Caonillas Dam

CAONILLAS RIVER· Jayuya, Puerto Rico· Built 1948· Concrete· 235 ft tall

High Hazard Hydroelectric Recreation Public Utility

Key Takeaway

Caonillas Dam is classified as high hazard in Puerto Rico. It was completed in 1948 and is 78 years old. Its primary use is hydroelectric. 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	235 ft (taller than 94.4% in PR)
Dam Type	Concrete
Max Storage	55.0K acre-ft
Normal Storage	35.2K acre-ft

Surface Area	700 acres
Drainage Area	50 sq mi
Max Discharge	107,000 cfs
Year Completed	1948 (78 years old)
NID ID	PR00011

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 4, 2019

State Regulated: Yes

Regulatory Agency: PREPA

Ownership

PUERTO RICO ELECTRIC POWER AUTHORITY

Public Utility

Nearby Dams

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Pellejas Dam

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Adjuntas Dam

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Garzas Dam

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Portugues Dam

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Cerrillos Dam

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Guineo Dam

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Ana Mariaâ Ii Dam

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Frequently Asked Questions

What is the hazard classification of Caonillas Dam?

Caonillas Dam 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 Caonillas Dam?

Caonillas Dam is owned by PUERTO RICO ELECTRIC POWER AUTHORITY (Public Utility). The owner is responsible for maintenance, inspections, and compliance with dam safety regulations.

When was Caonillas Dam built?

Caonillas Dam was completed in 1948, making it 78 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 Caonillas Dam?

Caonillas Dam serves the following purposes: Hydroelectric, Recreation. Many dams in the U.S. are multi-purpose, supporting flood control, water supply, recreation, and other uses.

How tall is Caonillas Dam?

Caonillas Dam has a dam height of 235 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 Caonillas Dam last inspected?

Caonillas Dam was last inspected on September 4, 2019. 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.