It is now official. On December 13, 2021, the Paris 2024 Committee announced the news: the opening ceremony of the Paris Olympic Games will take place on July 26, 2024, on the river Yonne! This event will be broadcast live around the world. It will gather together 600,000 spectators along the river to attend the river parade of the 10,500 athletes sailing on Yonne water. Outside the stadium, this ceremony is therefore unprecedented. It will highlight the natural element that has shaped the identity of the department of Yonne for centuries.

A hydrological truth

This festive 6-kilometre parade will not take place between the Paul Bert and Jean Moreau bridges  in Auxerre. It will pass under the Pont Neuf, not the one that connects the two banks in Sens but the Pont Neuf in Paris. Because it is the Yonne river that flows in Paris and not the Seine. It is the Yonne that flows precisely where this spectacular ceremony will take place, between Pont d’Austerlitz and Pont d’Iéna that connect the Trocadéro to the Eiffel Tower and the Champ de Mars.

Yonne will host the opening ceremony of the Olympic Games because it is so from a hydrological point of view which is the science that studies all aspects of the water cycle. Indeed, Yonne river takes its source in the Morvan and it is joined by the Seine – its tributary – in Monterault-Fault-Yonne in the department of Seine-et-Marne. At the confluence, Yonne has a flow and catchment area greater than those of the Seine: respectively 93 m³/s and nearly 10,800 km² for Yonne and 80 m³/s and 10,300 km² for the Seine.

If the hydrological measures are unquestionable, how to explain that its Séquan tributary usurped its status as a river and therefore eclipsed its name in all the places it crosses? Yonne-et-Marne, Yonne-Maritime, Yonne-Saint-Denis, Neuilly-sur-Yonne… as many appellations as the Seine has wrongly appropriated by taking over Yonne’s bed.