Graphene sieve makes seawater drinkable Meanwhile Cape Town’s four million residents are being urged to conserve water and use no more 87 litres (19 gallons) a day.
A growing number of technology companies are focusing their work on water management – applying "smart" solutions to water challenges.
More Technology of Business Could these apps help you lose weight for good this year?
For example, French company CityTaps is on a mission to streamline water access in urban homes with its smart water meters linked to an internet-based management system.
Users buy "water credits" via their mobile phones and a smart meter dispenses only as much water as has been paid for.
"The internet of things offers new avenues for technological innovation in the water field, mostly by providing real-time data that – we hope – can be used to help utilities become ever more efficient and high-performing," says Gregoire Landel, chief executive of CityTaps.
Better water management also helps save on the electricity and chemicals required to produce drinkable water.
Meanwhile, other companies are using technology to harvest water from new sources.
US-based WaterSeer, for example, is developing a device capable of collecting water from the air.
"The priority is mobilising resources and paying sufficient attention to the management arrangement to keep people connected," says Mr Casey.