Granby

Oswego River· Oswego, New York· Built 1926· Masonry· 15 ft tall
Significant Hazard Hydroelectric Navigation State Government

Key Takeaway

Granby is classified as significant hazard in New York. It was completed in 1926 and is 100 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 37.1% in NY)
Dam Length509 ft
Dam TypeMasonry
Max Storage620 acre-ft
Normal Storage620 acre-ft
Surface Area33 acres
Drainage Area5,018 sq mi
Max Discharge37,500 cfs
Year Completed1926 (100 years old)
NID IDNY00406

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: June 28, 2022
State Regulated: No

Ownership

New York State Canal Corporation

State Government

Nearby Dams

Frequently Asked Questions

What is the hazard classification of Granby?

Granby 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 Granby?

Granby is owned by New York State Canal Corporation (State Government). The owner is responsible for maintenance, inspections, and compliance with dam safety regulations.

When was Granby built?

Granby was completed in 1926, making it 100 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 Granby?

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

How tall is Granby?

Granby 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 Granby last inspected?

Granby was last inspected on June 28, 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.