Union Valley
Key Takeaway
Union Valley is classified as high hazard in California. It was completed in 1962 and is 64 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 | 440 ft (taller than 99.5% in CA) |
| Dam Length | 1,990 ft |
| Dam Type | Earth |
| Max Storage | 266.4K acre-ft |
| Normal Storage | 204.0K acre-ft |
| Surface Area | 2,860 acres |
| Drainage Area | 84 sq mi |
| Max Discharge | 44,500 cfs |
| Year Completed | 1962 (64 years old) |
| NID ID | CA00816 |
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
Sacramento Municipal Utility District
Public Utility
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High Hazard 91 ftFrequently Asked Questions
What is the hazard classification of Union Valley?
Union Valley 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 Union Valley?
Union Valley is owned by Sacramento Municipal Utility District (Public Utility). The owner is responsible for maintenance, inspections, and compliance with dam safety regulations.
When was Union Valley built?
Union Valley was completed in 1962, making it 64 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 Union Valley?
Union Valley serves the following purposes: Hydroelectric, Recreation. Many dams in the U.S. are multi-purpose, supporting flood control, water supply, recreation, and other uses.
How tall is Union Valley?
Union Valley has a dam height of 440 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 Union Valley last inspected?
Union Valley was last inspected on August 30, 2023. Inspection dates indicate when a formal review occurred, not the results of that inspection.