Pre-Conference “Water, Megacities and Global Change”: putting science at the service of water security and adaptation to climate change in Megacities

06 - Clean Water and Sanitation
11 - Sustainable Cities and Communities
13 - Climate Action

What are the main challenges that Megacities face in coping with the effects of climate change? What tools can they put in place to address these challenges, in an increasingly fragile urban context? How can the integration of water stakeholders in a Megacity through a common platform and knowledge exchange enable them to benefit from innovative initiatives and, ultimately, enhance their resilience?

These were among the key questions addressed by the online Pre-Conference “Water, Megacities and Global Change” that UNESCO Division of Water Sciences co-organized with the Greater Paris Metropolis, SIAAP and ARCEAU-IdF from 7 to 11 December 2020.

This online Pre-Conference aimed to respond to the urgent and pressing need of initiating discussion on the challenges and solutions related to water, Megacities and global change which was planned to take place during the Second International Conference “Water, Megacities and Global Change”, but had to be postponed to December 2021.

Indeed, by 2050, around 40% of the world population is likely to live in areas experiencing severe water stress, and by the same time, 68% of worldwide inhabitants will most probably live in urban agglomerations[1]. The demands of increased population and unsustainable urbanization will further exacerbate the current levels of water stress experience in cities worldwide. Together with climate change, these global changes set new requirements and higher standard to better manage and plan our water infrastructure and system, land use, balance of users and governance. In Megacities and metropolitan areas, these negative impacts are becoming more and more visible and substantial. 

Because water is a connector, bringing together many other important aspects of human life, including agriculture and food, energy, ecosystem and health, a holistic and integrated approach is needed. Water is at the core, connecting all SDG's.

Mr. Abou Amani, Director a.i., Division of Water Sciences and Secretary a.i., UNESCO-IHP

A Pre-Conference to update on the current and most pressing issues

Through the presentation of 30 scientific papers, produced and delivered by researchers, operators, PhD students and civil society representatives, the Pre-Conference has provided a brief scientific and technical overview of current water challenges Megacities face and solutions they use to mitigate the effects of climate change.  In particular, ten thematic sessions were held, to tackle the following topics:

  • Disaster Risk Reduction
  • Knowledge of the Technical and Social Conditions
  • Holistic Water Management
  • Service Continuity
  • Strengthening of Sustainable Solidarity
  • Innovative Initiatives
  • Planning Tools
  • Technical and Technological Solutions
  • 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.

A broad and global participation, raising awareness on major and common issues

The online tool used for the event through Zoom Webinar and YouTube live enabled a wide global participation and made this knowledge sharing experience accessible to the greatest number of people around the world. A large panel of various actors of the water field such as operators, civil society, political representatives, researchers, scientists and students, were mobilized for the pre-conference and have made it possible to maintain the momentum that has been built up over the last few months for the initiative. An average of 1280 people per day participated at the Pre-Conference, watched and listened to the presentations. The online conference helped increase the dissemination of knowledge and experiences towards new groups. In particular, young experts were able to join easily and participate actively, whereas it is usually more difficult for them to join international conferences for financial reasons. The high level of participation from them reflects this, as 23% of the registered participants were student or PhD candidates.

Youth engagement in the Pre-Conference

The conference placed special emphasis on youth, in line with UNESCO’s Global Priority on Youth, and it was demonstrated during the Youth Declaration that was shared on the last day before the Closing Ceremony. Building on the Youth Panel, which brought together youth representatives from all over the world and organized by the EauMega Youth Steering Committee in the framework of the Pre-Conference, youth representatives have issued a Call for Action relaying various demands:

  • Acknowledgement of the youth’s perspectives on the issues of water, Megacities and global change;
  • Opening up spaces and opportunities to include the youth and the marginalized communities;
  • Taking holistic approach to understand the interlinkages between water, climate and livelihoods;
  • Keeping in mind the local ecology, geography, social and political economy of the region for any policies and solutions.

An update of the Youth Declaration of the Pre-Conference will be proposed at the EauMega 2021 conference scheduled for December 2021, to take stock on the progress made on the identified issues.

Towards the Second International Conference “Water, Megacities and Global Change” in December 2021 in UNESCO Headquarters

The EauMega Pre-Conference is indeed a one-step forward for the Second International Conference “Water, Megacities and Global Change” scheduled to take place in December 2021 at UNESCO Headquarters in Paris, France, 6 years after its first edition, EauMega 2015 that took place during COP 21. In addition, the one-year postponement of the physical conference will be used to update the themes of EauMega 2021 by adding new content, for example, the impact of Covid-19 pandemic in water management and the unprecedented climatic disasters of the year 2020. Among others, the physical conference will be the opportunity to officially establish the cooperation platform and launch the Strategic Global Framework of the Megacities Alliance for Water and Climate (MAWAC) at the flagship event of the General Assembly of Megacities’ Mayors.


UNESCO Division of Water Sciences would like to express its most sincere thanks to the estimated 37 panelists, to the 7 high-level representatives for their presence in the opening and in the closing, to the 12 moderators, to the Steering Committee members and close partners, the Greater Paris Metropolis, SIAAP and ARCEAU-IdF, to the dear sponsors Eau de Paris and Agence de l’Eau Seine Normandie, to the Programme Committee Co-Chairpersons and members and to the Youth Steering Committee members and associated. Last but not least, UNESCO is grateful towards the 6040 participants without whom this event would not have been possible nor successful. The hope of meeting all of you in person in December 2021 in UNESCO House is as high as the challenges encompassed by the conference themes.

More information:



[1] 2020 World Water Development Report, UNESCO