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.

The European Water Archive (EWA) collected long-term daily flow data and catchment information from more than 4000 river gauging stations in 30 countries. In October 2014 the EURO-FRIEND-Water meeting in Montpellier concluded that the EWA will no longer be updated and will be "frozen at its current state". By release and on behalf of the data providers, the former EWA stations and flow data will be integrated in the Global Runoff Database. The archived data remain unchanged and will be provided by GRDC on special request by writing to grdc@bafg.de. Please use the GRDC station catalogue on the GRDC Portal for up-to-date data of stations in Europe.

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 "Major River Basins of the World" is a web application provided by the Global Runoff Data Centre (GRDC) to present the "Major River Basins of the World" data product. The "Major River Basins" and "Major River Networks" layers represent 520 river/lake basins considered “major” in basin size, or in their hydro-political importance or interest. 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 the GIS layers of GRDC Major River Basins 2020, GRDC Major River Networks 2020 and GRDC Major Rivers 2007.

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 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.

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 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.

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.

The GRDC Freshwater Fluxes into the World’s Oceans is a web application provided by the Global Runoff Data Centre (GRDC) to present the Freshwater Fluxes into the World’s Oceans data product. Continental freshwater input into the oceans is computed by the GRDC at irregular intervals, most recently in December 2020 referencing the time period 1901–2016. Previous data sets prepared in 2004, 2009 and 2014 are integrated into the service.