April 22 has been set as "Day Zero" for Cape Town, but it's not a celebratory date. Time reports that following three years of record-setting drought, the South African city has enough water left in its reservoirs to last about 90 days—meaning it will become the planet's first big city to run out of water (on Earth Day, ironically) if things don't change drastically. If the worst-case scenario happens and reservoirs drop to 13.5% capacity, the city's 4 million or so residents will see their taps run dry (only essential services like hospitals will get water piped in) and will be forced to head to select "water points" guarded by armed security to pick up a max of 6.6 gallons a day. A Johannesburg ecology professor told Bloomberg in December that such a development would be "catastrophic." "I know of no example of a city the size of Cape Town running out of water," he said.
Residents have been told to keep water use down to 23 gallons per person per day, meaning two-minute showers, not using water to wash cars, and keeping dishwasher and washing machine use and flushing to a minimum. But those efforts haven't sufficed, and authorities fear the city is fast approaching what Time calls a sort of "Mad Max territory." The cause for the shortage is a combination of little rainfall over the last three years—a "less than once in a millennium" occurrence, climatologists told Bloomberg—a 50% population spurt in Cape Town over the past 10 years, and local politics. The city is now scrambling to see if it can set up groundwater extraction and costly desalination factories, but these alternatives likely won't be ready by April. "We have to change our relationship with water," one resident told Bloomberg. "We have to plan for being permanently in a drought-stricken area." (A Corona brewery has been accused of draining Mexico's water supply.)