What Is a Watershed?
The purpose of the lesson is to help learners understand the importance of watersheds and ways in which they can reduce water pollution in their watershed.
The learner will:
- write a definition for watershed (the land area that drains into a particular lake, river, or ocean).
- name ways 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
- Projected image of local watershed
Each learner writes on sticky notes five ways that they use water -- one sticky note for each response. They bring their ideas together and organize their sticky note responses into categores of their choosing (ex. recreation, health, household, etc). Lead to a discussion of why water is important to us.
Ask where they think the water in the tap comes from. (They may indicate a well or nearby lake.) Tell them that their water source is part of a system of watersheds.
Provide a simple definition for a watershed – the land area that defines what water drains into a river, lake, or other body of water.
Teacher Note - boundaries of watersheds are high points of land that slope downward toward the body of water. The Earth is made up of numerous watersheds, some containing more of the Earth’s (fresh) water than others. There are watersheds within watersheds.
Do the following activity to demonstrate what a watershed is. It can be done individually or in groups. Ask each group or individual to:
- 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:
The paper represents a watershed. The spray represents precipitation and condensation and water from streams and rivers. Ask the following questions:
- Why does water flow down into the creases?
- What does the water that runs down in the creases represent from a real watershed?
- What does the water that collects in pools represent from a real watershed?
- 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 is similar to a local area.Where in the community would there be the most pollutants? Where does the rain, snow, and other water end up in their area? They may name local rivers streams, lakes, or bays, etc.
Look at a local watershed map that shows the streams and rivers flowing through their watershed. Have them identify the lowest point in the watershed – the point to which all water flows - and have them trace the paths they believe the water would flow to get there.
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. You may need to do some advance research about your individual community, and share the information with the learners.
Discuss any potential pollution, not only by being directly put into the drainage area, but also indirectly through other streams, rivers, lakes, and even through groundwater. This may include run-off from crop and forest land, failing septic systems, construction sites, irrigation drainage systems, and automobile exhaust. Discuss how waste materials like old motor oil, pesticides, and raw sewage get into the watershed.
The responsible use of watershed is an example of stewardship.We live on Mother Earth and we need to take care of her for ourselves and for those who come after us. Discuss things we can do to innovate or communicate to make a difference for the watershed we share.
Flint Water Crisis 2015-16
The Flint River is a healthy ecosystem, part of a watershed with healthy biomes, including diverse plants and animals. When the Flint water crisis brought lead-contaminated water into homes, it was because the city shifted from lake water to river water without changing the way they treated the water. River water stripped protective coatings off water pipes and released lead into the water. This showed a careless lack of oversight and planning. Many people had the misconception that the river itself was toxic. What should have happened in city and state government before they decided to switch from lake to river water? How can citizens and scientists make this information available so oversight like this doesn't happen in other communities?
Students may research this issue and local watershed and water systems and advocate for wise action regarding their own community's water.
Strand PHIL.II Philanthropy and Civil Society
Standard PCS 03. Philanthropy and Economics
Benchmark E.5 Recognize the wise use of resources as <i>stewardship</i>.