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Texas Stream Team
Enviroscape Watershed Model:Sample Presentation
Materials
The Enviroscape watershed model includes everything you need, except:
Paper towels (approx. 1/2 roll per presentation)
Garbage bag
Extra cocoa powder andunsweetened drink mix packets
Water to fill the spray bottles, and extra water depending on how many presentations in a row
Time needed: 25 minutes.
Ideal number of students: 15 maximum per group.
Grade level: Works best for 4th through 8th grade, but can be done for lower or higher with appropriate adaptations.
Set up the model with all the “prop” pieces in place ahead of time, place the plug in the lake, place one of the empty Tupperware containers underneath the lake’s drain hole to catch the waste water at the end of the presentation, and fill the lake no more than halfway with water.
Introduction
My name is Julie Tuason and I work for Texas Stream Team at TexasStateUniversity in San Marcos. One of the things that we do at Texas Stream Team is to travel around to classrooms with this watershed model to teach about water quality and water pollution. This is a hands-on presentation, and everybody is going to get to participate.
In this demonstration, you’re going to learn three things: (1) What is a watershed? (2) What is nonpoint source pollution? and (3) What are some things that you can do to prevent nonpoint source pollution?So let’s start…
Presentation
Question: Does anybody know what a watershed is? (Take several answers until you get one that is close to correct.)
Answer: A watershed is an area of land that, when it rains, the water runs across the land and drains to a specific waterbody such as a stream or a lake.
Question: Raise your hand if you live in a watershed. (Trick question: Everybody lives in a watershed! Everybody lives in an area of land that drains to a specific waterbody.)
Question: Can anyone name the watershed we’re in right now? When it rains a lot and the water runs off, where does the water go?
Answer: (Example, if the presentation were here in San Marcos.) The San MarcosRiver watershed.
Question: Do you know what river the San Marcos drains into?
Answer: The GuadalupeRiver.
Question: And the GuadalupeRiver drains into what river next?
Answer: The San AntonioRiver, just before it empties into the Gulf of Mexico.
So, watersheds exist around all these rivers you’ve just named. They also exist for all the smaller streams that drain into each of these rivers. Now, take a look at this model.
Question: First of all, what is a model?
Answer: It’s a small representation of something much larger in the world.
Demonstration: (Have each of the kids cup their hands to make a bowl shape.)You’ve just made a tiny model of a watershed.
Question: What happens if it rains in an upper part of the watershed? Where does the water flow?
Demonstration: (Use the spray bottle to squirt a little “rain” onto anupper side of their tiny watersheds.)
Question: Which way is the water flowing?
Answer: Downward, toward the line in the middle of their cupped hands. (The middle of their cupped hands can represent a lake or a stream. It’s a leaky one, though!)
Question: Why does the water flow down to the center? What force is acting on it?
Answer: Gravity.
Now shake the water off your hands, and take a look at this bigger watershed model.
Question: If it rains on this upper portion of the model (point to the hilly area), which way is the water going to flow?
Answer: Down toward the lake.
Question: Again, why? What force is acting on the water?
Answer: Gravity.
So now let’s see what are some of the effects of pollution on this watershed. First, notice that there are different types of land use shown on this model.
Question: What kinds of land use do you see? What have people built on all these different areas?
Answer: (May include: houses/residential, farm/agricultural, factory/industrial, roads/transportation, lake/recreational.)
It’s important to notice the different kinds of land use because each one will produce different kinds of water pollution. There are many specific kinds of pollution. Can you name some different things that can pollute the water?
Answer: (May include: trash, oil, poop, chemicals, etc.)
You can put all these different kinds of pollution into two broad categories called “point source pollution” and “nonpoint source pollution.”
Question: Can anyone guess what “point source pollution” is?
Answer: Pollution that comes from one specific point that you can clearly see.
An example of point source pollution is this factory right here. Let’s pretend that this is a factory that makes motor oil (or any such example). Let’s see what happens if this factory is releasing its waste oil and chemicals directly into the nearby stream.
Demonstration: (Call for your first volunteer. Have them use the cocoa powder to simulate the waste oil. Sprinkle lots of it (lots!) into and around the hole in the top of the factory. They can also sprinkle a little pile of cocoa power at the end of the effluent pipe that sticks out of the factory into the stream.)
Demonstration: (Call for a different volunteer. Have them spray water onto the cocoa powder to represent the factory releasing the waste oil into the stream. Have them spray lots and lots of water until the water with the cocoa powder runs down the stream and enters the lake.)
Question: If you were swimming in the lake right there, what would you do right now?
Answer: Get out of the water!
Question: Now, pollution is a bad thing, right? But, in fact, if you think about it, there is actually one GOOD thing about point source pollution. Can anyone guess what that one good thing is?
