Williamson No. 1
Key Takeaway
Williamson No. 1 is classified as significant hazard in California. It was completed in 1926 and is 100 years old. Its primary use is water supply. Significant hazard means failure could cause economic or environmental damage. Learn more.
Physical Details
| Dam Height | 42 ft (taller than 50.1% in CA) |
| Dam Length | 240 ft |
| Dam Type | Earth |
| Max Storage | 117 acre-ft |
| Surface Area | 11 acres |
| Drainage Area | 1 sq mi |
| Year Completed | 1926 (100 years old) |
| NID ID | CA00608 |
Safety Information
No probable loss of human life, but can cause economic loss, environmental damage, or disruption of lifeline facilities.
Hazard potential describes downstream consequences of failure, not the dam's current condition. What does this mean?
Ownership
Private Entity
Private
Nearby Dams
Schubin
El Dorado, CA
Significant Hazard 55 ftIndian Creek
El Dorado, CA
High Hazard 36 ftJacobs Creek
El Dorado, CA
Low Hazard 53 ftCross Creek Ranch
El Dorado, CA
Low Hazard 23 ftGastaldi
El Dorado, CA
Low Hazard 36 ftVolo Mining Company
El Dorado, CA
High Hazard 35 ftShaffer
El Dorado, CA
Significant Hazard 33 ftStraza
El Dorado, CA
Low Hazard 62 ftFrequently Asked Questions
What is the hazard classification of Williamson No. 1?
Williamson No. 1 is classified as Significant Hazard. No probable loss of human life, but can cause economic loss, environmental damage, or disruption of lifeline facilities. This classification refers to the potential downstream consequences of a failure, not the dam's current structural condition.
Who owns and operates Williamson No. 1?
Williamson No. 1 is owned by Private Entity (Private). The owner is responsible for maintenance, inspections, and compliance with dam safety regulations.
When was Williamson No. 1 built?
Williamson No. 1 was completed in 1926, making it 100 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 Williamson No. 1?
Williamson No. 1 serves the following purposes: Water Supply, Irrigation, Recreation. Many dams in the U.S. are multi-purpose, supporting flood control, water supply, recreation, and other uses.
How tall is Williamson No. 1?
Williamson No. 1 has a dam height of 42 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 Williamson No. 1 last inspected?
Williamson No. 1 was last inspected on April 12, 2023. Inspection dates indicate when a formal review occurred, not the results of that inspection.