Phoenix Lake

Ross Creek· Marin, California· Built 1907· Earth· 90 ft tall

High Hazard Water Supply Public Utility

Key Takeaway

Phoenix Lake is classified as high hazard in California. It was completed in 1907 and is 119 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	90 ft (taller than 79.3% in CA)
Dam Length	320 ft
Dam Type	Earth
Max Storage	612 acre-ft

Surface Area	23 acres
Drainage Area	2 sq mi
Year Completed	1907 (119 years old)
NID ID	CA00206

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: September 15, 2022

State Regulated: Yes

Regulatory Agency: DWR, Division of Safety of Dams

Ownership

Marin Municipal Water District

Public Utility

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Frequently Asked Questions

What is the hazard classification of Phoenix Lake?

Phoenix 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 Phoenix Lake?

Phoenix Lake is owned by Marin Municipal Water District (Public Utility). The owner is responsible for maintenance, inspections, and compliance with dam safety regulations.

When was Phoenix Lake built?

Phoenix Lake was completed in 1907, making it 119 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 Phoenix Lake?

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

How tall is Phoenix Lake?

Phoenix Lake has a dam height of 90 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 Phoenix Lake last inspected?

Phoenix Lake was last inspected on September 15, 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.