This research aims to assess recent and future trends in climate and water in Lake Guiers, Senegal. Climate simulations based on representative concentration pathways RCP 4.5 and 8.5 were analyzed and future water availability and demand were modeled according to climate change and population growth scenarios using the model of assessment and monitoring system. Water Planning (WEAP). The results show that the future climate of Lake Guiers seems to be exposed to the worst conditions and that the availability of water and demand will be subject to much greater stress. To ensure the security of water supply, this research recommends integrating the results into a DPSIR as an analytical tool allowing water resource managers to mitigate or anticipate future impacts.