This study aims at assessing how small dams and/or climate change could impact river basin’s hydrology with the case study of the Faga River at Liptougou gauging station located in Burkina-Faso. For this purpose, the hydrological changes of the Faga river basin throughout 1982-2010 were assessed using the WaSiM hydrological model. Future changes of the river flow under increasing small dams and/or change climate scenarios were also estimated for 2040-2070 period using three GCMs’ runs under RCP4.5 and RCP8.5. Results showed a slight increase flow over 1982-2010. However, projections showed varying rainfall-runoff relationship based on the climate models, climate and reservoirs scenario used in simulation process as well.