The objective of this work is to analize the present interactions between groundwater and surface water at Del Gato creek basin. A monitoring network has been installed since January 2001. This was carried out in selected areas near the creek as a result of geological, geomorphological and hydrological surveys. Performed measurements show general states of groundwater and surface water behavior. An influent condition of stream relative to water table is indicated at the high and middle zone of the basin, whereas at the low stream zone efluent condition is maintained. Chemical features of the surface water at low water situation verify influent state of stream, because variations related to groundwater do not exist. Analyzed data allow the definition of groundwater flow modifications that are produced from their natural conditions. To continue obtaining data of this monitoring network is necessary to recognize hydraulic and chemical evolutions of groundwater and surface water besides to determine possibles causes for water quality modifications.