Red indicates additions ESLI members have made to the Watershed game provided by Hemlock
Understanding Watershed Game
- Introduce water with the first page activity, but the main activity and prep material is on the second page. Adapted from Adventure Links at Hemlock Overlook.
- Materials for the game:
- 10 cones for marking river boundary (We made the boundary in papertowels, this was fine until it ripped.)
- About 100 Poker chips in different colors, to represent various pollution sources. (We used colorful popsicle sticks)
Main Activity
THE WATERSHED GAME
Modified from Project WET “The Incredible Journey” pg.161
Intended Results:
Conceptualize the way that water systems are part of the larger ecological system
Know what a watershed is, and how everything in a watershed affects water quality
Background:
Watersheds: (From Project WET) “When the ground is saturated or impermeable to water during heavy rains or snowmelt, excess water flows over the surface of land as runoff. Eventually, this water collects in channels such as streams. The land area that drains water into the channels is called the watershed or drainage basin. Areas of higher elevation, called ridge lines or divides, separate watersheds from each other. Eventually, water collects in a wide river that empties into a body of water, such as a lake or ocean.
From an aerial view, drainage patterns in watersheds resemble a network similar to the branching pattern of a tree. Tributaries, similar to twigs and small branches, flow into streams, the main branches of the tree. Streams eventually empty into a large river, comparable to the trunk.
Watersheds are either closed or open systems. In closed systems, water collects at a low point that lacks an outlet. The only way water naturally leaves the system is through evaporation or seepage into the ground. Most watersheds, like those in Virginia, are open: water that collects in smaller drainage basins overflows into outlet rivers and eventually empties into the sea.”
Point source pollution: This type enters directly into the water from a certain area, such as a factory or water treatment plant. This type of pollution is intentionally dumped into the water and can be traced to a specific source.
Nonpoint source pollution: This pollution usually comes into a water system unintentionally through runoff, from a variety of sources that can’t be traced. Ex: Water running from a parking lot picking up oil dripped from cars, then through a manicured lawn picking up fertilizers and pesticides, and then into a river.
Main sources of pollution:
Litter: In most towns and cities, storm drains flow directly to streams and rivers. Litter on sidewalks and streets and in gutters is swept into the storm drain system when it rains. According to the Ocean Conservancy, 60% to 80% of trash found on ocean beaches is washed, blown, or dumped from shore.
Sediment: Occurs in high influxes because of development and clearing of vegetation and forests. Increased sediment in water bodies makes them dirty and smothers critters living on the bottom. It also changes the pH and O2 levels making conditions unfavorable to certain organisms.
Fertilizer: Nitrogen and Phosphorous are two of the main components. Although they are necessary nutrients, when an overabundance of them enters the water system they cause a large amount of algae to bloom. The algae blocks sunlight from the rest of the water, changes the temperatures, and creates unfavorable conditions for certain organisms to survive. It also throws off the balance in the food chain, and some organisms will starve.
Various Pollutants: Some of these come in the forms of herbicides and pesticides from lawn care, spraying, etc, and are toxic to plants and animals in the water as well. Other pollutants come from oil, antifreeze, gas, etc, dripping from cars, from washers and dryers, from cleaning fluids dumped down the drain, from sewage plants and farms dumping human and animal waste (treated or untreated) in or near water bodies, etc.
Temperature Pollution: Temperature pollution is harmful for a few different reasons:
1) It can cause some animals that would usually migrate, to stay in the area, because they do not sense the change in seasons. Food will generally become scarce and offspring will not learn migratory patterns. 2) Some organisms are very sensitive to temperature, and cannot live out of their normal range. 3) A change in temperature will cause a change in flora and fauna that can throw off the food web.
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Timeframe: 35 min.
Supplies:10 cones for marking river boundary
About 100 Poker chips in different colors, to represent various pollution sources (coins also work).
Prep: Place the cones in a V formation with the top of the V pointing up hill, to serve as the boundary for your river. Place the hulla hoop at the bottom of the V to represent the body of water. Distribute poker chips around the area between the cones.(Instead of using a representation of a hill, we stood on the hill behind the blacktop. Another variation would be to play the second round of the game on the blacktop)
Framing:Ask the students where they think all the water they use comes from. How does water get into the ponds and streams we will be visiting today? Question them until you come to the point where the group agrees that the water comes in from rain running down slopes, underground sources, and springs, eventually gathering into rivers, ponds, and streams. Explain that this is how we define a watershed, the land that slopes down into where the water is collected. Explain that watersheds are divided by the highest points of land between them, the ridges. Ask students, “What are some of the things raindrops might do as they hit the slope and begin to run to bodies of water?” Tell them that you all are about to play a game that will show some of those things.
