This lesson was developed by Dr. Cynthia Annett. There is a notebook in the attachment section that can be printed out on 4x6 cards and bound with book rings. It can be used in conjunction with Caring For The Kaw Part 1: What's Your Water Footprint?
On top of that, running all of the pumps required to move water around takes energy. Producing electricity requires the use of water and has an impact on the river. The more water you waste the more electricity you waste-- and that's a double whammy for the river.
Comparing the amount of water used by the average American family to families in different parts of the world is startling-- we use many times as much water as a family in Sub-Saharan Africa, and we use much more water even than European families in industrialized countries. That's why it is important to figure out what we are doing-- where does all the water go?
Activity: Students will make a rough calculation of how much water they use for different activities. We will use a set of approximations to simplify calculations. Students can use different tactics for measuring the amount of water that comes out of a faucet or hose, for example by filling a pail or jar and measuring the total volume filled over a specified period of time (this gives a rate such as cups/minute or gallons/hour). The student page activity uses a measuring cup in the bathroom sink, with the student filling and emptying it multiple times to drive home the idea that a simple activity can waste a lot of water if it is not thought through (turning off the faucet while you brush your teeth is a good example of an easy way to reduce your Water Footprint).
If you don't want to go through all of the measurements and calculations you can provide students with an online Water Footprint Calculator that is very easy to use. This will give general, average values. Please notice that the standard values that they provide for comparison are for Canadian families (you can set up the calculator with US in the dropdown, but the information for comparison remains the same). The comparison is also in liters, so you will have to convert to gallons to compare Canadians and Americans. We provide a comparison on the activity page with an American family of 4 in gallons.
Some activities will be easy to measure and completely under the student's control (like how long they shower or whether they turn the water off when they brush their teeth). Others will be harder to measure directly and may include other family members (like washing clothes). We provide average data that can be used for activities that can't be easily measured. They are given a simple pie chart with a generalized water budget (the data are the percent of total water use devoted to each activity) and a chart with the amount of water typically used in different activities. These materials can help to calculate a total water budget for a family.
Try to have the students record as much data as they can on all of the different activities. For example, they may not be able to measure the amount of water their washing machine uses, but they can record the number of times during a week that their family washes clothes. They can also check to see if the washing machine is full or partially empty. They can then use the chart to calculate the approximate amount of water used by each of these activities. To this they can add in the amount of water they measured for their shower and grooming activities (washing hands and face, brushing teeth, etc.). All of this can go into their water budget calculations. We provide note cards to help organize data and to give prompts for calculations, but if you prefer you can have students make their own notebooks to record their observations (this would be preferable for older students). If you use the note cards you can punch holes in them and bind them with book rings to form a notebook.
We focus on indoor activities so that students who live in apartments or who do our exercise during the winter can make all of the suggested measurements. If you are doing this activity during the summer and have a yard of your own you can easily adapt the activities to include estimates of outdoor water use.
If you have a Google Account (you must be over 14, so younger children will need a parent or teacher to help) you can use Google Documents-Spreadsheets to make very nice graphs and tables. Go to https://docs.google.com for more information. A water budget (Water Footprint in the currently fashionable terminology) can be graphed as bar graphs or pie charts to quickly show which activities use the greatest amount of water. When you make the graphs, make sure everything is in the same units such as cups per minute, gallons per hour, etc. or in percent of the total. You may have to convert units to standardize the data.
The students should then come up with suggestions for how they can reduce their water use. By understanding which activities use the greatest amount of water, and which activities are under their control, this becomes more manageable. Their plan can include things like turning off the water while they wash dishes or brush their teeth, using more efficient faucets and shower heads (if their parents are able to make changes like this), making sure the washing machine and dishwasher are completely full before washing the load, and getting a spray head for the hose that will allow them to stop the water when they do not need it while washing the car (an inexpensive way to cut outdoor water use). You can find more suggestions at the EPA and USGS websites below.
If you wish to expand this activity, the USGS website provides information on how much water is used to grow the ingredients for a hamburger and other interesting kid friendly information.
ResourcesEPA Water Efficiency Resources
EPA Water Sense for Kids
USGS Water Science