We use the Bio-physical Model Applications framework (BioMA) to simulate the maize yield response to water availability in current and future climatic conditions. Two different realizations of the A1B scenario from dynamically downscaled global circulation models within the ENSEMBLES project, which capture the most contrasting situations with respect to changes in precipitation and temperature, have been selected for this purpose. The CropSyst crop model has been used to simulate the water-limited and potential maize yield as well as total crop water requirement and total water consumption. The water deficit productivity index has been introduced for the purpose of the study, describing the gain in crop yield when water deficit is reduced. The results have shown that the maize yield is expected to decrease over Southern Europe as well as regions around the Black Sea during the 2030s. The water could become more productive in central and Western Europe and slightly less productive in the Southern Europe.