Cape Town in South Africa was earlier this year just weeks away from hitting Day Zero, when the city would officially be declared "dry". That crisis has been averted for now, but the magnitude of the situation, and the implications if the scenario were to be repeated in other major cities, is a terrifying prospect.

In Australia, the millennium drought, which parched the country for the first decade of the new century, left cities such as Melbourne a year away from running out of water. But suppose the rains hadn’t come and Melbourne experienced its very own Day Zero? What would that look like, what were the mistakes that would have led us there, and how would we reset and respond? 

Monash experts Professor Diego Ramirez, Dr Briony Rogers and Dr David McCarthy take up the conversation …