Yvelines: Drought alert, restrictions in place, towns affected

The drought is settling in the Yvelines (78). After weeks of heatwave and a sharp drop in rainfall, the prefect of the department has placed the entire Seine basin, i.e., the northern portion of the territory, under drought alert as of July 2, 2026. Concretely, water restrictions are now in effect in more than a hundred communes, from Mantes-la-Jolie to Saint-Germain-en-Laye via Poissy, Sartrouville and Versailles. The rest of the department remains under watch.

Why have the Yvelines been placed under a drought alert?

The heatwave early in summer 2026 and the lack of rain have reduced the flow of the department's rivers. According to the prefecture of Yvelines, alert thresholds for the Seine and the Marne have been reached, while the Rémarde and the Orge remain under watch.

This decision comes amid a tense situation for water resources, a few days after the heatwave that put Île-de-France on red alert at the end of June. [NOTE: insert here the Sortiraparis internal link to the heatwave article for Île-de-France if available]

What water restrictions are currently in place?

In the municipalities affected, the measures apply to everyone: households and businesses alike, regardless of the source of the water used. Here are the restrictions in place:

• Watering parks, gardens and green spaces, sports fields and racecourses (excluding agricultural use) is prohibited between 11:00 and 18:00;
• Golf course irrigation is prohibited from 08:00 to 20:00;
• Filling private pools is prohibited, except to top up the water level;
• Washing vehicles is prohibited at home and at service stations, unless the station is equipped with water-saving or recycling facilities;
• Agricultural irrigation by sprinklers is forbidden between 11:00 and 18:00 (drip irrigation remains allowed);
• Group boats as needed to ease passage through the locks.

• To be read
• This week's top picks for July 6–12, 2026 in Paris and Île-de-France

Which municipalities in Yvelines are affected?

Here is the list of municipalities placed on alert, in alphabetical order:

• A: Achères, Aigremont, Andelu, Andrésy, Arnouville-lès-Mantes, Aubergenville.
  
  
• B: Bennecourt, Blaru, Boinville-en-Mantois, Boissy-Mauvoisin, Bonnières-sur-Seine, Bouafle, Bougival, Brueil-en-Vexin, Buchelay.
  
  
• C: Carrières-sous-Poissy, Carrières-sur-Seine, Chambourcy, Chanteloup-les-Vignes, Chapet, Chatou, Chaufour-lès-Bonnières, Conflans-Sainte-Honorine, Cravent, Croissy-sur-Seine.
  
  
• D-F: Drocourt, Ecquevilly, Épône, Évecquemont, Flins-sur-Seine, Follainville-Dennemont, Fontenay-Mauvoisin, Fontenay-Saint-Père, Freneuse.
  
  
• G: Gaillon-sur-Montcient, Gargenville, Gommecourt, Goupillières, Goussonville, Guernes, Guerville, Guitrancourt.
  
  
• H: Hardricourt, Hargeville, Houilles.
  
  
• I-J: Issou, Jambville, Jouy-Mauvoisin, Jumeauville, Juziers.
  
  
• L: L'Étang-la-Ville, La Celle-Saint-Cloud, La Villeneuve-en-Chevrie, Lainville-en-Vexin, Le Chesnay-Rocquencourt, Le Mesnil-le-Roi, Le Pecq, Le Port-Marly, Le Vésinet, Les Mureaux, Limay, Limetz-Villez, Lommoye, Louveciennes.
  
  
• M: Magnanville, Maisons-Laffitte, Mantes-la-Jolie, Marcq, Mareil-Marly, Marly-le-Roi, Maurecourt, Médan, Ménerville, Méricourt, Meulan-en-Yvelines, Mézières-sur-Seine, Mézy-sur-Seine, Moisson, Montalet-le-Bois, Montesson, Morainvilliers, Mousseaux-sur-Seine.
  
  
• N-O: Notre-Dame-de-la-Mer, Oinville-sur-Montcient, Orgeval.
  
  
• P-R: Perdreauville, Poissy, Porcheville, Rolleboise, Rosny-sur-Seine.
  
  
• S: Sailly, Saint-Germain-en-Laye, Saint-Illiers-la-Ville, Saint-Martin-la-Garenne, Sartrouville, Soindres.
  
  
• T: Tessancourt-sur-Aubette, Thoiry, Triel-sur-Seine.
  
  
• V: Vaux-sur-Seine, Verneuil-sur-Seine, Vernouillet, Versailles, Villennes-sur-Seine, Viroflay.

To quickly check the status of your address, the official platform VigiEau lets you see the restrictions that apply to your area, simply by geolocation.

What are the consequences of not complying with the restrictions?

The prefecture warns: inspections are being conducted under the inter-agency Environmental Police mission. Non-compliance with the measures could expose the offender to a fine of up to €1,500.

For the rest of the department under watch, residents are urged to adopt best practices to conserve water: these measures aim to safeguard the priority uses—health, public sanitation, civil security, and drinking-water supply. Restrictions could be adjusted up or down depending on the weather in the coming weeks in the Yvelines and in Île-de-France.