Cape Town has officially declared its drought a "national disaster." The South African coastal city has become the first major city in the modern era at risk of running out of Earth's most precious resource.
But it's not just Cape Town that's racing towards "Day Zero" of no water. One in four of the world's 500 largest cities are in a situation of "water stress."
Right now, over 1.2 billion people (almost one-fifth of the world's population) lack access to fresh drinking water, and another 2.7 billion have trouble finding water for at least one month each year.
The world without enough fresh water looks grim and imminent: Crops will likely fail, ecosystems and industries will collapse, disease and poverty will worsen, and violent conflicts over access to water will undoubtedly erupt.
Plus, climate change, human action and population growth is only going to make things worse. According to UN projections, global demand for fresh water will exceed supply by 40 percent in 2030. That's just over a decade away.
So while Cape Town may be the first to run out of water, it's unlikely to be the last.
Below are 10 other cities at risk of running out of drinking water, according to a recent BBC report.
1. São Paulo
São Paulo is Brazil's largest city, and water shortages in the drought-ridden region are inevitable. During a dangerous drought in 2014, the city's main reservoir dropped 4 percent below capacity. At its worst, deprived residents resorted to looting emergency water trucks.
In 2016, the drought was declared finished, but just one year later, the city was put at risk again when the main water reserves were 15 percent below expected levels.
"This is cyclical. It happened in 2004, it happened in 2014. We don't have a crystal ball to know when it might happen again," said Anicia Pio, head of São Paulo state industry association Fiesp's environmental department.
2. Mexico City
The 21 million people currently living in Mexico City are used to limited water. One in five residents receive just a few hours of running water every day, and 20 percent have running water for just part of the day.
The inland city now imports as much as 40 percent of its water from remote sources, yet more than 40 percent of that water is wasted from leaking pipes and pilfering.
Less than half of the 10 million residents living in Jakarta have access to piped water. As a result, illegal well-digging is a common practice which has drained the city's underground aquifers to a dangerous level.
The low level of the underground aquifers in combination with rising sea levels has placed the coastal city at risk of quite literally being drowned. Currently, about 40% of Jakarta now lies below sea level, according to World Bank estimates.
Russia is home to a quarter of the world's fresh water, but that doesn't mean its cities are safe from water scarcity. The level of air pollution in Russia has put the quality of water at great risk.
In Russia, 70 percent of the water used is surface water - the kind that is especially susceptible to contamination from air pollution. As a consequence, 35% to 60% of total drinking water reserves in Russia do not meet sanitary standards.
Bangalore's water and sewer systems have struggled to keep up with India's booming population. As a result, the city loses more than half of its viable drinking water from its out-dated plumbing system.
Like Moscow, the surface water in Bangalore is also highly susceptible to contamination from air pollution. For instance, a comprehensive study of the city's lakes found that 85% had water that could only be used for irrigation and industrial cooling. None of the lakes were deemed suitable for bathing or drinking.
In Cairo, the River Nile really is the source of life. It provides 97% of Egypt's water. Unfortunately, the river is struggling more and more with pollution from untreated agricultural and residential waste. So much so, that Egypt ranks high among lower middle-income countries when it comes to deaths related to water pollution, according to the World Health Organization.
The UN estimates critical shortages of water in the country by 2025.
China is home to nearly 20 percent of the world's population, but it has only 7 percent of the world's fresh water. For large cities like Beijing, this means water is extremely scarce.
In 2014, each of the more than 20 million inhabitants in Beijing had only 145 cubic metres of water, which is nearly 900 cubic meters under the standard needed to be defined as "water scarce."
Thanks to climate change, pollution and population growth, the problem is only getting worse. A Columbia University study estimates that China's reserves declined 13 percent from 2000 to 2009.
Ever since Turkey's per capita supply fell below 1,700 cubic metres in 2016, the country has been experiencing "water stress." For heavily populated areas like Istanbul, this means water shortages in drier months.
While the problem may not be drastic now, it is increasingly headed in that direction. In 2014, the city's reservoir levels dropped 30 percent below capacity. If things continue, local experts have warned that the situation could worsen to water scarcity by 2030.
Florida gets a ton of rain compared to other U.S. cities, but the city of Miami is still at risk of running out of wate. Thanks to an old project that drained swamps near Miami, the city's main source of fresh water, the Biscayne Aquifer, is being contaminated with water from the ocean.
Even though officials were aware of the problem all the way back in the 1930s, the contamination persists. And the rising sea level isn't making things any better. In recent decades, the ocean has managed to breach underground defence barriers numeous times.
The city is already feeling the effects. A few miles north of Miami, Hallandale Beach has had to close six of its eight wells because of saltwater intrusion.
London is notorious for rain, but that isn't necessarily deserved. The city averages about 600 mm of rainfall per year, which is less than the Paris average and only about half that of New York. As a result, London gets 80 percent of its water from rivers, like the Thames.
Now, the capacity of these rivers is truly being tested. According to the Greater London Authority, London is likely to have water supply problems by 2025 and "serious shortages" by 2040.