Río Putagán flows westward out of the foothills of the Andes Mountains through Linares Province in Chile's Maule Region, eventually joining the Loncomilla River near the Villa Alegre sector. The name "Putagán" derives from the Mapudungun language, meaning "water stream" — an apt description for this freestone river that drains a basin of nearly 953 square kilometers. Rising from a source elevation of approximately 1,875 meters above sea level, the river travels roughly 52 kilometers from the Andean foothills across the Central Valley, with an average basin width of about 30 kilometers. The Putagán forms the northern boundary of the municipality of Linares, bordering the municipalities of Colbún, Yerbas Buenas, and Villa Alegre from east to west as it makes its way toward the Loncomilla confluence. The Colbún reservoir sits in the northern sector of the basin, and agriculture — primarily through irrigation canals — dominates water use throughout the watershed.