Official regulatory bodies admit that 35% to 60% of total drinking water reserves in Russia do not meet sanitary standards

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7. Istanbul

According to official Turkish government figures, the country is technically in a situation of a water stress, since the per capita supply fell below 1,700 cubic metres in 2016.

Local experts have warned that the situation could worsen to water scarcity by 2030.

In recent years, heavily populated areas like Istanbul (14 million inhabitants) have begun to experience shortages in the drier months.

The city's reservoir levels declined to less than 30 percent of capacity at the beginning of 2014.

8. Mexico City

Water shortages are nothing new for many of the 21 million inhabitants of the Mexican capital.

One in five get just a few hours from their taps a week and another 20% have running water for just part of the day.