Authentic Lessons for 21st Century Learning

Water We Going to Do?

Floodplains and Watershed Management

K20 Center, Quentin Biddy, Brandi Williams | Published: November 18th, 2022 by K20 Center

  • Grade Level Grade Level 6th, 7th, 8th
  • Subject Subject
  • Course Course
  • Time Frame Time Frame 2-3 class period(s)
  • Duration More 150 minutes

Summary

In this lesson, students will explore how water behaves on various substrates (ground surfaces), what occurs during a flood, and the causes of flash floods. This lesson concluded with students designing and testing various floodplain models intended to mitigate the effects of flash floods. Acknowledgement: This lesson was written through a partnership with the Oklahoma Floodplain Management Association division of the Oklahoma Water Resource Board.

Essential Question(s)

What can scientists do to understand the factors involved in flash floods and how can the effects from flash floods be mitigated?

Snapshot

Engage

Students view an EAS (Emergency Alert System) flash flood warning and/or flash flood video clip and utilize a KWL chart to organize what they know about flash floods.

Explore

Students use clay models and graph paper to investigate watersheds and explore how water behaves in a general watershed. Students also investigate how water behaves on various substrates.

Explain

Students participate in collaborative group discussion to summarize the findings from the watershed and substrate experiment.

Extend

Students investigate specific watersheds containing different substrates and how these would relate to flash floods.

Evaluate

Students design and create a community watershed model to represent an "ideal" community design to mitigate flooding. Students also create a presentation showcasing their model addressing flash flooding using the theme "Turn Around Don’t Drown."

Materials

Engage

Begin by playing the flash flood warning for the students.

Provide the students with the KWL chart (See K20 Tools Sheet). Have the students fill out the first two columns of the chart with information that they currently know (K) and information they would like to know (W) concerning floods and floodplains.

Sample KWL Chart

Explore

Investigation #1

Begin by providing each student group a ball of modeling clay atop a sheet of wax paper or paper plate. Direct the students to create an island using the modeling clay. The island should not be flat - it should have hills or peaks and valleys.

Provide each student group with an eyedropper and a container of water. Direct the students to drop water on different locations on their island and observe the path of the water as it runs off of the island. (Note: If the water pools in one location, direct students to add more water to the pool until it runs off.)

Next, give each group of students a spool of blue string and a pair of scissors. The blue string will represent the island’s streams. Direct students to push the blue string into the clay at the locations where the water runs off the island. Finally, direct each group of students to outline the boundaries of the watershed areas with the green or red string.

Have students do a Gallery Walk. Ask students to walk around the room and make observations of the other groups’ watershed model noting similarities and differences.

Sample Clay Watershed Model

Investigation #2

Give each group of students a copy of the Hydrology Data sheet to record their data (attached to end of lesson).

Provide each student group with a rectangular food storage container ("drainage" container), a watering can, a 100 mL graduated cylinder, a plastic cup, a sponge, and flooring tiles.

Direct students to prop up the short end of the container (the end without the hole) using wooden blocks.

Instruct students to place several tiles in the bottom ¼ of the drainage container, and then pour 100 mL of water into the watering can while holding the can over the elevated end of the drainage container.

Have a second student should collect the drained water in a cup, while a third student times the water collection.

Have students collect the water for 30 seconds and capture the remaining water in a separate container, then discard it. Direct the students to record the amount of water collected on a data table.

Direct students to repeat the investigation using sponges instead of tiles.

Finally, direct students to repeat the investigation at least three times using both tiles and sponges, varying the ratio of tiles to sponges with each trial. For instance, have students could test a ratio of 75% tile to 25% sponge, or 50% tile to 50% sponge. A sample picture of a 75% tile to 25% sponge set up is shown below.

Top view of Floodplain Model Surface Set-up (75% tile/25% sponge)

Explain

Direct students to graph the data collected during investigation #2 using the included data table.

At this point you may need to define pervious and impervious for the class.

  • Pervious - allowing water to pass through; permeable.

  • Impervious - not allowing fluid to pass through; impermeable.

Lead a discussion with students in which they analyze the impact of different substrates on water runoff, relate that to the effect of real-world land surface substrates on water runoff, and explain how flash floods occur and can be prevented. Sample questions and responses include:

How do the different substrates affect water run off? (Probe to have them cite evidence from their experiment.)

Which real-world land surfaces would result in greater run off? Which would result in less runoff? (Probe to have them cite evidence from their experiment.)

How do surfaces that are already saturated affect runoff? (Probe to have them cite evidence from their experiment.)

How do surfaces that are extremely dry affect runoff? (Probe to have them cite evidence from their experiment.)

How do surface types contribute to, or mitigate, flash flooding? (Probe to have them cite evidence from their experiment.)

Extend

Provide each group with a transparency and three different colors of dry erase markers.

Give each group an aerial photo map of one of the regions (maps can be local maps or you can use maps from the following websites:

Ask the students to look at the picture, give the students time to study it, then ask them what they see when looking at the photo.

After the students have shared with the class, have their group create 3-4 categories to classify the land use. Ex. Wild, Agriculture/Farming, City/Municipal, Forest, etc..

Give each category a color (Ex. - Agriculture = red, Municipal = Blue, Forest = Green)

Instruct students to place the grid transparency over the map and to color in the squares according to the land use. Have the students do this for the other maps as well so they can compare how the land use has changed over time. See examples on next page:

Map Key
1936 Aerial Map