Did You Know?
The City That Published the Date It Would Run Out of Water
1. In early 2018, Cape Town told four million people exactly which day the taps would be turned off.
They called it Day Zero. It was defined as the moment the city's dams fell to 13.5% of capacity — at which point municipal supply would be cut to hospitals and other critical services only, and everyone else would queue for water at 200 collection points.
After three consecutive years of poor rainfall, dam levels had fallen to 25% by late January 2018.
2. The ration was 25 litres a day. The target to avoid it was 50.
A typical urban resident uses around 200 litres a day. Cape Town asked its residents to live on 50 — the lowest target ever set during a drought anywhere, and in line with the WHO's minimum for maintaining health and safety. Under Day Zero itself, the figure would have dropped to 25 litres, collected by hand and carried home.
3. The city put a countdown on the motorway.
Electronic boards on the freeways, normally used for traffic information, displayed how many days of water the city had left. A public dashboard published weekly dam levels. A city-wide map let households compare their consumption with their neighbours'. The weekly water report became a topic on the radio and at dinner tables.
4. And then the date kept moving.
Day Zero was first projected for April. Then fixed at 12 April 2018. Then pushed to 11 May. Then to 4 June. Then to 9 July.
In June 2018 the region received average rainfall for the first time in four years, dam levels rose, and the city called Day Zero off indefinitely.
By then Capetonians had cut their water use by almost 60% from 2015 levels, giving the city one of the lowest per capita consumption rates of any major city in the world.
The clock: South Africa runs a single time zone, UTC+2, calculated for the 30th meridian east. Johannesburg sits close to that line and is only about eight minutes off its own solar noon.
Cape Town is at 18.4° east — nearly twelve degrees west of the 30th meridian — which leaves it roughly 46 minutes ahead of its own sun. Same country, same clock, a thirty-eight minute difference in what that clock actually means.
So: a city that scheduled its own catastrophe, published the date, watched it move four times, and then cancelled it — by getting four million people to use less than half the water they had used three years earlier.
Sources
- Northeastern Global Resilience Institute (Dams reduced to 25% by the end of January 2018; Day Zero defined at 13.5% capacity; 25 liters per person at 200 distribution points; April 12, 2018)
- ScienceDirect, Brühl & Visser (Target of 50 liters per person per day in the 2016-2018 drought — the lowest target ever set in a drought; compliance with WHO minimum)
- Grist (number of remaining water days on electronic signs on highways; weekly dam reports; citywide consumption map; first average rainfall in four years in June 2018)
- Princeton Successful Societies (approximately 60% decrease from 2015 levels; one of the lowest per capita consumption rates in the world)
- AP/Fox News (date postponed from April 12 to May 11, June 4, and July 9)
- National Geographic Education (population of four million; typical urban consumption is ~200 liters)
- Longitude calculation: Cape Town 18.4°E and Johannesburg 28.0°E, UTC+2 meridian 30°E