Prieto Dam
Prieto Dam is a gravity dam located in Maricao County, Puerto Rico, built in 1955. It carries a High hazard potential classification and has a satisfactory condition assessment.
About Prieto Dam
The primary purpose of Prieto 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 Electric Power Authority (public utility). It impounds the Prieto River near Maricao.
The dam stands 98 feet tall and stretches 260 feet across, creates a reservoir covering 20 acres, has a maximum storage capacity of 880 acre-feet, and collects water from a drainage area of 9 square miles. Completed in 1955, 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 12/11/2021.
At 98 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.
Search for dams near your address to see all dams in your area with hazard classifications and safety data.
Location
| State | Puerto Rico |
| County | Maricao |
| Nearest City | Maricao |
| River/Stream | Prieto River |
| Coordinates | 18.18583, -66.86381 |
Physical Characteristics
| Dam Type | Gravity |
| NID Height | 98 ft |
| Dam Height | 98 ft |
| Dam Length | 260 ft |
| Year Completed | 1955 (71 years old) |
Storage & Hydraulics
| NID Storage | 880 acre-ft |
| Max Storage | 880 acre-ft |
| Normal Storage | 600 acre-ft |
| Surface Area | 20 acres |
| Drainage Area | 9 sq mi |
| Max Discharge | 32,000 cfs |
| Spillway Type | Uncontrolled |
Ownership & Safety
| Purpose | Hydroelectric |
| Owner | PUERTO RICO ELECTRIC POWER AUTHORITY |
| Owner Type | Public Utility |
| Hazard Classification | High |
| Condition Assessment | Satisfactory |
| Last Inspection | 12/11/2021 |
| Emergency Action Plan | Yes |
Identifiers
| NID ID | PR00002 |
| Federal ID | PR00002 |
| More Info | State Dam Safety Program |