In this episode, Callum and author Tim Smedley take a deep dive into why the UK is more water-stressed than most people realise—and how solutions from both the ancient world and modern engineering could transform our future. From Australia’s household rainwater tanks to Mexico City’s ambitious urban schemes, and from Iranian qanats to forgotten cisterns in Europe, this conversation uncovers the systems that once sustained entire civilisations and the technologies that could help us do the same today. They also explore emerging UK initiatives—like smart water butts and slow-drain systems—that could ease pressure on overwhelmed sewers and help communities adapt to extremes of drought and downpours.