The Global Runoff Data Centre is an International data centre operating under the auspices of the World Meteorological Organization (WMO). Its primary objective consists in supporting the water and climate related programmes and projects of the United Nations, its specialised agencies and the scientific research community by collecting and disseminating hydrological data across national borders in a long-term perspective.

The Global Terrestrial Network for River Discharge (GTN-R) is the river discharge component of the Global Terrestrial Network - Hydrology (GTN-H) to support the Global Climate Observing System (GCOS) and the Hydrology and Water Resources Programme of the WMO (HWRP). The basic idea of the GTN-R project is to draw together the already available discharge data provided by the National Hydrological Services (NHS) and to redistribute it in a standardised way. Core component is the GCOS Baseline River Network of gauging stations located near the mouth of the world's major rivers. In cooperation with the Hydrological Services of the WMO Member States this network is continually being extended by confirmation of additional stations.GRDC contributes to the GTN-H by collection of discharge data. Access to GTN-R data follows GRDC's data policy of free and unrestricted but identified access and is limited to noncommercial applications. Use the GCOS/GTN-R stations catalogue to create your individual list of project stations for download via GRDC Data Portal.

The Arctic-HYCOS forms the Arctic region component of the the World Hydrological Cycle Observing System (WHYCOS) implemented to support existing international initiatives. The objective of the Arctic-HYCOS Project is to allow the collection and sharing of hydrological data to evaulate freshwater fluxes to the Arctic Ocean and Seas, monitor the changes and enhance understanding of the hydrological regime of the Arctic region. GRDC hosts this dataset on behalf of the Arctic-HYCOS member countries.

BALTEX (the Baltic Sea Experiment) was launched in 1992 as a Continental-scale Experiment (CSE) of the Global Energy and Water Exchanges Project (GEWEX) within the World Climate Research Program (WCRP). The research focus of BALTEX was primarily on the hydrological cycle and the exchange of energy between the atmosphere and the surface of the Earth. The study region of BALTEX is the Baltic Sea and its huge catchment region. In 2015, the BALTEX Hydrological Dataset moved from Swedish Meteorological and Hydrological Institute (SMHI) to the GRDC in order to ensure sustainable operation and regular updates as an integral part of the Global Runoff Database. By release and on behalf of the National Hydrological Services, the former BALTEX stations and flow data are integrated in the Global Runoff Database.

The GRDC Data Portal is for web-based selection and download of river discharge data collected by GRDC on behalf of the World Meteorological Organization (WMO). Calibrate your hydrological model, evaluate model results, or validate remote sensing data with in-situ data.

WMO Basins and Sub-Basins (WMOBB) is an ongoing GIS project of the Global Runoff Data Centre (GRDC). This dataset was created for the generation of GRDC map products and will be updated from time to time whenever extensions are required by future GRDC projects. At present the dataset comprises GIS layers of WMO Basins 2020 and WMO River Networks 2020.

National Hydrological Services have identified “climate sensitive” stations on request of the WMO Commission for Hydrology in order to assess the variability and trends in hydrological data associated with climate variability and change. GRDC has offered to integrate this dataset into the Global Runoff Database.

The GEMStat Data Portal provides access to freshwater quality data and statistical vizualisations at different spatial scales. The data are voluntarily provided by countries and organizations worldwide within the framework of the GEMS/Water Programme of the United Nations Environment Programme (UNEP) .

The Watershed Boundaries of all GRDC Stations are generated on the basis of HydroSHEDS (Lehner et al., 2008) and the Multi-Error-Removed Improved-Terrain (MERIT) Hydro dataset (Yamazaki et al., 2019). It is updated as soon as changes in the metadata occur or new stations have to be implemented. The dataset is licensed under CC-BY-4.0. Source: Lehner, B., Verdin, K., and Jarvis, A.: New Global Hydrography Derived From Spaceborne Elevation Data, EOS, 89, 93-94, https://doi.org/10.1029/2008EO100001, 2008. Yamazaki, D., Ikeshima, D., Sosa, J., Bates, P. D., Allen, G. H., and Pavelsky, T. M.: MERIT Hydro: A High-Resolution Global Hydrography Map Based on Latest Topography Dataset, Water Resources Research, 55, 5053-5073, https://doi.org/10.1029/2019WR024873, 2019.

The Southern Africa Flow Database, established between 1992 and 1997 to support rainfall-runoff modelling, contains flow time series data from about 815 stations across Southern Africa (SA). Initially hosted at the University of Dar es Salaam during the SA FRIEND Phase I and maintained by CEH in Wallingford in Phase II, the SA Flow Database is operated by GRDC since November 2010.