San Diego Reservoir

Tr Mormon Cr· Tuolumne, California· Built 1860· Earth· 39 ft tall
High Hazard Water Supply Irrigation Recreation Public Utility

Key Takeaway

San Diego Reservoir is classified as high hazard in California. It was completed in 1860 and is 166 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 39 ft (taller than 44.4% in CA)
Dam Length155 ft
Dam TypeEarth
Max Storage40 acre-ft
Surface Area5 acres
Drainage Area0 sq mi
Year Completed1860 (166 years old)
NID IDCA00900

Safety Information

High Hazard

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?

Emergency Action Plan: Yes
Last Inspection: January 28, 2022
State Regulated: Yes
Regulatory Agency: DWR, Division of Safety of Dams

Ownership

Yosemite Community College District

Public Utility

Nearby Dams

Frequently Asked Questions

What is the hazard classification of San Diego Reservoir?

San Diego Reservoir 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 Diego Reservoir?

San Diego Reservoir is owned by Yosemite Community College District (Public Utility). The owner is responsible for maintenance, inspections, and compliance with dam safety regulations.

When was San Diego Reservoir built?

San Diego Reservoir was completed in 1860, making it 166 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 Diego Reservoir?

San Diego Reservoir 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 San Diego Reservoir?

San Diego Reservoir has a dam height of 39 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 Diego Reservoir last inspected?

San Diego Reservoir was last inspected on January 28, 2022. Inspection dates indicate when a formal review occurred, not the results of that inspection.

Data from the National Inventory of Dams (NID) maintained by the US Army Corps of Engineers. Dam conditions may have changed since the last update. This site is not affiliated with USACE. Do not use for emergency planning — contact your local dam safety program.