Mammoth Pool
Key Takeaway
Mammoth Pool is classified as high hazard in California. It was completed in 1960 and is 66 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 | 411 ft (taller than 99.4% in CA) |
| Dam Length | 820 ft |
| Dam Type | Earth |
| Max Storage | 122.2K acre-ft |
| Normal Storage | 120.0K acre-ft |
| Surface Area | 1,100 acres |
| Drainage Area | 995 sq mi |
| Max Discharge | 235,000 cfs |
| Year Completed | 1960 (66 years old) |
| NID ID | CA00443 |
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
Southern California Edison Company
Private
Nearby Dams
Frequently Asked Questions
What is the hazard classification of Mammoth Pool?
Mammoth Pool 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 Mammoth Pool?
Mammoth Pool is owned by Southern California Edison Company (Private). The owner is responsible for maintenance, inspections, and compliance with dam safety regulations.
When was Mammoth Pool built?
Mammoth Pool was completed in 1960, making it 66 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 Mammoth Pool?
Mammoth Pool serves the following purposes: Hydroelectric, Recreation. Many dams in the U.S. are multi-purpose, supporting flood control, water supply, recreation, and other uses.
How tall is Mammoth Pool?
Mammoth Pool has a dam height of 411 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 Mammoth Pool last inspected?
Mammoth Pool was last inspected on August 29, 2023. Inspection dates indicate when a formal review occurred, not the results of that inspection.