The Site is an important complex of rivers, lakes and alluvial forest, featuring more than 400 ponds, four reservoirs, streams, gravel pits and meadows. Abundant wildlife is found within this mosaic of habitats. Various migrant birds are found: the Site is an essential refuge for nearly 150,000 wintering waterbirds; nearly 150 black stork individuals have been recorded in summer, and up to 300,000 migrating common crane. In addition, it is one of the last breeding sites in the Grand Est region for purple heron, little bittern and great reed warbler. The wet meadows, reed beds and forests also support a very large number of plant species (including small fleabane Pulicaria vulgaris and greater spearwort Ranunculus lingua). The most significant threats are tourism, urbanization, invasive species, drainage and the use of grasslands for intensive farming. A management plan is implemented, which is frequently reviewed to preserve the Site’s characteristics.