These activities encourage students to explore, think like engineers, and have fun! Designing and building dams call upon students’ problem solving skills and introduces them to some of civil engineering’s most important and fascinating challenges. (Plus, who doesn’t love playing with water?)
Busy as a Beaver (Grade Level 3-4)
Time: 45 minutes
The purpose of this activity is to introduce students to some of the issues engineers face in building dams: they must be both waterproof and strong enough to withstand the pressure of water. To begin the activity, ask students what they know about beaver dams. How do beavers build dams, and why do they build them in the first place? Explain that beavers are natural engineers who build dams out of rocks, earth, wood, and other materials from their environment. By damming water, beavers can create a still pond in which they can build their home, a beaver lodge. Creating a deep pond also helps protect them from predators who aren’t the expert swimmers that beavers are. Then ask students if they know some of the reasons why humans build dams. Explain that dams create reservoirs (artificial lakes) to store drinking water and to grow crops. Reservoirs are also used for swimming, boating, and other recreational activities. Another important reason for building dams is that the energy of flowing water from dams can be used to generate hydroelectric power—the electricity that lights up our homes and cities may be the result of a dam!
Note: This activity can get messy—do it outside, if possible.
Materials & Directions
For a group of 10 students:
- 5 extra large disposable aluminum baking pans (approx. 17"x12"x 3")
- 2 bucketsful of sand
- 2 bucketsful of pebbles and rocks
- craft sticks (packet of 150)
- water
- Have students work in pairs, and emphasize teamwork—two heads are better than one!
- Explain that the goal of the activity is to construct a dam that blocks water and creates a pool. Ask them to think about ways to use the materials to make the dam strong and fairly leak-proof—explain that some leaking is fine.
- Have students use the materials to construct a dam across the middle of the baking pan.
- Then have them add water to one side of the pan—what happens? Does the dam hold back the water, forming a pool? (It’s fine if the dam leaks a little.) If their dam collapses, have students redesign and test again.
- Ask students to discuss what challenges they encountered in building their dam: Did you need to make adjustments to your design? Which materials contributed to making the dam strong? Which materials helped to stop leaks?
National Science Education Standards, Grades K-4
A: Science as Inquiry: Abilities necessary to do scientific inquiry
B: Physical Science: Properties of objects and materials
E: Science and Technology: Abilities of technological design; abilities to distinguish between natural objects and objects made by humans
G. History and Nature of Science: Science as a human endeavor
Clockwise from left top: embankment dam, buttress dam, gravity dam, and arch dam.
Four Corners Reservoir (Grade Level 5–6)
Time: 45 minutes; if possible, complete in two sessions. Air-dry clay is used in this activity, so it’s ideal to wait a day (or at least several hours) to give the clay a chance to dry. But if no waiting period or extra session is possible, the clay dams will still hold back water—just not as long.
The purpose of this activity is to introduce students to the four major types of dams—embankment, gravity, arch, and buttress dams—and to explore how they work. After a short introduction to different dams, students will build models of all four, each in a different corner of an aluminum pan “reservoir.” Once the dams are built, students place marshmallow (or cotton ball) “people” behind the dams, fill the reservoir with water, and find out just how sturdy, safe, and watertight each dam is. Begin the activity by introducing students to the four major types of dams. Show them photographs, discuss how each type of dam functions, and point out the kinds of environments they’re best suited for. For succinct descriptions and illustrations, see Types of Dams.
Materials & Directions
For a group of 10 students:
- images of embankment, arch, gravity, and buttress dams, from books or the Internet. Recommended online sources: Types of Dams, or Dam Basics
- 5 extra-large disposable aluminum baking pans (approx. 17"x12"x 3")
- 25 lbs. air-dry clay (Can be bought online in bulk.)
- box of bendable straws
- 5 rolls masking tape
- bucket of soil
- box of sealable plastic bags
- roll of plastic wrap
- cardboard, any type(3 8½"x 11" sheets or the equivalent)
- package of craft sticks
- a few large flat rocks, broken brick or concrete, or several smaller stones or gravel
- package of marshmallows or cotton balls
- 1 set of colored markers
- water
- This is an open-ended activity with lots of creative possibilities. Feel free to improvise and include other materials as well.
- Have students work in pairs and emphasize the benefits of teamwork.
- Explain that the goal of the activity is to construct four different types of dams, each built in a corner of an aluminum pan. Then they’ll fill the center of their “reservoir” with water, and put their dams to the test. The dams must prevent water from leaking into the corners of the pan. To raise the stakes even higher, each of the four dams must protect a marshmallow “person,” who has been placed in each corner.
- Pass out one aluminum pan to each pair of students. Display the other materials, and allow students to use whatever they want to build their dams.
A few rules and tips:
- The dams can be any size, just as long as there’s enough room to fit four dams into each of the corners of the pan.
- The dams can be connected to the walls of the pan.
- The gravity dam must be made from a heavy material (like rocks).
- The embankment dam must be made mostly from soil. Tip: Loose soil will quickly lose its shape in water. Put the soil in a plastic bag or wrap it in plastic wrap to keep it together.
