«L’eau c’est la vie ». This simple proverb says everything about our dependence on water. In November 2024, Paris hosted the inaugural conference on Sustainable Water Management and Resource Adaptation (SWMRA). Participants from around the world converged to explore one shared conviction: that protecting water is inseparable from protecting life itself. Water forms the living nexus between climate, society, and ecosystems, making its wise stewardship the cornerstone of climate-change resilience. The contributions gathered in this volume put the spotlight on the most promising strategies for securing both surface and groundwater, improving quality and balancing the needs of cities, farms and industries. Chapters range from advanced monitoring and modelling tools to governance frameworks and nature-based solutions that reinforce water security. Experimental researchers also featured emergent sustainable materials for water and wastewater treatment—many derived from repurposed agro-wastes. While these innovations hold great promise, authors remain alert to possible ecotoxicological side-effects and call for rigorous assessment to ensure that today’s solutions do not become tomorrow’s problems. By blending scientific insight, technological innovation and policy perspectives, this book offers a holistic roadmap for anyone committed to safeguarding water—academics, practitioners, decision-makers and students alike. Water sustains life; our collective ingenuity must now sustain water.