This dataset contains model code, input and output data for the MGB hydrological model applied to the Upper Paraná Basin. Output files (QTUDO_XXX.QBI) are binary ones (single format) containing daily discharges for all model unit-catchments for each simulation scenario. Simulation scenarios are a combination of storage representation and operation rule types. Storage representation types: L=Lumped reservoir E=Equally distributed reservoir V=Variably distributed reservoir Operation rules: T=Three points rule Tg=rule T with global-based configuration R=regression-based rule Rg=rule R with global-based configuration S=inflow-based rule (based on Shin et al. 2019 WRR) Sg=rule S with global-based configuration Additionally, simulation scenarios with pristine conditions (i.e., without reservoirs) and without floodplains are also provided. For further details please contact Ayan Fleischmann at 'ayan.fleischmann at gmail.com'.