Lempa River

The Lempa River () is a long river in Central America.
Geography.
Its sources are located in between the Sierra Madre and the Sierra del Merendón in southern Guatemala, near the town of Olopa. In Guatemala the river is called "Río Olopa" and flows southwards for before entering Honduras and changing its name to Lempa river at . In Honduras it flows through Ocotepeque Department for , and crosses the border with El Salvador at the town of Citalá () in the department of Chalatenango. The river continues its course for another in El Salvador, flowing in a generally southwards direction until it reaches the Pacific Ocean in the department of San Vicente. The river forms a small part of the international boundary between El Salvador and Honduras.
The river's watershed covers , of which (56 percent) is in El Salvador, in Honduras and in Guatemala. Forty-nine percent of El Salvador's territory is covered by the Lempa river basin, and 77.5 percent of the Salvadoran population lives in cities, towns, and villages that are in its basin, including the capital city of San Salvador.
Hydroelectricity.
There are several hydroelectric dams along the river. In El Salvador there is the Guayojo dam, the Cerrón Grande Hydroelectric Dam, the 5 de Noviembre dam, and the 15 de Septiembre dam which can be easily seen from the Pan-American highway.