Sweetwater

Sugar River· Sullivan, New Hampshire· Built 1922· Concrete· 33 ft tall
Significant Hazard Hydroelectric Private

Key Takeaway

Sweetwater is classified as significant hazard in New Hampshire. It was completed in 1922 and is 104 years old. Its primary use is hydroelectric. Significant hazard means failure could cause economic or environmental damage. Learn more.

Physical Details

Dam Height 33 ft (taller than 89.6% in NH)
Dam Length314 ft
Dam TypeConcrete
Max Storage150 acre-ft
Normal Storage150 acre-ft
Surface Area17 acres
Drainage Area270 sq mi
Max Discharge10,668 cfs
Year Completed1922 (104 years old)
NID IDNH00140

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: August 17, 2022
State Regulated: Yes
Regulatory Agency: NHDES DAM BUREAU

Ownership

Sweetwater Hydroelectric, Inc.

Private

Nearby Dams

Frequently Asked Questions

What is the hazard classification of Sweetwater?

Sweetwater 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 Sweetwater?

Sweetwater is owned by Sweetwater Hydroelectric, Inc. (Private). The owner is responsible for maintenance, inspections, and compliance with dam safety regulations.

When was Sweetwater built?

Sweetwater was completed in 1922, making it 104 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 Sweetwater?

Sweetwater 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 Sweetwater?

Sweetwater has a dam height of 33 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 Sweetwater last inspected?

Sweetwater was last inspected on August 17, 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.