West Valley
Key Takeaway
West Valley is classified as high hazard in California. It was completed in 1936 and is 90 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 | 65 ft (taller than 70.3% in CA) |
| Dam Length | 305 ft |
| Dam Type | Earth |
| Max Storage | 23.0K acre-ft |
| Surface Area | 1,050 acres |
| Drainage Area | 136 sq mi |
| Year Completed | 1936 (90 years old) |
| NID ID | CA00300 |
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
South Fork Irrigation District
Public Utility
Nearby Dams
Frequently Asked Questions
What is the hazard classification of West Valley?
West 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 West Valley?
West Valley is owned by South Fork Irrigation District (Public Utility). The owner is responsible for maintenance, inspections, and compliance with dam safety regulations.
When was West Valley built?
West Valley was completed in 1936, making it 90 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 West Valley?
West Valley 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 West Valley?
West Valley has a dam height of 65 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 West Valley last inspected?
West Valley was last inspected on June 16, 2022. Inspection dates indicate when a formal review occurred, not the results of that inspection.