"When the Seine will overflow", on France 5: Is Paris sinking?

The muddy water infiltrates, surges, floods everything

"When the Seine will overflow", on France 5: Is Paris sinking?

The muddy water infiltrates, surges, floods everything. Place de la Concorde looks like a huge lake, the Eiffel Tower has its feet under water. In the courtyard of the Louvre, only the top of the pyramid is still dry. Roads, car parks, cellars, metro stations, building halls, water is everywhere.

These images with very realistic special effects resemble those of a disaster movie. But as this scientific documentary explains, enriched by multiple insights from experts and benefiting from the wise advice of geographer Magali Reghezza-Zitt, these disturbing scenes could well become reality.

Because the risk of a hundred-year flood equal to or greater than that of January 1910 which paralyzed the capital for several months (with a level of the Seine peaking at 8.62 meters, an unequaled record) seems high. So much so that the question is not whether the risk exists but when it will occur, global warming only increasing this possibility of a gigantic flood.

1910 trauma

For more than a century and after the trauma of 1910, the filmed archives of which show a Venetian-style Paris, with boats and canals in the flooded city center, the public authorities have constantly tried to prevent the risk of floods. Pontoons have been destroyed, arches enlarged, excavations carried out to improve the flow of the river.

Over time, technical means and knowledge have certainly progressed. Hundreds of experts and researchers (engineers, hydrogeologists, climatologists, town planners, etc.) spend their time studying these phenomena, seeking ways to reduce the power of the river, imagining new protections, finding solutions to avoid the predicted catastrophe. .

Since 1910, paradoxically, the capital has also been weakened with underground infrastructures which now extend over seven levels. Underground, there are metro lines, car parks, installations for gas, electricity, heating, telephone networks.

Protection installations

Despite the multiple measures described in this documentary to protect this underground system, its fragility is a reality. The first network to drop under water would be district heating, the last would be drinking water. During a hundred-year flood, it is estimated that 5 million Ile-de-France residents would experience interruptions to some of these basic services.

Anti-flood plans, ParisPluie plan… public authorities and political leaders take this risk of flooding very seriously. In the metro, the sewers, we are constantly monitoring and perfecting the protective installations. Knowing that despite all the measures taken, unpleasant surprises can occur at any time.

We remember the major flood that occurred from late May to early June 2016 in part of Europe (the Seine had reached 6.10 meters) and the heavy damage, particularly in Val-de-Marne. And more recently, in July 2021, of the terrible toll (more than 200 dead) in Germany and Belgium, following floods linked to global warming. This phenomenon raises fears in the future of extreme floods which would pass that of 1910 for an average flood.