Willow Lake #1
Key Takeaway
Willow Lake #1 is classified as high hazard in California. It was completed in 2004 and is 22 years old. Its primary use is other. 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 | 40 ft (taller than 46.3% in CA) |
| Dam Length | 750 ft |
| Dam Type | Earth |
| Max Storage | 89 acre-ft |
| Surface Area | 6 acres |
| Drainage Area | 0 sq mi |
| Year Completed | 2004 (22 years old) |
| NID ID | CA01463 |
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
C. Mondavi and Son, Inc.
Private
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High Hazard 30 ftFrequently Asked Questions
What is the hazard classification of Willow Lake #1?
Willow Lake #1 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 Willow Lake #1?
Willow Lake #1 is owned by C. Mondavi and Son, Inc. (Private). The owner is responsible for maintenance, inspections, and compliance with dam safety regulations.
When was Willow Lake #1 built?
Willow Lake #1 was completed in 2004, making it 22 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 Willow Lake #1?
Willow Lake #1 serves the following purposes: Other, Irrigation, Water Supply. Many dams in the U.S. are multi-purpose, supporting flood control, water supply, recreation, and other uses.
How tall is Willow Lake #1?
Willow Lake #1 has a dam height of 40 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 Willow Lake #1 last inspected?
Willow Lake #1 was last inspected on November 1, 2021. Inspection dates indicate when a formal review occurred, not the results of that inspection.