Back to Teachers Home

Flood!

Classroom Activity

Objective
To construct a model of a river system with levees.

• copy of "Overflowing the Banks" student handout (PDF or HTML)

• A large flat container or tray with sides, such as a wallpaper trayor aluminum baking pan

• A sufficient amount of modeling clay to cover the bottom of the pan

• water
• some sponges
• drawing paper
• pencils

1. St. Louis, Missouri, was protected from serious flood damage because of the walls that were built to hold the river on course even in predicted maximum flooding conditions. To demonstrate the effects of such a wall, construct a model with this activity.

2. Divide the class into several groups, gather materials for each group, and distribute the "Overflowing the Banks" student handout to students.

3. Have students use the instructions on the student handout to build a version of their terrain without levees, pour water through it, and observe the effects caused by water rushing through the riverbanks and across plains.

4. Have students predict what will happen when they add levees to their models.

5. After completing the activity, review the scenario the students observed in the program. What were some of the consequences of building such a high wall in St. Louis, Missouri?

The first model will show what would happen without any human interference in the banks of the river. When flooding conditions occur, the entire floodplain is covered with water. However, when the banks of the river are artificially shored up—as with the second model—conditions change. Under non-flood conditions, the water remains within its banks, but when more water is added into the system, water will back up in all places except where the artificially high walls are too low, causing floods. This situation is similar to what happened in St. Louis, Missouri, and the surrounding areas during the flood of 1993. The sponges act as a wetland area would, soaking up some of the water that would overflow from the river.