W hat lessons are learnt when a modern city of four million people comes to face the prospect of running out of water? In 2017-2018, in the third consecutive year of an unprecedentedly severe drought, the water shortage in Cape Town escalated to a full-blown water crisis, posing a near-existential threat to the city. Residents faced the unthinkable prospect of a disastrously disruptive ‘Day Zero’, when dam levels would be so low that reticulation to most households and businesses would be switched off and they would collect their daily water rations of twenty five litres per person from central distribution points.

In the end, catastrophe was averted. But how did it come to this? How did government and citizens respond to drought conditions, water shortage, and finally water crisis? How did the city manage to avoid going over the precipice? Most importantly: what were the lessons learnt from the experience?

Cape Town’s water crisis had precedents: São Paulo 2014, Barcelona 2008, Australia’s large cities in the 2000s. Far from being an event of merely local significance, the Day Zero story is an instance of two of the defining, coincident challenges of the 21st century: rising demands by human populations bumping up against resource availability limits, and the urgent need to adapt to a rapidly changing climate.

What can be learnt from this searing and costly narrowly averted disaster? Faultlines were exposed. A harsh light was thrown on an array of uncomfortable truths. And some notable successes were achieved. What should be done differently in future? What can be emulated elsewhere?

The lessons that were learnt in Cape Town resonate with relevance far beyond the sphere of water management, applying to urban resilience challenges broadly and to other cities globally. As climate change brings disruption through extreme events, it becomes ever more urgent that we distil and apply the lessons that can be learnt from these periodic crises.

Building on the work he did as co-lead of the Cape Town Drought Response Learning Initiative for which he made nearly 100 film outputs with accompanying text components, director Victor van Aswegen draws on extensive, in-depth filmed interviews to present a lucid, comprehensive exposition of the lessons learnt in a 100-minute documentary – the capstone of a multiyear undertaking of enquiry and learning.

Interview material with the leading experts and senior officials involved in the crisis is intercut with striking footage of the city, its water supply system and the drought period, and combined with animated graphics encapsulating the facts, figures and key learnings.

The film tells the riveting story of a brush with contemporary urban catastrophe, and sets out an authoritative account of the lessons learnt with clarity and dispassion, articulating sharp, actionable conclusions – invaluable around the world today, as water supply systems globally come under strain, buckling under the combined impact of inexorable population growth and increasingly frequent extreme climatic events.

In pre-production.