Paris 1910 flood marks

In 1910 there has been a terrible flood in Paris. Water not only flooded along the river Seine but went through the newly built Metro network into the center of the city. On January 28, 12 days after the beginning of the flood, water was 6 meters higher than usual at the Pont d'Austerlitz... Needless to say that damages have been enormous! What is "interesting" though, is that throughout the city you can still find marks of this flood. Here is one, located inside the Conciergerie (a building where queen Marie Antoinette was kept prisoner during the French revolution). By the way, the authorities have already said that a new flood like this could happen anytime now...