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Chesapeake Bay

Activity 6 (Explore/Explain):

Rain, Pollution, and Watersheds

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Activity Overview

Activity Summary

In this activity, students learn about watersheds, and how pollution that is initially on the land gets into the water. They do this by making a simulated watershed from a crumpled piece of paper, and then “raining” on the watershed to wash pollution into waterways. Using their paper watersheds, students create definitions and apply their definitions to understanding the Chesapeake Bay watershed.

Activity Objectives & Materials

Approximate Time: 45 minutes​


  • Students will be able to define watershed, geosphere, and hydrosphere, and explain how they connect

  • Students will be able to describe how land-based nutrient pollution gets into the Chesapeake Bay

  • Students will know that some pollution gets into the Bay when it washes off the land



  • Plain paper (enough for all students.

  • Spray bottle(s) with water (one or more)

  • Water-soluble markers (see below for more details) – enough for all students

  • Paper towels for cleanup

  • Crumpled Paper Watershed teacher guide

  • Word wall words: watershed, geosphere, hydrosphere

  • Computer & projector


  • Watershed Notes sheet

Standards Connection

DCI: ESS3.C: Human Impacts on Earth Systems



Where would you find things like manure and fertilizer? What about other kinds of animal feces?

  • Use this warmup to help kids make the connection that these things are often found on farms, but they also are commonly found in other places too. Pet feces are a major contributor to pollution in Rock Creek Park (DC) and fertilizer from lawns is a problem in both urban and suburban communities. You can use the graphic from the previous activity to point out that “fertilizer” appears in both the agriculture sector and the stormwater sector.


1. Frame the Activity

Remind students that during the last activity, they shared some ideas about how pollution on the land gets into the water. For example, how manure from a farm or fertilizer from a lawn might get into the water. Today they’re going to figure out how that happens. Since a lot of the nitrogen pollution that is making the algae grow is coming from the land, figuring out how it gets into the water will provide some clues as to how to stop it.

Step 1

2. Crumped Paper Watershed

Follow the teacher guide below to lead this activity with students. Make sure to clean up before moving to the next part of the activity so the wet watersheds are not a distraction.

3. Defining the Chesapeake Bay Watershed

Ask students to think about the Chesapeake Bay watershed. Where do they think the Chesapeake Bay watershed is? (It is the area of land around the Chesapeake Bay. Put up a map of the Chesapeake Bay watershed like the one below and point out the area of land that is the Bay’s watershed.

Have students turn to a partner and talk about what they notice about the Chesapeake Bay watershed. When they are ready, have students share with the class. Use questions to help make sure they identify key takeaways:

  • The area of land around the Bay is much larger than the Bay itself.

  • The map has lots of rivers marked on it (because these rivers all flow into the Bay)

  • The watershed is in many states (6 + Washington, DC).

  • They live in the Chesapeake Bay watershed.


Chesapeake Bay watershed.png

Point at different parts of the map, and ask students “If it rains here, where will the water go?” Point to parts of the map that are in the watershed, and not in the watershed. You can be specific about where the water will go before it gets to the Bay (ex. it goes into the Susquehanna River and then into the Chesapeake Bay), but the key is that all the water in the Chesapeake Bay watershed goes to the Bay. Have students write the definition of the Chesapeake Bay watershed on their notes sheet: “All the land that drains its water into the Chesapeake Bay.”

Teacher Tip: Most of the land to the west of the Chesapeake Bay watershed is in the Mississippi River watershed. To the south is the North Carolina Sound watershed, to the east is the Delaware River and Atlantic Ocean watersheds, and to the north is mostly the Hudson River and Great Lakes watersheds.

Step 4

4. Defining Geosphere and Hydrosphere

Put the word “geosphere” on the word wall. Ask students if they know what the prefix “geo-“ means as in “geography” or “geology”. Use student responses to help them understand that geo- means Earth or land, and that the “geosphere” is the part of the Earth that is land. Ask students what part of the map represents the geosphere, and make sure that they understand it is the land.

Put up the word “hydrosphere” on the word wall. Ask students if they know what the prefix “hydro” means is in “hydrated” or “fire hydrant”. Use student responses to help them understand that hydro- means water, and that the “hydrosphere” is the part of the Earth that is made of water including rivers, lakes, and streams. Ask students what part of the map represents the hydrosphere, and make sure that they understand that it is the water (rivers, the Bay, the ocean, etc.).

NGSS Connection: The terms geosphere and hydrosphere (along with biosphere and atmosphere) are used extensively in NGSS, so brining these terms in here is designed to help students make the broader connection to Earth Science concepts. If you have already used these terms with students, this is a good time to make the connection to the atmosphere and the biosphere as well.

5. Defining the Watershed in Terms of Geosphere & Hydrosphere

Write or display the sentence: “A watershed map shows how the land connects to the water.” Ask students what this sentence means. Use discussion to help students realize that a watershed map (like the Chesapeake Bay map they were just looking at) shows what land will drain into what water. In the sentence, replace the words “land” and “water” with “geosphere” and “hydrosphere” and ask students if the sentence still makes sense. Tell them that scientists use these words “geosphere” and “hydrosphere” to define the land and the water, just like they use the word “atmosphere” to talk about everything in the air.

6. Formative Assessment

Have students explain in their own words how fertilizer from a lawn in Northwest Maryland could get all the way into the Chesapeake Bay.

  • Possible answer: When it rains, the fertilizer washes of the lawn and down into the storm drain. The storm drain connects to a local stream. That local stream connects to the Potomac River. The Potomac River connects to the Chesapeake Bay. So the fertilizer washes all the way from the lawn to the Bay.

Phenomenon Connection: If it feels useful, take a moment to help students make a connection back to the original phenomenon. They’re trying to figure out what made the algae grow so much. They know that it has something to do with nutrient pollution. The watershed helps them understand where the pollution is coming from.

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