Diamond Island Diversion Dam

BLACK RIVER· Jefferson, New York· Built 1914· Concrete· 13 ft tall
Low Hazard Hydroelectric Public Utility

Key Takeaway

Diamond Island Diversion Dam is classified as low hazard in New York. It was completed in 1914 and is 112 years old. Its primary use is hydroelectric.

Physical Details

Dam Height 13 ft (taller than 29.9% in NY)
Dam Length710 ft
Dam TypeConcrete
Normal Storage134 acre-ft
Surface Area31 acres
Drainage Area1,889 sq mi
Max Discharge52,000 cfs
Year Completed1914 (112 years old)
NID IDNY01534

Safety Information

Low Hazard

No probable loss of human life and low economic/environmental losses expected.

Hazard potential describes downstream consequences of failure, not the dam's current condition. What does this mean?

Emergency Action Plan: No
Last Inspection: July 31, 1998
State Regulated: Yes
Regulatory Agency: NYS DEC

Ownership

NIAGARA MOHAWK POWER CORPORATION

Public Utility

Nearby Dams

Frequently Asked Questions

What is the hazard classification of Diamond Island Diversion Dam?

Diamond Island Diversion Dam is classified as Low Hazard. No probable loss of human life and low economic/environmental losses expected. This classification refers to the potential downstream consequences of a failure, not the dam's current structural condition.

Who owns and operates Diamond Island Diversion Dam?

Diamond Island Diversion Dam is owned by NIAGARA MOHAWK POWER CORPORATION (Public Utility). The owner is responsible for maintenance, inspections, and compliance with dam safety regulations.

When was Diamond Island Diversion Dam built?

Diamond Island Diversion Dam was completed in 1914, making it 112 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 Diamond Island Diversion Dam?

Diamond Island Diversion Dam 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 Diamond Island Diversion Dam?

Diamond Island Diversion Dam has a dam height of 13 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 Diamond Island Diversion Dam last inspected?

Diamond Island Diversion Dam was last inspected on July 31, 1998. 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.