The largest city in South Africa is poised to run out of water by April, following severe droughts two years in a row, and the government has begun warning residents it will soon have to ration water.
Cape Town's drought experience is so extreme that some calculations indicate it is a once-in-a-millennium event, and climate research indicates the problem will worsen as time goes on.
The situation arises at a time that the world is scrambling to mitigate the effects of climate change, though some countries are making more progress than others.
[S]tates will fail, large populations subjected to famine, flood or disease will migrate across international borders, and national and international agencies will not have the resources to cope.
Residents of Cape Town are seeing the effect firsthand.
The drought-stricken city announced on Thursday that it will begin marking 200 collection points where its 3.7 million residents will be required to queue for a rationed supply of water on "Day Zero" – currently forecast to be April 21.
If it happens, Cape Town would become the first major city in the world to shut down entirely the supply of running water in all of its homes.
Mayor Patricia de Lille said the city has reached a "point of no return":
"Day Zero is now very likely," she said. "Despite our urging for months, 60 per cent of Capetonians are callously using more than 87 litres per day. It is quite unbelievable that a majority of people do not seem to care and are sending all of us headlong towards Day Zero."
Nearby dams supply the city with water, but levels are now at just 28 percent of their capacity. "Day Zero" will be declared when the levels hit 13.5 percent.
Under the plans for Day Zero, each resident of Cape Town would be allowed only 25 litres of water per day, which must be collected from neighbourhood taps. Each supply point would be shared by about 20,000 people per day. The city is consulting police and army officials to decide how to maintain law and order at the collection points.
Only vital services, such as hospitals and clinics, would be allowed to continue their existing water supply after Day Zero. Most schools and many businesses would have to close.
Because climate change will continue affecting the area's rainfall, officials are trying to discern other ways to acquire enough water to meet the city's needs.
As part of its long-term response to the crisis, the city is building desalination plants to obtain drinking water from the Atlantic Ocean. But a large-scale use of desalination plants would be too expensive for the city to afford, experts say.