In early 2018, people around the world prayed for rain in South Africa. Outside Cape Town, the city’s reservoirs were down to 26 percent capacity. Inside the city, officials begged people to use just 13 gallons of water a day – just 20 percent of what the average American uses daily. Cape Town’s government said it would have to shut off drinking water to homes across the city. The police worried about riots.
By April, it became clear the city would just avoid reaching “Day Zero,” the date when Cape Town was forecast to run out of water. The world breathed a cautious sigh of relief. Cape Town’s predicament received a lot of attention as people across the globe grappled with the idea that a major city could run out of water — and wondered whether they could be next. Experts say Africa’s four largest cities — Cairo, Kinshasa, Lagos and Johannesburg — could all see their water supplies similarly strained soon, as could Karachi, Lahore, Mumbai and Kathmandu in Asia. Delhi is already struggling, and wealthier cities like Beijing and even Los Angeles will also face long-term supply problems if global warming continues to reduce rainfall in their traditional water supply areas.