The Global Water Quality database and information system GEMStat is hosted, operated, and maintained by the International Centre for Water Resources and Global Change (ICWRGC) in Koblenz, Germany, within the framework of the GEMS/Water Programme of the United Nations Environment Programme (UNEP), and in cooperation with the Federal Institute of Hydrology. GEMStat hosts water quality data of ground and surface waters providing a global overview of the condition of water bodies and the trends at global, regional and local levels.