What Is a Watershed? (6-8)
The purpose of the lesson is to educate learners about watersheds, ways in which water pollution occurs, and how important proper use of watersheds is to them. After understanding the importance of the watersheds, they will recognize that wise usage of their local watershed is an example of stewardship.
The learner will:
- write a definition for watershed.
- draw a picture of their watershed.
- write a short story detailing at least one way their watershed could become polluted.
- list three reasons why it is important to protect their watershed.
- per group or individual: scrap paper, water-based markers (blue, black, brown, & red), paper towel, spray water bottle
- Computer access (for teacher)
- For water pollution Demonstration (optional) – see instructions for details two clear 2-Liter bottles, utility knife, drill, coffee filter, two inches of sand (six cm.) tape, water, red food coloring
- Maps of your local watershed (see Bibliographical References)
- Colored pencils (per student)
- projected image of the local watershed
- drawing paper
- examples of fish, plant life, or animals found in your watershed area
- writing paper and pencils
- Handout One: Water Usage Information
Interactive Parent / Student Homework: The students will write a letter home to their parents, explaining their study of the watershed and asking them to help devise a plan to reduce water usage in their household. Learners should share information from their family’s plan with the class. The entire class can brainstorm a list of ideas for saving water, which can be sent home with the letters as a springboard for discussion. The learners may choose to include information from the chart concerning water usage in their letters. The letter might take the form of: Dear Mom and Dad, Did you know…? After sharing the letters with parents learners may have other ideas gained from their discussions with parents that may be shared with the class. These ideas may be springboards for other service learning projects that concern protecting the watershed.
Conservation Technology Information Center. "Know Your Watershed" http://www.ctic.purdue.edu/Know%20Your%20Watershed/
EPA "Surf Your Watershed" site http://cfpub.epa.gov/surf/locate/index.cfm
Ask the learners to write ten ways that they use water on individual siicky notes. As a group, organize their responses on a chart. The students can work together to make categories and add more ideas.
Example categories might be Recreation, Health, Household, and Work.
Discuss where the water in their taps comes from.
Write the word Watershed on the board. Ask learners for definitions. Provide a simple definition for a watershed – a body of land that drains into a river, lake, or other body of water.
(Teacher Note: Boundaries are high points of land that slope downward towards the body of water). Add that all water in our area is part of a common watershed, and the Earth is made up of numerous watersheds, some containing more of the Earth’s (fresh) water than others.
Do the following activity to demonstrate what a watershed is. It can be done individually or in groups. Ask each group or individual to follow these instructions:
- Crumple a piece of paper into a loose ball.
- Partially open the paper, and place it on a desk. The paper should still be crumpled enough to have portions that resemble mountain ridges and valleys. Be sure there is a paper towel under the paper.
- Using a blue water-based marker, have students mark streams or rivers on their papers, and also have them mark where they think the water will collect as it runs downhill. (This could represent a lake.).
- Using a black water-based marker, have students outline the ridges that separate onestream or river from another.
- Using brown water-based markers, have students draw exposed soil that could erode or wash away into the lake as the water flows through the watershed.
- Using red water-based markers, have students draw in some pollutants that may be found in their watershed, such as soap from washing cars, pesticides from lawns, and animal waste from a nearby farm. Keeping the model on the desks, have students spray (or you go around with a sprayer and spray) a very light mist of water over it.
- Observe where water runs down and collects. Questions to consider:
- What do you think the paper represents?
- What do you think the spray represents?
- Why does water flow down into the creases?
- What would you call the water that runs down in the creases
- And the water that collects in “pools”?
- What happened to the ink from the markers as the water flowed? Where did it end up?
- How is this a problem if the inks represent pollutants?”
Ask learners to consider how this model is similar to and/or different from local areas.Where in the community would there be the most pollutants?
Ask learners to identify where the rain and snow in their area drains. They may name local rivers, lakes, or bays, etc.
Provide them with a county or state map which indicates/labels the rivers and streams flowing through their watershed. Indicate the lowest point in the watershed (the point to which all water flows) and have them trace the path they believe the water would flow to get there.
