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Drought Threatens Huge Man-Made Lake

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Grades

Grades 2-up

News Content

If Lake Mead continues to dry up, many peoples water and power supplies could be affected.

Anticipation Guide

Before reading, ask students to locate on a U.S. map the states of Arizona, California, Colorado, New Mexico, Nevada, Utah, and Wyoming. In addition, students might look for and trace the path of the Colorado River. If the location of Lake Mead [see locator map] is clear on your map, point that out to students too. These geographic locations are important to students understanding of this weeks News for Kids news story.

News Words

Next, introduce these words that appear in the News Word Box on the students printable page: reservoir, climate, businesses, drought, population, and levels. Discuss the meanings of any of those words that might be unfamiliar. Then ask students to use one of those words to complete each of these sentences:

  • A summertime _____ threatened farmers crops across the South. (drought)
  • The _____ in Alaska means people there will experience mild summers and very cold winters. (climate)
  • Gasoline prices have climbed to their highest _____ in many years. (levels)
  • The new shopping center will have space for six new _____. (businesses)
  • Thousands of miles of pipe carry water from the _____ to our homes. (reservoir)
  • As the _____ of the area grew, new homes and schools were built. (population)

    Read the News

    Click for a printable version of this weeks news story Drought Threatens Huge Man-Made Lake.

    You might use a variety of approaches to reading the news:

    Read aloud the news story to students as they follow along.

    Students might first read the news story to themselves; then you might call on individual students to read sections of the news aloud for the class.

    Photocopy the news story onto a transparency and project it onto a screen. (Or use your classroom computer's projector to project the story.) Read the story aloud as a class, or ask students to take turns reading it.

    Arrange students into small groups. Each student in the group will read a paragraph of the story. As that student reads, others might underline important information or write notes in the margin of the story. After each student finishes reading, others in the group might say something -- a comment, a question, a clarification -- about the text.

    More Facts to Share

    You might share these additional facts with students after they have read this weeks news story.

  • Scientists at the Scripps Institution of Oceanography in La Jolla, California, estimate that there is a 50 percent chance that Lake Mead could be dry by 2021. (Read more about this news story)
  • Las Vegas, Nevada, gets about 90 percent of its water from Lake Mead. Even though the city continues to grow, conservation efforts have resulted in a reduction in overall water use since 2002. Other areas that get their water from the lake must follow Las Vegass conservation lead if Lake Mead is to survive.
  • Besides providing water for people, Lake Mead also provides electricity. Las Vegas, for example, gets most of its electricity from the hydroelectric generators at the Hoover Dam. If current conditions persist, some scientists say there is a 50 percent chance the reservoir will no longer be able to generate hydropower by 2017. Other experts dispute those numbers, but the message is clear: residents of Nevada and Arizona, the two U.S. states with the fastest-growing populations, must take measures to conserve water and better plan their growth.
  • This picture shows the white bathtub ring" that is a clear illustration of Lake Meads former water level. One source says the lakes current elevation is 118 feet below its maximum elevation. The white ring is the result of mineral deposits from the water on the lakes bedrock walls; they indicate the lakes former high-water mark. (If you dipped a water glass partway into the lake and then set it out to dry, you would clearly see the mineral deposits left behind by the lakes water.)
  • Shrinking water levels force homeowners around the lake to move their docks from time to time as they chase the lowering waterline.
  • The lower water levels mean boaters must take more care. They are in danger of running into unmarked reefs that used to be -- but are no longer -- far below the lakes surface.
  • A town once stood where Lake Meade sits today. The town of St. Thomas, settled in 1865, included farms, homes, and stores. But the building of the Hoover Dam forced the residents of St. Thomas to move. Foundations of some building of the old town remain exposed. (Learn more about St. Thomas)
  • Lake Mead was named in honor of Dr. Elwood Mead. As Commissioner of Reclamation from 1924 - 1936, he drafted specifications for a giant project that would dam the Colorado River and create the world's (at that time) largest artificial lake.
  • Some might consider it a bit ironic that the building of the Hoover Dam, which enabled the Southwest to grow, is now at the heart of a threat to continued growth.

    Additional Resource of Interest
    Construction History of Hoover Dam

    Comprehension Check

    Recalling Detail

  • What is causing water levels to drop in Lake Mead? (growing populations and high demand for water; drought caused by warming temperatures)
  • What is the largest source of water for Lake Mead? (melting snow)
  • How large is Lake Mead? (it is 250 square miles in area)
  • In what states is Lake Mead located? (Nevada and Arizona)
  • In what year was the Hoover Dam built? (1935)
  • How many gallons of water are in Lake Mead today? (9 trillion gallons)

    Think About the News
    Discuss the Think About the News question that appears on the students news page. You might use the think-pair-share strategy with students to discuss this question. If you use this strategy

  • First, arrange students into pairs to discuss and list responses to the question.
  • Then merge two pairs of students together to create groups of four students. Have them discuss and add to the ideas they generated in their pairs.
  • Next, merge two groups of four students to form groups of eight students. Have students create a new combined list of ideas.
  • Finally, bring all students together for a class discussion about water conservation measures.

