Today wasn’t Day Zero in Cape Town, but the water crisis isn’t over

The mayor of Cape Town, South Africa, predicted in October 2017 that the city would run out of water the following March. Since then, the date for what officials call "Day Zero" has changed from April 21 to April 12 and April 16. Today, May 11, was another potential Zero Day, but the last thing in the city is that the threat was postponed at some point in 2019. What's wrong?

Somehow, changing estimates are a good thing: they reflect how Cape Town's success has been in conserving its water. Now, no one is washing their car, or bathing with hoses on the sidewalks, and there are fewer pipes leaking. But the moving target also reflects the uncertain future of Cape Town's water supply as the city enters the rainy season that, so far, has not provided enough rain.

The zero day is when the four million residents of Cape Town will be required to collect daily water rations: less than seven gallons (25 liters) per person. Cape Town's water comes almost entirely from rainfall, which is captured and stored in six large reservoirs in the city. But the city is currently in the midst of a three-year drought, so Cape Town's reservoirs are dangerously low, just over a fifth of its capacity. That's even worse than it seems, since the last 10 percent of the water is hard to reach, like the last jet of liquid soap in a pump bottle.

In terms of conservation, "Cape Town has done fantastically in that, mainly because the sight of these empty dams has scared everyone away," says Peter Johnston, climate scientist at the University of Cape Town. . The city established strict water limits; Each person is allowed 13 gallons (50 liters) of water per day. According to the USGS, for a scale, that is approximately the amount of fresh water that goes down the drain in three or four discharges from an older toilet. People who use too much could be fined, and may have to agree to install a device that cuts off their supply if they use too much.

The city has also reduced water waste by repairing leaking pipes and reducing the speed of water flow. Lower water pressures mean less water seeps through cracked pipes, but it also reduces the amount of people you use when you turn on your faucets, says Cape Town Deputy Mayor Ian Neilson. Together, replacement pipes and reduced water pressure save 13 million gallons (50 megaliters) per day.

Not only are they citizens: the crops have also had to cope with less water. The share of water reserved for agriculture is 60 percent lower than in the years before the drought, according to a city report. Once the farmers reached their limit, they were cut, says Janse Rabie, who represents the South African agricultural lobbying group Agri SA. "These strict water restrictions cost farmers dearly," says Rabie in an email to The Verge. "It also had a huge impact on agricultural workers (especially seasonal workers) who could not be employed or had to be fired."

The squeeze made help delay the date of Day Zero, though – far enough in the rainy season that city officials decided to suspend it altogether. At that point, Neilson says, "it was completely unrealistic to base it on the assumption that there would be no rain." The date would have changed with each storm, making it a bad reference point for saving water in the city.

Therefore, canceling Day Zero does not mean that there is a pardon, although that is the message that it seems to be sending. The reservoirs still have a fifth of their normal capacity, but last week water consumption increased. In addition, suspending Day Zero could take away the warning of its force the next time an official notices that the deposits are drying up dangerously. And it could happen again as increasing global temperatures make droughts in the region more likely.

Even if in the future new water sources, such as desalinated seawater, groundwater and icebergs towed from Antarctica are connected, Johnston says that this culture of water conservation should continue, no matter what the day. "We are facing disaster on all fronts, whether agriculture, pollution, soil, water, pesticides, the human race is engaged in destruction," he says. "It's a case of looking at the future and saying that we'll have to get used to using less water permanently."