Beardsley

Middle Fork Stanislaus River· Tuolumne, California· Built 1957· Earth· 278 ft tall
High Hazard Hydroelectric Recreation Flood Risk Reduction Public Utility

Key Takeaway

Beardsley is classified as high hazard in California. It was completed in 1957 and is 69 years old. Its primary use is hydroelectric. 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 278 ft (taller than 98% in CA)
Dam Length1,000 ft
Dam TypeEarth
Max Storage97.8K acre-ft
Normal Storage97.5K acre-ft
Surface Area720 acres
Drainage Area310 sq mi
Max Discharge90,000 cfs
Year Completed1957 (69 years old)
NID IDCA00263

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: July 25, 2023
State Regulated: Yes
Regulatory Agency: DWR, Safety of Dams

Ownership

South San Joaquin Irrigation District

Public Utility

Nearby Dams

Frequently Asked Questions

What is the hazard classification of Beardsley?

Beardsley 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 Beardsley?

Beardsley is owned by South San Joaquin Irrigation District (Public Utility). The owner is responsible for maintenance, inspections, and compliance with dam safety regulations.

When was Beardsley built?

Beardsley was completed in 1957, making it 69 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 Beardsley?

Beardsley serves the following purposes: Hydroelectric, 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 Beardsley?

Beardsley has a dam height of 278 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 Beardsley last inspected?

Beardsley was last inspected on July 25, 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.