 ft (taller than 59.6% in NH)
Dam Length400 ft
Dam TypeMasonry
Max Storage377 acre-ft
Normal Storage377 acre-ft
Surface Area55 acres
Drainage Area218 sq mi
Max Discharge8,000 cfs
Year Completed1929 (97 years old)
NID IDNH00127

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: No
Last Inspection: May 19, 2022
State Regulated: Yes
Regulatory Agency: NHDES DAM BUREAU

Ownership

Aclara Meters LLC

Private

Nearby Dams

Frequently Asked Questions

What is the hazard classification of Somersworth?

Somersworth 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 Somersworth?

Somersworth is owned by Aclara Meters LLC (Private). The owner is responsible for maintenance, inspections, and compliance with dam safety regulations.

When was Somersworth built?

Somersworth was completed in 1929, making it 97 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 Somersworth?

Somersworth serves the following purposes: Hydroelectric, Fire Protection, Stock, Or Small Fish Pond, Water Supply. Many dams in the U.S. are multi-purpose, supporting flood control, water supply, recreation, and other uses.

How tall is Somersworth?

Somersworth has a dam height of 17 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 Somersworth last inspected?

Somersworth was last inspected on May 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.