Lower Valley

Sugar River· Sullivan, New Hampshire· Built 1921· Concrete· 33 ft tall
Significant Hazard Hydroelectric Water Supply Private

Key Takeaway

Lower Valley is classified as significant hazard in New Hampshire. It was completed in 1921 and is 105 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 Length145 ft
Dam TypeConcrete
Max Storage24 acre-ft
Normal Storage24 acre-ft
Surface Area2 acres
Drainage Area252 sq mi
Max Discharge7,172 cfs
Year Completed1921 (105 years old)
NID IDNH00139

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 26, 2022
State Regulated: Yes
Regulatory Agency: NHDES DAM BUREAU

Ownership

Lower Valley, LLC

Private

Nearby Dams

Frequently Asked Questions

What is the hazard classification of Lower Valley?

Lower Valley 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 Lower Valley?

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

When was Lower Valley built?

Lower Valley was completed in 1921, making it 105 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 Lower Valley?

Lower Valley serves the following purposes: Hydroelectric, Water Supply. Many dams in the U.S. are multi-purpose, supporting flood control, water supply, recreation, and other uses.

How tall is Lower Valley?

Lower Valley 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 Lower Valley last inspected?

Lower Valley was last inspected on August 26, 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.