Water resources are essential for humanity. Today, major challenges concerning water resources include the identification of the spatial and temporal dynamics of water availability and how these are impacted by climate change and anthropogenic pressure. The vulnerability and resilience of water resources depend on their geographic context, from mountains to plains, across arid to humid climates, and the extent of impact from water abstraction. The course covers these general themes and concludes with a special focus on the Greater Geneva Region. This will include the role of water supply from Lake Geneva and its surrounding glaciers, the impacts of climate change such as severe glacier retreat, heatwaves, and droughts, as well as groundwater lowering. The course ends with perspectives on responsible water management.