Most of the water that is discharged by the hot springs appears to be precipitation, which enters the ground east and southeast of El Tatio. The source of heat of the whole complex appears to be the Laguna Colorada caldera, the El Tatio volcanic group or the Cerro Guacha and Pastos Grandes calderas. The movement of the water in the ground is controlled by the permeability of the volcanic material and the Serrania de Tucle-Loma Lucero tectonic block west of El Tatio that acts as an obstacle. As it moves through the ground, it acquires heat and minerals and loses steam through evaporation. Unlike geothermal fields in wetter parts of the world, given the dry climate of the area, local precipitation has little influence on the hot springs hydrology at El Tatio. The time the water takes to traverse the whole path from precipitation to the springs is about 15 years.