Standards: MS-ESS2-4, MS-LS2-3

Purpose: This demonstration uses simple materials to create a living example of the water cycle, so students can observe the ways that water, the sun, and gravity interact to drive the movement of water around our planet.

Time needed: 15-20 mins

Materials:  a large bowl, a pitcher or bucket, a sheet of clear plastic wrap, a large rubber band or string, water, dry ceramic coffee mug or heavy cup, ice cube

ENGAGE: 

Ask students to work with a partner to recall the steps of the water cycle (precipitation, evaporation, etc.). They can do this orally, on a whiteboard, or scratch paper. Then, tell them we’re going to create a model of the water cycle right here at school.

EXPLORE:

1. Put the bowl in a sunny place outside. (NOTE: If you don’t have sunny weather, you can also do this experiment inside using a heat lamp.)

2. Using the pitcher or bucket, pour water into the bowl until it is about ¼ full. Tell students that this bowl full of water represents the ocean.

3. Place the mug in the center of the bowl. Be careful not to splash any water into it. Tell students that this mug represents a lake.

4. Cover the top of the bowl tightly with the plastic wrap. Place an ice cube on top. The plastic wrap will represent the atmosphere and the ice cube represents cold, gathered molecules - clouds!

5. Put the rubber band or string around the top of the bowl to hold the plastic wrap in place.

6. Watch the bowl for 3-5 minutes to see what happens. (The length of time this takes will depend on the brightness of the sun/heat lamp on the bowl.)

EXPLAIN:

The condensation that forms on the inside of the plastic wrap will slowly become larger drops of water that will begin to drip. (You can speed up the dripping by carefully moving the bowl – don't splash! – into the shade.) Explain to students that the droplets on the plastic wrap represent the water that precipitates from the clouds as rain.

Carefully peel back the plastic. Is the coffee mug still empty? Water from the "ocean" of water in the bowl evaporated. It condensed to form misty "clouds" on the plastic wrap. When the clouds became saturated it "rained" into the mug (lake), representing precipitation.

EXPAND: 

Ask students to record, in their Journals, a sketch of this experiment. Instruct them to include all of the main elements (bowl, water, mug, plastic, sun) and to use arrows and notations to show what happened and what steps of the water cycle it represented.

EVALUATE: 

Can students name the parts of the water cycle and describe where they occur and how they connect to each other? Can they identify energy from the sun and gravity as the two factors that drive the movement of water through the cycle.

Purpose: This demonstration uses simple materials to create a living example of the water cycle, so students can observe the ways that water and the sun interact to drive the movement of water around our planet.

Time needed: 15-20 mins

Materials:  a large bowl, a pitcher or bucket, a sheet of clear plastic wrap, a large rubber band or string, water, dry ceramic coffee mug or heavy cup, ice cube

Instructions:

ENGAGE: Briefly review the steps of the water cycle with your students (precipitation, evaporation, etc.). Then, tell them we’re going to create a model of the water cycle right here at school.

EXPLORE:

Step 1) Put the bowl in a sunny place outside. (NOTE: If you don’t have sunny weather, you can also do this experiment inside using a heat lamp.)

Step 2) Using the pitcher or bucket, pour water into the bowl until it is about ¼ full. Tell students that this bowl full of water represents the ocean.

Step 3) Place the mug in the center of the bowl. Be careful not to splash any water into it. Tell students that this mug represents a lake.

Step 4) Cover the top of the bowl tightly with the plastic wrap. Place an ice cube on top. The plastic wrap will represent the atmosphere and the ice cube represents cold, gathered molecules - clouds!

Step 5) Put the rubber band or string around the top of the bowl to hold the plastic wrap in place.

Watch the bowl for 3-5 minutes to see what happens. (The length of time this takes will depend on the brightness of the sun/heat lamp on the bowl.)

EXPLAIN:

The condensation that forms on the inside of the plastic wrap will slowly become larger drops of water that will begin to drip. (You can speed up the dripping by carefully moving the bowl – don't splash! – into the shade.) Explain to students that the droplets on the plastic wrap represent the water that precipitates from the clouds as rain.

