The Global Runoff Database at GRDC is a unique collection of river discharge data collected at daily or monthly intervals from more than 8000 stations in 157 countries. This adds up to around 320.000 station-years with an average record length of 40 years. The GRDC provides discharge data and data products for non-commercial applications. The GRDC operates under the auspices of the World Meteorological Organisation (WMO) and supports research on climate variability and global change. The German Federal Institute of Hydrology (Bundesanstalt für Gewässerkunde or BfG) hosts the GRDC in Koblenz near the confluence of the Moselle and Rhine Rivers.