A hydrometeorological study o f flood discharges has been carried out in the El Burguillo subbasin (Alberche River, Tajo Basin, Central Spain), using the Temez's modification of the rational method and the Sherman's únit-hydrúgraph method. The maximum precipitation data of 15 meteorological stations were analyzed through statistical and rainfall-flow models, appfmg additionaltechnics such as geographical information systems (CIS). The results show us that the curve number (CN) is the most important factor for defining the raihfall-stream model. The SCS methodology to obtain it needs the application of a regional