Social inequality is the biggest problem for poorer people getting access to water for their everyday needs.
Rich elites are overconsuming water for their own personal leisure and leaving poorer people without basic access in cities across the world, research has found.
Social inequalities are exacerbating urban water crises more than climate change or population growth, as the richest people use water for swimming pools, gardens and washing cars when others lack basic means.
The international team of researchers from the UK, Sweden and the Netherlands focused their study on Cape Town, South Africa, but found similar issues in 80 cities worldwide including: London, Miami, Barcelona, Beijing, Tokyo, Melbourne, Istanbul, Cairo, Moscow, Bangalore, Chennai, Jakarta, Sydney, Maputo, Harare, Sao Paulo, Mexico City and Rome.
Professor Hannah Cloke, a hydrologist at the University of Reading who co-authored the study, said: “Climate change and population growth mean that water is becoming a more precious resource in big cities.
"But we have shown that social inequality is the biggest problem for poorer people getting access to water for their everyday needs.
“More than 80 big cities worldwide have suffered from water shortages due to droughts and unsustainable water use over the past 20 years, but our projections show this crisis could get worse still as the gap between the rich and the poor widens in many parts of the world.
“This shows the close links between social, economic and environmental inequality. Ultimately, everyone will suffer the consequences unless we develop fairer ways to share water in cities.”
The UK National Infrastructure Commission has said about four billion extra litres of water will be needed in England by 2050.
Half of this will be met by increased supply, the government has said, with the other half coming from improving water efficiency, reducing demand, and cutting wasted water.
As part of its Plan for Water, published on Tuesday, the Government wants to reduce UK household consumption to 110 litres per person per day by 2050, down from the current level of 144.
It said it also wants to see a 50 per cent reduction in leakage from water company infrastructure and a 15 per cent reduction in non-household water usage.
The current study was led by Dr Elisa Savelli of Uppsala university, Sweden, along with colleagues from the University of Reading, Vrije Universiteit Amsterdam, and the University of Manchester.
They analysed the domestic uses of water in Cape Town to understand the differences between social classes, separating them into five groups ranging from elite (people who live in spacious homes with large gardens and swimming pools) to informal dwellers (people who live in shacks on the outskirts).
Elite and upper-middle-income households make up less than 14 per cent of Cape Town’s population but use more than half of the city’s water.
Informal and lower-income households account for 62 per cent of the population but use just 27% of the water.
The researchers said that reactive efforts to manage water supplies such as developing more efficient infrastructure are insufficient and counterproductive.
Instead, there should be a more proactive approach they said, aimed at reducing the overconsumption of the elites.
Danny Halpin is the PA environment correspondent.