On Monday, September 4, Governor Koike met with Diane d'Arras, President of the International Water Association (IWA), at the Tokyo Metropolitan Government. The IWA will organize the IWA World Water Congress & Exhibition 2018, to be held in Tokyo.

The IWA is a non-profit organization founded with the goal of providing the world with a safe and stable supply of water and contributing to public health through the advancement of water treatment technology and efficient water management. Once every two years, they hold an international conference. The 2018 World Congress will be held in Tokyo in September 2018, marking the first time for it to be held in Japan.

President d'Arras said, "Water is a huge issue for the world. Over two billion people are up against water-related problems, including waste water." "I want next year's World Congress to serve as a forum where people from Japanese and international facilities and universities can share their expertise."

In response, Governor Koike said, "Water is essential for humanity. Securing safe water is the most basic element of government and administrative services." She also touched on Tokyo's potable tap water and the low rate of leakage from water pipes, saying, "I hope to pass along Tokyo's various experiences, technologies and systems."