The Zwin natural reserve, shared by Belgium (Flemish Region; 125 ha) and the Netherlands (33 ha), is the relict of a marine floodplain and important navigation route from Bruges to the North Sea. It has the characteristics of a slufter area, dominated by tidal inflow and outflow of North Sea water through an entrance channel twice a day. Although parts of the reserve are maintained in the present state artificially, ecological processes and patterns still are mainly influenced by morphological and hydrodynamic processes. Due to the reduced size of the area (caused by drainage, canalisation and land reclamation), the disconnected discharge of fresh (river) water and sand transport processes along the shoreline, the area suffers from a silting up pressure. However, it is still an important saltwater intertidal area, and therefore part of the European Natura 2000 network. If nothing is undertaken, this relatively small but ecologically rare intertidal zone will develop itself into a desalinated and silted up dune valley, dominated by grasses, reed and willows. Biological rich mudflats and marshes will disappear. The importance of the slufter valley for migrating and wintering birds will decrease considerably. Since 1950, the International Zwin Commission studies on long term (technical) solutions to preserve the nature values. The main question is how to control the (accelerated) silting up process in a sustainable way. Firstly, the paper gives an overview of the studied management scenarios with their estimated strengths and weaknesses. Secondly, the positions and perceptions of the involved stakeholders are briefly presented. Finally, principles of transboundary and integrated water management are discussed in relation to the approach of the International Zwin Commission.