Clear Lake

LOST RIVER· Modoc, California· Built 1910· Gravity· 42 ft tall
High Hazard Irrigation Federal Government

Key Takeaway

Clear Lake is classified as high hazard in California. It was completed in 1910 and is 116 years old. Its primary use is irrigation. 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 42 ft (taller than 50.1% in CA)
Dam Length564 ft
Dam TypeGravity
Max Storage584.1K acre-ft
Normal Storage374.1K acre-ft
Surface Area23,960 acres
Drainage Area735 sq mi
Max Discharge0 cfs
Year Completed1910 (116 years old)
NID IDCA10141

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 15, 2020
State Regulated: No

Ownership

RECLAMATION

Federal Government

Nearby Dams

Frequently Asked Questions

What is the hazard classification of Clear Lake?

Clear Lake 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 Clear Lake?

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

When was Clear Lake built?

Clear Lake was completed in 1910, making it 116 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 Clear Lake?

Clear Lake serves the following purposes: Irrigation. Many dams in the U.S. are multi-purpose, supporting flood control, water supply, recreation, and other uses.

How tall is Clear Lake?

Clear Lake has a dam height of 42 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 Clear Lake last inspected?

Clear Lake was last inspected on July 15, 2020. 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.