Maipo River is the main river flowing through the Santiago Metropolitan Region and the Valparaiso Region of Chile. It is located just south of capital Santiago. Its headwaters are on the west slope of Maipo volcano, in the Andes. Its most famous tributary is the Mapocho River. The Maipo River is by far the major source of irrigation and potable water for the region.
In its upper course the river runs as an entrenched torrent through the Andes mountains. Here, it receives three major tributaries: El Volcán River, Yeso River and Colorado River. After leaving the Andes, the Maipo flows through the valley that bears its name. It is the best known wine-producing region in Chile. The Maipo River travels 250 km before emptying into the Pacific Ocean near the locality of Llolleo, south of the port of San Antonio.