New Water Culture Sessions organized during this five-day period, were held from 13:00 to 15:00 (CET time), to enable as many people as possible from all over the world to join the conference. Each session consisted of three presentations of 15 minutes each, followed by a 20-minutes Open Discussion. To enhance interaction, participants were able to ask questions to the authors during the Q/A session through the chat. The Pre-Conference was simultaneously translated in English and French and accessible on Zoom and YouTube and is streaming online. Reinforcing the “Science-Policy-Interface” The Pre-Conference has highlighted the role of scientists and researchers in supporting decision-making process by contributing their professional insights, methodologies, advanced tools and assessment. They have brought together a wide spectrum of expertise across the world among a diversity of subjects such as flooding, water scarcity, nature-based solutions or governance, among many others. By bringing this network of scientists together, the Pre-Conference “Water, Megacities and Global Change” has allowed to put science at the service of populations across the world and improved the conditions for better water management in Megacities.