Loon Lake Auxiliary
Key Takeaway
Loon Lake Auxiliary is classified as significant hazard in California. It was completed in 1963 and is 63 years old. Its primary use is hydroelectric. Significant hazard means failure could cause economic or environmental damage. Learn more.
Physical Details
| Dam Height | 90 ft (taller than 79.3% in CA) |
| Dam Length | 910 ft |
| Dam Type | Rockfill |
| Max Storage | 69.3K acre-ft |
| Normal Storage | 51.0K acre-ft |
| Surface Area | 1,450 acres |
| Drainage Area | 8 sq mi |
| Max Discharge | 15,300 cfs |
| Year Completed | 1963 (63 years old) |
| NID ID | CA00820 |
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
Sacramento Municipal Utility District
Public Utility
Nearby Dams
Gerle Creek
El Dorado, CA
Low Hazard 65 ftRobbs Peak
El Dorado, CA
Low Hazard 50 ftBuck Island Auxiliary
El Dorado, CA
Low Hazard 25 ftHell Hole
Placer, CA
High Hazard 410 ftRubicon Auxiliary
El Dorado, CA
Low Hazard 13 ftUnion Valley
El Dorado, CA
High Hazard 440 ftJunction
El Dorado, CA
Significant Hazard 168 ftL. L. Anderson
Placer, CA
High Hazard 231 ftFrequently Asked Questions
What is the hazard classification of Loon Lake Auxiliary?
Loon Lake Auxiliary 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 Loon Lake Auxiliary?
Loon Lake Auxiliary is owned by Sacramento Municipal Utility District (Public Utility). The owner is responsible for maintenance, inspections, and compliance with dam safety regulations.
When was Loon Lake Auxiliary built?
Loon Lake Auxiliary was completed in 1963, making it 63 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 Loon Lake Auxiliary?
Loon Lake Auxiliary 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 Loon Lake Auxiliary?
Loon Lake Auxiliary has a dam height of 90 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 Loon Lake Auxiliary last inspected?
Loon Lake Auxiliary was last inspected on August 28, 2023. Inspection dates indicate when a formal review occurred, not the results of that inspection.