Under the project “Climate Change and Hydrology in Switzerland” (CCHydro) run by the FOEN, the effects of climate change on the water balance in Switzerland by the year 2100 were studied. The water resources will only change slightly by then. However, as a result of the rise in the snow line associated with increasing air temperature, the volumes of snow and ice stored in the Alps will be greatly reduced. This will combine with a seasonal redistribution of the precipitation (drier in summer, wetter in winter) to cause a seasonal flow redistribution. High and (particularly) low water flow events will probably occur more frequently – mainly in sensitive regions such as the Swiss Plateau, Valais and Ticino.