Building a Water Run Off Model
Observing water runoff can greatly enhance a student's understanding of watersheds and the reality of water pollution. To help my students observe the pollutants that enter our water system, I constructed a water run off model that includes five different types of common surface areas. To make your own, follow the steps below!
Material:
- Five two clear two liter bottles of pop.
- A large piece of wood (The size can vary depending on your preferences but it must be able to fit the five liters vertically.)
- Sandpaper
- Razer blade
- Five metal washers and screw drivers
- Cheese clothes / landscaping paper
- Five pony tail holders or rubber bands
- Five surface materials to place in the bottles
STEP 1: Collect at least five clear two liter bottles of pop. Remove the lid, peel off the labels, wash them and allow them to dry out.
STEP 2: Take your razor blade and cut the bottles about two inches from the bottom. There is usually a little indented line on the bottle that allows you to make a nice even cut. Keep both pieces of the bottle.
STEP 3: Take your board and sand it down. Then measure evenly where to put your bottles. I left four inches from the edges and then marked every five inches for my bottles.
STEP 4: Take the landscaping clothes or cheese cloth and cut it into 4x4 squares. Then secure them of the top of the pop bottle with a pony tail holder or a rubber band.
STEP 5: With your razor blade make small holes about two inches blow the top of your bottle. Then press a screw through the bottle being careful not to tear the plastic. Make a starter hole in the wood where you want your bottle to be placed. With a hand held screw driver, screw in your washer and screw to secure the pop bottles to the piece of wood. Repeat this for each bottle.
STEP 6: Fill each bottle with different surface materials. I chose to use wood chips (because that's what the kids have on their playground), rocks, long native grass from the marsh outside our school, grass from my front yard and compost material (leaves, needles, and dirt from under our trees.
Have students measure our a half a cup of water to put in each bottle for a week. Have them track the amount of water that is filtered through compared to what was put in. You can also have students time to see how long each it takes each of the five bottles to filter through the water and start to drain.
This model was extremely helpful for my students. They loved to water it and watch it drain. This served as a great introduction for my students as they gathered knowledge to help them build their own filters to clean polluted water.
