The aim of this study is to highlight the combined effects of climate change and anthropization on surface waters in the Agnéby watershed. The global hydrological balances produced by the SWAT model show that in the year 2050, precipitation will record a deficit of 1.87%, while actual evapotranspiration will be 2.80% higher. Groundwater recharge and runoff will be in deficit by 2.5% and 9.77% respectively, and stock variation will be in deficit by 36.62% compared with the reference period. For 2080, precipitation, groundwater recharge and runoff will be in deficit by 1.23%, 1.5% and 10.23% respectively. Actual evapotranspiration will show an excess of 3.37%, and the change in stock relative to the reference period will also show a deficit of 20.42%. The hydrological consequence of this state of affairs is the depletion of surface water resources over the years in the Agnéby watershed due to anthropogenic activities. The predominance of evapotranspiration can be explained by the fact that the area will be covered by large-scale farming operations. These could also be explained by the fact that the area will be less favorable to surface runoff than to infiltration.