PUBLISHED: 30 July 2012

World Water Facts

Water Supply

About 70% of the Earth’s surface is water-covered[1].
The oceans hold about 96.5% of all Earth’s water[1].
68.9% of the Earth’s fresh water exists in the form of glaciers and permanent snow cover[2].
About 30.8% of the world’s total freshwater supply is groundwater (this includes soil moisture, swamp water and permafrost) whereas only about 0.3% of total global fresh water is stored in lakes and rivers[2].
The volume of all water on Earth would be about 1,386 million cubic kilometers (km³)…A cubic kilometer of water equals about 264 billion gallons[1].
Of the freshwater on Earth, much more is stored in the ground than is available in lakes and rivers. More than 2,000,000 mi³ (8,400,000 km³) of freshwater is stored in the Earth, most within one-half mile of the surface. But, if you really want to find freshwater, the most is stored in the 7,000,000 mi³ (29,200,000 km³) of water found in glaciers and icecaps, mainly in the polar regions and in Greenland[1].
Almost two billion people were affected by natural disasters in the last decade of the 20th century, 86% of them by floods and droughts[2].

Around 3,800 cubic kilometres of fresh water is withdrawn annually from the world’s lakes, rivers and aquifers. This is twice the volume extracted 50 years ago[2].
Universal water metering has proven to reduce overall residential and ICI (Industrial-Commercial-Institutional) water consumption by 15-30%[2].
Asia has the greatest annual availability of fresh-water and Australia the lowest. But when population is taken into account the picture looks very different. By the mid-1990s, 80 countries home to 40% of world population encountered serious water shortages. Worst affected are Africa and the Middle East{11}.
Water withdrawals for industry: World – 22% of total water use; High-income countries – 59% of total water use; Low-income countries – 8% of total water use[2].
In all regions except Europe and North America, agriculture is by far the biggest user of water, accounting worldwide for about 69% of all withdrawals[2].
Worldwide, in 2012 over 324 million hectares are equipped for irrigation, of which about 85 percent or 275 million hectares are actually irrigated[8].
Irrigated agriculture represents 20 percent of the total cultivated land, but contributes 40 percent of the total food produced worldwide[8].

Almost one fifth of the world’s population (about 1.2 billion people) live in areas where the water is physically scarce. One quarter of the global population also live in developing countries that face water shortages due to a lack of infrastructure to fetch water from rivers and aquifers.
Millennium Development Goal number 7, target 10 aims to halve, by 2015, the proportion of people without sustainable access to safe drinking water and basic sanitation. Water scarcity could threaten progress to reach this target.
50% of the world’s wetlands have been lost since 1900[2].
Freshwater species face an estimated extinction rate five times greater than that of terrestrial species[3].

There are 780 million people without access to an improved drinking water source[4].
46% of the world does not have drinking water piped to their premises[4].
60% of the world’s 227 biggest rivers have interrupted stream flows due to dams and other infrastructure. Interruptions in stream flow dramatically decrease sediment and nutrient transport to downstream stretches, reducing water quality and impairing ecosystem health[5].
The first municipal water filtration works opened in Paisley, Scotland in 1832[2].

There are currently 2.5 billion people without access to improved sanitation[5].
Over 70% of the people who lack sanitation, or 1.8 billion people, live in Asia[5].
Every year almost 4 million people die from water related diseases[6].
A typical individual in the United States uses 500 litres of water each day[6].
Every day, 2 million tons of sewage and industrial and agricultural waste are discharged into the world’s water (UN WWAP 2003), the equivalent of the weight of the entire human population of 6.8 billion people[5].
Sanitation and drinking water investments have high rates of return: for every $1 invested, there is a projected $3-$34 economic development return[3].
Economic losses due to the lack of water and sanitation in Africa as a result of the mortality and morbidity impacts is estimated at $28.4 billion or about 5% of GDP[3].
In developing countries about 70% of the industrial wastes are disposed of untreated into waters where they contaminate existing water supplies.[3]
Worldwide, infectious diseases such as waterborne diseases are the number one killer of children under five years old[3].
More people die from unsafe water annually than from all forms of violence, including war[3].