Abstract: The present study carried out in the Highest Bandama watershed at Tortiya, in the northern of Côte d’Ivoire, aims to evaluate climate variability impact on groundwater resources in order to best management. It is based on rainfall and runoff data exploitation. Thus, application of low-pass filter of Hanning and statistic tests (Pettitt, Lee and Heghinian) shows a rainfall regime modification occurred around the seventies years. This modification reveals a decrease of rainfall between 12% and 22% according the stations, with an average of 16.5%. This decrease is very high for runoff (62.5%) at Tortiya station. The isohyets plots confirm the decrease of rainfall during five decades. Coefficients of depletion obtained by Maillet method become very high (more than 8 10-2 j-1) after the seventies years. Groundwater recharge decreases with an average efficace infiltration of 212 mm in decade 1980-1989, and 184 mm in the decade 1990-1999.Abstract: The present study carried out in the Highest Bandama watershed at Tortiya, in the northern of Côte d’Ivoire, aims to evaluate climate variability impact on groundwater resources in order to best management. It is based on rainfall and runoff data exploitation. Thus, application of low-pass filter of Hanning and statistic tests (Pettitt, Lee and Heg...Show More