Conn Creek
Key Takeaway
Conn Creek is classified as high hazard in California. It was completed in 1946 and is 80 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 | 125 ft (taller than 86.7% in CA) |
| Dam Length | 700 ft |
| Dam Type | Earth |
| Max Storage | 31.0K acre-ft |
| Surface Area | 790 acres |
| Drainage Area | 54 sq mi |
| Year Completed | 1946 (80 years old) |
| NID ID | CA00104 |
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 Napa
Local Government
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Significant Hazard 36 ftFrequently Asked Questions
What is the hazard classification of Conn Creek?
Conn Creek 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 Conn Creek?
Conn Creek is owned by City of Napa (Local Government). The owner is responsible for maintenance, inspections, and compliance with dam safety regulations.
When was Conn Creek built?
Conn Creek was completed in 1946, making it 80 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 Conn Creek?
Conn Creek serves the following purposes: Water Supply, Irrigation. Many dams in the U.S. are multi-purpose, supporting flood control, water supply, recreation, and other uses.
How tall is Conn Creek?
Conn Creek has a dam height of 125 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 Conn Creek last inspected?
Conn Creek was last inspected on December 21, 2022. Inspection dates indicate when a formal review occurred, not the results of that inspection.