Lake Alta
Key Takeaway
Lake Alta is classified as high hazard in California. It was completed in 1862 and is 164 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 | 22 ft (taller than 18.8% in CA) |
| Dam Length | 955 ft |
| Dam Type | Earth |
| Max Storage | 270 acre-ft |
| Surface Area | 23 acres |
| Drainage Area | 0 sq mi |
| Year Completed | 1862 (164 years old) |
| NID ID | CA00355 |
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
Placer County Water Agency
Local Government
Nearby Dams
Dutch Flat Forebay
Nevada, CA
Low Hazard 77 ftDutch Flat Afterbay
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Low Hazard 165 ftDrum Afterbay
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Low Hazard 102 ftChicago Park Forebay
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Low Hazard 60 ftSugar Pine
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High Hazard 251 ftDrum Forebay
Placer, CA
High Hazard 65 ftMorning Star
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Low Hazard 44 ftScotts Flat
Nevada, CA
High Hazard 175 ftFrequently Asked Questions
What is the hazard classification of Lake Alta?
Lake Alta 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 Lake Alta?
Lake Alta is owned by Placer County Water Agency (Local Government). The owner is responsible for maintenance, inspections, and compliance with dam safety regulations.
When was Lake Alta built?
Lake Alta was completed in 1862, making it 164 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 Lake Alta?
Lake Alta 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 Lake Alta?
Lake Alta has a dam height of 22 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 Lake Alta last inspected?
Lake Alta was last inspected on February 7, 2023. Inspection dates indicate when a formal review occurred, not the results of that inspection.