Mackay
Key Takeaway
Mackay is classified as high hazard in Idaho. It was completed in 1918 and is 108 years old. Its primary use is other. 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 | 75 ft (taller than 88.4% in ID) |
| Dam Length | 1,430 ft |
| Normal Storage | 45.0K acre-ft |
| Surface Area | 1,392 acres |
| Drainage Area | 788 sq mi |
| Max Discharge | 7,000 cfs |
| Year Completed | 1918 (108 years old) |
| Year Modified | 1956 |
| NID ID | ID00181 |
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
Private
Nearby Dams
Frequently Asked Questions
What is the hazard classification of Mackay?
Mackay 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 Mackay?
Mackay is owned by information not available (Private). The owner is responsible for maintenance, inspections, and compliance with dam safety regulations.
When was Mackay built?
Mackay was completed in 1918, making it 108 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 Mackay?
Mackay serves the following purposes: Other. Many dams in the U.S. are multi-purpose, supporting flood control, water supply, recreation, and other uses.
How tall is Mackay?
Mackay has a dam height of 75 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 Mackay last inspected?
Mackay was last inspected on October 4, 2019. Inspection dates indicate when a formal review occurred, not the results of that inspection.