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Program Strange Days on Planet Earth


1. Introduce the vocabulary.
Introduce the vocabulary term watershed. Ask students what they think the term means. Display for students the satellite image of the Chesapeake Bay watershed. Then explain that a watershed is the land area from which surface runoff drains into a stream, channel, lake, reservoir, or other body of water. Tell students that people are either directly or indirectly connected to bodies of water, which connect to land.

2. Distribute the worksheet.
Distribute copies of the worksheet Components of a Watershed to each student. Have students label the watershed components using the words along the bottom of the diagram. (Answers: 1. River Source, 2. Upstream, 3. Downstream, 4. Main River, 5. Tributaries, 6. Floodplain, 7. Watershed Boundary, 8. Meanders, 9. Wetlands, 10. River Mouth)

3. Have students identify examples of pollution.
Tell students that people use water for agriculture, industry, manufacturing, power, transportation, and recreation. Explain the meaning of terms point source pollution and nonpoint source pollution. Show students the photo gallery and ask students to identify examples of each. Point sources include facilities such as sewage treatment plants and factory discharges; Nonpoint source pollution includes excess fertilizers from lawns and farms, oil from roads, overflows from city sewers, and animal waste.

4. Have students make a 3-D model of a watershed.
Divide students into small groups. Have each group begin by molding clay to represent mountains in a plastic or metal tray. Next, ask students to form the watershed by gradually leveling the clay so that it leads to the mouth of their river. Then, have them form river channels and coat with blue enamel paint and color the land with tempera paint. Finally, have students place construction paper figures on the model to simulate users of a river system, using the diagram in the worksheet as a guide. Let the model dry overnight.

5. Simulate the flow of water in a watershed.
The next day, have a volunteer from each group pour a slow, steady stream of water from the top of the mountain area. Have students watch how the "river" runs from its source to its mouth and orally describe it.

6. Have students apply their understanding to their own watershed.

Use the models to discuss your community's watershed. Ask:

  • Where are its boundaries?
  • What are the main sources of pollution in our watershed?
  • Who is impacted?
  • How can we ensure the watershed is a clean resource for the community?


Subjects & Disciplines

Learning Objectives

Students will:

  • define the terms
  • create a 3-dimensional model of a watershed
  • apply what they learned to their own community’s watershed

Teaching Approach

  • Learning-for-use

Teaching Methods

  • Discussions
  • Hands-on learning

National Standards, Principles, and Practices

National Geography Standards

Standard 1
How to use maps and other geographic representations, geospatial technologies, and spatial thinking to understand and communicate information
Standard 14
How human actions modify the physical environment

National Science Education Standards

(5-8) Standard F-2
Populations, resources, and environments


What You’ll Need

Materials You Provide

  • Blue enamel paint
  • Construction paper
  • Modeling clay
  • Plastic or metal trays
  • Scissors
  • Tempera paint
  • Toothpicks
  • Water

Background & Vocabulary

Background Information

People in a watershed are either directly or indirectly connected to bodies of water that connect to land.

Prior Knowledge

  • None

Recommended Prior Activities

  • None


Term Part of Speech Definition Encyclopedic Entry

nonpoint source pollution


toxic chemicals that enter a body of water from many sources.

point source pollution


pollution from a single, identifiable source.



entire river system or an area drained by a river and its tributaries.

Encyclopedic Entry: watershed

For Further Exploration



Media Credits

The audio, illustrations, photos, and videos are credited beneath the media asset, except for promotional images, which generally link to another page that contains the media credit. The Rights Holder for media is the person or group credited.


Fred H. Walk


Christina Riska, National Geographic Society
Emmy Scammahorn, National Geographic Society
Alice Manning, National Geographic Society
Kim Hulse, National Geographic Society

Expert Reviewer

Tierney Thys


Special thanks to Jeff Dow and Rita Bunzel


adapted from National Geographic “Strange Days on Planet Earth Educator Activity Guide”

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