Lake Mission Viejo

Oso Creek· Orange, California· Built 1976· Earth· 123 ft tall
High Hazard Water Supply Recreation Private

Key Takeaway

Lake Mission Viejo is classified as high hazard in California. It was completed in 1976 and is 50 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 123 ft (taller than 86.1% in CA)
Dam Length1,750 ft
Dam TypeEarth
Max Storage4.3K acre-ft
Surface Area150 acres
Drainage Area4 sq mi
Year Completed1976 (50 years old)
NID IDCA01122

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: January 20, 2022
State Regulated: Yes
Regulatory Agency: DWR, Division of Safety of Dams

Ownership

Lake Mission Viejo Association, Inc.

Private

Nearby Dams

Frequently Asked Questions

What is the hazard classification of Lake Mission Viejo?

Lake Mission Viejo 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 Lake Mission Viejo?

Lake Mission Viejo is owned by Lake Mission Viejo Association, Inc. (Private). The owner is responsible for maintenance, inspections, and compliance with dam safety regulations.

When was Lake Mission Viejo built?

Lake Mission Viejo was completed in 1976, making it 50 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 Lake Mission Viejo?

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

How tall is Lake Mission Viejo?

Lake Mission Viejo has a dam height of 123 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 Lake Mission Viejo last inspected?

Lake Mission Viejo was last inspected on January 20, 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.