Watershed: Exploring Run-Off and Infiltration in the Classroom

Learning Goals:
1. The students are making a model to understand infiltration and run-off. After an understanding of this model the students will go outside and observe how our rain garden is similar/different from their model and make connections.
2. Ultimately, students will be asked what happens if too much water moves through a system. This will lead to discussions of flooding and the impacts. Also, this will lead into discussions about the movement of pollutants through a system and that impact on the greater ecosystem.
Key Concepts:
1. Water moves through a system and changes along the way.
2. Objects affect the amount of water and water quality of a system.
3. Paved surfaces impact water shed.
4. If water can't be taken into the soil, it can go through various routes of the water cycle.
Vocabulary Words:
1. Erosion
2. Infiltration
3. Run-off
4. Evaporation
5. Transportation
6. Respiration
7. Pollution
8. Rain garden

I believe that this activity is relevant for my teaching because the water cycle is already embedded into the second grade curriculum. Also, our school has the pleasure of having an actual rain garden on campus. This submitted lesson is one piece of a much larger pie that could be woven into instruction throughout the year. The submitted lesson is intended for students to do in partners or in small groups. After a brief demo, the students should be able to explore and take data independently. I would do this lesson in the springtime when the idea of flooding is especially relevant. Before this point, I would plan on building a bigger model (similar to the cup) for a whole class demonstration. Before the students began, I would want to make sure that they realized that water moves through the system and it changes systems along the way. I would take a large plastic container, cut it off half way with a plastic wall with a hole in it. The top half would be filled with soil. I would dump water into the top half and watch as the water moves the soil through the system and what the water looks like as it get to the second half of the box. With this understanding, the students are ready to investigate with various objects to see if they can affect the outcome.

BACKGROUND
Students should come to this activity with a background that water moves through a system and changes along the way!
GETTING SET UP
Depending on the level of your students the beginning of this experiment may involve prep work. For example, make sure there are large plastic solo cups ready with holes in the bottom. I would make the holes about the size of a pencil. Also, have the other materials ready. This is the part of the lesson where you can be creative! Perhaps the day before the kids even want to help brainstorm ideas for objects to use in the system. I would recommend a sponge, tin foil, clay, and coffee filter to begin with. Make sure that the clay and the tin foil have small holes poked in the bottom since they will not let the water run through like the sponge or the coffee filter. This is something you may wish to bring up to your students, or let them discover it on their own! I would poke holes with a pinhead, so the water can get through, but the holes are not too big. You will also want to prep the soil with a reasonable size scoop, so you can instruct the students to take "two scoops" into their cup. Also, make sure to have the students (or you ahead of time) label their three cups A, B, and C as to not confuse the experiment. You will also need clear glass or plastic containers to keep the run off for observation. This could be anything from a graduated cylinder (if you wanted the students to quantify the amount) or baby food jars. It may also be helpful to have timers, but looking at a second hand on a clock, or setting one on your computer will work too.
BEGINNING
To begin this activity, demonstrate the experiment without an object at the bottom of Cup B, just soil. Tell the students to take 2 scoops of soil. Show the students how they will fill Cup A with water from the sink to the line indicated. Then, show them how to dump the water from Cup A into Cup B. Then, observe what comes out the bottom into Cup C. Introduce the word run-off for what is found in Cup C. Talk with the students about the amount and the color of the water. As the water is flowing it will begin to slow. Tell the students that when they do this experiment in their group, they will have someone timing for 1 minute to see how much water comes out of the cup. After 1 minute they will transfer the water in Cup C to a baby food jar for later observation. Review the procedure one more time. "Now, you are going to be putting different objects at the bottom of your cup. How do you think tin foil will affect the water that comes into Cup C? How do you think a sponge will affect the water that comes into Cup C?" Let students discuss predictions.
Put students in cooperative groups of 4. With each foursome they will need three cups (one with each letter), clay, tin foil, sponge, and coffee filter, and soil bucket with scoop. They will also need glass containers. Since there are 4 students in a group, they can switch roles for each experiment. You have the water, soil, object set-up, and timer as the experiment leader. Students will take turns in this position. The other jobs are water pourer, holder of Cup B and holder of Cup C. Holder of Cup C can pour the run-off into the baby food jar. You can tell the students to put the baby food jar with the run-off on their data collection sheet as to not confuse the results. Then, the students clean out all Cups and repeat the process with the next object.
Bring the students back together to collect results.
1. Which object made the most run-off?
2. Which object made the darkest run-off?
3. (EXTENTION TO REAL WORLD)
Is it good to have a lot of run-off? What happens if we don't have any run-off? Data Record Sheet (Microsoft Word 36kB May31 11)

It needs to be noted that this lesson idea was originated from an embarrassing realization I had during the MNstep course. Last year I taught the water cycle as simple evaporation, condensation, and preciptiation. Thinking about it from a young child's point of view, this is the most abstract component of the whole system! Water shed and infiltration is something that students can observe with their own two eyes and replicate via experiment in the classroom. I think that beginning with these ideas about water will lead to a greater understanding of the water cycle as a whole and why it is important to us from an environmental standpoint. There are many different directions that you could take these ideas and adapt them to different levels. Even if you don't have a rain garden, a follow-up with a hose out on the driveway could be just as powerful!
**Please contact MinnAQUA for a CD containing all of their lessons. Their water stewardship lessons are what motivated me to write this lesson and I plan on using most of them in this unit.

Please see the data record sheet for assessment. Also, we will have a whole-group follow up discussion after the experiment when you can further assess student understanding.

2.I.b.2- Students will recognize and describe patterns in data.
2.III.a.1- Students will observe water.