Answer: We can see exactly where the pollution is coming from (point it out on the model).
Question: And why is that a good thing?
Answer: We can tell that factory to stop polluting. In other words, we can regulate point source pollution by watching for pollutants coming out of the pipe and making laws that limit how much pollution they’re allowed to release into the streams.
Question: So if point source pollution is pollution that comes from one specific point that you can clearly identify, can anyone tell me what “nonpoint source pollution” might be?
Answer: Nonpoint source pollution is pollution that comes from many, many different sources spread all across the watershed. It’s not coming from a factory or a wastewater treatment plant, but it’s coming from things that ordinary people like you and your neighbors and your parents might be doing, even without knowing it.So let’s take a look at some specific examples of nonpoint source pollution.
Demonstration: Who would like to volunteer as readers? (Pass out the six “situation cards.”)
Question: Who’s got Situation #1? Read nice and loud, and everyone else please listen closely. (Volunteer reads the card.)
Demonstration: So let’s pretend that Roger lives over in this house. He drives his car that’s leaking oil as he drives to work, and then home again later that day. (Drive the car to the factory and back.) Who’d like to volunteer to be Roger? (Call on different volunteer, other than the reader. Hand over one of the powdered drink mix containers and have them sprinkle the powder on the road everywhere that Roger has driven. Use lots of powder for greater effect in the end.)
Question: Now think about this. Roger is just one person. How many people do you think live in San Marcos (or your own town)?
Answer: 50,000 people!
Question: Of those 50,000, how many people do you think are driving cars that are leaking oil on the roads?
Answer: We don’t know for sure, but at least hundreds or maybe even thousands!
Question: Can you imagine the pollution from thousands of cars just like Rogers, making trips in this watershed every single day of the year? How polluted will the roads get?
Answer: Very polluted!
Demonstration: Okay, who’s got Situation #2? Read nice and loud, and everyone else please listen.[Repeat this type of questioning for each of the six situation cards.]
Now, take a look at this watershed.
Question: Is this a clean or a dirty watershed?
Answer: Dirty!
Question: Is this the kind of watershed you would like to live in?
Answer: No!
Question: Is this the kind of watershed that you actually do live in?
Answer: Yes, in fact it is, because people are producing all kinds of nonpoint source pollution in many places every single day.
Question: Now, I’m going to have you make a hypothesis. What is going to happen to all this pollution when it rains?
Answer: It will end up in the lake.
Question: Again, why will it end up in the lake? What force acts on the water?
Answer: Because of gravity.
Demonstration: Okay, let’s see if you are correct. (Hand out all the spray bottles. Tell them that everyone is going to get a chance to make it rain. They will take turns.) Okay, make it rain, rain, rain! (After a minute or two, say “Stop! Now switch to a new person.” Continue the rainstorm. (Tell them to look carefully at the model and watch what is happening. Where is the pollution going? (After a minute or two, say “Stop! Raise your hand if you haven’t had a chance to rain.” Redistribute the spray bottles and repeat until each kid gets a turn at making it rain. After another minute or two, say “Stop! End of rainstorm.) Collect all the spray bottles.
Now, take a look at this model.
Question: First of all, was your hypothesis correct?
Answer: Yes. The pollution ran downward into the lake.
Question: Take a look at the lake. What if this was the source of your drinking water? (Kids will probably say “Ewwww!”) What if this was where you like to go swimming in the summer? What if you were a fish trying to live in this lake?
Question: So if water pollution is a bad thing, what are some things that you can do to prevent this from happening in your watershed?
Answer: (See what examples the students come up with based on the six situations, or if they can think of any additional ones themselves. These will include: repair any leaks in your car, pick up litter and throw it in the trash can, follow the instructions when you use fertilizer, put a fence up around construction sites, put a fence between the cattle feeding areas and the nearby stream.)
Review and Clean-up
Question: Okay, now think about what we’ve talked about. Raise your hand if you understand what a watershed is. Who wants to tell me?
Question: Now, raise your hand if you understand what nonpoint source pollution is.
Question: Now, raise your hand if you can think of at least two things that you can do to prevent nonpoint source pollution.
Congratulations! Now give yourselves a nice big round of applause. The last thing today is that you now get to become environmentalists and clean up this watershed. Remove all the pieces and remember where they go so you can put them back again later.
(Ask one person to pull the plug on the lake. Hand out paper towels to everyone and have them spray the model down and wipe it clean. Collect used paper towels in a garbage bag. Have them put all the pieces back on the model, fill the lake with a little bit of water, empty the drained water into a bucket or sink, and the model is ready to be used for the next group. Refill the spray bottles and powdered drink mix containers if necessary.)