Río Longaví is a 120-kilometer river flowing through the Maule Region of south-central Chile, originating in the Andes at approximately 2,000 meters above sea level and draining westward across the Central Valley before joining the Perquilauquén River to form the Loncomilla River. The river's name derives from the Mapudungun language, meaning "snake's head," a fitting description for a waterway that winds through diverse terrain from high Andean headwaters down through agricultural lowlands. The sub-basin covers roughly 965.5 square kilometers and is shaped by the Longaví River and its tributaries, most notably the Blanco River, which drains the southeastern slopes of the Nevado de Longaví — a snow-covered extinct volcano rising to 3,230 meters and one of the defining landmarks of Linares Province. The upper watershed is defined by the presence of the Bullileo and Digua dams, which influence flow regimes in the upper reaches of the system. The river passes near the town of Longaví as it moves generally northwestward through the Central Valley, a region that accounts for a significant portion of Chile's agricultural production and exports.