Loiza Dam

About Loiza Dam

The primary purpose of Loiza Dam is hydroelectric. The dam generates hydroelectric power by channeling water through turbines, converting the energy of flowing water into electricity. The dam is owned by Puerto Rico Aqueduct And Sewer Authority (public utility). It impounds the Grande De Loiza River near Trujillo Alto.

The dam stands 95 feet tall and stretches 728 feet across, creates a reservoir covering 175 acres, has a maximum storage capacity of 30,000 acre-feet, and collects water from a drainage area of 207 square miles. Completed in 1954, the structure is well into its service life at over 50 years old.

This dam carries a high hazard potential classification, which means that a failure or uncontrolled release of water would likely cause loss of human life. This classification reflects the consequences of failure, not the likelihood — it indicates that people live or work in the area downstream. Its condition is rated satisfactory, indicating no existing or potential dam safety deficiencies are recognized. An emergency action plan is in place for this dam. The most recent inspection on record was 03/17/2022.

At 95 feet, this dam is taller than 98% of all dams in the United States.

Living Downstream

If you live or work downstream of this dam, consider taking these steps: learn your local evacuation routes, check whether your county emergency management office has a dam failure inundation map, and sign up for local emergency alerts. The Puerto Rico dam safety program can provide more specific information about emergency planning for this structure.

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