ENVIRONMENT
Watch these “pictures of practice” to see how students and teachers understand water pollution and water purification.

Photograph courtesy Shannon Switzer, National Geographic
Discussion Ideas
- “We often don’t think about where our water comes from,” says Steve Fleischli, director and senior attorney for the Natural Resources Defense Council (NRDC) Water Program in Los Angeles, in the Nat Geo News article. “Does it come from a nearby river or a lake, intermittent streams, isolated wetlands, or an aquifer? Yes, you may have a water treatment plant, but if your water source is not protected, people face a real risk.” Where is your watershed—where does your tap water come from?
- Find your watershed with this handy Surf Your Watershed feature from the EPA. All you need is your ZIP code.
- Read about Nat Geo Explorer Shannon Switzer’s exploration of the San Dieguito river in her article “Walking the Watershed.” Shannon gives a great outline of how communities use the river—and how they pollute it.
- Read “I am a citizen of the . . . Anacostia River?” by Sean, one of my favorite coworkers and fellow Anacostian. Sean gives some great tips about appreciating your watershed.
- Navigating watersheds isn’t always easy. Aqueducts, for example, can carry water hundreds and even thousands of miles from their natural outflow. Watch this “picture of practice” to better understand how sixth-graders in San Diego learn how water (from Northern California!) gets to their homes, schools, and hospitals.
- Once you find your watershed, think about how your community uses its freshwater.
- The USGS Water Science School is a great place to start to think about water use. Here’s a list of categories of use, in order from largest- to smallest-withdrawal of freshwater (either groundwater or surface water).
- Electricity. The largest freshwater use is for thermoelectric power. (Bet you didn’t see that one coming.) Water for thermoelectric power is used in generating electricity with steam-driven turbine generators.
- Irrigation. Almost 60 percent of all the world’s freshwater withdrawals go towards irrigation uses.
- Public Supply. These are government or privately-run facilities that withdraw water from rivers, lakes, reservoirs, and wells and then deliver it to our homes, businesses, and schools. The majority of the population (about 86 percent) of the United States nowadays gets their water in this manner.
- Industry. Probably every manufactured product uses water during some part of the production process.
- Aquaculture. Aquaculture water use is water associated with raising creatures that live in water—such as fish and shellfish—for food, restoration, conservation, or sport.
- Domestic Use. Domestic water use is water used for indoor and outdoor household purposes—all the things you do at home: drinking, preparing food, bathing, washing clothes and dishes, brushing your teeth, watering the yard and garden, and even washing the dog.
- Mining. Mining water use is water used for the extraction of minerals that may be in the form of solids, such as coal, iron, sand, and gravel; liquids, such as crude petroleum; and gases, such as natural gas. The category includes quarrying, milling (crushing, screening, washing, and flotation of mined materials), re-injecting extracted water for secondary oil recovery, and other operations associated with mining activities.
- Livestock. Livestock water use is water associated with livestock watering, feedlots, dairy operations, and other on-farm needs.
- The USGS Water Science School is a great place to start to think about water use. Here’s a list of categories of use, in order from largest- to smallest-withdrawal of freshwater (either groundwater or surface water).
- The Nat Geo News article lists several threats to different watersheds—from coal slurry in the Appalachians to hurricanes along the Gulf Coast to drought in my hometown of Salinas, California. Consider the industry, climate, and population in your watershed. What are some threats to your own water supply?
- Read through our terrific activity “In Your Watershed” for a great way to identify and analyze your watershed. In addition to working through the definition of a watershed and how to identify local water sources, the activity outlines how to create a 3-D model of your watershed (including point-source and nonpoint-source pollution). The model helps identify what local communities are most impacted by pollution, water shortages, or other threats to the watershed.
- What are individuals, communities, governments, and businesses doing to help ensure clean water for local communities?
- Individual. We all can start by measuring our own “water footprint” and working to reduce it.
- Individual. The Geography Collective has some great “missions” about understanding freshwater and how we use it—from flash-dancing to calculating your watershed’s animal-to-garbage ratio.
- Community: In 2010, Geography Awareness Week focused on freshwater and local watershed health. Look through these resources to understand how communities can improve the health and longevity of their watershed. The collection includes everything from a freshwater quiz to answers about the water-treatment process to a suggested movie list. (Chinatown isn’t on it! There is never not a great time to re-watch that movie: water, corruption of every sort, and the last great era of American filmmaking. Watch Chinatown.)
- Community: If you’re a teacher, read through our Environmental Literacy Guide on freshwater. (Yes, the one with the big saltwater lake on the cover. Way to go, guys.) The guide provides a clear outline of how different communities interact with freshwater, including analysis of biodiversity, pollution, industry, agriculture, and river management.
- Government: Read the very first article ever published on our website, “From Toilet to Tap.” The article describes how the Orange County (California) Water District’s Groundwater Replenishment System (GWRS) recycles sewage.
- Government: Read through our profile of Nat Geo’s Freshwater Fellow, Sandra Postel. She outlines how different national governments are dealing with water crises, from Turkey to Vietnam. Sandra’s best advice for getting involved in freshwater conservation? “Know your watershed!”