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Lesson Plan:

For Teachers: Building Earth and Sandbag Dikes

Type: Assignment
Subjects: Science
Grades: Grades 6-8
Duration: 2 lessons
Purpose: To explore the science of dike-building, to build a working model
Summary: Students will build a working model of an earth and sandbag dike.

Before Exploring

Lead a class discussion about dams: the purpose of dams, how they are constructed, and how natural and artificial dams differ.

Outline The Opportunity

Explain to students that they will be constructing a working dike. Direct students to the topic Red River Rising: Manitoba Floods on the CBC Digital Archives website.  Have them view the clip "One family's flood battle," including the Did You Know? section.

In pairs, students will discuss the various examples of dike building by sandbags and by earth-moving machinery that they viewed on the site. Students will use the information from the site to construct a three-dimensional working model of an earth or sandbag dike. Students should include a written explanation of why their dike will hold back water.

Revisit and Reflect

Invite students to demonstrate their working models to the class. Students should be prepared to ask and answer questions. Encourage students to test and comment on their classmates' models.


Have students calculate the number of sandbags it would take to construct a two-metre wall around a 10-metre by 20-metre building, keeping the base of the wall three metres away from the building.  The following website may be used for assistance in calculating: http://www.gov.mb.ca/emo/home/prepare/sandbag.html.


  • earth
  • small paper bags (such as lunchbags)
  • sand or soil
  • plastic sheeting
  • small weights