Hello, my name is Barbara and this activity is called Water, Water Everywhere.
In this lesson students watch a brief demonstration on the distribution of the world’s water and then calculate how much water they use on a daily basis, both directly and indirectly. There is a middle and high school version of this lesson and it works well in Environmental Science, Social Studies, Geography and Math classes.
By the end of this lesson students will be able to:
- Describe the locations of global water resources and their accessibility for human use.
- Estimate their daily direct water use and compare that figure to actual use.
- Identify and graph the amount of direct water used by the class on common human activities.
- Distinguish between direct and indirect use of water.
The main concept we want students to take away is that although water covers roughly three-fourths of the Earth, only a small fraction is available for human consumption, and as the population grows, water efficiency and conservation become more important.
Part 1: Water Distribution
To set up Part 1, you will need the following materials:
- 1,000 mL graduated cylinder. Fill it with water and a couple of drops of blue food coloring. You may want to measure out the 1,000 ml of water and pour it into a pitcher to start.
- One large clear container labeled as oceans
- Four smaller containers labeled frozen, deep groundwater, other, and accessible fresh water. Clear plastic cups work well for this. Place some sand or soil in the deep groundwater cup before you start the activity.
- You will also need to measure and set aside 35 grams of salt.
- And you may want some smaller graduated cylinders, to help make the more precise measurements that will be needed.
When starting the demonstration with students, remind them that the water in the pitcher represents all of the Earth’s water and that we will be dividing it up into the containers representing different areas, so they can see how Earth’s water is distributed.
In the middle level version of the lesson, we provide a printable 10 by 10 grid that students can color in as you do the demonstration to track the water distribution data for themselves.
Now let me show you how it’s done!
You’ll first pour 971 mL into the large “oceans” container which represents the 97.1 percent of all water on Earth is held in our oceans.
Since ocean water is 3.5 percent saline, we are going to add the 35 grams of salt to the “oceans” container, to match the salinity of the water sample with the salinity of the oceans.
Next you will pour 22 mL into the “frozen” container, since 2.2% of all the water on Earth is frozen in glaciers and icecaps. You might want to measure this beforehand and stick it in the freezer to demonstrate to students that we cannot easily access this water, since it’s frozen.
Then, you will pour 3 mL into the “deep groundwater” container with the soil, since 0.3 percent of our water is deep within the surface of the Earth.
After that, you will pour 1 mL into the “other” container, since 0.1 percent of water is found in clouds, saltwater lakes, and other places that can’t be accessed.
Finally, pour the remaining 3 mL into the “accessible fresh water” container. This 0.3 percent is the freshwater that is easily accessed and not saline.
After the demonstration, we offer some questions you can ask students. For example, which of the containers represents water that is readily available for humans to use? Only the container marked “accessible fresh water” represents a readily available, and drinkable, water supply. The deep groundwater is also freshwater, but it is not readily available.
Then ask students to consider how we can ensure that the supply of water will be sufficient to meet the needs of our growing population? This question will nicely lead you into part two of the activity, where students conduct a water audit!
Part 2: Student Water Audit
In this part of the lesson students will consider if they are “typical water users” by estimating how much water they use a day, and reflecting on ways they might be wasting water.
You will want to display the “domestic uses of water” table provided in the lesson, so students can calculate their estimated daily water use. You also can have students calculate the class average here, to see how they compare to their classmates, and even extrapolate to the approximate water use of their city or town.
Additionally, students can reflect on ways they might be able to reduce the amount of water they are using.
Then ask students if they think this table represents all the water they are using? You might need to remind them there are many indirect ways they are consuming water, and display the table provided in the lesson. Have students consider how they might be able to cut back on their indirect uses of water: like eating less meat, or buying less new clothing. Some ways they might not have thought of before!
Finally, as an extension activity, you can have students implement some of their ideas for reducing water waste by conducting a quick study. They’ll first read their water meters for a week, for a baseline of their family’s water usage. Then they’ll implement a water conservation plan for the next week, and read the meter again to find how much water they were able to save.
And that’s Water, Water Everywhere. To dive deeper into some of the topics introduced in this lesson, check out our lessons Almighty Aquifers or Meat of the Matter. And for even more activities, visit our website PopulationEducation.org.
Thank you for watching and we hope to see you soon!