Groundwater is of paramount importance in Haiti. It is the main source of drinking water for the Haitian population. The degradation of the quality of this resource is a major challenge in the context of climate change, where a rise in sea level of 200 to 300 mm by 2100 (IPCC, 2008) could irreversibly worsen this phenomenon. In this context, the identification of the sensitivity of groundwater to climate variations has become crucial due to climate change and the strong link between climate and the water cycle and thus water resources. The question we are asking relates to a coastal aquifer at a time when climate change is prolonging periods of drought in the Caribbean.