Río Grande de Loíza

Grande de Loíza
Loiza River mouth.
Location
CommonwealthPuerto Rico
MunicipalitySan Lorenzo, Gurabo, Caguas, Trujillo Alto, Carolina, Loíza
Physical characteristics
Source 
 • locationSierra de Cayey in Espino, San Lorenzo, Puerto Rico
 • elevation2,051 feet (625 m)
Mouth 
 • location
Atlantic Ocean between Torrecilla Baja and Loíza, Loíza, Puerto Rico
 • elevation
0 ft (0 m)
Length64 km (40 mi)
Basin features
Tributaries 
 • leftEmajagua River, Turabo River, Cagüitas River, Bairoa River, Cañas River
 • rightCayaguas River, Gurabo River, Canovanillas River, Canóvanas River

The Rio Grande de Loíza (English: Great River of Loíza or Loíza River) is a river in the main island of Puerto Rico. It is the largest river in Puerto Rico by discharge volume. Situated on the north coast of the island, it originates in the northeastern Sierra de Cayey, flowing from south to north, and draining into the Atlantic Ocean, a few miles east of San Juan.

Rio Grande de Loíza runs for approximately 40 miles (64 kilometers). It has its origin in the municipality of San Lorenzo at an altitude of approximately 3,500 feet (1,100 meters) above sea level. It runs through the municipalities of San Lorenzo, Caguas, Gurabo, Trujillo Alto, Carolina, Canóvanas and Loíza, forming the Loíza Lake along its route, making it one of the longest rivers on the island.