Engineering Dams

In this lesson, students engage in an engineering challenge by designing and building prototype dams to solve the problem of protecting a town from a river’s flood water.

• Beavers build dams to help protect themselves and their offspring.
• Engineers can mimic the behavior of beavers by designing dams across rivers. Dams can solve different problems.
  
  

• How does a dam help beavers protect their offspring? 
• How do dams create a flooded area? 
• How do beavers build dams? 
• How can dams protect people?  
• What other problems might a dam solve? 
• What do engineers need to think about when designing a dam?

Misconception: Humans are the only animals who can change their environment and build structures.

Fact: Many animals change their environment to meet their needs. For example, beavers can build dams that change the flow of a river, and lodges for their homes.

Comfort: to make another animal feel better

Dam: a special type of wall that holds back water, creating a reservoir

Offspring: the young born to living things

Protect: to keep safe from harm

Stimulus: anything in the environment that causes an organism to react

Engineers Mimic Beavers

Engineers can mimic how beavers build dams. Engineers sometimes design dams to go across big rivers. A dam has to be strong. It has to hold back moving water.

People cannot use their teeth like beavers do. Instead, people use tools and machines. Drills are tools that can make holes in hard materials like rock. Cranes are machines that make it easier to lift heavy objects.

There are different kinds of dams. Some dams are straight across the river. Other dams are curved. Dams are made of different materials. Some are made of clay or rock. Others are made of concrete.

Engineers build dams to protect people. Dams can keep rivers from flooding.

Dams also create reservoirs. A reservoir is the large supply of water that builds up behind the dam. Sometimes people use the water in a reservoir to drink. Sometimes they also use the water for electricity and to supply crops.

Acting as engineers, students summarize a problem presented in an engineering scenario, which is that a river floods every spring, ruining houses and stores in a nearby town, and design a solution. Then, students draw a scientific diagram of their chosen prototype solution and use their diagram as a guide for creating their prototype dam. Once students build their prototype, they test it to determine how well it solved the problem, meeting the requirements of the problem within the limits. Students use the data they gather from their first prototype solution to improve their second prototype so that it better solves the problem. Student teams present to the class their explanation about whether they would refine or replicate their prototype design. Different teams engage in scientific argumentation about which features best solved the problem, as well as any challenges they encountered.