Anderson Ranch
Key Takeaway
Anderson Ranch is classified as high hazard in Idaho. It was completed in 1946 and is 80 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 | 456 ft (taller than 99.5% in ID) |
| Dam Length | 1,350 ft |
| Dam Type | Earth |
| Max Storage | 503.5K acre-ft |
| Normal Storage | 464.2K acre-ft |
| Surface Area | 4,815 acres |
| Drainage Area | 960 sq mi |
| Max Discharge | 20,000 cfs |
| Year Completed | 1946 (80 years old) |
| NID ID | ID00279 |
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 Anderson Ranch?
Anderson Ranch 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 Anderson Ranch?
Anderson Ranch is owned by RECLAMATION (Federal Government). The owner is responsible for maintenance, inspections, and compliance with dam safety regulations.
When was Anderson Ranch built?
Anderson Ranch was completed in 1946, making it 80 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 Anderson Ranch?
Anderson Ranch serves the following purposes: Flood Risk Reduction, Irrigation, Hydroelectric. Many dams in the U.S. are multi-purpose, supporting flood control, water supply, recreation, and other uses.
How tall is Anderson Ranch?
Anderson Ranch has a dam height of 456 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 Anderson Ranch last inspected?
Anderson Ranch was last inspected on June 18, 2020. Inspection dates indicate when a formal review occurred, not the results of that inspection.