IWA - a 75-Year Heritage

An Influential Gathering of People & Ideas

In the run-up to the 2022 IWA World Water Congress and Exhibition, in Copenhagen, Denmark, the International Water Association has been revisiting its history which, as of 2022, extends back 75 years. The organisation’s origins can be traced back to two major worldwide professional/technical water associations: the International Water Supply Association (IWSA), formed in 1947, and the International Association of Water Pollution Research (IAWPR), founded in 1962/1965. In 1980, IAWPR was renamed the International Association of Water Pollution Research and Control (IAWPRC), and in 1990, it evolved again as the International Association of Water Quality (IAWQ). The International Water Association (IWA) was founded in 1999 as a result of the merger of IWSA and IAWQ.

This span of time and involvement of multiple organisations means IWA’s history is a complicated topic. The 75-year landmark prompted an initiative to better document this history. In a major first step, former IWA Executive Director Paul Reiter has undertaken and led extensive research to set down the history in written form. The result of that work is set out in the resources available below.

Before IWA, the two associations (IWSA and IAWQ) had separate causes, cultures, and working methods. The focus of IWSA was on drinking water and it aimed to improve the efficiency and effectiveness of water supply while simultaneously it was monitoring the emerging regulatory standards. By the 1930’s, most advanced countries had developed dependable drinking water solutions, at least in the bigger cities. The focus of IAWPR/IAWQ was on wastewater treatment. In terms of research and science on the aquatic environment and the effects of water pollution, the means and methods of pollution were in their early stages in the 1950’s.

The two organisations considered and eventually decided to join forces in 1999. The ensuing united associations could capitalise on the qualities of each of the predecessor organisations, resulting in the new, vibrant, and resilient IWA that exists today. Download the resources available on this page to learn more about our 75-year heritage.


IWA Historical Documents

IWA Complete History: A4 Version                  IWA Complete History: Letter Version


Appendix 1A – IWSA Establishment          Appendix 1B – IAWPR Establishment        Appendix 2 – WWTP History



Appendix 3A – 50th Anniversary Notice ECG Newsletter             Appendix 3B – IAWPRC 25 Years         



Appendix 4 – The 1999 Merger              Appendix 5 – IWA Annual Review 2007