Good news for residents across several Île-de-France departments: Vigicrues in Île-de-France has expanded its monitoring to include four additional watercourses since early November 2025. This extension covers the Mauldre in Yvelines (78), the Yerres which flows through Seine-et-Marne, Essonne, and Val-de-Marne (77, 91, 94), the Almont in Seine-et-Marne (77), and the Petit Morin, running through Aisne, Marne, and Seine-et-Marne (02, 51, 77). Additionally, vigilance has been increased along existing sections of the Grand Morin (77) and Serein (89, 21).
This measure comes amid ongoing concerns about flooding, which remains the region's most significant natural hazard in Île-de-France. The stakes are high: due to extensive urban development and high population density, a major flood in the Seine, Marne, or Oise rivers—similar in scale to the devastating 1910 flood—could impact over a million residents. Providing early information to residents about these risks is therefore crucial to minimize damage and enhance preparedness.
In practical terms, this service extension allows residents in 78 additional municipalities to be covered by the flood vigilance alert. They now receive high-quality information through a color-coded warning system and a bulletin that specifies the maximum risk expected within the next 24 hours regarding potential river overflows. In certain areas, quantitative forecasts are also provided to further enhance this system, offering precise predictions of water level changes over the coming day. A significant step forward in helping communities prepare for possible flooding events.
This expanded monitoring effort is part of the Local Flood Risk Management Strategy for Île-de-France (SLGRI), adopted by all regional prefects in 2024. This bold initiative aims to minimize the damage caused by major floods and strengthen the region's resilience against such natural events. It involves collaboration between local authorities responsible for flood prevention, government services, and private companies, including major utility operators.
The 24 strategic directives of SLGRI translate into practical actions aimed at better understanding flood risks, enhancing monitoring and alert systems, preparing for floods, reducing their impact, and limiting affected areas. A key focus is the expansion of river monitoring through the Vigicrues network, led by the services of the DRIEAT (Regional and Interdepartmental Directorate for Environment, Planning, and Transportation).
The new watercourses classified as being under closer monitoring mainly involve Seine-et-Marne (77), including the Yerres, Almont, and Petit Morin. The Yvelines (78) with the Mauldre, as well as Essonne (91) and Val-de-Marne (94) for the Yerres. This expanded coverage aims to improve response times during heavy rainfall events, which can cause water levels to rise rapidly.
In short, if you live near one of these waterways, you can now track water levels in real time and receive personalized alerts. All this information is freely accessible to everyone on the Vigicrues website and through the mobile app. These tools are customizable at no cost, allowing you to set up alerts by email or notification for events like rising water levels or alerts based on specific safety thresholds. We recommend configuring your alerts to stay informed quickly should water levels begin to rise. For more information on flood risk prevention in Île-de-France, visit the regional prefecture’s website.
