The "G" of "G-WADI" stands for "Global" and, as such, there is a global secretariat, described below. However, most of the activity takes place at the level of the regional networks. Global networks by their nature face challenges of language, geography, time zones and simply size. The existence of regional networks mitigates some of these factors and helps G-WADI to focus on activities that enjoy broad support within a region.

International Center for Integrated Water Resources Management (ICIWaRM)

The Global Technical Secretariat for G-WADI is the International Center for Integrated Water Resources Management (ICIWaRM). ICIWaRM is a UNESCO Category 2 water centre hosted by the USACE Institute for Water Resources (IWR) in Alexandria, Virginia, USA. "Category 2" centers are provided for and funded by the host nation, but are under the auspices of UNESCO. ICIWaRM was officially created by an agreement between the U.S. Government and UNESCO in October 2009. ICIWaRM was asked by UNESCO to become the Global Secretariat of G-WADI shortly after its approval, and has been assisting UNESCO IHP in G-WADI's communications, strategy, and capacity-building efforts since 2010.

ICIWaRM is a consortium of U.S. Government agencies, university departments, and non-governmental organizations committed to working together in support of the strategic program objectives of UNESCO's International Hydrological Programme (IHP). ICIWaRM works closely with the U.S. National Commission for UNESCO, the U.S. National Committee for the IHP, and category 2 centres in other nations.

The overall mission of ICIWaRM is the advancement of the science and practice of integrated water resources management (IWRM) to address water security and other water-related challenges by regional and global action, through new knowledge, innovative technologies, collaborative interdisciplinary scientific research, networking, training and capacity development. It focuses on readily transferable, practical science and technology.