Following is a factfile ahead of the 4th World Water Forum, taking place in Mexico City from March 16-22.
— 1.4 billion people do not have mains access to potable water, and 2.6 billion people, or 40 percent of the world's population, lack decent sanitation.
— On average, 15 people die every minute of a water-linked disease, such as cholera, diarrhoea and typhoid. The annual death toll is eight million.
— To meet the UN's Millennium Development Goals on water and sanitation, investment must roughly to double, to around 30 billion dollars a year, according to the World Water Council. The UN goal is to halve the number of people without access to clean water and sanitation by 2015 compared to a 1990 benchmark.
— Under UN criteria, a region is said to be suffering from water stress, when water resources fall belong 17,000 cu. metres (595,000 cu. ft.) per person per year.
— Water consumption rose sixfold in the 20th century, but per capita distribution is plummeting. In 1950, consumption was 16,800 cubic metres (588,500 cu. feet) per person; in 2000, it was 7,300 cu. metres (255,500 cu. ft.), in 2025, when the world's population is expected to be eight billion, it will be 4,800 cu. metres (168,000 cu. ft.) per person.
— Water consumption in residential areas varies from 10-20 litres (2.2-4.4 gallons) per person day in sub-Sarahan Africa to 200 litres (66 gallons) in Europe to 350 litres (77 gallons) in North America and Japan.
— Tensions over water rights are already a problem in many regions, ranging from the thirsty states in the western US to the Middle East and Southeast Asia. Scarcity is likely to worsen as a result of global warming, igniting what experts fear will be so-called water wars.
Sources: UN, World Health Organisation (WHO), World Water Council