Johnson Ranch

Mendocino, California· Earth· 26 ft tall

High Hazard Irrigation Private

Key Takeaway

Johnson Ranch is classified as high hazard in California. 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	26 ft (taller than 24.8% in CA)
Dam Length	680 ft
Dam Type	Earth
Max Storage	182 acre-ft

Surface Area	14 acres
NID ID	CA01479

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: December 5, 2022

State Regulated: Yes

Regulatory Agency: DWR, Division of Safety of Dams

Ownership

Beckstoffer Vineyards

Private

Nearby Dams

Feliz North Lake

Mendocino, CA

Significant Hazard 24 ft

Cornett

Mendocino, CA

Significant Hazard 31 ft

Bradford

Mendocino, CA

Significant Hazard 58 ft

Crawford Ranch

Mendocino, CA

High Hazard 80 ft

Mcnab

Mendocino, CA

Significant Hazard 40 ft

Hooper No. 1

Mendocino, CA

Significant Hazard 13 ft

Hooper No. 2

Mendocino, CA

Significant Hazard 13 ft

Peters

Lake, CA

Low Hazard 32 ft

Frequently Asked Questions

What is the hazard classification of Johnson Ranch?

Johnson Ranch 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 Johnson Ranch?

Johnson Ranch is owned by Beckstoffer Vineyards (Private). The owner is responsible for maintenance, inspections, and compliance with dam safety regulations.

What is the primary purpose of Johnson Ranch?

Johnson Ranch 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 Johnson Ranch?

Johnson Ranch has a dam height of 26 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 Johnson Ranch last inspected?

Johnson Ranch was last inspected on December 5, 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.