shutterstock-435513604

One million Parisians at risk, here’s what the new study reveals about the Seine flood

undefined undefined undefined 07h30

The Editor

© Frederic Legrand - COMEO / Shutter Stock

Published on Monday, June 1, 2026, a study from the Paris Region Institute (IPR) reveals that in the event of a flood, over 550,000 homes would be affected by the flooding, impacting more than a million people. In Île-de-France, it's Paris and its nearby suburbs that would be hit the hardest by these floods.

The floods of the Seine are characterized by a gradual rise in water levels and typically occur during heavy rainfall. The historic alert signal for overflow comes from the Zouave: an iconic statue on the Pont de l'Alma, whose feet in the water have been announcing the start of a flood since 1910.


What are the risks?

What the IPR highlights with this study is that over 555,000 homes, often collective, are exposed to the risk of flooding in the event of a flood from the Seine and the Marne. But that's not all: drinking water production plants, waste treatment centers, data centers, electrical substations… A significant flood would paralyze a large part of the infrastructure necessary for our daily comfort.

Experts today estimate that such an event has a one in a hundred chance of happening each year. But while floods remain unpredictable, they are thankfully not fast enough to catch us off guard: the rise in water levels is gradual and would give us time to minimize the risks.


Past Floods as a Reference

Back in January 1910, the Seine hit its record high of 8.62 meters at the Austerlitz Bridge: the Zouave was standing in water up to his shoulders! The water level rose over ten days, and it took another 35 days to return to normal. Fortunately, the human impact wasn't catastrophic, but the economic toll was significant: activities stopped, and transportation, communication, electricity, and gas were all paralyzed. Nowadays, such an event would cost around 30 billion euros for Île-de-France.

More recently, floods occurred in 1982 and in 2016, reaching 6.10 meters, and again in 2018. If such an event were to happen again, the study estimates...It shows that the neighborhood most affected in terms of residents exposed would be the 15th, especially Beaugrenelle, with 70,000 people living along the Seine. Proportionally, the most vulnerable municipalities would be Alfortville, Asnières-sur-Seine, Gennevilliers, Colombes, and Créteil. So, even though we all loved A Monster in Paris, let's keep our fingers crossed really tight that it stays on the big screen!