When it Rains it Pours

Transcription

1 Lesson Summary: Students will understand how water is absorbed into the ground. They will also be able to explain the difference between pervious and impervious surfaces. Students will also learn about watersheds and storm-water runoff. References: Lesson adapted with permission from: 1. Bullitt County s Water Quality Curriculum, Groundwater & Storm-water: To Soak In or Run Off That is the Question? 2. Bullitt County s Water Quality Curriculum, Watersheds Follow the Flow: Where does all the Rain Go? Teacher Resource: Classroom Activities Where Does All the Rain Go? page Time: Approximately 45 minutes Materials: 1 large plastic tarp Stools, chairs, boxes, etc, for creating a watershed (placed under the tarp they will form hills, mountains, etc). 5-7 large spray bottles filled with water (and/or sprinkling cans) Several Colors of Drink Mix Packets 1 cup of dirt 1 cup of sand 3-4 Sponges White/clear bowl 5-gallon bucket (filled about 2/3 of the way with water) Soaking Up the Water page Time: 40 minutes Materials: Sand Pea-sized gravel Tap Water Measuring spoons Blue & Green Food Coloring 4 clear plastic cups per group 1 Magnifying glass per group Worksheets Where Does All the Rain Go? page 176 Soaking Up the Water page 179 McCreary County Water District Water Quality Curriculum 171

2 Objectives: Science: SC-EP Students will understand that objects have many observable properties such as size, mass, shape, color, temperature, magnetism and the ability to interact and/or to react with other substances. Some properties can be measured using tools such as metric rulers, balances and thermometers. SC-EP Students will describe the properties of water as it occurs as a solid, liquid or gas. Matter (water) can exist in different states--solid, liquid and gas. Properties of those states of matter can be used to describe and classify them. DOK 2 SC-EP Students will describe earth materials (solid rocks, soils, water and gases of the atmosphere) using their properties. Earth materials include solid rocks and soils, water and the gases of the atmosphere. Minerals that make up rocks have properties of color, luster and hardness. Soils have properties of color, texture, the capacity to retain water and the ability to support plant growth. Water on Earth and in the atmosphere can be a solid, liquid or gas. DOK 2 SC-EP Students will explain the basic needs of organisms. Organisms have basic needs. For example, animals need air, water and food; plants need air, water, nutrients and light. Organisms can survive only in environments in which their needs can be met. DOK 2 SC Students will: describe human interactions in the environment where they live; classify the interactions as beneficial or harmful to the environment using data/evidence to support conclusions. All organisms, including humans, cause changes in the environment where they live. Some of these changes are detrimental to the organism or to other organisms; other changes are beneficial (e.g., dams benefit some aquatic organisms but are detrimental to others). By evaluating the consequences of change using cause and effect relationships, solutions to real life situations/dilemmas can be proposed. DOK 3 Social Studies: SS Students explain how factors in one location can impact other locations (e.g., natural disasters, building dams). SS Students will explain and give examples of how people adapted to/modified the physical environment (e.g., natural resources, physical geography, natural disasters) to meet their needs during the history of Kentucky and explain its impact on the environment today. DOK 3 McCreary County Water District Water Quality Curriculum 172

3 Lesson Plan: When it rains, wa ter can do one of three things: it can collect on vegetation and evaporate, it can soak into the ground (infiltration), or it can runoff over the ground s surface to the nearest drainage ditch, pipe, or stream. The rain s ability to absorb into the ground is most dependent on the ground cover where it lands. If the ground is pervious, such as a grassy lawn, a forest, or field, the rain can easily soak into the ground. If the ground is impervious, such as concrete driveways and sidewalks, asphalt roads and parking lots, and rooftops of houses, the rain cannot soak into the ground. Rather, the rain becomes storm-water runoff and goes directly into storm drains. Storm sewer pipes then carry the storm-water directly to the nearest creek, stream, river, or lake. Another big difference between groundwater infiltration and storm-water runoff is the quality of the water. When water soaks into the ground, the ground s sand and silt act as a natural filter. However, when water runs over impervious surfaces, it picks up all kinds of pollution along the way. It then carries the pollution to the nearest body of water untreated! That s a big difference. The topography of an area is what determines where each raindrop goes. If it lands on one side of a hill, it may travel to one stream, whereas if it lands on the other side of a slope, it may travel to a different stream. We all live in a watershed. The easiest way to determine what watershed you re in is by asking the question, where will a drop of water go if it lands at my feet? Where will it end up? (Big South Fork River Cumberland River Ohio River Mississippi River Gulf of Mexico) The definition of a watershed is the land where all of the water drains to a specific location, including surface runoff and groundwater flow. Watersheds range in sizes from very large to very small and are typically named after the largest stream or river in the watershed. For example, the Mississippi River Watershed drains 41% of the United States to the Gulf of Mexico. See the Rivers of the United States map (included). The key is that every drop of rain flows somewhere, whether it lands in your backyard, at your school, or the grocery store parking lot. We all live in a watershed. Kentucky is divided into 8 major watersheds. (See attached map, Kentucky Watersheds ). If a drop of rain lands in Lexington or Frankfort, the Kentucky River will carry it north to the Ohio River. If it lands in Bowling Green, the Green River will take it to the Ohio River. Can you figure out which Kentucky watershed you live in? Can you figure out which McCreary County watershed you live in? (See the attached Which Watershed do I live in map). Whether our watershed becomes polluted is largely up to us, because if it is on the ground, it is in your water. When someone throws something on the ground, the rain washes it into the nearest stream, river, or lake. Every time it rains, watersheds drain. McCreary County Water District Water Quality Curriculum 173

