Big Rock Ranch
Key Takeaway
Big Rock Ranch is classified as high hazard in California. It was completed in 2002 and is 24 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 | 45 ft (taller than 54% in CA) |
| Dam Length | 490 ft |
| Dam Type | Earth |
| Max Storage | 91 acre-ft |
| Surface Area | 7 acres |
| Drainage Area | 1 sq mi |
| Year Completed | 2002 (24 years old) |
| NID ID | CA01457 |
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
Lucasfilm, LTD
Private
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High Hazard 115 ftFrequently Asked Questions
What is the hazard classification of Big Rock Ranch?
Big Rock Ranch 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 Big Rock Ranch?
Big Rock Ranch is owned by Lucasfilm, LTD (Private). The owner is responsible for maintenance, inspections, and compliance with dam safety regulations.
When was Big Rock Ranch built?
Big Rock Ranch was completed in 2002, making it 24 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 Big Rock Ranch?
Big Rock Ranch serves the following purposes: Water Supply, Recreation. Many dams in the U.S. are multi-purpose, supporting flood control, water supply, recreation, and other uses.
How tall is Big Rock Ranch?
Big Rock Ranch has a dam height of 45 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 Big Rock Ranch last inspected?
Big Rock Ranch was last inspected on September 28, 2021. Inspection dates indicate when a formal review occurred, not the results of that inspection.