THE WATER CYCLE
Did you know that the water you drank this morning might have been the same water a dinosaur drank millions of years ago? Or it may have been the same water that supported Columbus' ships on the sea. There is the same amount of water on Earth today as there has always been. The water keeps moving around in an endless cycle called the water cycle.
Water itself is the only substance that exists in liquid, gas and solid form - the keys to the water cycle. Here's how the cycle works:
Water evaporates from oceans, rivers and lakes (water in its liquid form) and rises into the atmosphere (water in its gas form) where it condenses to form clouds. Precipitation then falls to the earth in the form of rain (water in its liquid) or snow (water in its solid form) where it flows into oceans, rivers and lakes and the process begins again.
THE EARTH'S WATER SUPPLY
Of all the water on Earth, only a small amount is available for us to use. It's true!
97.2% of the Earth's water supply is salt water.
Only 2.8% is fresh water!
Of the total supply of water on Earth,
- 0.6% is groundwater (we can use some of this water)
- 0.01% is in lakes and streams (we can use some of this water)
- 2.2% is in glaciers and icecaps
- 0.001% is water vapor
WHAT'S AN ACRE-FOOT?
In the water world, water is commonly measured in acre-feet. But what is an acre-foot? One acre-foot of water can fill one acre of land, approximately the size of a football field, 1 foot deep. An acre-foot contains 325,900 gallons of water, and can supply the annual indoor and outdoor needs of one to two urban households.
HOW MUCH WATER DOES IT TAKE TO...
- Brush your teeth? - 2 to 5 gallons
- Wash the car? - 50 gallons
- Use the dishwasher? - 8 to 15 gallons
- Flush the toilet? - 1.5 to 4 gallons (each flush)
- Take a shower or bath? - 17 to 24 gallons
- Run the washing machine? - 35 to 50 gallons (each load)
Indoors, most of the water a family uses is in the bathroom. Saving water is important. In the bathroom, the easiest way to save water is to shut off the faucet while you brush your teeth or take shorter showers and not using the toilet to flush trash. Installing low-flush toilets and low-flow showerheads can also help save lots of water. An ultra-low-flush toilet uses just 1.5 gallons per flush compared to 4 gallons per flush for a traditional toilet.
In the kitchen make sure you wash only full loads in the dishwasher. And if you need a new machine, ask your parents to take a look at some of the water-efficient models that can reduce water usage to 6 gallons per load. New washing machines also offer significant water savings, using up to 40 percent less water per load than older machines, and they can save energy too!
Check with your local water supplier to see if they will conduct a water audit of your home to see where and how you can save water. Also, check to see if they offer rebates on the purchase of water-efficient appliances - some do.
Learn more about how to reduce water use below.
WATER POLLUTION "NO-KNOWS"
Most people think water pollution comes directly from a factory or other known source, a type of pollution known as "point source pollution." Because of laws passed in the 1970s, most of those sources of pollution have cleaned up their act. Today, the biggest source of pollution is us - you and me. This type of pollution is known as "nonpoint source pollution" because it can't be traced to one single source; we can't tell how much pollution is coming from where.
Types of nonpoint pollution that ultimately end up in our waterways include used oil poured into storm drains, soil washed from construction sites, grease from restaurants, paint brushes cleaned in the street, or fertilizer and pesticides washed off farm fields and city lawns. That's why it is so important for all of us to clean up our act and learn how to prevent such pollution.
The Foundation's "No-Know Game" http://www.watereducation.org/store/itemdetail.asp?id=82 can help you learn about bad pollution practices and how to prevent pollution. Consider these two examples from Your Garage:
"Henry dumps the oil he drains from his car onto the ground in the backyard, which drains into the Dirty Old River. The oil from 1 engine can produce an oil slick of 8 acres on the river! That's a No-Know. Go back 2 squares."
"Henrietta recycles the oil and antifreeze by placing them separately in clean plastic containers and taking them to the recycling center and local gas station. Put-'er-there, Pard!"
Once you play this game, you'll never be able to say, "Oh no! I didn't know," again.