It shouldn't be a surprise, then, that Cape Town is just the tip of the iceberg. Here are the other 11 cities most likely to run out of water.

1. São Paulo

Brazil's financial capital and one of the 10 most populated cities in the world went through a similar ordeal to Cape Town in 2015, when the main reservoir fell below 4% capacity.

At the height of the crisis, the city of over 21.7 million inhabitants had less than 20 days of water supply and police had to escort water trucks to stop looting.

It is thought a drought that affected south-eastern Brazil between 2014 and 2017 was to blame, but a UN mission to São Paulo was critical of the state authorities "lack of proper planning and investments".

The water crisis was deemed "finished" in 2016, but in January 2017 the main reserves were 15% below expected for the period - putting the city's future water supply once again in doubt.

2. Bangalore

Local officials in the southern Indian city have been bamboozled by the growth of new property developments following Bangalore's rise as a technological hub and are struggling to manage the city's water and sewage systems.