Stanley A. Mahr Reservoir

Tr Encinitas Cr· San Diego, California· Built 1981· Earth· 79 ft tall
High Hazard Water Supply Other Irrigation Public Utility

Key Takeaway

Stanley A. Mahr Reservoir is classified as high hazard in California. It was completed in 1981 and is 45 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 79 ft (taller than 75.9% in CA)
Dam Length950 ft
Dam TypeEarth
Max Storage166 acre-ft
Surface Area8 acres
Drainage Area0 sq mi
Year Completed1981 (45 years old)
NID IDCA01280

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: March 24, 2022
State Regulated: Yes
Regulatory Agency: DWR, Division of Safety of Dams

Ownership

Vallecitos Water District

Public Utility

Nearby Dams

Frequently Asked Questions

What is the hazard classification of Stanley A. Mahr Reservoir?

Stanley A. Mahr Reservoir 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 Stanley A. Mahr Reservoir?

Stanley A. Mahr Reservoir is owned by Vallecitos Water District (Public Utility). The owner is responsible for maintenance, inspections, and compliance with dam safety regulations.

When was Stanley A. Mahr Reservoir built?

Stanley A. Mahr Reservoir was completed in 1981, making it 45 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 Stanley A. Mahr Reservoir?

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

How tall is Stanley A. Mahr Reservoir?

Stanley A. Mahr Reservoir has a dam height of 79 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 Stanley A. Mahr Reservoir last inspected?

Stanley A. Mahr Reservoir was last inspected on March 24, 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.