Orange County Reservoir

Tr Fullerton Cr· Orange, California· Built 1941· Earth· 103 ft tall
High Hazard Water Supply Public Utility

Key Takeaway

Orange County Reservoir is classified as high hazard in California. It was completed in 1941 and is 85 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 103 ft (taller than 82.8% in CA)
Dam Length655 ft
Dam TypeEarth
Max Storage217 acre-ft
Surface Area7 acres
Drainage Area0 sq mi
Year Completed1941 (85 years old)
NID IDCA00218

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: August 17, 2022
State Regulated: Yes
Regulatory Agency: DWR, Division of Safety of Dams

Ownership

Metropolitan Water District Of Southern California

Public Utility

Nearby Dams

Frequently Asked Questions

What is the hazard classification of Orange County Reservoir?

Orange County 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 Orange County Reservoir?

Orange County Reservoir is owned by Metropolitan Water District Of Southern California (Public Utility). The owner is responsible for maintenance, inspections, and compliance with dam safety regulations.

When was Orange County Reservoir built?

Orange County Reservoir was completed in 1941, making it 85 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 Orange County Reservoir?

Orange County Reservoir 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 Orange County Reservoir?

Orange County Reservoir has a dam height of 103 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 Orange County Reservoir last inspected?

Orange County Reservoir was last inspected on August 17, 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.