In order for students to understand why water conservation matters, it is critical that educators teach beyond the water cycle to help students understand that how and why we use water is complex.
Download a full (PDF) version of this presentation and teachers notes.
Is There More To Water Than the Water Cycle? Yes.
Teaching about water often means teaching about the water cycle or water pollution and can often be somewhat limited, but water education incorporates hydrology and aquatic biology, natural resource management and climate science and even social sciences and the arts.
Educators who want to go beyond the water cycle might not know where to start. One approach that is very engaging for students is the water footprint, a concept developed to account for and analyze the ways humans use, overuse and generally depend on water.
As humans, we use water in many ways. How many uses can you identify in this illustration?
What is a Water Footprint?
Your water footprint includes the water you use from a tap plus the “virtual water” used to produce the food you eat, the products you buy and the energy you use. This virtual water makes up most of your water footprint.
With increasing strain on water resources, it’s important to learn how you use water in different parts of your life.
Water footprints determine the volume of water consumed, evaporated and polluted to make items or conduct a service. They can be split into three corresponding categories:
- Blue Water Footprint: The amount of surface water and groundwater required (evaporated or used directly) to produce an item.
- Green Water Footprint: The amount of rainwater required (evaporated or used directly) to make an item.
- Grey Water Footprint: The amount of freshwater required to dilute the wastewater generated in manufacturing, in order to maintain water quality, as determined by state and local standards.
How is Water Distributed on Planet Earth?
It is crucial to understand how we use water because the amount of freshwater on Planet Earth is limited.
This might be surprising because 70 percent of the Earth is covered in water. In reality, less than 3 percent of that is freshwater (the rest is too salty for our uses).
Unfortunately, most of that freshwater is unavailable for our use because it is frozen in glaciers or snow or is trapped underground in unavailable aquifers.
The small amount that is accessible – a whopping 1.2 percent! – is spread out amongst rivers, lakes and other water bodies.
This is all the water that living organisms have available to meet our needs.
Look more closely at that “Other” section that is available to us. It’s clear that our freshwater sources can easily become overused or even scarce.
How Do We Use Water?
All water uses fall into types of water use: direct and indirect (or virtual).
What is “Direct Water Use?”
“Direct” water use includes water from a tap for things like flushing the toilet, washing clothes and watering the lawn.
A breakdown of our indoor water use in the United States reveals where we use the most water. Are you surprised by these results?
Did you know?
Gallon for gallon, toilets are often the biggest indoor water users in the United States, and most of the time, that water has been treated to drinking water standards!
What is “Indirect” or “Virtual” Water Use?
Indirect or “virtual” water use, also called “embedded water,” is the water “hidden” in the products, services and processes you buy and use every day, like crop irrigation, power production and consumer goods manufacturing.
In the United States, agricultural water use is one of the big ones. This is because most animals are fed grain and other feed types from irrigated crops, and it takes a lot of water to keep all those crops productive.
Your diet uses the most water and is the biggest indicator of what your personal water footprint will be, especially if you eat animal products.
The water footprints of some common foods are shown to the left.
In general, we use water for three main purposes which often compete with each other.
Three General Categories of Water Use:
- Domestic;
- Agricultural; and
- Industrial.
In the United States, we use water in the following ways:
- Public supply and domestic use;
- Industrial uses: thermoelectric power production, manufacturing and mining; and
- Agricultural uses: irrigation, livestock production and aquaculture.
The United States isn’t alone in its water use, though. Worldwide, in the last century, the rate of water use has increased at twice the population growth rate and domestic water use grew over 600 percent since the 1960s.
What is Water Security?
The problem with increasing worldwide water use is that water isn’t equally distributed and, in some places, it is scarce. There are many places around the planet that lack enough water to meet even basic needs. They lack what is known as water security.
The United Nations defines water security as “The capacity of a population to safeguard sustainable access to adequate quantities of acceptable quality water for sustaining livelihoods, human well-being and socio-economic development, for ensuring protection against water-borne pollution and water-related disasters and for preserving ecosystems in a climate of peace and political stability.”
In short, everyone has enough water to meet their needs sustainably.
Of all the countries in the world, the United States is Number 3 on the list of top water users. All countries use water for similar activities but in varying amounts and percentages, for things like household (or domestic) use, food and agricultural use and industrial uses (for energy and consumer goods production).
Places that struggle with water insecurity often also struggle with droughts that leave fields that can’t be farmed and communities that can’t meet their water needs for drinking and sanitation sustainably.
Unfortunately, any place can have a drought, and climate change is making them longer and more intense.
This is why it’s so important for teachers and students alike to know and understand their own water use.
Why should you go beyond the water cycle and teach your students about water footprints?
Do you and your students know how much water you use each day?
Our Water Footprint Calculator can help you and your students find your personal daily water footprints. In fact, almost 2 million users have already gotten their water footprints, and most of them were students.
You can also find resources to help you teach your students all about water footprints and how to save water.
Check out our standards-aligned lesson plans, created for both middle- and high-school grade bands.
These free, downloadable, engaging lessons provide a range of teaching strategies and real-world exercises that help teachers meet curriculum requirements. Some of the activities are interactive and get kids thinking about the steps they can take to use less water.
We also offer information for students about careers in water, the latest research and reports on water footprints and over 100 water saving tips.
Find out more about the Water Footprint Calculator.
