In this work was done the characterization of physical properties of the Rio Sucio basin, one Tona River tributary, this is an important water source used to supply the Bucaramanga City. Geology, geomorphology, type and uses of soil and vegetative cover were characterized by feld work campaigns. A complete inventory of surface water fows as well as groundwater points was made. We applied surface mapping tools for the various variables. Two hydro-logical models, the model added semi distributed NAM and the conceptual model distributed (SHIA) were imple-mented. Both models represent the phenomena of physical transport and water storage in the basin, but they differ in the type of algorithm used and the scale of application. The models were calibrated with fow data, obtained by daily measures during six months (1987) and the results were compared with data from the Carrizal gauge station, located downstream on the Tona River. The results allow us to get a good ft between rain events and hydrograph peaks as the hydrographs recession. Flow from Berlin Altiplan is observed and the base fow controls discharge minimum in the basin. Both models show a good ft with the fow averages and they can be used as a frst tool for simulation of this basin.