Upper Blue Lake
Key Takeaway
Upper Blue Lake is classified as high hazard in California. It was completed in 1901 and is 125 years old. Its primary use is hydroelectric. 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 | 21 ft (taller than 17.3% in CA) |
| Dam Length | 786 ft |
| Dam Type | Earth |
| Max Storage | 7.3K acre-ft |
| Normal Storage | 6.8K acre-ft |
| Surface Area | 333 acres |
| Drainage Area | 3 sq mi |
| Max Discharge | 1,400 cfs |
| Year Completed | 1901 (125 years old) |
| NID ID | CA00385 |
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
Pacific Gas and Electric Company
Private
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Low Hazard 38 ftFrequently Asked Questions
What is the hazard classification of Upper Blue Lake?
Upper Blue 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 Upper Blue Lake?
Upper Blue Lake is owned by Pacific Gas and Electric Company (Private). The owner is responsible for maintenance, inspections, and compliance with dam safety regulations.
When was Upper Blue Lake built?
Upper Blue Lake was completed in 1901, making it 125 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 Upper Blue Lake?
Upper Blue Lake serves the following purposes: Hydroelectric. Many dams in the U.S. are multi-purpose, supporting flood control, water supply, recreation, and other uses.
How tall is Upper Blue Lake?
Upper Blue Lake has a dam height of 21 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 Upper Blue Lake last inspected?
Upper Blue Lake was last inspected on June 13, 2022. Inspection dates indicate when a formal review occurred, not the results of that inspection.