4 Classroom Activity: Where Does All the Rain Go? In this activity, students will learn what watersheds are and what they look like. They will also examine the impact that storm-water runoff has on a watershed. It will take approximately 45 minutes to complete this activity. You ll also need 1 large plastic tarp, stools/chairs/boxes, 5-7 large spray bottles filled with water, 1 cup of dirt, 1 cup of sand, 3-4 sponges, several colors of drink mix packets, white/clear bowl, One 5 gallon bucket (filled about 2/3 of the way with water). Here s what to do Take the class outside. Have students carry the necessary supplies 2. Spread the tarp out over the boxes, chairs, etc. Be sure to arrange the tarp so that the majority of the surface will drain to one point. Place the bowl at that point along the edge of the tarp. 3. Tell the students to visualize that this is a large area of land with mountains, hills, and valleys, and that they are looking at it from above (i.e. a helicopter). Remind them of the concept of a watershed. Ask them to predict where the water will flow by looking at the topography of the tarp (before spraying it with water). 4. Have the students spray into the air over the tarp with the spray bottles, creating rain (allowing the rain to gently fall from the sky, rather than directly spraying the tarp with the bottles). The area of the tarp that drains to the bowl is called a watershed. Water drops that flow off the tarp in other directions are a part of other watersheds. As the water falls onto the tarp and begins to flow, ask the students to compare what actually happens with their prediction. 5. Ask the students how this is similar to a real watershed. Ask them how it is different. Remind them about their previous lesson involving groundwater and infiltration. Does the tarp allow any infiltration into the ground? Observations Water drops slowly join with other droplets, forming bigger drops. As the bigger drops begin to move downhill, they continue to join with other drops and become even bigger As they become bigger, they also seem to move faster Once enough drops of water join together, they form a small stream of water As you continue to move down the valley, small streams (tributaries) join to become larger streams. The area of the tarp that drains to the bowl is called a Watershed. Since the tarp allows no infiltration into the groundwater, the mock watershed responds similarly to an urban watershed. In cities, building rooftops, streets, sidewalks, and parking lots are also impervious, and respond much like the water does on the tarp. 6. Ask the students what else is missing in the watershed. Aren t there a lot of things on the ground in our real watershed? (e.g., plants, dirt, pollution, etc.). 7. After the tarp has mostly dried, empty the bowl of water and place items at various locations throughout the watershed. Pollution such as drips of oil, spilled gasoline at the gas station, paint, fertilizer, pesticides, McCreary County Water District Water Quality Curriculum 174

