Lake Mary

Mono, California· Built 1934· Earth· 10 ft tall
High Hazard Water Supply Recreation Flood Risk Reduction Federal Government

Key Takeaway

Lake Mary is classified as high hazard in California. It was completed in 1934 and is 92 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 10 ft (taller than 2.3% in CA)
Dam Length205 ft
Dam TypeEarth
Max Storage1.3K acre-ft
Normal Storage1.0K acre-ft
Drainage Area8 sq mi
Year Completed1934 (92 years old)
NID IDCA10388

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: No
Last Inspection: October 24, 2013
State Regulated: No

Ownership

USDA FS

Federal Government

Nearby Dams

Frequently Asked Questions

What is the hazard classification of Lake Mary?

Lake Mary 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 Lake Mary?

Lake Mary is owned by USDA FS (Federal Government). The owner is responsible for maintenance, inspections, and compliance with dam safety regulations.

When was Lake Mary built?

Lake Mary was completed in 1934, making it 92 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 Lake Mary?

Lake Mary serves the following purposes: Water Supply, Recreation, Flood Risk Reduction. Many dams in the U.S. are multi-purpose, supporting flood control, water supply, recreation, and other uses.

How tall is Lake Mary?

Lake Mary has a dam height of 10 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 Lake Mary last inspected?

Lake Mary was last inspected on October 24, 2013. 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.