Guineo Dam

TORO NEGRO RIVER· Ciales, Puerto Rico· Built 1931· Rockfill· 115 ft tall

High Hazard Hydroelectric Irrigation Public Utility

Key Takeaway

Guineo Dam is classified as high hazard in Puerto Rico. It was completed in 1931 and is 95 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	115 ft (taller than 52.8% in PR)
Dam Type	Rockfill
Max Storage	2.2K acre-ft
Normal Storage	1.9K acre-ft

Surface Area	77 acres
Drainage Area	2 sq mi
Max Discharge	7,000 cfs
Year Completed	1931 (95 years old)
NID ID	PR00012

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 23, 2020

State Regulated: Yes

Regulatory Agency: PREPA

Ownership

PUERTO RICO ELECTRIC POWER AUTHORITY

Public Utility

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Ana Mariaâ Ii Dam

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Poncenaâ Dam

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Ana Mariaâ V Dam

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Caonillas Dam

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Frequently Asked Questions

What is the hazard classification of Guineo Dam?

Guineo 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 Guineo Dam?

Guineo 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 Guineo Dam built?

Guineo Dam was completed in 1931, making it 95 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 Guineo Dam?

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

How tall is Guineo Dam?

Guineo Dam has a dam height of 115 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 Guineo Dam last inspected?

Guineo Dam was last inspected on January 23, 2020. 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.