Middlefield Reservoir
Key Takeaway
Middlefield Reservoir is classified as high hazard in California. It was completed in 1958 and is 68 years old. Its primary use is water supply. 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 | 147 ft (taller than 89.6% in CA) |
| Dam Length | 1,017 ft |
| Dam Type | Earth |
| Max Storage | 22 acre-ft |
| Surface Area | 2 acres |
| Year Completed | 1958 (68 years old) |
| NID ID | CA00896 |
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
Alameda County Water District
Local Government
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High Hazard 210 ftFrequently Asked Questions
What is the hazard classification of Middlefield Reservoir?
Middlefield 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 Middlefield Reservoir?
Middlefield Reservoir is owned by Alameda County Water District (Local Government). The owner is responsible for maintenance, inspections, and compliance with dam safety regulations.
When was Middlefield Reservoir built?
Middlefield Reservoir was completed in 1958, making it 68 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 Middlefield Reservoir?
Middlefield Reservoir serves the following purposes: Water Supply. Many dams in the U.S. are multi-purpose, supporting flood control, water supply, recreation, and other uses.
How tall is Middlefield Reservoir?
Middlefield Reservoir has a dam height of 147 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 Middlefield Reservoir last inspected?
Middlefield Reservoir was last inspected on October 26, 2021. Inspection dates indicate when a formal review occurred, not the results of that inspection.