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Why Is Water So Important? (post-assessment)

Why Is Water So Important? (post-assessment)
  • Grades:
  • Length: 60 Minutes


Students review points covered in this unit and reach conclusions regarding the importance of water to human health. Student sheets are provided in English and in Spanish.

This activity is from The Science of Water Teacher's Guide. Although it is most appropriate for use with students in grades 3-5, the lessons are easily adaptable for other grade levels. The guide also is available in print format.

Teacher Background

Water is essential for all life on our planet. People need water every day to keep their bodies healthy and clean, and to do many other things.

Water has many uses for individuals and the community—from brushing teeth, to washing dishes, running automobiles, growing vegetables, manufacturing paper and machinery, and generating electricity. We even use water for recreation! However, while Earth’s population and the demand for water continue to grow, the planet’s supply of usable fresh water remains fixed. So we must use water wisely.

Water constantly is used and reused as it is circulates through the natural water cycle. Unfortunately, the same unique properties that make water vital for all life also make it susceptible to contamination. Nutrients, soils and sediments, chemicals, heavy metals and disease-causing organisms all can be dissolved in, or mixed with water through human activities. Pollution from these sources can harm human health and cause irreparable damage to valuable ecosystems. The best way to keep water supplies clean is through prevention.

In this activity, students will review (individually or collectively) the role of water in their lives and reach some conclusions regarding the importance of clean water to human health.

Objectives and Standards


  • Water is a special chemical compound with unique properties.

  • All life on Earth depends on water.

  • Water can be polluted easily from a variety of sources.

  • Everyone can help keep our water supplies safe.

Science, Health and Math Skills

  • Problem solving

  • Drawing conclusions

Materials and Setup

Materials per Student Group

  • Colored markers, pencils, pens, paints or crayons

  • Drawing paper (1 sheet per student) or large sheet of butcher paper (1 per group)

Materials per Student

  • Copies of completed pre-assessments

  • Copy of “What Do You Know About Water?”page


Have students work individually or in groups of four.

Procedure and Extensions

  1. For the post-assessment, lead a class discussion of water pollution and the importance of water to health. Have the students suggest different ways in which water impacts human health (both positive and negative). List their suggestions on the board or on an overhead projector.

  2. Explain to students that they will be drawing (or, with older students, writing about) what they consider the most important aspects of water for health. Explain that they may consider anything they have learned over the course of the unit, and that they may include both negative and positive impacts of water and water pollution on health.

  3. Have students fold a sheet of paper into fourths and draw an important health-related aspect of water in each box. Have older students also write a sentence or paragraph explaining the significance of each drawing. If students have kept journals through the entire unit, their new drawings and paragraphs can be added to the journals.


    Have the students work in groups. Give each group a large piece of butcher paper and let students divide it into four sections. Have groups decide on the uses of water they will depict in their “water and health murals.”     

  4. Display the drawings or murals around the classroom. Let each student or group share their work with the rest of the class.

  5. Distribute a copy of the post-assessment to each student. Have students complete the assessment individually or within their groups.

  6. Give each student his or her completed Water unit pre-assessment. Ask, Did your answers to some of the questions change? Have each student identify any question(s) that he or she answered differently on the post-assessment, and write one or two sentences explaining why he or she selected the different answer.


  • Let students collect pictures from magazines and newspapers to use in their pictures or murals.

  • Challenge students to imagine what Earth would be like if clean water quickly began to disappear. Have each student share an idea about one consequence of limited supplies of clean fresh water. Using the cooperative group concept, have the Recorder in each group write down the ideas. Then, have each group present its ideas to the rest of the class.

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National Institute of Environmental Health Sciences, NIH

National Institute of Environmental Health Sciences, NIH

My Health My World: National Dissemination
Grant Number: 5R25ES009259
The Environment as a Context for Opportunities in Schools
Grant Number: 5R25ES010698, R25ES06932