- Check carefully for places where water might seep through—especially the base of the dam and the sides where it connects to the walls of the pan. - When they are finished building, have students draw faces on four marshmallows (or cotton balls), and place one in each corner, behind a dam. If they’ve designed and built their dams well, the marshmallow people will stay safe and dry!
- If you have the time, wait several hours—or an entire day—so the clay used in the dams can dry. But if the activity must be done in a single session, continue on to step 6. The clay dams will hold, just not as long as they would if they had time to dry.
- Add water to the center of the pan, until the reservoir is filled. Ask students: Do all your dams hold up under the pressure from the water? If you were to redesign one or more of your dams, how would you do it? Which type of dam is your favorite? Why?
National Science Education Standards, Grades 5-8
A: Science as Inquiry: Abilities necessary to do scientific inquiry
B: Physical Science: Properties of objects and materials; motion and forces
E: Science and Technology: Abilities of technological design
G: History and Nature of Science: Science as a human endeavor
Hydropower! (Grade Level 7–8)
Time: 45 minutes
The purpose of this activity is to help students understand one of the most important functions of dams: the creation of hydroelectric power. In this activity, student are challenged to design and build a turbine that spins rapidly when it comes in contact with a forceful stream of water. While designing a turbine is technically a mechanical engineering activity, it’s a fun and dynamic way to help students understand the connection between dams and hydroelectricity. It can also lead to a discussion about renewable energy. Begin the activity by explaining how hydroelectricity is generated: Powerful streams of water, channeled through a dam, turn a wheel-like device called a turbine. The turbine rotates a shaft in an electric generator to produce electricity.
You may wish to display this diagram, Inside a Hydropower Plant.
Tell students that about one-fourth of the world’s electricity is produced this way, and that hydroelectric power is the most widely used source of renewable energy. Ask them if they know what renewable energy is and how it helps preserve our natural resources. Fill in details they may not know: renewable energy comes from natural resources like sun, wind, and water that can be used over again—they don’t run out. Even more importantly, hydroelectric power is “clean” energy. Unlike coal and oil, it does not cause carbon emissions and air pollution.
This activity is an ideal one for introducing students to the design process. Explain to students that the design process is a series of steps engineers use to arrive at solutions. In this activity, they’ll follow these steps:
- Identify the problem: What are you trying to accomplish with your water turbine? Have a clear idea goal in mind before you begin.
- Brainstorm: Use your creativity to come up with lots of ideas for your turbine before deciding on the one you decide to pursue.
- Design: Sketch out and plan how you’ll build it.
- Build, test and evaluate, and redesign: The way to know if your turbine design works is to test it. If it doesn’t work or needs improvement, it’s time to redesign until you are satisfied with the results.
- Share solutions: When you’re finished, share what you’ve learned so others can benefit from your knowledge. Communication and collaboration is the important final step in the design process.
Materials & Directions
For a group of 10 students:
- paper and pencil (for each student)
- scissors (for each student)
- tape (3 or 4 to share)
- stapler (3 or 4 to share)
- straws (1 package)
- wooden skewers (1 package)
- string (1 roll)
- 3-ounce paper cups (1 package)
- paper plates (1 package)
- index cards (1 package)
- flowing water from a faucet, hose, or pitcher
- This is an open-ended activity with lots of creative possibilities. Students will probably use just some of the materials provided above. Feel free to improvise and include other materials as well.
- Have students work individually.
- Tell them that their goal is to design a model of a turbine that rotates when hit by a force of water. They will need to design a turbine that they can hold with one or two hands under a stream of water. Speed is important—the turbine must be able to spin rapidly, the way a turbine in a hydroelectric dam would. Explain that this is the first step in the design process: understanding the problem.
- Display the materials, explaining that there are many different creative ways to design and build their turbine. It’s time for step 2 in the design process: brainstorming. They are free to use whatever materials they want; it’s unlikely they’ll need all the materials.
- Have kids sketch out some possible designs on paper before beginning, and encourage them to test as they build. This is step 4 in the design process: build, test and evaluate, and redesign.
- Then have them demonstrate their water turbines for the group, using water flowing from a faucet, hose, or pitcher. This is the final step of the design process: sharing solutions. During the demonstrations, ask questions to reinforce what they’ve learned about dams and hydroelectric power. How might a dam produce fast-moving water?
How might gravity help?
Can you think of ways to make it move even faster? (A dam raises the level of water, which is then channeled downward through a pipe. As the water moves down the pipe, the water pressure increases and flows faster.)
What happens to the water after it has passed through the turbine?
Why is hydroelectric power called “renewable energy?” (Once the water flows through the turbine, it joins the water on the other side of the dam, and continues down the river—as clean and as reusable as it was before it flowed through the dam.)
National Science Education Standards Grades 5-8
A: Science as Inquiry: Abilities necessary to do scientific inquiry
B: Physical Science: Motion and forces
E: Science and Technology: Abilities of technological design; understandings about science and technology
F: Science in Personal and Social Perspectives: Populations, resources, and environments
G: History and Nature of Science: Science as a human endeavor
