The project of the Conservatoire du Littoral consists of a land acquisition programme covering these two areas for a total area of 114 ha 35 a with a view to protecting and restoring the natural environment: —The western marsh which, due to its periurban location, was subjected to an old agricultural fallout which led to the anarchic installation of cottages and cottages for leisure purposes; —The Broucq farm located in the heart of the Clairmarais basin is a real estate complex of which two-thirds correspond to wet meadows of high heritage value.