In November 2001, the 31st General Conference of UNESCO recommended that water resources and supporting ecosystems be given as a priority for UNESCO activities between 2002 and 2007, with particular attention given to water resource management in arid and semi-arid areas. This was also confirmed as a priority by the 15th Intergovernmental Council of the International Hydrological Programme (IHP) of UNESCO in 2002.

Following a meeting of international experts in December 2002, UNESCO supported the establishment of a Global Network on Water Resources Management in Arid and Semi-arid Zones by bringing together an international group of experts to develop the concept, objectives, and an outline of the Network. The first meeting in Paris, in April 2003, was attended by 24 participants from 17 countries and representing water authorities and institutions related to arid zones, UNESCO, FAO, WMO, SAHRA, IAEA, Sahara and Sahel Observatory (OSS), International Association of Hydrogeologists (IAH), the European Space Agency (ESA), Programme SudMed and L'Institut de Recherche pour le Développement (IRD). In work groups and plenary sessions, the participants created a draft implementation plan that outlined the organizational structure, membership, links, objectives, and initial timetables.

This plan included the establishment of a global network, G-WADI, which was launched by UNESCO in 2003 to support networking among centres and individuals across the arid and semi-arid regions of the world. Strengthening the capacity to manage the water resources of arid and semi-arid areas through the established G-WADI network was one of the priorities of the Seventh Phase of IHP (2008-2013) “Water Dependencies: Systems under Stress and Societal Responses”. It continues to be of high importance within the framework of the Eighth Phase of IHP (2014-2021) “Water Security: Addressing Local, Regional and Global Challenges”. In particular, G-WADI plays a key role in the focus areas on “Addressing Water Scarcity and Quality” and “Water Related Disasters and Hydrological Changes”.

Since its inception, G-WADI has grown into a global network with a prominent presence in drought-prone regions such as Asia, Sub-Saharan Africa, and Latin America. Much of its early leadership came from Asia, and a regional network was established for that region in 2005. Beginning in 2010, the network began to develop more broadly, with the establishment of the Global Technical Secretariat at the International Center for Integrated Water Resources Management (ICIWaRM) Category II Centre under the auspices of UNESCO in Alexandria, Virginia, USA. ICIWaRM works with the IHP leadership to implement responsibilities related to communications, training and capacity-building, planning and record-keeping through the management of a Global G-WADI web server.

Around the same time, other regional networks and secretariats were created. These are described under the Global Secretariats section of this website.