In this work water extremes and the influence of changes in land use and crop management practices on the water balance of the Santa Catalina basin are analyzed with the continuous semi-distributed Soil and Water Assessment Tool model. SWAT represents groundwater flow and surface runoff and allows analyzing the impacts of hypothetical land use and management practice scenarios in the basin’s hydrological cycle. Simulations for a 6-year period (2006-2012) are used as reference scenarios and compared with the hypothetical scenarios. Results show a reduction of daily surface runoff ranging between 14% and 28% and an increase in soil moisture content of 9%, therefore reducing the impact of floods and droughts in the basin.