Carefully peel back the plastic. Is the coffee mug still empty? Water from the "ocean" of water in the bowl evaporated. It condensed to form misty "clouds" on the plastic wrap. When the clouds became saturated it "rained" into the mug (lake), representing precipitation.

EXPAND: Ask students to record, in their Journals, a sketch of this experiment. Instruct them to include all of the main elements (bowl, water, mug, plastic, sun) and to use arrows and notations to show what happened and what steps of the water cycle it represented.

EVALUATE: Can students name the parts of the water cycle and describe where they occur and how they connect to each other?

Standards: MS-ESS3-3, MS-ESS2-2*

Purpose: This activity, which can be done as a small group or as a teacher demonstration, builds on the previous simple model of a watershed which helped show how water droplets flow and how the shape of the land helps collect water. This extension can be down right after the Entry Event or later in the unit. This time, by adding materials such as food coloring or beads to their landscapes, students will observe how water carries pollutants through the land and sea. Because this extension is more messy, it is recommended to build your model on a tray or other protective surface for easier clean up.

Time needed: 45-50 mins

Materials (per pair of students): 1 tray (If making a large model, you can put a larger sheet of plastic down first as a base or do it outside.),1 sheet of clear or light-colored plastic (e.g., shower curtain, or cut-open shopping bag), 2 spray bottles, 2 small squeeze bottles of food coloring, 1 squeeze bottle of cooking oil, dried spices, towels for cleaning up spills, 4-6 various sized containers (e.g., 12-oz. cups or soda bottles, coffee can, soup or soda can, paper cup, yogurt container, etc.)  cake sprinkles, pieces of confetti/beads or other small objects, sponges (if doing the Elaborate activity).

ENGAGE: 

1. 1. Remind students of their models in the Entry Event. Tell them that they are going to be using a similar model today.

   2. Hand out the materials listed, except for the cooking oil, food coloring, spices, cake sprinkles and spray bottles.

   3. Have students build their own watershed using the tray to build on, and the containers to represent mountains and hills; the flat areas are the valleys, lakes, and rivers in between. Be sure they include a “land” section and flat “ocean” section adjoining the land.

   4. Instruct students to lay the plastic sheet over their landscape, gently pressing it down between the “mountains” to create low spaces in the “valleys” and “rivers”.

   5. Like before, hand out spray bottles, and tell kids to take turns being "clouds" and observers. Use the spray bottles to make it “rain” on their watersheds.

EXPLORE:

1. Next, students will experiment with how pollutants might travel through their watersheds. Ask them to brainstorm what kinds of pollutants we might find in the environment, and write these on the board. Then show them the bottles of cooking oil, food coloring, glitter, and other materials, and explain how these will represent pollutants in the environment such as motor oil, chemicals, plastics, etc. Be sure students understand they should place the materials all over their models.

2. Distribute the bottles of oil (1 per group). Tell students to SLOWLY AND CAREFULLY squeeze a few drops of oil on different areas of the watershed, including the mountains and valleys; this represents motor oil that can leak out of cars.

3. Distribute the bottles of food coloring (1 per group). Tell students to again SLOWLY AND CAREFULLY squeeze a few drops of food coloring on different areas of the landscape, including the mountains and valleys; this represents toxic chemicals that could escape from factories, houses, etc. 

4. Distribute the “pollutant” materials (plastic wrappers, bottle caps, soda bottles, etc.) Have students again sprinkle these across their watershed.

5. Tell students that now they will again make it rain to observe how these pollutants travel in their watershed. Have students use the spray bottles to liberally “rain” across their watershed.

EXPLAIN:

Ask students to share where and how the pollutants traveled in their landscape. They should conclude that both the water and the pollutants tend to flow from the highest to the lowest points on the watershed, and collect in the valleys, lakes and rivers, eventually making their way to the ocean. This downward migration is due to gravity. They may also make the connection that the faster the water travels the more it can carry, and that when it slows down, the sediments and pollutants get dropped.

