More than 1M people in Paris region exposed to major flood risk: Study

More than 1 million people in the Paris region live in areas directly exposed to the risk of a major flood similar to the historic 1910 Seine flood, according to a study published on Monday by the Paris Region Institute (IPR).

The report found that over 1 million residents, representing more than 8% of the population of the Ile-de-France region, are vulnerable to severe flooding caused by the overflow of the Seine and Marne rivers.

Nearly 555,000 homes, predominantly apartment buildings, are located in flood-prone areas, the study said, warning that the slow-rising nature of the region’s rivers could still cause extensive disruption and damage.

The findings underscore the need to identify and inform vulnerable populations about flood risks, particularly in light of the devastating Seine flood of January 1910, when water levels rose above 1 meter and left numerous neighborhoods submerged for weeks.

The study noted that Paris and its inner suburbs account for more than 70% of the population potentially exposed to major flooding.

Paris’ 15th arrondissement has the highest number of residents at risk, with nearly 70,000 people living in vulnerable areas, largely around the Beaugrenelle district on the banks of the Seine.

The municipality of Alfortville, southeast of Paris, is proportionally the most exposed community in the region, with around 45,000 residents at risk. Other highly exposed municipalities include Asnieres-sur-Seine, Gennevilliers, Colombes and Creteil.

According to the report, more than 100,000 homes have been built in flood zones since the introduction of the first flood risk prevention plans in the early 2000s.

While the plans have been effective in limiting urban expansion into high-risk areas, the study said increased housing density in flood-prone districts remains a challenge.

The report also warned that residents living above ground level would not be immune to the consequences of major flooding, citing potential disruptions to electricity, drinking water supplies and transportation networks.

Separate projections by the Paris Urban Planning Workshop estimate that a flood on the scale of the 1910 disaster could affect 600,000 people across the Greater Paris metropolitan area, leave 5 million residents without drinking water and cut electricity supplies to 1 million people.