Map of All 36 Puerto Rico Dams
Puerto Rico has 36 dams in the National Inventory of Dams — and 36 are classified as high hazard (100% of the state’s total), meaning failure would likely cause loss of life. 12 Puerto Rico dams are both high-hazard and in poor or unsatisfactory condition.
Use the interactive Puerto Rico dams map below to explore every dam in the state, color-coded by hazard level. Click any dam for its condition assessment, last inspection date, and Emergency Action Plan status. Or view the full US Dams interactive map to compare Puerto Rico to every other state.
Hazard
Condition
Purpose
Puerto Rico Dams by the Numbers
- 36 total dams in Puerto Rico
- 36 high hazard — failure would likely cause loss of life
- 0 significant hazard
- 0 low hazard
- 12 in poor or unsatisfactory condition (10 poor, 2 unsatisfactory)
- 12 Puerto Rico dams are both high-hazard AND in poor/unsatisfactory condition
Data source: US Army Corps of Engineers, National Inventory of Dams (NID).
The Tallest Dams in Puerto Rico
The tallest dam in Puerto Rico is Cerrillos Dam at 323 feet, completed in 1992. The 10 tallest Puerto Rico dams from the National Inventory of Dams:
| Dam | Height | Year | Primary Purpose | Condition | County |
|---|---|---|---|---|---|
| Cerrillos Dam | 323 ft | 1992 | Flood Risk Reduction | Satisfactory | Ponce |
| Caonillas Dam | 235 ft | 1948 | Hydroelectric | Satisfactory | Jayuya |
| Portugues Dam | 220 ft | 2015 | Flood Risk Reduction | Satisfactory | Ponce |
| Toa Vaca Dam | 215 ft | 1972 | Irrigation | Satisfactory | Villalba |
| Garzas Dam | 201 ft | 1943 | Hydroelectric | Unsatisfactory | Adjuntas |
| Guayo Dam | 190 ft | 1956 | Hydroelectric | Poor | Adjuntas |
| Dos Bocas Dam | 188 ft | 1942 | Hydroelectric | Satisfactory | Arecibo |
| Lucchetti Dam | 169 ft | 1952 | Irrigation | Satisfactory | Yauco |
| La Plata Dam | 131 ft | 1974 | Water Supply | Satisfactory | Toa Alta |
| Guayabal Dam | 130 ft | 1913 | Irrigation | Poor | Villalba |
High-Hazard Puerto Rico Dams in Poor Condition
The most concerning dams are those classified as high-hazard that also carry a Poor or Unsatisfactory condition rating — 12 dams in Puerto Rico. Notable examples:
- Garzas Dam (201 ft, Adjuntas County) — Hydroelectric, Unsatisfactory condition
- Guayo Dam (190 ft, Adjuntas County) — Hydroelectric, Poor condition
- Guayabal Dam (130 ft, Villalba County) — Irrigation, Poor condition
- Comerio Ii Dam (128 ft, Comerío County) — Hydroelectric, Poor condition
- Patillas Dam (127 ft, Patillas County) — Hydroelectric, Poor condition
Filter the interactive US Dams map by hazard and condition to see all of them on one view.
Dam Safety in Puerto Rico
Dam safety in Puerto Rico is overseen by the state dam safety program, in coordination with federal regulators: the US Army Corps of Engineers, the Bureau of Reclamation (for federal water projects), the Tennessee Valley Authority where applicable, and the Federal Energy Regulatory Commission (FERC) for licensed hydropower dams. Emergency Action Plans are typically required for high-hazard dams under state regulations.
Frequently Asked Questions
How many dams are in Puerto Rico?
Puerto Rico has 36 dams in the National Inventory of Dams tracked by the US Army Corps of Engineers: 36 high hazard, 0 significant hazard, and 0 low hazard.
What is the tallest dam in Puerto Rico?
The tallest dam in Puerto Rico is Cerrillos Dam at 323 feet, completed in 1992. It is primarily a flood risk reduction structure.
How many Puerto Rico dams are in poor condition?
12 Puerto Rico dams are currently rated as being in Poor or Unsatisfactory condition. Of those, 12 are also classified as high-hazard — meaning failure would likely cause loss of life.
