More than 2.5 billion people don’t have access to basic levels of fresh water for at least one month each year – a situation growing ever more critical as urban populations expand rapidly
In the southern reaches of Egypt, the city of Aswan is one of the hottest and sunniest in the world. Temperatures reach 41C in the summer and less than a millimetre of rain falls each year. Some years it doesn’t rain at all.
Aswan may be one of the world’s least rainy places, but it’s not even close to being the most water-stressed city. It nestles on the east bank of the Nile, close to the Aswan High Dam and the vast Lake Nasser, one of the largest manmade lakes in the world. With a capacity of 132 cubic km, the dam serves the irrigations needs not just of Aswan, but Egypt and neighbouring Sudan as well.
Water stress – where the human or ecological demand for water is not met – is caused by a variety of factors. There’s the physical scarcity of water due to lack of rainfall, the natural aridity of the area and, increasingly, changes in climate; but poor management and investment in water infrastructure, and pollution, also play their parts.
The problem affects an estimated 2.7 billion people for at least one month of every year, across every continent – and is particularly pressing in cities as the global urban population grows. At present, almost four billion people live in cities, with a further 2.5 billion expected to join them by 2050.
As the urban population grows, so too does the number of people living in settlements that are not connected to a formal piped water supply. Currently, some 860 million people live in slums around the world; their lack of access to clean water carries enormous health consequences. […]