ELABORATE:

Pass out the sponges. Have the students place the sponges where they might find an estuary, and cut up a sponge to place along one of their rivers. Then have them compare what happens to the polluted stream that has a healthy riparian zone and estuary, with one that does not.

EVALUATE: 

Have students design a method for monitoring and minimizing human impacts within their watershed. They could choose to focus on the watershed as a whole, a particular area they identified in the Explore Your Watershed investigation, or the area around your school. In the product, students should be able to explain what a watershed is, including the various parts such as land, water, rainfall, and pollutants, and explain how their method would improve their watershed. Optional extension: have students share their ideas in a project fair, or pitch their ideas to a local/school leader.

Standards: MS-ESS2-2, MS-ESS2-4, MS-LS2-3

Purpose: This activity demonstrates the relationship between precipitation, vegetation, and soil loss, allowing students to observe water erosion in action and guiding them to understand the need to protect waterways and vegetation, especially in riparian zones.

Time needed: 20-30 mins to prepare bottles; 1-2 days to see results

Materials: Three large identical plastic bottles, such as 1 liter soda bottles; small gardening trowel; string; hole puncher; three clear plastic cups, strong scissors, adhesive glue, pan or bucket; large measuring cup; flat surface to glue experiment onto, such as a large piece of cardboard or plywood.

Prior preparation: Make sure bottles are emptied and cleaned. Lay each bottle down on its side. Cut the top half of the bottle off, horizontally. Attach them to a flat surface using glue with the top ends protruding a few inches off. Then, punch two holes in the sides of each plastic cup towards the top. Attach these with string to the tops of each bottle so they are hanging below the opening. Visit https://www.lifeisagarden.co.za/soil-erosion-experiment/   for some excellent pictures and further explanation of this process. 

ENGAGE: 

Explain how these bottles are going to represent different parts of a watershed. We are going to place different types of soil into each bottle, add water representing rainfall, and then see which type of soil holds the most water.

EXPLORE:

1. Go out to the schoolyard and use your trowel to collect three samples, each of a size and shape that will fit in the bottles: 1. A patch of grass, including the grass, soil, and roots; 2. A patch of soil containing dead plant matter such as twigs and leaves; 3. A patch of dirt without any plant matter, such as clay.

2. Back in the classroom, place each of the three samples into the bottles, packing them tightly into the bottle. Tell students: these represent a place with lots of living vegetation; a place with some vegetation; and a place with no plant life.

3. Fill the measuring cup with water and pour into the first bottle over the vegetation/dirt - just enough so that it begins to run out of the dirt. Repeat with the same amount of water for the other two bottles. This represents rainfall.

4. Now we wait! Tell students our mini ecosystems need some time to absorb the rain and we’ll check back tomorrow. 

EXPLAIN: 

The next day, observe the plastic cups that have collected water runoff from each bottle. You should find that the bottle with the grass has lost the least water, while the bottle with no vegetation has lost the most. Explain the concept of runoff and ask students why they think this has occurred? The roots of the grass work to hold in more water, and the dead vegetation does the same to the lesser extent. The dirt with no plant life cannot hold much water and so it runs off, causing a lot more erosion.

EXPAND: 

Ask students what they think would have happened if they’d had a bottle with just sand in it. Would it have washed away more or less quickly than the other bottles? Remind them that this is what happens on sandy beaches all day every day: sand is constantly being moved back and forth by the ocean waves.

EVALUATE: 

Can students describe this experiment, the results, and what it taught them about the relationship between vegetation and erosion?

Standards: MS

Purpose: Students will research and describe the impacts beavers have on the environment, exploring how living and nonliving elements of an ecosystem interact and affect each other. They will then compare this to the impacts that humans have on rivers.

Time needed: 35-45 mins

Materials: Journals, pencils, tablets/computers and access to the internet OR printed articles

Prior preparation (optional): If you’d prefer students read copies of the research materials rather than use computers, print a copy of the below linked pages for each student. If using physical copies, students can paste or staple these into their journals at the end of the activity.

