Pursuant to the prefectoral order of 14 April 2014 and in view of the findings of the impact study, the Yvelines prefect approved the building of public facilities (highways, networks, Château Vanderbilt park, area of ecological interest, etc.) at the “Ecopôle Seine Aval” integrated development zone (ZAC) in Carrières-sous-Poissy and Triel-sur-Seine. Designed as a business district opening out onto the city and natural areas, Écopôle will eventually provide 2,500 jobs.

Of the 200 hectares making up the ZAC, 60 hectares are intended for the installation of businesses, 30 hectares for public areas, 5 hectares for the urban park and 25 hectares for the area of ecological interest. For the project designers, the aim was to safeguard the existing landscaping perspectives between the hills and the Seine river, as well as the ecological continuity through the development of two large malls.