Long Lake

Gray Eagle Creek· Plumas, California· Built 1938· Rockfill· 12 ft tall
Significant Hazard Water Supply Irrigation Private

Key Takeaway

Long Lake is classified as significant hazard in California. It was completed in 1938 and is 88 years old. Its primary use is water supply. Significant hazard means failure could cause economic or environmental damage. Learn more.

Physical Details

Dam Height 12 ft (taller than 4% in CA)
Dam Length110 ft
Dam TypeRockfill
Max Storage1.5K acre-ft
Surface Area141 acres
Drainage Area1 sq mi
Year Completed1938 (88 years old)
NID IDCA00534

Safety Information

Significant Hazard

No probable loss of human life, but can cause economic loss, environmental damage, or disruption of lifeline facilities.

Hazard potential describes downstream consequences of failure, not the dam's current condition. What does this mean?

Emergency Action Plan: No
Last Inspection: June 22, 2022
State Regulated: Yes
Regulatory Agency: DWR, Division of Safety of Dams

Ownership

Graeagle Water Company

Private

Nearby Dams

Frequently Asked Questions

What is the hazard classification of Long Lake?

Long Lake is classified as Significant Hazard. No probable loss of human life, but can cause economic loss, environmental damage, or disruption of lifeline facilities. This classification refers to the potential downstream consequences of a failure, not the dam's current structural condition.

Who owns and operates Long Lake?

Long Lake is owned by Graeagle Water Company (Private). The owner is responsible for maintenance, inspections, and compliance with dam safety regulations.

When was Long Lake built?

Long Lake was completed in 1938, making it 88 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 Long Lake?

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

How tall is Long Lake?

Long Lake has a dam height of 12 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 Long Lake last inspected?

Long Lake was last inspected on June 22, 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.