Under the rule of Louis XIV, France gradually expanded her territory to the Alps in the southeast and part of the Rhine in the immediate east in order to acquire better geographic armor.
Other countries in central Europe are also reinforcing their flood defenses, water levels on the Rhine, the Danube and many tributaries are at dangerous levels.
Well, the Rhine River, R-H-I-N-E, crosses through, it goes through Switzerland, Germany, France, and the Netherlands, whereas the Rhone River is mainly in France.
Rotterdam is particularly vulnerable to storm surges — because of its coastal location, and because it sits in the delta created by the Rhine and Meuse rivers.