From the Cabeza de San Juan, which is the northeast extremity of the island, to the cape of Mala Pascua, which lies to the southeast, 9 rivers fall into the sea.
From Cape Mala Pascua to Point Aguila, which forms the southwest angle of the island, 16 rivers discharge their waters on the south coast.
On the west coast 3 rivers, 5 rivulets, and several fresh-water lakes communicate with the sea. In the small extent of 330 leagues of area there are 46 rivers, besides a countless number of rivulets and branches of navigable water.
The rivers of the north coast are stocked with delicious fish, some of them large enough to weigh two quintals.
From the river of Arecibo to that of Manati, a distance of 5 leagues, a fresh-water lagoon, perfectly navigable for small vessels through the whole of its extent, runs parallel to the sea at about a mile from the shore.
In the fertile valley of Anasco, on the western coast, there is a canal formed by nature, deep and navigable. None of the rivers are of real military importance; for, though considering the shortness of their course, they attain quite a volume, still it is not sufficient for good-sized vessels.
The rivers emptying on the north coast are Loisa, Aguas Prietas,
Arecibo, Bayamon, Camuy, Cedros, Grande, Guajaraca de la Tuna,
Lesayas, Loquillo, Manati, Rio Piedras, Sabana, San Martin, Sibuco,
Toa, and Vega.
Those emptying on the east coast are Candelero, Dagua, Fajardo,
Guayanes, Majogua, and Maonabo.
On the south coast: Aquamanil, Caballon, Cana, Coamo, Descalabrado, Guanica, Guayama, Guayanilla, Jacagua, Manglar, Penuela, Ponce and Vigia.
On the west coast: Aguada, Boqueron, Cajas, Culebrina, Chico,
Guanajibo, Mayaguez, and Rincon.