Henry J. Mills Reservoir
Key Takeaway
Henry J. Mills Reservoir is classified as high hazard in California. It was completed in 1979 and is 47 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 | 23 ft (taller than 21.2% in CA) |
| Dam Length | 2,038 ft |
| Dam Type | Earth |
| Max Storage | 83 acre-ft |
| Surface Area | 6 acres |
| Drainage Area | 0 sq mi |
| Year Completed | 1979 (47 years old) |
| NID ID | CA01085 |
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
Metropolitan Water District Of Southern California
Public Utility
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High Hazard 44 ftFrequently Asked Questions
What is the hazard classification of Henry J. Mills Reservoir?
Henry J. Mills 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 Henry J. Mills Reservoir?
Henry J. Mills Reservoir is owned by Metropolitan Water District Of Southern California (Public Utility). The owner is responsible for maintenance, inspections, and compliance with dam safety regulations.
When was Henry J. Mills Reservoir built?
Henry J. Mills Reservoir was completed in 1979, making it 47 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 Henry J. Mills Reservoir?
Henry J. Mills 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 Henry J. Mills Reservoir?
Henry J. Mills Reservoir has a dam height of 23 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 Henry J. Mills Reservoir last inspected?
Henry J. Mills Reservoir was last inspected on November 30, 2021. Inspection dates indicate when a formal review occurred, not the results of that inspection.