To construct a model of a river system with levees.
- copy of "Overflowing the Banks" student handout
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
- some sponges
- drawing paper
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.
Divide the class into several groups, gather materials for each group,
and distribute the "Overflowing the Banks" student handout to students.
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.
predict what will happen when they add levees to their models.
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,
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.