IWA was founded in September 1999 by the merger of the International Association of Water Quality (IAWQ) and the International Water Supply Association (IWSA). Through membership in IWA, water professionals from many specialties benefit from the synergistic gains that result from collaboration across the boundaries of specialties, professions and different parts of the world. Through its network of experts in research, practice, regulation, consulting and manufacturing, IWA can address the unique expressions of global challenges in communities throughout the world to create expanded knowledge and integrated, sustainable solutions. 

The American Water Works Association (AWWA) is an international nonprofit scientific and educational society dedicated to the improvement of drinking water quality and supply. AWWA is defined by six core competencies, through which we communicate and interact with all of our audiences. More information about each competency is available by clicking the links listed across the top of every page on the Web site. Together, the competencies distinguish AWWA as the authoritative resource for knowledge, information, and advocacy to improve the quality and supply of drinking water in North America and beyond.

The Australian Water Association is a professional membership organisation formed in 1962 to promote the responsible management of water and its related resources. They have approximately 4,000 members across Australia and abroad, including both organisations and individuals. Their members come from a broad range of disciplines, including engineers, resource managers and public health professionals.

The Canadian Water and Wastewater Association was established in 1986 to represent the common interest of Canada's municipal water and wastewater systems, particularly those related to federal and interprovincial bodies' policies, programs and legislation or to national Codes or Standards.

The European Water Association (EWA) is an independent non-governmental and non-profit making organisation dealing with the management and improvement of the water environment. It is one of the major professional associations in Europe that covers the whole water sector, wastewater as well as drinking water and water related waste. it not only includes the current European Union member states, Norway , and Switzerland , but also most of the future EU members from Central and Eastern Europe .

The Indian Water Works Association is a voluntary body of professionals concerned and connected with water supply for municipal, industrial, agricultural uses and treatment and disposal of wastewater. IWWA focuses basically on the entire "Water Cycle" encompassing the environmental, social, institutional and financing issues. IWWA was founded in 1968 with headquarters at Mumbai.

PERPAMSI is the association of Indonesian drinking water companies. The organisation was founded in semi-professional capacity on 8 April, 1972 . At present, about 300 water enterprises in the country are regular members of the Persatuan Perusahaan Air Minum di Seluruh Indonesia ; in addition, there are over 60 extraordinary members who are working in the field of water supply (suppliers, manufacturers, contractors, etc.).