American Falls
Key Takeaway
American Falls is classified as high hazard in Idaho. It was completed in 1927 and is 99 years old. Its primary use is flood risk reduction. 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 | 87 ft (taller than 91% in ID) |
| Dam Length | 5,277 ft |
| Dam Type | Concrete |
| Max Storage | 1.7M acre-ft |
| Normal Storage | 1.7M acre-ft |
| Surface Area | 58,076 acres |
| Drainage Area | 13,580 sq mi |
| Max Discharge | 87,000 cfs |
| Year Completed | 1927 (99 years old) |
| NID ID | ID00274 |
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
RECLAMATION
Federal Government
Nearby Dams
Frequently Asked Questions
What is the hazard classification of American Falls?
American Falls 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 American Falls?
American Falls is owned by RECLAMATION (Federal Government). The owner is responsible for maintenance, inspections, and compliance with dam safety regulations.
When was American Falls built?
American Falls was completed in 1927, making it 99 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 American Falls?
American Falls serves the following purposes: Flood Risk Reduction, Fire Protection, Stock, Or Small Fish Pond, Irrigation, Fish And Wildlife Pond, Recreation. Many dams in the U.S. are multi-purpose, supporting flood control, water supply, recreation, and other uses.
How tall is American Falls?
American Falls has a dam height of 87 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 American Falls last inspected?
American Falls was last inspected on April 15, 2020. Inspection dates indicate when a formal review occurred, not the results of that inspection.