The permanent part of the lake body covered approximately 1,000 square kilometres (390 sq mi) and it was the second-largest lake in the country.[3] The lake received most of its water from the Desaguadero River, which flows from Lake Titicaca at the north end of the Altiplano. Since the lake lacked any major outlet and had a mean depth of less than 3 m (10 ft), the surface area differed greatly seasonally.[5]