The Rhine, in the heart of Europe, is seen globally as one of the most significant rivers, especially in social-economic terms. Within the scope of the project "Discharge regime of the Rhine and its tributaries in the 20th century", the International Commission for the Hydrology of the Rhine Basin (CHR) commissioned research into if, and to what extent, in the course of the last hundred years there have been significant changes in the discharge, behaviour of the river system. This is the first time this has been investigated in such a major river basin over a long period. It could be established that the "future has already started" in the Rhine area; i.e. climate change characteristics predicted in the forecasting models for the future of Central Europe, together with their consequences for the river regime, have already manifested themselves in the hydrological events of the last 100 years.