The GEMS/Water Data Centre operates the global water quality database and information system GEMStat of the UN Environment Global Environment Monitoring System for Water (GEMS/Water). GEMStat provides scientifically-sound data and information on the state and trends of global inland water quality required as a basis for the sustainable management of the world’s freshwater to support global environmental assessments and decision-making processes.

Established in June 2008 as a global data centre, the International Data Centre on Lakes and Reservoirs (HYDROLARE ) closes one of the most critical gaps in surface water observations. The centre is hosted by the State Hydrological Institute in St Petersburg, Russian Federation, and operates under the auspices of WMO.

The Global Precipitation Climatology Centre (GPCC) provides global precipitation analyses for monitoring and research of the earth's climate. The centre is a German contribution to the World Climate Research Programme (WCRP) and to the Global Climate Observing System (GCOS).

IGRAC has been founded to promote the acquisition and processing of groundwater data and to facilitate the exchange of groundwater knowledge for the benefit of all those who have a stake in groundwater. The Centre has adopted a demand-driven approach: within its fields of activity it will prioritise those activities that are prompted by the international groundwater community.