They may start by marking their town with a red dot, and then find the river nearest to their school or town and draw a blue line from there to the lowest point in the watershed - indicating any rivers it may flow through along the way.
Make sure they include arrows showing the direction the water flows.It may be best to use an overhead projector and guide them through this process, frequently asking for student input. Students should label the rivers, lakes, etc. on the map.
You could further the process by having the students write a short paragraph explaining how water gets from their house, school, or community in general to this “end” point. Maps can be found at the EPA Surf Your Watershed site https://cfpub.epa.gov/surf/locate/index.cfm and background info on your watershed can be found at the Know Your Watershed site http://www.ctic.purdue.edu/Know%20Your%20Watershed/
Have the learners visit and/or research a local stream, river or lake to determine the conditions of a local water supply. You may ask a local city or county official to visit teh class to talk about the condition of local water and concerns. Learners will create a list of environmental problems associated with the body of water and then develop a plan to clean or protectthe area.If possible learners will plan an “action” day to go to the water source and clean/protect the area. Planning and implementing this projectwill take place simultaneously with teaching the next lessons.
Day Two Anticipatory Set: Tell the learners that yesterday, we discovered what our watershed is. Think of at least one way you use our watershed and one way our watershed could be harmed. (Think, pair, share to get all learners participating).
Look at yesterday’s maps and continue the discussion of pollution.
As you look at this map, discuss how the health of a watershed is determined by many factors, including the use of land throughout the watershed, and what pollutants each uses that may be put into the watershed.
Discuss what types of land use are present within your community and your overall watershed.Ask: Are there factories that produce heavy metals such as mercury and cadmium and organic chemicals like PCBs (Polychlorinated Biphenyls) and PAHs (Polyhydroxyalkanoates). Are there farms that use nitrates from fertilizers and livestock waste. Are there small businesses using things that might pollute the watershed?
Discuss how each of these uses could lead to pollution, not only by being directly put into the drainage area, but also indirectly through other rivers, lakes, and streams, and even through groundwater. Define ground water as. water that soaks into the ground.
Discuss ways in which pollution could occur: run-off of crop and forest land, failing septic systems, construction sites, irrigation drainage systems, automobile exhaust, etc. How can waste materials like old motor oil, pesticides, and raw sewage (from overflowing septic tanks) get into the watershed?
Do a water pollution demonstration (optional) at this point to show how easily contaminants can get into the water source.
Using two clear plastic two liter bottles create a model of the water table. Using a utility knife cut the bottom two inches of a plastic two liter bottle off, recycle the top.
Drill six holes in the bottom of the remaining piece. This can be done with a low speed drill or a hot nail.
Cut off the top two inches (five cm) of the other bottle. Insert the bottom of the first bottle into the second bottle with the holes pointing up.
Cut a coffee filter or other filtering material to fit into the second bottle. Cover the coffee filter and the bottle bottom with two inches (five cm) of sand. You may tape the top of the second bottle back on, but it is not necessary. You now have a working model of ground water and pollution.
To demonstrate how water pollution seeps into ground pour one cup of water on the sand. The water will filter through the sand and collect at the bottom of the bottle.
To demonstrate pollution, place five drops of red food coloring on the sand to simulate a pollutant. Slowly pour one cup of water on top of the food coloring. It will filter through the sand and appear in the bottom of the bottle. The ground water has been polluted. Is the soil above the water polluted? How do you clean the ground water?
Generate a list of why it is important to protect their local watershed.
Explain to learners that it is important to know that the responsible use of watershed is an example of stewardship. We live on this Earth and we need to take care of it for ourselves and for those who come after us.
Tell the learners that they work for the EPA (Environmental Protection Agency) and that they have to write a report about the conditions of a local watershed. The report is to be sent to the local government of a city explaining that the local water supply is becoming polluted by factories and farms in the area. They should include reasons why it is important to create policies to enforce the law. The learners should include information gained from activities done in the lesson.
Learners will locate a river, stream, of body of water in their area that needs to be cleaned. They will develop an action plan on how to do that.
Strand PHIL.IV Volunteering and Service
Standard VS 01. Needs Assessment
Benchmark MS.1 Identify a need in the school, local community, state, nation, or world.