What’s Your Water Footprint?

We can help the Kaw by cutting down on the amount of water we use in everyday life. When we waste water more needs to be taken out of the river system, so less is available to the the creatures that live in the river. In addition, more sewage goes to wastewater treatment plants, which can make it harder to get it all cleaned up before it is sent back to the river. It takes energy to move all this water around, so we produce more pollution from electrical power plants. All of that reduces the amount and quality of water in the river.

If we want to figure out how to reduce the amount of water we use we need to have a plan. Let’s start by figuring out how much water we use for different activities around the house.

Determining Water Usage

The first step is to look at how much water a typical American uses in a year. That will give us something to compare our own water use to. Without some standard, we won’t know if the amount of water we use is high or low!

Research has shown that the average American uses about 90 gallons of water each day, which includes indoor activities like washing dishes and running the washing machine, as well as outdoor activities like watering the lawn.

Is the amount used by Americans higher or lower than in other countries? Research has shown that the average European uses 53 gallons per day, and the average Sub-Saharan citizen uses 5 gallons of water per day. That means we use 1.7 times as much water as Europeans and 18 times as much as people in Sub-Saharan Africa!

 

Which activities use the most water?

Again, we need something to compare to, so let’s look at an average American family and see what percent of the water they use is for outside activities and what percent is for indoor activities.

homewaterbudget

You can see in the pie graph above that roughly half of our water is used for outdoor activities like watering the lawn, washing the car, and filling swimming pools. The other half goes for activities inside the house like flushing the toilet, taking showers, washing dishes and clothes, brushing our teeth and washing our faces. (Washing your face and brushing your teeth are lumped into the category “faucet” in the chart above.)

To calculate the average amount of water used by an American family of four over one year you will have to multiply the amount we estimated for a single person in a day (90 gallons per person per day) by four people for 365 days in a year. What answer do you get?

We got an answer of 131,000, but to make things easier let’s round that off to 130,000. So if an average American family uses approximately 130,000 gallons of water each year, and if about half of that water is used for indoor activities, how many gallons of water are used inside the home each year?

If we divide our 130,000 by half we get 65,000 gallons/year of water used for indoor activities for a family of four.

These numbers are a helpful staring point, but how can we measure how much water you yourself use? Can you think of ways to measure the amount of water you use for different activities?

Here’s an example: To measure how much water you use to brush your teeth, you might do something like this:
Next time you brush your teeth, look at a clock and note how long you leave the water while you brush.
Now, take a measuring cup and put it under the faucet, turn on the the water, and let it run for the amount of time you noted in the first step. Once the time is up, turn off the water and note how much water was used.
So how did you do? Did the water fill the cup more than once during your “brushing time?” Can you think of ways to use less water while still getting your teeth clean?

Next, get a notebook or use the note cards in the Attachment section at the bottom of the page to keep track of how long you keep the water on when you take a shower, wash dishes by hand in the sink, brush your teeth and any other things that you do inside the house that uses water. Try to measure how much water you use for each activity.

For some activities it may be too hard to actually measure the amount of water you use. In this case, count how many times you do the activity or the amount of time you use for that activity and then use use average values for the amount of water from the chart below. To do this, count how many times a day your family uses the dish washer or washing machine (you may have to count how many times a week your family washes clothes since you don’t do it every day). Then multiply by the amount of water in the chart. For example, you can multiply the number of times you use the dishwasher each day by the average amount of water the dishwasher uses per load to get a daily total for the number of gallons used to wash dishes.

These average values were measured by the US Geological Survey:

BathA full tub is about 36 gallons
Shower2 gallons/minute; old shower heads use as much as 5 gallons/minute
Teeth BrushingLess than 1 gallon, especially if water is off during brushing; newer faucets use about 1 gallon/minute, older models can use over 2 gallons
Hand/Face Washing1 gallon
Face/Leg Shaving1 gallon
Dishwasher4 to 10 gallons/load, depending on the dishwasher's efficiency
Dishwashing by Hand20 gallons; newer faucets use about 2.2 gallons/minute, older ones use more
Clothes Washer25 gallons/load for newer washers, about 40 gallons/load for older models
Toilet Flush3 gallons; most all new toilets use 1.6 gallons/flush, but older ones use about 4 gallons
Drinking Water8 ounces/glass; if you drink the recommended 8 glasses per day that would be 1/2 gallon
Outdoor Watering5 to 10 gallons/minute

Now that you have a list of different daily or weekly activities that use water and an estimate of how much water they require, can you calculate what your personal Water Footprint is?

The average American family of four uses 65,000 gallons of water for indoor activities each year, do you use more or less? Can you think of ways to reduce the amount of water you use?

The best way to figure this out is to look at each individual activity (like washing your face or doing laundry) and come up with a strategy for each activity. For example, you may want to make sure the washing machine is completely full before you use it, since this is a more efficient way to use water. Or you may want to turn the water off while you brush your teeth. What other ideas can you think of? Test out your ideas and measure to determine the amount of water you save!