ENGAGE: 

Ask students to think about how one could stop the flow of water if they needed to. The answer is dams! Referencing the video from this unit, remind students that both beavers and humans make different kinds of dams to serve their own purposes. Tell students they’ll now be using internet resources to learn about the impacts of both beaver and human dams.

EXPLORE:

1. Ask students to access this article about beavers and their dams online OR have them read the printed copies: https://animals.howstuffworks.com/mammals/beaver-dam.html 

2. Ask students to list the pros and cons of a beaver dam in their journal. Encourage them to think about other pros and cons that may not have been shared in the article. Then, have them share and discuss these as a group. Pros may include the creation of wetlands which clean water and create biodiversity, while cons may include flooding and impacts on agriculture.

3. Ask students to access this article about human dam impacts online OR have them read their printed copy: https://blog.arcadia.com/pros-cons-dams/ 

4. Ask students to list the pros and cons of a human dam in their journal. Encourage them to think about other pros and cons that may not have been shared in the article. Then, share and discuss these as a group. Pros may include the creation of clean electricity and recreation areas, while cons may include the disruption of salmon runs and poor water quality.

5. Ask students to pair up in groups of two. Then, instruct them to work together, referencing the articles and their notes, to discuss the following question: Which has a greater negative impact on the environment: a beaver dam or human dam?

EXPLAIN: 

As a class, ask students to share results from their discussions. Encourage them to cite facts from the articles to defend their statements. At the end of your discussion, synthesize their findings: what are some pros and cons of both beaver and human dams?

ELABORATE:

Share with students how people are using artificial beaver dams to help restore rivers, using the info and story map from the USDA: https://www.climatehubs.usda.gov/hubs/northwest/topic/incised-stream-restoration-western-us. (Click the “Going with the flow” link to enlarge the story map.) Highlight the Oregon case studies.

EVALUATE: 

Can students explain how beaver dams and human dams are both alike and different, and the impacts (both positive and negative) of each one?

EXTENSION: 

The “Hooks and Ladders” activity from Project Wild is a great way to demonstrate the impacts of dams on salmon. You may also wish to return to the watershed models from LC1 Activity A and have students build dams in their model to observe the ways it changes water flow.

Purpose: Invite students to imagine what the earth might be like without water, identifying all of the ways that water affects their lives, other organisms, and the appearance of our planet.

Time needed: 30-40 mins

Materials: large sheets of paper (1 per student), colored pencils, teacher’s computer and projector (optional)

Instructions: (NOTE: this could also be assigned as a longer-term project, either in groups or individually. Students could create their depictions with any materials or media they choose.)

ENGAGE: Write the following on the board: Imagine a world in which there was no water. What would our planet look like? Ask students to read this and think about it independently and quietly for a few minutes. Ask them to record their thoughts in their journals. Then, divide them into groups of 3-4 students each.

EXPLORE: 

Step 1) Tell students they are going to work together to create a depiction of what the world would be like without water. Emphasize that this isn’t about artistic capability; they can depict their thoughts any way they wish! They may choose to draw pictures, create a word map, write a poem or story together, etc. 

Step 2) Distribute paper and markers and give students plenty of time to make their creations - about 15-20 mins or more.

Step 3) After all of the groups feel done, have students do a “gallery walk” to view everyone else’s work: each group should leave their work on the table, then everyone should stand up and walk around to view everyone’s products.

EXPLAIN: After students are seated again, discuss all of the ways that the earth would be different without water. Are there any examples in nature of a planet without water? Yes - Mars! Share pictures and footage from the Perseverance Mars expedition, at: https://mars.nasa.gov/mars2020/. Mars is a great example of a place with no water and thus, no life (that we know of) and no water-driven erosion.

EXPAND: Ask students to brainstorm all of the ways they use water every day. Some obvious ones may be drinking, brushing teeth, showering, etc. Remind them of some less obvious, but equally important uses of water including watering the plants and animals we eat, creating electricity, making materials like clothes and plastics, etc. This EPA website has a useful list: https://www.epa.gov/watersense/how-we-use-water 

EVALUATE: Can students point out all of the things around them that use water (including people!), explain how it uses water, and describe what the world might look like without it?