Making a Watershed Model
This activity can be used with students of all grade levels. The model can be basic to complex, using simple objects to create topography or going as far to create a model of your watershed using topographical maps. Your class can explore different types of surface water, how water drains in a watershed, and how waters get polluted.
A watershed is all of the land area that drains water into a common body of water. Ridges form the boundaries of watersheds (easy to see in some areas, such as mountains; but difficult in flatter terrain). Surface water consists of rivers, streams, lakes, and reservoirs. In the U.S. 74% of water used is surface water ( Surface water is used for a variety of purposes, including irrigation, industry, mining, thermoelectricity, raising livestock, and domestic needs. A great resource for researching surface water is: Here you can access researched data and real-time stream flow. You can also “surf” your watershed at
To make a watershed model, you will need:
- Large plastic tub or storage container, e.g. a rectangular under-the-bed container
- A variety of objects of different sizes to create watershed topography, such as balled-up aluminum foil, rocks or plastic cups
- Paper maiche (flour, water, newspaper, mixing bowl) or clear, heavy plastic to cover entire watershed
- Dry erase markers or paints for marking on the watershed
- Water supply
- Watering can or spray bottle (to see how watershed is affected by different precipitation events, use watering cans or sprayers with different flow rates)
- Map of local watershed (optional)
Procedures:
- In the bottom of the large plastic container, lay out the “topography” of the watershed, using the materials you have chosen (cups, rocks, etc.). If you are using your local watershed, you will want to use topographical maps to lay it out.
- Cover the objects with either the plastic or paper maiche. Using plastic & dry erase and will allow your students to change around their watershed. Paper maiche will preserve it for the future. Use enough plastic to drape over the sides or tape it around the bottom of the container.
- Let the fun begin! Using different “precipitation” events, let your students explore their watershed. Trace the streamflow with markers. Where does it collect? How does it flow in the different parts? How would the flow affect housing or industrial development in the watershed?
Extensions:
- Allow your students to develop their watershed. Draw on the plastic with markers or use objects, such as Legos, to represent houses, farms, industry, etc.
- Pollute the watershed. Using substances such as hot chocolate mix, kool aid, raisins, marshmallows, etc. Just add pollution.
- Assign your students different roles in the watershed. Where do the different types of pollution come from? Who is responsible for it? Who is responsible for cleaning it up? Have your students create a watershed management and clean-up plan for their watershed.