San Marcos
Key Takeaway
San Marcos is classified as high hazard in California. It was completed in 1958 and is 68 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 | 85 ft (taller than 77.8% in CA) |
| Dam Length | 400 ft |
| Dam Type | Earth |
| Max Storage | 320 acre-ft |
| Surface Area | 14 acres |
| Drainage Area | 0 sq mi |
| Year Completed | 1958 (68 years old) |
| NID ID | CA00785 |
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
Vallecitos Water District
Public Utility
Nearby Dams
San Marcos
San Diego, CA
High Hazard 52 ftOlivenhain
San Diego, CA
High Hazard 309 ftStanley A. Mahr Reservoir
San Diego, CA
High Hazard 79 ftMelrose Avenue
San Diego, CA
High Hazard 57 ftLake Hodges
San Diego, CA
High Hazard 131 ftSan Dieguito
San Diego, CA
High Hazard 51 ftSanta Fe Seasonal Storage
San Diego, CA
High Hazard 22 ftMaerkle
San Diego, CA
High Hazard 165 ftFrequently Asked Questions
What is the hazard classification of San Marcos?
San Marcos 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 San Marcos?
San Marcos is owned by Vallecitos Water District (Public Utility). The owner is responsible for maintenance, inspections, and compliance with dam safety regulations.
When was San Marcos built?
San Marcos was completed in 1958, making it 68 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 San Marcos?
San Marcos 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 San Marcos?
San Marcos has a dam height of 85 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 San Marcos last inspected?
San Marcos was last inspected on March 24, 2022. Inspection dates indicate when a formal review occurred, not the results of that inspection.