Fern Lake
Key Takeaway
Fern Lake is classified as high hazard in California. It was completed in 1921 and is 105 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 | 40 ft (taller than 46.3% in CA) |
| Dam Length | 300 ft |
| Dam Type | Earth |
| Max Storage | 241 acre-ft |
| Surface Area | 14 acres |
| Drainage Area | 0 sq mi |
| Year Completed | 1921 (105 years old) |
| NID ID | CA00007 |
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
Sonoma Developmental Center
State Government
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Low Hazard 38 ftFrequently Asked Questions
What is the hazard classification of Fern Lake?
Fern Lake 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 Fern Lake?
Fern Lake is owned by Sonoma Developmental Center (State Government). The owner is responsible for maintenance, inspections, and compliance with dam safety regulations.
When was Fern Lake built?
Fern Lake was completed in 1921, making it 105 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 Fern Lake?
Fern Lake 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 Fern Lake?
Fern Lake 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 Fern Lake last inspected?
Fern Lake was last inspected on September 9, 2022. Inspection dates indicate when a formal review occurred, not the results of that inspection.