Many natural systems are being affected by regional climate change. This paper aims to determine the effects of climate change on the relationship between drain spacing, corn productivity and profitability. The focus is on productivity and profitability on different types of soils in Campinas (Sao Paulo/Brazil). This study also evaluates the performance of the Eta model, using the observed and simulated meteorological data of precipitation and temperature. Observed and simulated evapotranspiration (calculated by Thorntwaite method) and precipitation data were used as input for the SISDRENA drainage simulation model, which evaluates the performance of one-dimensional drainage systems. The general conclusion was that temperature and precipitation variations predicted by the Eta model will reduce corn profitability and change the potential productivity.