In the frame of various water resource management projects carried out in Eastern Europe, Central Asia, Latin America, and South East Asia, IOWater supports national authorities in developing their online metadata catalogue. Such a tool facilitates the inventory and description of available data sources and makes them easier to discover. After a configuration phase, the online tool is generally presented at the national data management workshops, and a specific password is given to each institution to allow them to capture online the descriptions of their data sources.