Agglomeration communities in France


An agglomeration community is a consortium of communes in France, created as a government structure by the Chevènement Law of 1999. It is one of four forms of an intercommunal structure with fiscal power, less integrated than a métropole or a communauté urbaine but more integrated than a communauté de communes. Agglomeration communities must consist of a contiguous grouping of communes with a total population of at least 50,000, including a central commune with at least 15,000 inhabitants. In the case of an agglomeration community that includes a prefecture, the 50,000 threshold is reduced to 30,000 and the 15,000 threshold does not apply.
As of January 2025, there are 230 agglomeration communities in France. The population of the agglomeration communities ranges from 28,318 inhabitants to 364,744 inhabitants.
Several former communautés d'agglomération have been converted into communautés urbaines or métropoles, for instance those of Strasbourg, Rouen, Saint-Étienne and Caen.

List of communautés d'agglomération

The table below lists the communautés d'agglomération with more than 200,000 inhabitants.
NameSeatNumber of communesPopulation
CA Grand AnnecyAnnecy34216,729
CA Grand AvignonAvignon16201,600
CA Pays BasqueBayonne158334,316
CA Béthune-Bruay, Artois-Lys RomaneBéthune100278,892
CA Cergy-PontoiseCergy13219,620
CA Cœur d'EssonneSainte-Geneviève-des-Bois21209,923
CA Lens – LiévinLens36244,474
CA Lorient AgglomérationLorient25213,310
CA Mulhouse Alsace AgglomérationMulhouse39276,825
CA Nîmes MétropoleNîmes39265,741
CA Nord de La RéunionSaint-Denis3218,801
CA Paris-SaclayOrsay27323,618
CA Grand Paris Sud Seine-Essonne-SénartCourcouronnes23363,513
CA Paris - Vallée de la MarneTorcy12233,856
CA Roissy Pays de FranceRoissy-en-France42364,744
CA Saint Germain Boucles de SeineLe Pecq19347,443
CA Saint-Quentin-en-YvelinesTrappes12236,416
CA Territoire de la Côte OuestLe Port5221,532
CA Valence Romans AggloAlixan54229,539
CA Val ParisisBeauchamp15291,093
CA Versailles Grand ParcVersailles18273,663