 In Chile the river drains an area of 2,350 km².In the Bolivian Altiplano, the Lauca collects the waters of the rivers Sajama and Coipasa, raising its flow rate up to 8 m³/s before turning south to empty into Coipasa Lake, close to the salt flat of the same name.During the 1930s, the Chilean government begun to use the hydrical resources of Lauca river for irrigation in the Azapa Valley, generating a complaint from Bolivian government who argued that Chilean authorities were altering the course of an international river.