La Plata Dam
La Plata Dam is a gravity dam located in Toa Alta County, Puerto Rico, built in 1974. It carries a High hazard potential classification and has a satisfactory condition assessment.
About La Plata Dam
The primary purpose of La Plata Dam is water supply. The dam stores water for municipal, industrial, or agricultural use, helping ensure a reliable supply for the surrounding area. The dam is owned by Puerto Rico Aqueduct And Sewer Authority (public utility). It impounds the La Plata River near Toa Alta.
The dam stands 131 feet tall, creates a reservoir covering 560 acres, has a maximum storage capacity of 37,000 acre-feet, and collects water from a drainage area of 181 square miles. Completed in 1974, 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 10/21/2020.
At 131 feet, this dam is taller than 99% 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 | Toa Alta |
| Nearest City | Toa Alta |
| River/Stream | La Plata River |
| Coordinates | 18.34352, -66.23591 |
Physical Characteristics
| Dam Type | Gravity |
| NID Height | 131 ft |
| Dam Height | 131 ft |
| Year Completed | 1974 (52 years old) |
Storage & Hydraulics
| NID Storage | 37,000 acre-ft |
| Max Storage | 37,000 acre-ft |
| Normal Storage | 22,700 acre-ft |
| Surface Area | 560 acres |
| Drainage Area | 181 sq mi |
| Max Discharge | 270,000 cfs |
| Spillway Type | Controlled |
Ownership & Safety
| Purpose | Water Supply |
| Owner | PUERTO RICO AQUEDUCT AND SEWER AUTHORITY |
| Owner Type | Public Utility |
| Hazard Classification | High |
| Condition Assessment | Satisfactory |
| Last Inspection | 10/21/2020 |
| Emergency Action Plan | Yes |
Identifiers
| NID ID | PR00017 |
| Federal ID | PR00017 |
| More Info | State Dam Safety Program |