Moccasin Lower

Moccasin Creek· Tuolumne, California· Built 1930· Earth· 60 ft tall
High Hazard Other Hydroelectric Water Supply Local Government

Key Takeaway

Moccasin Lower is classified as high hazard in California. It was completed in 1930 and is 96 years old. Its primary use is other. 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 60 ft (taller than 67.2% in CA)
Dam Length720 ft
Dam TypeEarth
Max Storage554 acre-ft
Surface Area29 acres
Drainage Area26 sq mi
Year Completed1930 (96 years old)
NID IDCA00122

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 19, 2023
State Regulated: Yes
Regulatory Agency: DWR, Division of Safety of Dams

Ownership

San Francisco Public Utilities Commission

Local Government

Nearby Dams

Frequently Asked Questions

What is the hazard classification of Moccasin Lower?

Moccasin Lower 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 Moccasin Lower?

Moccasin Lower is owned by San Francisco Public Utilities Commission (Local Government). The owner is responsible for maintenance, inspections, and compliance with dam safety regulations.

When was Moccasin Lower built?

Moccasin Lower was completed in 1930, making it 96 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 Moccasin Lower?

Moccasin Lower serves the following purposes: Other, Hydroelectric, Water Supply. Many dams in the U.S. are multi-purpose, supporting flood control, water supply, recreation, and other uses.

How tall is Moccasin Lower?

Moccasin Lower has a dam height of 60 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 Moccasin Lower last inspected?

Moccasin Lower was last inspected on January 19, 2023. 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.