Vallée de la Haute-Sûre is part of a Transboundary Ramsar Site in Belgium and Luxembourg, composed of a complex of forested wetlands, peatlands, wet grasslands, reed beds, springs and rural zones. The Esch-sur-Sûre barrage forms a 380 hectare reservoir in the Luxembourg part (Site number 1408). The valley’s mosaic of habitats supports internationally-threatened mammals including the European otter Lutra lutra, the brown long-eared bat Plecotus auritus, the common pipistrelle Pipistrellus Pipistrellus and the badger Meles meles. It also supports some 20 species of fish, as well as the endangered freshwater pearl mussel Margaritefera margaritifera which depends on the river trout Salmo trutta for the first stages of its development. Besides typical wetland plants such as Comarum palustre and Menyanthes trifoliata, the rare Epipactis palustris and Pedicularis palustris are also present. The Site is an important stopover and nesting area for many birds, notably the black stork. The barrage provides drinking water for 80% of Luxembourg’s population. Pollution from intensive agriculture and untreated wastewater have affected the water quality of the River Sûre and its tributaries, while the introduction of resinous tree species has upset the balance of aquatic ecological communities. Uncontrolled activities such as hunting, water sports, leisure fishing and cycling also disturb the Site. For the Belgian part of the Site, a management plan has been implemented since 2007. Several projects (including transboundary projects) have supported the protection and restoration of wetlands and raised public awareness.