Land and Water
Lesson 12
Dams: How Humans Change the Direction and Flow of Water
Students will apply knowledge from previous investigations to choose materials and the structure of the dam. Students will work together to solve the problem of the placement, making and testing of the dam.
3. Lesson set up and Management
INQB: Scientists plan and conduct different kinds of investigations, depending on the questions they are trying to answer.
INQC: An experiment involves a comparison. For an experiment to be valid and fair, all of the things that can possibly change the outcome of the experiment should be kept the same, if possible.
INQF: A scientific model is a simplified representation of an object, event, system, or process created to understand some aspect of the natural world.
APPA: Technology involves changing the natural world to meet human needs or wants.
APPC: Problems of moderate complexity can be solved using the technological design process. This process begins by defining and researching the problem to be solved.
APPD: Scientists and engineers often work in teams with other individuals to generate different ideas for solving a problem.
APPE: Possible solutions should be tested to see if they solve the problem. Building a model or prototype is one way to test a possible solution.
ES2C: Erosion is the movement of Earth materials by processes such as wind, water, ice, and gravity.
- Students will use knowledge from the other lessons to solve the problem about where to build a dam.
- Students will use an assortment of materials based on what they know about the different materials.
- Students will design, build and test their dam to see if it solves the problem.
3. Lesson set up and Management
Materials:
- Students can break or cut the craft sticks and/or toothpicks.
Student Management:
- Students may get distracted and start building things other than dams.
- Stress that the students need to think of the properties of the different earth materials to use in their dam.
- Consider doing this lesson using the stages in the "Design/Application Process."
- Define the problem: "Can a dam in our stream table model prevent enough erosion so the houses don't move?"
- Scientifically gather information and/or collect measured data: Have the students review their results from the other lessons. Have them look at the diagrams in their science notebooks and the "Big Book of Streams."
- Explore ideas. Have the student groups brainstorm a list of things they could try to make landscape minimize erosion.
- Have the students consider what they learned about fast and slow water before making their dam (Lesson 4, 9, 10).
- Have the students consider how each of the earth materials affected the water flow (Lesson 5, 6, 7).
- Have the students consider how different land features affected the flow and direction of the water (Lesson 11).
- Summarize the plan: Have the students summarize in a few sentences what features they are going to use in their stream table dam.
- List steps to do the plan: Have the teams list the steps for building their dam.
- Diagram the solution: Have the students draw a diagram of their dam. Have them label all the features they are adding. Also, have them label the different centimeter cubes with the name of the team member.
- Scientifically test the solution: The class should plan how they are going to test to see if the dam minimized erosion. A possible test suggestion: after pouring the water into the cup, none of the houses in the town [centimeter cubes] moved. It is helpful to plan the test prior to the Exploring Ideas stage.
- This lesson may take awhile. You may need to have the students reflect and record in their journals the following day. However, it is very important that students reflect on what happened and record those ideas in their journal.
Stream table with a dam before adding water.
The water is flowing into the stream table.
Writing Support:
- Have each student use Record Sheet 12-A, or record the steps of the Application process in their science notebook. (See the GLE above and Teacher Tip bullets 1-4.)
Reading Support:
- Independent reading opportunity: My World of Geography: Lakes by Angela Royston. This book could be used as independent reading for students who need a lower reading level. It has a small section on describing dams.
- Have students read the selection, "“Releasing a River." Have students work as a team to complete a comparison of the river without a dam and with the dam using information from the selection.
Without a dam
With a dam
No Lake Powell, just a continuation of the river
Lake Powell, reservoir
Water flowed naturally into the canyon
Control water into the canyon
Water used by wildlife & plants in ecosystem
Water in reservoir used for electricity
No electricity for towns
Towns get electricity
Natural flooding
Irrigation for farmers
Swimming, boating & fishing in river
Swimming, boating & fishing in reservoir
Flooded every spring
Floods when scientists let water out of the dam
Beaches & sandbars formed
None formed
Fish could hide and lay eggs
Ecosystem changed
River full and flowing
Trees in middle of river, river doesn't reach the sea
Math Support:
- Have the students use the diagram on student sheet Record Sheet 12-A. Have the student calculate the length of the land compared to the length of Gaveo Bay. This distance should be used by each group so that they will have similar sized pieces of land.