Cooney
Key Takeaway
Cooney is classified as high hazard in Montana. It was completed in 1937 and is 89 years old. Its primary use is irrigation. High hazard means loss of life is likely if the dam fails — it does not indicate the dam's current condition. Learn more.
Physical Details
| Dam Height | 102 ft (taller than 99.1% in MT) |
| Dam Length | 2,369 ft |
| Dam Type | Earth |
| Max Storage | 28.2K acre-ft |
| Normal Storage | 28.1K acre-ft |
| Surface Area | 1,078 acres |
| Drainage Area | 206 sq mi |
| Max Discharge | 880 cfs |
| Year Completed | 1937 (89 years old) |
| Year Modified | 1982 |
| NID ID | MT00001 |
Safety Information
Loss of human life is likely if the dam fails.
Hazard potential describes downstream consequences of failure, not the dam's current condition. What does this mean?
Ownership
STATE WATER PROJECTS
State Government
Nearby Dams
Frequently Asked Questions
What is the hazard classification of Cooney?
Cooney is classified as High Hazard. Loss of human life is likely if the dam fails. This classification refers to the potential downstream consequences of a failure, not the dam's current structural condition.
Who owns and operates Cooney?
Cooney is owned by STATE WATER PROJECTS (State Government). The owner is responsible for maintenance, inspections, and compliance with dam safety regulations.
When was Cooney built?
Cooney was completed in 1937, making it 89 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 Cooney?
Cooney serves the following purposes: Irrigation. Many dams in the U.S. are multi-purpose, supporting flood control, water supply, recreation, and other uses.
How tall is Cooney?
Cooney has a dam height of 102 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 Cooney last inspected?
Cooney was last inspected on November 8, 2023. Inspection dates indicate when a formal review occurred, not the results of that inspection.