12 February 2026

24 minutes

Available for over a year

Chennai, São Paulo, Mexico City, Tehran, Cape Town - these cities have all faced the threat of a ‘Zero Day’, or, having no fresh water left in their taps.

The UN says we’re entering a ‘water bankruptcy’ era, meaning our water ‘current accounts’ are running empty, while our ‘savings accounts’ - the long term stores of water deep underground - have been depleted, with some beyond repair.

So how did we get here?

From clearing forests for cattle grazing, to thirsty AI data centres, Rajan Datar examines the pressures on our global water supply and looks for solutions.

Contributors:

Jayshree Vencatesan, Co-founder, Care Earth Trust, India

Augusto Getirana, research scientist at NASA's Hydrological Sciences Laboratory, USA

Prof Bridget Scanlon, Bureau of Economic Geology, University of Texas, USA

Dr Jie-Sheng Tan Soo, Director, Institute for Environment and Sustainability, National University of Singapore

Presenter: Rajan Datar

Producer: Phoebe Keane

Researcher: Evie Yabsley

Editor: Richard Fenton-Smith

Technical Producer: Cameron Ward

Production Management Assistant: Liam Morrey

(Photo: Indian women with empty plastic pots protest as they demand drinking water. Credit: Arun Sankar/Getty Images)