    Follow-Up Activities

    Math -- read the graph. Print out or project this graph of Lake Mead water levels over the years. The graph will give students a visual reference that enables them to see clearly that the lakes water levels today are among the lowest in its history. Ask the following question about the graph:

  • When was the last time water levels in Lake Mead were as low as they are today? (The water levels have not been this low since 1965, and 1956 before that.)
  • When were water levels at their highest point? (between 1983 and 1984)
  • Were water levels in the lake higher in 1995, 2000, or 2005? (2000)
  • During the 1990s, were the lakes water levels above or below average? (above average)
    You might share this bar graph, which illustrates Lake Meads water levels each October; it provides for students another view of the lakes water levels throughout its history.

    Geography -- read a map. Share with students this map, which shows the fastest growing states (in population) in the United States. Cover the text in the left margin that lists the fastest growing states. Then ask students to use the map to identify, in order, the ten fastest growing states. (Based on 2006 population data, the ten fastest growing states, in order, are 1. Arizona, 2. Nevada, 3. Idaho, 4. Georgia, 5. Texas, 6. Utah, 7. North Carolina, 8. Colorado, 9. Florida, and 10. South Carolina.)

    Math -- place value. Currently, Lake Mead holds about 9 trillion gallons of water. To help students grasp the concept of a trillion, write the following numbers on a board or chart:

    TOPIC 1 TOPIC 2
    1 one
    1,000 one thousand
    1,000,000 one million
    1,000,000,000 one billion
    1,000,000,000,000 one trillion
    To provide another perspective, share with students the MegaPenny Project. There students can view images of stacked pennies in growing quantities of a thousand, a million, a billion, and a trillion.

    Assessment

    Use the Comprehension Check (above) as an assessment. Or have students work on their own (in their journals) or in their small groups to respond to the Think About the News question on the news story page.

    Lesson Plan Source

    Education World

    National Standards

    LANGUAGE ARTS: English
    GRADES K - 12
    NL-ENG.K-12.1 Reading for Perspective
    NL-ENG.K-12.2 Reading for Understanding
    NL-ENG.K-12.7 Evaluating Data
    NL-ENG.K-12.11 Participating in Society
    NL-ENG.K-12.12 Applying Language Skills

    MATHEMATICS: Number and Operations
    GRADES Pre-K - 2
    NM-NUM.PK-2.1 Understand Numbers, Ways of Representing Numbers, Relationships Among Numbers, and Number Systems
    GRADES 3 - 5
    NM-NUM.3-5.1 Understand Numbers, Ways of Representing Numbers, Relationships Among Numbers, and Number Systems
    GRADES 6 - 8
    NM-NUM.6-8.1 Understand Numbers, Ways of Representing Numbers, Relationships Among Numbers, and Number Systems
    GRADES 9 - 12
    NM-NUM.9-12.1 Understand Numbers, Ways of Representing Numbers, Relationships Among Numbers, and Number Systems

    MATHEMATICS: Representation
    GRADES Pre-K - 12
    NM-REP.PK-12.3 Use Representations to Model and Interpret Physical, Social, and Mathematical Phenomena

    SOCIAL SCIENCES: Civics
    GRADES K - 4
    NSS-C.K-4.5 Roles of the Citizen

    GRADES 5 - 8
    NSS-C.5-8.5 Roles of the Citizen
    GRADES 9 - 12
    NSS-C.9-12.5 Roles of the Citizen

    SOCIAL SCIENCES: Economics
    GRADES K - 4
    NSS-EC.K-4.1 Productive Resources
    NSS-EC.K-4.8 Supply and Demand
    GRADES 5 - 8
    NSS-EC.5-8.1 Productive Resources
    NSS-EC.5-8.8 Supply and Demand
    GRADES 9 - 12
    NSS-EC.9-12.1 Productive Resources
    NSS-EC.9-12.8 Supply and Demand

    SOCIAL SCIENCES: Geography
    GRADES K - 12
    NSS-G.K-12.1 The World in Spatial Terms
    NSS-G.K-12.2 Places and Regions
    NSS-G.K-12.3 Physical Systems
    NSS-G.K-12.4 Human Systems
    NSS-G.K-12.5 Environment and Society
    NSS-G.K-12.6 Uses of Geography

    TECHNOLOGY
    GRADES K - 12
    NT.K-12.4 Technology Communications Tools
    NT.K-12.5 Technology Research Tools

    See recent news stories in Education Worlds News Story of the Week Archive.

    Article by Ellen Delisio and Gary Hopkins
    Education World®
    Copyright © 2008 Education World

    05/07/2008


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