Whale Rock

Old Creek· San Luis Obispo, California· Built 1960· Earth· 193 ft tall

High Hazard Water Supply Irrigation Public Utility

Key Takeaway

Whale Rock is classified as high hazard in California. It was completed in 1960 and is 66 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	193 ft (taller than 94.1% in CA)
Dam Length	850 ft
Dam Type	Earth
Max Storage	40.7K acre-ft

Surface Area	594 acres
Drainage Area	21 sq mi
Year Completed	1960 (66 years old)
NID ID	CA00029

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: October 21, 2021

State Regulated: Yes

Regulatory Agency: DWR, Division of Safety of Dams

Ownership

Whale Rock Commission

Public Utility

Nearby Dams

Hartzell

San Luis Obispo, CA

Significant Hazard 50 ft

Frequently Asked Questions

What is the hazard classification of Whale Rock?

Whale Rock 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 Whale Rock?

Whale Rock is owned by Whale Rock Commission (Public Utility). The owner is responsible for maintenance, inspections, and compliance with dam safety regulations.

When was Whale Rock built?

Whale Rock was completed in 1960, making it 66 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 Whale Rock?

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

How tall is Whale Rock?

Whale Rock has a dam height of 193 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 Whale Rock last inspected?

Whale Rock was last inspected on October 21, 2021. 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.