(Lesson Courtesy Teach Engineering.) Grade Level: 4 (3-5). Group Size: 2. Time Required: 50 minutes

Summary:

In this scenario-based activity, students design ways to either clean a water source or find a new water source, depending on given hypothetical family scenarios. They act as engineers to draw and write about what they could do to provide water to a community facing a water crisis. They also learn the basic steps of the engineering design process.

Engineering Connection:

Water sources are increasingly becoming polluted by human-made and natural contaminants. In addition, water sources are beginning to retain less and less water for people’s’ daily needs. Engineers have long recognized this as a growing problem, and they are being called upon to design better ways to manage our water resources and develop advanced technologies to clean our water and to preserve and protect our water sources. Finding solutions to meet a community’s water needs requires that engineers take into consideration the region’s climate as well as the available natural and human resources.

Learning Objectives

After this activity, students should be able to:

• List several real scenarios that involve threats to community water resources.
• Explain the importance and challenges involved in cleaning water for human use.
• Describe how engineers are involved with finding and cleaning water.

Materials List

Each group needs:

• One large sheet of paper, poster board or chart paper
• Colored pencils or markers
• One water problem scenario from the Family Scenario Note Cards

Introduction/Motivation

What would happen if you woke up tomorrow, turned the water tap on for a drink, and dirty brown water came out? How about if you turned the water faucet and no water came out? What would happen if, at home this evening, people came by your house and said that you should not drink your water because a terrible contaminant (pollution) had been found in it? What if people said you had to limit your water use because we were running out? What would you do? This all sounds really bad, but it actually happens!

All over the world, problems of water quality and quantity are very real. In Bangladesh, a contaminant known as arsenic was found in many water sources. Arsenic in very small amounts causes skin and internal cancers. Yikes! You don’t want to drink arsenic! In other parts of the world people must walk very long distances everyday to get water because it is not piped to where they live. They do not have water faucets or wells. Sometimes their trek to get water is tiring or dangerous. In the U.S., after Hurricane Katrina, water supplies in parts of New Orleans were too dirty for drinking. The water was filled with dirt and sand. You don’t want to drink water filled with dirt, do you? Also, regions in the southwestern U.S. have been having a water shortage for years. There just is not enough water for everyone who needs it.
How about getting water in the first place? What type of climate do you live in? Do you know the source of your drinking water? Often, people collect precipitation. In Asia and Africa, communities collected rainwater as a source of fresh water. Rainwater is still collected today to use for drinking and daily water use (see Figure 1).

What do we do when these water problems occur? Environmental engineers, water resource engineers, chemical engineers and many other people work on ways to solve these problems. Engineering teams and companies often develop new technologies to clean up dirty or polluted water, and collect and conserve our water sources. Today we are going to act as engineering companies, looking at different situations in which water sources are threatened. We will even design ways to handle specific water problems. Are you ready?

Procedure

Background Information: Engineering Design Process

Engineers design and build all types of structures, systems and products that are important in our everyday lives. The engineering design process is a series of steps that engineering teams use to guide them as they solve problems:

1. Understand the need: What is the problem? What do I want to do? What are the project requirements? What are the limitations? Who is the customer? What is the goal? Gather information and research what others have done.
2. Brainstorm and design: Imagine and brainstorm ideas. Be creative. Explore, compare and analyze many possible solutions. Select the most promising idea.
3. Plan: Draw a diagram of your idea. How will it work? What materials and tools are needed? How will you test it to make sure it works?
4. Create: Assign team tasks. Build a prototype (model). Does it work? Talk about what works, what doesn’t and what could work better.
5. Improve: Talk about how you could improve your product. Make revisions. Draw new designs. Make your product the best it can be.

Engineers use their science and math knowledge to explore options and compare many ideas. This is called open-ended design because when you start to solve a problem, you don’t know what the best solution will be. The process is cyclical and may begin at, and return to, any step.

The use of prototypes (model), or early versions of the design helps the design process by improving the understanding of the problem, identifying missing requirements, evaluating design objectives and product features, and getting feedback from others.

