Water Facts

 

How much do you really know about the world’s freshwater? Did you know that the amount of freshwater on the planet hasn’t changed for millennia? That wet weather is simply moisture returning to the world’s surface, not new moisture being added to it? That it takes 1,000 gallons of water to produce one gallon of milk? See many more facts and figures below. This page will be updated on a regular basis.

From UN Water:

• In July 2010 the United Nations declared access to clean water and sanitation a human right.
• 783 million people do not have access to clean water and almost 2.5 billion do not have access to adequate sanitation.
• 6 to 8 million people die annually from the consequences of disasters and water-related diseases.
• Estimates indicate that about 3.5 planets Earth would be needed to sustain a global population with the current lifestyle of the average European or North American. Global population growth projections of 2–3 billion people over 40 years, combined with changing diets, result in a predicted increase in food demand of 70% by 2050.
• Over half of the world population lives in urban areas, and the number of urban dwellers grows each day. Urban areas, although better served than rural areas, are struggling to keep up with population growth (WHO/UNICEF, 2010).
• With expected increases in population, by 2030, food demand is predicted to increase by 50% (70% by 2050) (Bruinsma, 2009), while energy demand from hydropower and other renewable energy resources will rise by 60% (WWAP, 2009). These issues are interconnected — increasing agricultural output, for example, will substantially increase both water and energy consumption, leading to increased competition for water.
• Water availability is expected to decrease in many regions. Yet future global agricultural water consumption alone is estimated to increase by ~19% by 2050, and will be even greater in the absence of any technological progress or policy intervention.
• The daily drinking water requirement per person is 2-4 liters (L), but it takes 2,000 to 5,000 liters of water to produce one person’s daily food.
• Water for irrigation and food production constitutes one of the greatest pressures on freshwater resources. Agriculture accounts for ~70% of global freshwater withdrawals (up to 90% in some fast-growing economies).
• Economic growth and individual wealth are shifting diets from predominantly starch-based to meat and dairy, which require more water. Producing 1 kg of rice requires ~3,500 L of water, 1 kg of beef ~15,000 L, and a cup of coffee ~140 L (Hoekstra and Chapagain, 2008). This dietary shift is the greatest to impact on water consumption over the past 30 years, and is likely to continue well into the middle of the 21st century (FAO, 2006).

From the U.S. Environmental Protection Agency:

• Only 3% of Earth’s water is freshwater; 97% of the water on Earth is salt water. (Other estimates cite 2.5%.)
• The water found at the Earth’s surface in lakes, rivers, streams, ponds, and swamps makes up only 0.3% of the world’s fresh water.
• 68.7% of the freshwater on Earth is trapped in glaciers.
• 30% of freshwater is in the ground.
• 1.7% of the world’s water is frozen and therefore unusable.
• Water covers 70.9% of the Earth’s surface.
• Water makes up between 55-78% of a human’s body weight.
• Water can dissolve more substances than any other liquid, including sulfuric acid.
• A 10-meter rise in sea levels due to melting glaciers would flood 25% of the population of the United States.
• There is more fresh water in the atmosphere than in all of the rivers on the planet combined.
• If all of the water vapor in the Earth’s atmosphere fell at once, distributed evenly, it would only cover the earth with about an inch of water.
• Water boils quicker in Denver, Colorado than in New York City.
• Approximately 400 billion gallons of water are used in the United States per day.
• Nearly one-half of the water used by Americans is used for thermoelectric power generation.
• In one year, the average American residence uses over 100,000 gallons (indoors and outside).
• It takes six and a half years for the average American residence to use the amount of water required to fill an Olympic-sized swimming pool (660,000 gallons).
• American residents use about 100 gallons of water per day.
• The average faucet flows at a rate of 2 gallons per minute.  You can save up to four gallons of water every morning by turning off the faucet while you brush your teeth.
• Taking a bath requires up to 70 gallons of water.  A five-minute shower uses only 10 to 25 gallons.
• A running toilet can waste up to 200 gallons of water per day.
• The first water pipes in the U.S. were made from wood (bored logs that were charred with fire).
• The first municipal water filtration works opened in Paisley, Scotland in 1832
• A gallon of water weighs 8.34 pounds.
• A cubic foot of water weighs 62.4 pounds
• An inch of water covering one acre (27,154 gallons) weighs 113 tons.
• Water vaporizes at 212 degrees F, 100 degrees C.
• It takes more water to manufacture a new car (39,090 gallons) than to fill an above ground swimming pool.
• Water is the only substance found on earth naturally in three forms: solid, liquid and gas.
• At 1 drip per second, a faucet can leak 3,000 gallons per year.

From the Water Footprint Network:

• It takes more than 10 gallons of water to produce one slice of bread.
• More than 713 gallons of water go into the production of one cotton T-shirt.
• 1,000 gallons of water are required to produce 1 gallon of milk.
• Roughly 634 gallons of water go into the production of one hamburger.
• Water scarcity affects more than 2.7 billion people for at least one month each year.

From the World Water Council:

• At 50 gallons per day, residential Europeans use about half of the water that residential Americans use.
• Residents of sub-Saharan Africa use only 2-5 gallons of water per day.

Illustrations are by London-based artist Sally Hancox.