O'Neill Forebay
Key Takeaway
O'Neill Forebay is classified as high hazard in California. It was completed in 1967 and is 59 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 | 88 ft (taller than 78.9% in CA) |
| Dam Length | 14,300 ft |
| Dam Type | Earth |
| Max Storage | 64.8K acre-ft |
| Normal Storage | 56.4K acre-ft |
| Surface Area | 2,250 acres |
| Drainage Area | 18 sq mi |
| Max Discharge | 3,250 cfs |
| Year Completed | 1967 (59 years old) |
| NID ID | CA10171 |
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 O'Neill Forebay?
O'Neill Forebay 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 O'Neill Forebay?
O'Neill Forebay is owned by RECLAMATION (Federal Government). The owner is responsible for maintenance, inspections, and compliance with dam safety regulations.
When was O'Neill Forebay built?
O'Neill Forebay was completed in 1967, making it 59 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 O'Neill Forebay?
O'Neill Forebay serves the following purposes: Hydroelectric. Many dams in the U.S. are multi-purpose, supporting flood control, water supply, recreation, and other uses.
How tall is O'Neill Forebay?
O'Neill Forebay has a dam height of 88 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 O'Neill Forebay last inspected?
O'Neill Forebay was last inspected on March 2, 2020. Inspection dates indicate when a formal review occurred, not the results of that inspection.