Water is arguably the most precious natural resource on the planet. Water keeps people alive, keeps crops growing, and keeps natures cycles flowing. Water isn’t just all around; it is also inside everyone, making up between 55 and 60 percent of the average person’s body weight! That is why it is important to learn about water: what it is, where it goes, and how to conserve it. Though about 70 percent of the Earth is covered in oceans, only two percent of Earths water is fresh and safe to drink. Water goes through a constant cycle: evaporating, entering the atmosphere, raining down, and evaporating again. When this cycle is disrupted by pollution, water can become unusable for a lifetime – or forever. That’s how water, which seems so abundant, can become a non-renewable resource.

Uses of Water

Everyone on Earth needs clean water to drink. On an average day, a persons body loses about 2.5 liters of water from sweat, breathing, and other causes. Doctors recommend drinking plenty of water to stay hydrated and healthy. Water is all around every day in the bathroom, and at parks, pools, and beaches. But millions of gallons of water a year go to other important uses. Agriculture uses water to irrigate crops, and aquaculture to maintain and harvest fish. Water is used to keep the equipment in thermoelectric plants cool, and can also create electrical power using dams. All kinds of industries use water: it’s indispensable for producing plastics, gasoline, metals, and other things the modern world depends on.

Water Science for Schools: All about water use from the U.S. Geological Survey.

Water Use in the United States: Detailed information from the National Atlas.

Irrigation and Water Use: Irrigation data from the Department of Agriculture.

Global Water Use Map: Part of the Worldmapper project of Sheffield University.

Electricity and Water Use: How water is used in the production of electricity.

Water Footprint: Analysis of water use for products, nations, and corporations.

Water Uses: Seven categories of water use described.

The Different Water Users: International water use compared.

Estimated Water Use in Aquaculture: Government assessment of water use in industries.

Recreational Waters: The World Health Organizations recreational waters info page.

Water Pollution

Water pollution comes in “point” and “non-point” forms. Point pollution comes from one source that is easy to identify and does not go very far, like a factory smokestack or waste drainage pipe. Non-point pollution affects water under the ground, in the water table. It spreads over a much wider area and may come from processes like irrigation and using fertilizers or poisons on lawns. Because water is always “on the go”, it can be hard to measure pollution precisely. Researchers can measure pollutants in a given quantity of water to estimate pollution in an area. They can also examine animals that live in the water to see how healthy they are. Everyone has a role to play in preventing water pollution by carefully disposing of wastes that might contaminate water. Lawmakers try to limit pollution with laws to make polluters clean up, and scientists try to make pollution easier to detect, remove, and prevent.

Guide to Water Pollution: Causes, treatment, prevention, and more.

Water Pollution: Water pollution facts and action in the state of California.

Introduction to Agricultural Water Pollution: Facts from the United Nations.

Nonpoint Source Water Pollution Management: Texas tackles non-point pollution.

Nitrate Contamination of Groundwater in the U.S.: Includes diagrams and maps.

FedCenter: Pollution-control and environment-related laws from the U.S. government.

Water Pollution Guide: Thorough resource from the Environmental Protection Agency.

Effects of Polluted Runoff: Including environmental and human impact of pollution.

Acid Rain: All about this common symptom of water cycle contamination by air.

Water Pollution Prevention: Guides to prevent water pollution in common situations.

Ways to Conserve

There are hundreds of ways to conserve water, and they all add up. Gallons of water can be lost every week through small leaks in faucets and pipes; make sure faucets are tight and leaky pipes get fixed. Toilets can easily be replaced with modern, low-flow models to save as much as 4,000 gallons of water per person a year! Low-flow shower heads may save up to 18,000 gallons per person each year. Shorten your showers and be sure not to run the water while washing dishes. Lawns should be watered only when necessary, and never on windy days, to accomplish more with less water. Remember, any time you wash or clean something, there is probably a way to do it with less water. Be creative, and you will help make sure there’s enough water to go around for a long time to come!

Household Water Use Calculator: Find ways to conserve water in the home.

Using and Saving Water: From the Environmental Protection Agency.

H2ouse.org: Room-by-room water conservation tips.

H2OConserve.org: More on calculating and reducing your water footprint.

World Water Assessment Program: United Nations conservation effort.

How to Conserve Water In Your Home and Yard: Four pages of great tips.

Why Conserve?: More about the importance of family water conservation.

Drip Accumulator: Find out how much water a leaking faucet wastes.

Water Conservation in the Home: Including collection and reuse of grey water.

Conservation at Home: Interactive clickable map of home conservation opportunities.