Wacky Watershed
Objective: This activity is designed to introduce students to the concept of a
watershed. After building a watershed of their own design, students will analyze
how water moves over the land and collects into a common area. They will also be
able to discuss how land use affects the quality of surface water.
Introduction:
A watershed includes all of the land area that drains into a river system, a network of connected streams
and rivers. Since water moves downhill, the boundary of watersheds are located at the highest elevations.
Any substance located at a higher elevation will run downhill and enter the river system altering the
ecosystem and communities existing at a lower altitude. Different types of land uses such as agriculture,
mining, forests, and residential areas have different types of pollutants associated to the ways in which they
use the land. These pollutants eventually run off and effect the health of the river system.
Land Use and Types of Pollution:
1. Research the 5 types of pollutants discussed in the Environmental Science (9)
book on pages 436-438. Record information in the data tables below.
2. Using your research, complete the chart in the data section indicating what types
of pollution is associated to each land use. There will be more than one type of
pollution for each land use.
Type of Water Pollution
Nutrient Pollution
Toxic-Chemical Pollution
Sediment Pollution
Thermal Pollution
Biological Pollution
Causes/Effect
Procedure:
Create a Watershed:
1. The box will serve as the base of the watershed. As a group, students will
decide which materials they will use to shape the “land” inside their
watershed. Students should include both high and low points in their model.
2. Once the bottom layer of the model has been assembled, place the trash
bag over the model so that it covers the contours of the model’s landscape.
Use the binder clips to secure the edges of the bag to the box lid.
3. Pour water into the lowest elevation to represent surface water.
4. After the trash bag is secure, students will use a sharpie to mark off and
label areas representing the following land uses: forested areas;
farms/agriculture; mined areas; residential areas; wastewater treatment
plant; industrial areas/factories; development/construction/roads.
5. Create a sketch of your watershed in the data section.
Modelling a watershed in action:
1. Assign each type of water pollution a color. Create a key in the space below:
Type of Water pollution
Nutrient
Toxic-Chemical
Sediment
Thermal
Biological
Color
2. Color the land use areas on your watershed with the assigned colors. This
will represent the types of pollutants associated to that land use. Some land
uses will have multiple colors (make stripes).
3. Use a spray bottle to simulate a rain storm. Make observations.
4. Answer the discussion questions.
Data:
Picture of watershed:
Land Use and Types of Water Pollution
Land Use
Agriculture
Mining
Forestry
Residential
Wastewater Treatment
Industrial
Development/Construction/Roads
Types of Water Pollution
Discussion: Answer the following questions…
1. Where did the water pool on your model? Why did it stay in these areas?
2. What color is the water in the pool(s) at the end of the experiment? What does
this color represent to you?
3. How would you describe a watershed?
4. What happens in a watershed when it rains?
5. How is this model not a perfect model of an actual watershed?
6. To help conserve water quality, a buffer needs to be preserved. What is a
buffer? What could you use to illustrate a buffer in this activity? What is the
purpose of a buffer?