Antioch Reservoir
Key Takeaway
Antioch Reservoir is classified as high hazard in California. It was completed in 1935 and is 91 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 | 30 ft (taller than 30.4% in CA) |
| Dam Length | 450 ft |
| Dam Type | Earth |
| Max Storage | 722 acre-ft |
| Surface Area | 61 acres |
| Drainage Area | 2 sq mi |
| Year Completed | 1935 (91 years old) |
| NID ID | CA00057 |
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
City of Antioch
Local Government
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High Hazard 231 ftFrequently Asked Questions
What is the hazard classification of Antioch Reservoir?
Antioch Reservoir 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 Antioch Reservoir?
Antioch Reservoir is owned by City of Antioch (Local Government). The owner is responsible for maintenance, inspections, and compliance with dam safety regulations.
When was Antioch Reservoir built?
Antioch Reservoir was completed in 1935, making it 91 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 Antioch Reservoir?
Antioch Reservoir serves the following purposes: Flood Risk Reduction, Water Supply. Many dams in the U.S. are multi-purpose, supporting flood control, water supply, recreation, and other uses.
How tall is Antioch Reservoir?
Antioch Reservoir has a dam height of 30 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 Antioch Reservoir last inspected?
Antioch Reservoir was last inspected on January 20, 2022. Inspection dates indicate when a formal review occurred, not the results of that inspection.