Extreme rainfall, rising sea levels, and chronic flooding are no longer future risks — they are already reshaping cities, displacing communities, and placing growing pressure on infrastructure systems worldwide. As climate impacts accelerate, the central challenge is not only how to defend against water, but how to adapt cities and societies to live with it over the long term.

In November 2025, the Holcim Foundation for Sustainable Construction convened an international Forum in Venice to address this challenge. Held in a city shaped for centuries by its relationship with water, the Holcim Foundation Forum brought together architects, engineers, urban planners, climate scientists, policymakers, and economists from around the world for three days of intensive discussion on flood-resilient cities and communities.

Across presentations, workshops, and moderated debate, a set of shared concerns and lines of inquiry emerged. While approached from different disciplinary and geographic perspectives, discussions repeatedly returned to five critical questions:

• How much time do cities have to adapt to escalating flood risk?
• What are the social and ethical implications of managed retreat?
• How can nature function as essential infrastructure for flood defense?
• How can resilience be planned and delivered under financial constraints?
• Who ultimately pays for resilience, and how should responsibility be shared?

This book brings together the insights that arose from those conversations. Drawing on expert contributions, case studies, and cross-disciplinary exchange, it captures how participants grappled with the urgency of action, the long time horizons of adaptation, and the need to balance technical solutions with social responsibility.

By translating the Forum’s discussions into a durable publication, the book extends the impact of the event beyond Venice. It offers a shared reference point for practitioners, decision-makers, and institutions working to shape flood-resilient futures — recognising that living with water is not a one-off challenge, but a defining condition of the decades ahead.

The Holcim Foundation Forum brought together leading practitioners and scholars working across climate science, engineering, urban planning, design, governance, and finance. Their perspectives reflect the breadth of expertise required to address flood resilience — from long-term infrastructure planning and nature-based solutions to questions of equity, governance, and risk.

Contributors featured in this publication include Justin Abbott (Arup), Jola Ajibade (Emory University), Kate Ascher (Columbia University GSAPP), Maria Atkinson (Holcim Foundation, former chair), Karina Barquet (Stockholm Environment Institute), Ana P. Barros (University of Illinois Urbana-Champaign), Kai-Uwe Bergmann (BIG – Bjarke Ingels Group), Hanna Billmayer (City of Halmstad, Sweden), Matthijs Bouw (One Architecture and Urbanism), Pierpaolo Campostrini (CORILA – Venice Lagoon Research Consortium), Alice Charles (Arup), Craig Dykers (Snøhetta), Anne-Marie Hitipeuw (Dutch Ministry of Infrastructure and Water Management), Nirmal Kishnani (National University of Singapore), Alys Laver (Wildfowl & Wetlands Trust), Stefan Rahmstorf (Potsdam Institute for Climate Impact Research), Sofian Sibarani (URBAN+), Daniel Stander (Resilient Cities Network / Climate Resilience Center), Michael Szönyi (Zurich Climate Resilience Alliance / Z Zurich Foundation), Thomas Thaler (BOKU University Vienna / IIASA), and Chris Zevenbergen (IHE Delft / TU Delft).