5 Classroom Activity: Where Does All the Rain Go? (Continued) cigarette butts and other litter can be represented by the Kool-Aid or food coloring. Place the dirt and sand in two small piles each on the tarp. Place a sponge immediately downstream of one pile of dirt and one pile of sand. Place a sponge downstream of some of the Kool-Aid as well. Ask the students what they think the sponges represent (runoff barrier). Observations How does the water in the bowl after this rain compare with the first rain? (dirty vs. clean) Compare the effects of the sponge to the areas that had no sponges. The sponges helped to hold much of the pollution back. Plants have the same effect, holding the soil together with their roots. Areas of thick vegetation such as tall grasses and shrubs can act as a filter to pollution that gets in the water when it rains. 8. Ask the students to once again predict what will happen when it rains. Have them compare their predictions with what actually happened. Where did all the pollution go? (Look in the bowl). 9. Knowing that water in the grass has a better chance at being filtered than water on the parking lot, where should we dump the dirty water from the bowl? Dump the water from the bowl on the grass, and observe how it soaks into the ground. 10. Take the class and the 5-gallon bucket, filled with clean water over to the parking lot. Try to do the experiment about 50 feet up from a catch basin, drain, or outlet of the parking lot, so that the students can follow the water all the way to the drain. Have them recall what happens to water when it hits the pavement (from their previous lesson), and predict what will happen. Pour the bucket and watch the flow. 11. Take the students back inside and have them follow-the-flow of their parking lot water on their watershed maps (either print outs, or on the computer). Bring home the point that all of the water that lands on their parking lot ends up in the nearest stream, and eventually all the way down to the Gulf of Mexico, UNTREATED. Observations If the water goes to a ditch, ask the students to predict where the ditch goes. (Ditch to small tributary to the Salt River to the Ohio River, etc). If the water disappears into a catch basin or drain, ask the students to predict where the pipe goes. Ask if they think it will be treated before making it to the river. The answer is NO. Water from streets and parking lots is not treated before making it to the nearest stream or river. McCreary County Water District Water Quality Curriculum 175

6 Worksheet: Where Does All the Rain Go? Name: What did you see? Describe what happened when it rained on the tarp. Discussion Questions 1. Where does a raindrop that lands at our school end up? 2. What is a Watershed? 3. Name 2 activities that can affect our streams. & 4. List one thing you learned about our watershed today? McCreary County Water District Water Quality Curriculum 176

7 Classroom Activity: Soaking Up the Water In this activity, students will learn the difference between pervious and impervious ground. They will also learn about the results of storm-water runoff. It will take approximately 40 minutes to complete this activity. You ll need 4 clear plastic cups (per group), blue and green food coloring, measuring spoons, tap water, gravel, sand, 1 magnifying glass, and copies of the Worksheet: Soaking Up the Water. Ask students what happens to the rain when it hits the ground? Explain that it can either soak into the ground or runoff over the ground. Ground that allows the water to soak in is known as pervious. Ground that is too hard for water to soak in causes the water to runoff. This ground is known as impervious. Talk about how different ground covers either help or prevent groundwater infiltration. Tell the students that today they ll be investigating sand, gravel, and asphalt pavement to determine if it helps or prevents groundwater infiltration. 1. Give each group of students 2 clear plastic cups and have them fill them about half full with sand in one and gravel in the other. 2. Have the students make diagrams of what their cups look like. Have them write down predictions of what will happen when they fill their cups with the dyed water. 3. Give each group 2 clear plastic cups: 1 with water dyed blue and 1 with water dyed green. Have the students add the dyed water 1 tablespoon at a time to their cups of sand and gravel (blue for sand, green for gravel). 4. After each tablespoon, have the students record their observations. Encourage them to use the magnifying glass for closer observations. Have them write down any differences they see between the sand and the gravel. 5. They should continue to add the dyed water, 1 tablespoon at a time, until their cups of sand and gravel are filled with water. Remind them to continue to describe their observations on their sheets. The degree to which groundwater is filtered depends on the make-up of the soil. Sandy/Silt filled soil typically filters out pollutants very well, while Karst (cracked and layered limestone) allows pollutants to stay in the water. Although McCreary County has some Karst, the soil here is mostly sand/silt. 6. Discuss their observations. What were the differences between the sand and the gravel? For example, they may suggest that sand tended to hold the water. McCreary County Water District Water Quality Curriculum 177

8 Classroom Activity: Soaking Up the Water (Continued) 7. Ask them what they think happens to water when it hits asphalt parking lots. Will it soak into the ground or runoff? 8. Have the students fill their cups with water and go outside to the parking lot as a class. Test their theories by pouring the water on the parking lot. What happens to the water? (e.g., does the water soak into the ground or runoff over the pavement?) 9. Discuss the difference between water running off and soaking into the ground. (e.g., when water soaks into the ground, the ground s sand acts as a natural filter) However, when water runs over parking lots and roads, it picks up all kinds of pollution along the way. It then carries the pollution to the nearest body of water UNTREATED! That s a big difference. Remind the students that groundwater can end up in surface water via springs and other connections with the water table. Also, many people use groundwater as their drinking water source via wells, so it is very important to protect. McCreary County Water District Water Quality Curriculum 178

9 Worksheet: Soaking Up the Water Name: 1. Make diagrams of what your cups look like 2. Predict what will happen when you fill the cups with dyed water. 3. Record observations: Add water until cups are full Water Tablespoons Sand Cup Gravel Cup McCreary County Water District Water Quality Curriculum 179

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