Conservation
of Resources
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Lesson 2
Conservation of Water
Introduction | Invitation | Exploration | Explanation | Taking Action | Conclusion
In this lesson you will learn about the uniqueness and ultimate importance of water in our world. You will also discuss why we sometimes have water shortage, and what we can do as individuals to conserve water.
Objectives
Upon completion of this lesson, you should be able to discuss the factors that are contributing to our global water shortage and make practical suggestions that can be used by you and others to conserve water.
Materials
- 1 small apple per group
- plastic knife
- paper plate
- towel
From your teacher,
one person from each lab group should get an apple, a
plastic knife, and paper plate or towel.
Cut the apple into
quarters. Hold 3/4 in one hand and 1/4 in the other.
Discuss in your group what you think the 3/4
represents.
It is comforting at first to know that about 75% of our planet consists of the most biologically important molecule on the planet. But we will soon see there's more to the story.
Of the 3 remaining quarters that represent water, set aside two of them to represent the vast regions (over 50%) of the ocean that are unable to support many living things due to a lack of life-supporting nutrients. Cut the remaining quarter in half and this 1/8th of the ocean water represents the productive zones of ocean that are usually found along the equator and the western margins of the continents. In these areas, strong currents cause an upwelling of water which brings food and nutrients to the surface. These nutrients support a large number and variety of plants and animals in these areas.
However, these organisms are concentrated in the photic zone, the top 100 meters of the ocean where light can penetrate to a sigificant degree (at 100 meters the amount of light is only 1% of what it is at the surface). Since this light is necessary to support photosynthesis, almost all ocean life is concentrated in in this shallow photic zone. So don't fish too deep when you're deep sea fishing. To approximate the photic zone, peel off the skin from the 1/8th of your apple that remains.
If this seems like a tiny piece, it is a giant amount compared to the amount of fresh water that we have on the planet. Only 3% of the water on our big green earth is fresh and most of that is frozen in the polar icecaps. Only around 1/1000th of our total water supply is found in the lakes, rivers and groundwater which we depend on for our water needs. From any remaining piece of the apple, carefully cut out what you estimate to be 1/1000th of the apple. Kind of makes you thirsty, doesn't it?
As a group, take a few minutes to discuss your feelings regarding the amount of freshwater available to us on the planet.
Internet Exploration
As
we have seen, the amount of freshwater on the planet is
limited. To make matters worse, a great deal of this
water has been polluted in one way or another. For
example, some scientists estimate that over 40% of our
ground water has been contaminated by industrial,
agricultural, and even household pollution. To find
out more about this problem, check out the following links
and then answer the questions below.
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Questions:
1. What percentage of streams, lakes, and wetlands are currently not clean enough to safely swim or fish in?
2. List a few of the leading pollutants that are being dumped into these waters.
3. How many acres of wetlands are being lost per year in the U.S. ?
4. Describe
how water run-off contributes to our water pollution
problems.
Top
Explanation
While it is important to consider how much water we are polluting, it is also important to cut down on our daily consumption of water. The average american uses about 500 liters of water a day and although most of it can be recycled, it must be treated and disinfected before it can return to our water supply. This requires time, resources, and money, all of which tend to be in short supply. To get some idea of how much water we waste each day, let's see how much water we consume just during the simple process of washing our hands.
Procedure:
Go to a sink and turn on the faucet like you normally do when washing your hands. Collect the water for the first 10 seconds in a bucket or container. Measure how many liters of water you have in the bucket using old plastic bottles or some other type of measuring device. Record volume of water in liters. Now, with someone keeping track of the time, continue to wash your hands for as long as you think you normally wash. Record this time in seconds and plug it into the equation below.
To estimate the total water used plug in the following formula:
Volume used
= X
liters
10
secs
Total # of secs
Cross multiply and divide to obtain the total volume of water that you used to wash your hands.
Next, washyour hands again, but this time turn the water off after wetting your hands and use the water only when you need to the rest of the way. During this process have someone measure the total number of seconds that you were actually running the water. Plug the new total number of seconds into the above equation and solve for X to see how much water you saved. A little conservation by each of us makes a big difference. A little effort on our part can save a lot of water.
Taking Action
Around the world, some communities are taking important steps to conserve water and lessen their environmental impact. For example, in the city of Winnepeg Canada residents have developed and started a plan to conserve water on a daily basis. As part of the plan, they provide a list of several practical actions that can be made to save water. Check out the link below to see what suggestions they have to offer.
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In order to make a difference in our own place and time, it is time to tour your school or worksite and find places where water may be being wasted. Make a list of those places and brainstorm together to come up with ideas of how water might better be conserved. Make a nice copy of this list and the suggestions that you've developed and present this list to your principal or director. Hopefully, you can work together to make some positive conservation changes.
Finally, each one of us should consider which of these tips we can use personally to conserve water. With this in mind, develop your own list of actions that you intend to take in order to do your part in the conservation of this precious resource. Finally, if time permits in your class, pick out one key action that can be taken and develop a picture, poem, bumper sticker, or a commmecial to promote this action as a worthwhile environmental endeavor.
Conclusion
In this lesson we discussed the factors that are contributing to our global water shortage and we outlined practical ways in which we can act to conserve water and help improve this problem.