Abstract

Water availability at Mediterranean climatic zones reaches critical levels during the dry season that is characterized by low rainfall, high water demand and that streamflow is mostly generated by snowmen and groundwater liberation. This article presents the characterization of two groups of springs that produce most of streamflow at the upper part of the Diguillin River watershed, located at the Andean Mountains of the Region of the Biobio in Chile (36.9 degrees S). A group is located at the headwaters of the river, in the Valle de Aguas Calientes and the second is located in a sector named Agua Bonita. For both groups of springs were characterized the hydrogeological systems that drain and the origin of water recharges, taking into account geological and geomorphological information, as well as hydrochemistry and water isotope data of water samples taken from river, springs and precipitation. The springs of the Valle de Aguas Calientes contribute with approximately 2.5 m(3)/s from an aquifer system located to the interior of the Volcano Chillan; the springs of Agua Bonita contribute. approximately with 4.5 m(3)/s from a fractured rocks aquifer.