Theresa

Indian River· Jefferson, New York· Built 1929· Gravity· 40 ft tall
Low Hazard Hydroelectric Private

Key Takeaway

Theresa is classified as low hazard in New York. It was completed in 1929 and is 97 years old. Its primary use is hydroelectric.

Physical Details

Dam Height 40 ft (taller than 88.1% in NY)
Dam Length127 ft
Dam TypeGravity
Max Storage482 acre-ft
Normal Storage482 acre-ft
Surface Area75 acres
Drainage Area323 sq mi
Max Discharge2,300 cfs
Year Completed1929 (97 years old)
NID IDNY00407

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: June 15, 2022
State Regulated: Yes
Regulatory Agency: NYS DEC

Ownership

Niagara Mohawk Power Corp.

Private

Nearby Dams

Frequently Asked Questions

What is the hazard classification of Theresa?

Theresa 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 Theresa?

Theresa is owned by Niagara Mohawk Power Corp. (Private). The owner is responsible for maintenance, inspections, and compliance with dam safety regulations.

When was Theresa built?

Theresa 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 Theresa?

Theresa 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 Theresa?

Theresa has a dam height of 40 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 Theresa last inspected?

Theresa was last inspected on June 15, 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.