Mariposa Dam
Key Takeaway
Mariposa Dam is classified as high hazard in California. It was completed in 1948 and is 78 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 Length | 1,330 ft |
| Dam Type | Earth |
| Max Storage | 21.5K acre-ft |
| Normal Storage | 4.3K acre-ft |
| Surface Area | 510 acres |
| Drainage Area | 107 sq mi |
| Max Discharge | 30,000 cfs |
| Year Completed | 1948 (78 years old) |
| NID ID | CA10107 |
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
USACE - Sacramento District
Federal Government
Nearby Dams
Frequently Asked Questions
What is the hazard classification of Mariposa Dam?
Mariposa Dam 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 Mariposa Dam?
Mariposa Dam is owned by USACE - Sacramento District (Federal Government). The owner is responsible for maintenance, inspections, and compliance with dam safety regulations.
When was Mariposa Dam built?
Mariposa Dam was completed in 1948, making it 78 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 Mariposa Dam?
Mariposa Dam serves the following purposes: Flood Risk Reduction, Hydroelectric. Many dams in the U.S. are multi-purpose, supporting flood control, water supply, recreation, and other uses.
When was Mariposa Dam last inspected?
Mariposa Dam was last inspected on March 22, 2023. Inspection dates indicate when a formal review occurred, not the results of that inspection.