ENGAGING INTRO:
- We started by reading the Magic School Bus Raindrop book. (Only the ten pages about the water cycle)
- Then we used a white board to draw out the cycle. The bigger the white board the better. Multiple colors of markers would help.
- This can be used throughout the lesson to explain the detriments of pollution in the water cycle.
The Activity (EXPLORATORY ACTIVITY):
Round 1
- Separate your group in half, as trees and raindrops.
- Have the trees disperse themselves in the area above the cone river. They cannot move their feet, as trees are deeply rooted, but they can move their arms like branches. Have the raindrops stand above the area where the trees and poker chips are. Ask them how they are representing a watershed in this set-up.
- Tell the group that there is about to be a huge rainstorm. Once it begins, the raindrops will wash down the hill towards the river. As the raindrops run toward the river, they must try to pick up as many chips as possible.
- Ask, “What do you think happens to water when it comes to a tree on its way to a pond or stream?” Come to the answer that the tree slows it down, or sucks it up, depositing whatever sediment or pollution it has picked up into it’s own tissues, the atmosphere, or the soil. To show this, if a student is tagged by a tree, they have to drop everything they have picked up and run around the tree 3 times before beginning to gather chips again on their journey to the stream.
- Once they hit the stream, they deposit all of their sediment and pollution into it and wait for the game to be over (whenever you call time—about 30 seconds from the beginning of the game). They cannot come back up the hill once they have hit the river.
- Have the students count the poker chips and assign a student to remember the numbers.
Round 2
- Have kids switch roles to avoid complaining i.e. trees become raindrops and raindrops become trees.
Round 3
- Have the raindrops return to the top of the hill and scatter the poker chips around once again amongst the trees. Before they start this time, tell the group that you are a developer who has decided to put a shopping mall in this area. Explain that a few trees have been left for ambience, but most of the land has been paved, and the trees have been chopped down.
- Tell at least half of your trees that they have been turned to pavement or rock. As rock, they cannot tag raindrops, but actually hand them any sediment or pollution around them (they still cannot move their feet). Ask students why the pavement or rocks would be “handing over” the sediment or pollution. Explain that this shows the way impermeable surfaces do not absorb any water. They instead create a direct runoff effect with pollutants mixing with water as it runs downhill. It also shows that land with no vegetation gives up its soil easily as there are no roots to hold it together.
- Call the game in the same amount of time as for the first round and have all the students gather around the river. Count the poker chips again. The number gathered will be far greater this round.
Safety:
Do not let the kids run if it is too muddy out
Be sure the trees tag gently
Make sure students realize this is an activity with a point, not a prize.
If you let the trees and raindrops switch places between the two rounds, make sure they do not think of the game as a competition.
Processing (EXPANDING THE DISCUSSION):
Review the activity with the students. What happened? How did pollution get into the stream? (Run-off brought it there) What happened when the land was developed? (There was more pollution in the water)
Ask the students why more sediment and pollution ended up in the river or stream on the second round. Make sure they realize that impermeable surfaces cause water to flow quickly to its collection point, carrying soil and pollutants, and causing erosion, flooding, and water pollution. Ask, how could you slow down water so it will filter the run-off? Discuss the fact that planting trees and vegetation help to slow erosion because they function as sponges, keeping the soil loose so the water running over the ground is absorbed.
Ask students where they think pollution comes from. Is it just one place, one person? Tell them each poker chip color represents a different source of pollution. Brainstorm together what those different sources would be. Introduce the difference between point and nonpoint source pollution. Ask them if they can think of any ways to reduce or prevent non-point source pollutants.
Now, ask students what effect they think the pollution has on the stream environment. Use as a general question to get them started thinking about pollution, water quality, and the stream ecosystem. Ask them why they should be concerned about this one river. What if it was where they got their drinking water?
- Then we brought the students outside to play the game. It was set up before we came outside.
- Make sure students get to switch roles.
- Stress that it’s not a competition, but a demonstration of the water cycle.