Drum Afterbay
Key Takeaway
Drum Afterbay is classified as low hazard in California. It was completed in 1968 and is 58 years old. Its primary use is hydroelectric.
Physical Details
| Dam Height | 102 ft (taller than 82.6% in CA) |
| Dam Length | 356 ft |
| Dam Type | Concrete |
| Max Storage | 341 acre-ft |
| Normal Storage | 181 acre-ft |
| Surface Area | 10 acres |
| Drainage Area | 12 sq mi |
| Max Discharge | 5,300 cfs |
| Year Completed | 1968 (58 years old) |
| NID ID | CA00421 |
Safety Information
No probable loss of human life and low economic/environmental losses expected.
Hazard potential describes downstream consequences of failure, not the dam's current condition. What does this mean?
Ownership
Pacific Gas and Electric Company
Private
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Low Hazard 60 ftFrequently Asked Questions
What is the hazard classification of Drum Afterbay?
Drum Afterbay is classified as Low Hazard. No probable loss of human life and low economic/environmental losses expected. This classification refers to the potential downstream consequences of a failure, not the dam's current structural condition.
Who owns and operates Drum Afterbay?
Drum Afterbay is owned by Pacific Gas and Electric Company (Private). The owner is responsible for maintenance, inspections, and compliance with dam safety regulations.
When was Drum Afterbay built?
Drum Afterbay was completed in 1968, making it 58 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 Drum Afterbay?
Drum Afterbay serves the following purposes: Hydroelectric. Many dams in the U.S. are multi-purpose, supporting flood control, water supply, recreation, and other uses.
How tall is Drum Afterbay?
Drum Afterbay has a dam height of 102 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 Drum Afterbay last inspected?
Drum Afterbay was last inspected on September 20, 2022. Inspection dates indicate when a formal review occurred, not the results of that inspection.