Magic Spillway
Key Takeaway
Magic Spillway is classified as high hazard in Idaho. It was completed in 1910 and is 116 years old. Its primary use is hydroelectric. 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 | 50 ft (taller than 79.7% in ID) |
| Dam Length | 1,200 ft |
| Dam Type | Concrete |
| Max Storage | 195.0K acre-ft |
| Normal Storage | 191.5K acre-ft |
| Surface Area | 3,740 acres |
| Drainage Area | 1,600 sq mi |
| Max Discharge | 100,000 cfs |
| Year Completed | 1910 (116 years old) |
| NID ID | ID00039 |
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
Big Wood Canal Company
Private
Nearby Dams
Frequently Asked Questions
What is the hazard classification of Magic Spillway?
Magic Spillway 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 Magic Spillway?
Magic Spillway is owned by Big Wood Canal Company (Private). The owner is responsible for maintenance, inspections, and compliance with dam safety regulations.
When was Magic Spillway built?
Magic Spillway was completed in 1910, making it 116 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 Magic Spillway?
Magic Spillway serves the following purposes: Hydroelectric, Irrigation. Many dams in the U.S. are multi-purpose, supporting flood control, water supply, recreation, and other uses.
How tall is Magic Spillway?
Magic Spillway has a dam height of 50 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 Magic Spillway last inspected?
Magic Spillway was last inspected on May 23, 2022. Inspection dates indicate when a formal review occurred, not the results of that inspection.