Engineers select the solution that best uses the available resources and best meets the project’s requirements. They consider many factors: Cost to make and use, quality, reliability, safety, functionality, ease of use, aesthetics, ethics, social impact, maintainability, manufacturability.

Before the Activity

• Gather materials.
• Make copies of the Family Scenario Note Cards (contains five different scenarios) and cut out the water problem scenarios.

With the Students: Design

Scenes shows water sources in four different climates: rain and river in a forest, a tropical beach, a desert oasis, an alpine lake.

1. Divide the class into teams of two or three students each. Tell the students that each team represents a water engineering company that helps solve the problems of families or communities that need clean drinking water.
2. Conduct the pre-activity assessment activity described in the Assessment section.
3. Write the steps of the engineering design process on the board. Review with students how all engineers like to solve problems to make things better. These are the usual steps they take when working on a problem, just like what they are doing today.
4. Hand each team a water problem scenario.
5. Allow each team time to brainstorm a way to fix the problem. Let them know that any design or method is fine, except they must be realistic for their situation. Consider the resources and limitations of the climate of their scenario. Encourage them to be creative! As needed, guide and evaluate them with questions provided in the Assessment section. Have teams draw their engineering method(s) to fix their water problem scenarios on large paper using markers or colored pencils. Ask students to label the parts of their designs and be as detailed as possible. Point out how designing, planning and creating a model are steps in the engineering design process.
6. Have students decide on a name for their engineering company and write it on the top of their design drawing.

With the Students: Presentation

1. Have each engineering team present its design to the class, and explain how it will solve the family’s water problem.
2. Conclude by leading a class discussion. Why do we need clean water? Is finding water different in different climates? What are the types of real-world situations that can threaten our community water resources? What are the problems we might have in trying to clean dirty water so it is okay for human use? How do engineers help us? (Possible answers: Water collection, water treatment.) What are the steps of the engineering design process? Any time you are solving a problem or building something, think about the engineering design process. It helps you think through all aspects of a problem to find a good solution. When you saw other team presentations, did you get any ideas that would improve your design?
3. Conduct the post-activity assessment activity described in the Assessment section.

Attachments

Family Scenario Note Cards (doc)
Family Scenario Note Cards (pdf)

Troubleshooting Tips

When coming up with design solutions, make sure students use realistic approaches and think about the climate conditions. Some teams made need a little encouragement to find a solution.

Assessment

Pre-Activity Assessment

On Your Toes Brainstorming: In small groups, have students engage in open discussion. Remind students that no idea or suggestion is “silly.” All ideas should be respectfully heard.

Assign each team a particular climate (tropical, coastal, alpine, desert, etc.). For two minutes ask them to brainstorm and write down different water sources for their particular climate.
Disaster strikes! After two minutes, go around to each group and tell them that they could no longer get water from the major water source they listed! Ask them to brainstorm what they could do if this water source was removed.

Activity Embedded Assessment

Group Questions: During the activity, visit each group and ask the following questions:

1. How does this design relate to the climate in which your family or community lives?
2. Why did you choose this design?
3. What sort of power or energy needs would your design need? (For example, if the design involves moving or pumping the water, do they need a pump? What will power the pump? Batteries or electricity, etc.)

Post-Activity Assessment

Re-Engineering: Have each team switch their original family scenario note card with another group. Ask students to evaluate their current design for this new scenario. Have students discuss if and why their design would or would not work in this different situation in a different climate. Ask them to think about what they could do to make it work for the new conditions.

Activity Extensions

Have other student engineering teams in the class evaluate and offer suggestions for improvements to each design.

Have the students make physical models of their solutions to the water problems.

Have students present their designs to another class.

Owner: Integrated Teaching and Learning Program, College of Engineering, University of Colorado at Boulder

Contributors: Jay Shah, Malinda Schaefer Zarske, Denise W. Carlson

Copyright: 2006 by Regents of the University of Colorado

Filed under: Grades K-5, Lesson Plans

Tags: Clean Water, Grades 3-5, Water management