This text reflects on the enduring relationship between architecture and water. It revisits Thales of Miletus' proposition of water as the primordial principle, aligning it with the contemporary imperative to reassess its presence and agency across landscapes, cities and architectural practice. Water is considered not merely as a natural resource but as a cultural and symbolic medium capable of structuring territories and shaping modes of inhabitation. Throughout history, works such as the Alhambra and architects including Barragan, Scarpa, Navarro Baldeweg and Zumthor have integrated it into their architecture as a spatial, aesthetic and ethical material. Today, in the face of the planet's technologisation, the climate crisis and our increasing detachment from the natural substrate, the need to reconnect architecture with nature has become pressing. This requires revisiting and reinstating traditional hydraulic knowledge, systems and architectures that uphold a respectful and symbiotic relationship with water. Only then might we hope to restore a sense of harmony with our surroundings.