Source: The Library Of Congress Country Studies
The Dominican Republic has seven major drainage basins. Five of these rise in the Cordillera Central and a sixth, in the Sierra de Yamasá. The seventh drainage system flows into the Lago Enriquillo (Lake Enriquillo) from the Sierra de Neiba to the north and from the Sierra de Baoruco to the south. In general, other rivers are either short or intermittent.
The Yaque del Norte is the most significant river in the country. Some 296 kilometers long, with a basin area of 7,044 square kilometers, it rises near Pico Duarte at an altitude of 2,580 meters in the Cordillera Central. It empties into the Bahía de Monte Cristi on the northwest coast, where it forms a delta. The Yaque del Sur is the most important river on the southern coast. It rises at an altitude of 2,707 meters in the southern slopes of the Cordillera Central. Its upper course through the mountains constitutes 75 percent of its total length of some 183 kilometers. The basin area is 4,972 square kilometers. The river forms a delta near its mouth in the Bahía de Neiba.
The Lago Enriquillo lies in the western part of the Hoya de Enriquillo. Its drainage basin includes ten minor river systems and covers an area of more than 3,000 square kilometers. The northern rivers of the system rise in the Sierra de Neiba and are perennial, while the southern rivers rise in the Sierra de Baoruco and are intermittent, flowing only after heavy rainfall. The Lago Enriquillo itself covers some 265 square kilometers. Its water level varies because of the high evaporation rate, yet on the average it is forty meters below sea level. The water in the lake is saline.