Lesson One – the Watershed Connection T Objective: Students Review the Water Cycle and Learn How a Watershed Functions
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5 Lesson One – The Watershed Connection T Objective: Students review the water cycle and learn how a watershed functions. E A Time: 45 minutes C H Key words: watershed, precipitation, runoff, tributaries, species, polluted, condensation, evapora- tion E R Materials: 4 pieces of wide, heavy-duty aluminum foil about 2.5 feet long Large aluminum foil lasagna pan P 1 egg carton A One 9 x 4 x 1.5 inch piece of floral foam (Oasis) [a full sized block cut lengthwise] G Spray bottle of water mixed with blue food coloring E Advance Preparation: • Make a watershed model. An egg carton placed across one end of the lasagna pan makes the Sierra Nevada. A block of foam next to the egg carton forms the Central Valley. The trough at the other end of the pan is the Pacific Ocean. Loosely roll three pieces of foil into hollow tubes. • Gently press the first roll along the Sierra Nevada for added height and shape. • Use the second roll to transition from mountains to valley, creating the foothills. • Press the third tube along the far side of the valley, to make a Coastal Range, much lower than the Sierra Nevada. Use the fourth piece of foil as a skin over the model, gently molding it to your landscape. Create a small gully around the edges of the pan to keep water in the model. With fingertips, gently depress one or two main rivers down the mountains, across the valley, through the Coastal Range, to the ocean. (Leave no gaps or holes, and you can reuse your model again and again.) • Make copies of the Student Pages titled “What is a Watershed?,” and “Sacramento Area Rivers Map” and the Worksheets titled “Your Place in the Watershed” and “Watershed Crossword & Word Search.” Procedure: 1. Create student portfolios where all information will be kept. 2. Review the water cycle (hydrologic cycle) with the students. Draw a quick sketch on the board. (See drawing on Page 6.) Review the concept that all water on Earth keeps re-circu- lating in a never-ending cycle. Review evaporation, condensation and precipitation. Have students draw the water cycle on a piece of paper and add it to their portfolio. 3. Pass out and read Student Page “What is a Watershed?” Add to portfolio. 4. Choose a student volunteer to use the spray bottle. As you hold the model at a “downhill” angle, have the student model a winter storm that comes in off the Pacific Ocean, across the Central Valley and over the Sierra Nevada. Observe how water collects and flows downhill in streams to the ocean. Introduce key words using the model. 5. Discuss different forms of precipitation, such as rain in the Coastal Range and the Central Valley, and snow in the Sierra Nevada. Discuss the snow pack of the Sierra Nevada as a critical water supply for Californians. 6 Procedure (continued): 6. Make shallow depressions in the flat Central Valley to simulate vernal pools. Have the T student spray the Central Valley with colored water. This simulates a storm in our local E watershed and shows how vernal pools fill during winter rains. A 7. Reinforce the concept that every spot on the model (and any place you can stand on the C Earth) is in a watershed. All the land “sheds” the water, which runs off the land like rain runs H off an umbrella. In our watershed the runoff from the land runs into urban creeks, and even- E tually reaches the Sacramento River. But our runoff also flows into vernal pools and other R wetlands that do not connect to streams. 8. Pass out Student Page “Sacramento Area Rivers Map” and Worksheet “Your Place in the Watershed.” Use the map to complete the worksheet. P A Evaluation/Extension: G • Students complete the two Worksheets and add them to their portfolios. E • You could make a separate model of a vernal pool grassland to better show how rain in our area of the watershed can end up in streams or trapped in vernal pools. • Ask students if they know the names of any local creeks or streams. Have students describe any familiar creeks near their homes or school. What has happened to these creeks? How do they compare to natural streams the students might have seen? (Urban creeks often look more like ditches than streams. Some were straightened and deepened by farmers. Others have been used to carry runoff and flood waters away from developed areas.) • We say that, “all rivers flow into the sea,” but what about rivers that flow down the east side of the Sierra Nevada? They do not reach the ocean. These rivers dump rain and snow melt into lakes called saline (salty) “playa lakes” on the floor of the Great Basin. There the water evaporates in the sun, leaving salts and minerals behind. (The Great Salt Lake of Utah is an example of how much salt can accumulate in a playa lake. If you have a U.S. map, you can find two big playa lakes on the east side of the Sierra Nevada: Pyramid Lake and Honey Lake.) 7 The Watershed Connection What is a Watershed? A watershed is all the land connected by the fresh water flowing through it. Everybody lives in a watershed and everything we do takes place in a watershed. In Sacramento we live in the Sacramento River Watershed, the largest watershed in California. Northern California storms produce precipitation either in the form of rain or snow. The rain runs off the land in the Sacramento River Watershed. This is called runoff. The earth’s gravity pulls all runoff downhill into a branching network of streams or tributaries. Streams come in all sizes from small creeks to big rushing rivers. Each stream connects to a larger one until it reaches the biggest stream in the watershed. The Sacramento River is the biggest stream in the Sacramento River Watershed. It carries the runoff from the entire watershed toward the Pacific Ocean. Less than one percent of the earth’s water is freshwater; the rest is saltwater, ice caps, or glaciers. Only a small portion of the freshwater is available for use by people. Streams provide freshwater for many people in California. We could not survive without them or the clean, fresh water they collect from our watershed. When we take care to keep our streams clean and healthy, we are actually taking care of ourselves and every other living thing in the watershed. Clean water supports many more species (forms of life) than polluted water. In a watershed, everyone is someone’s downstream neighbor. People upstream of Sacramento send us their used water. Then we turn around and send our used water to people living downstream of us. Since we all share the same water, it’s everyone’s job to keep it clean. The quality of water depends on us. 8 The Watershed Connection Sacramento Area Rivers Map 9 Name:_______________________ S Your Place in the Watershed Worksheet T U This activity helps you find your place in the watershed. Study the map of the Sacramento River D Watershed, then answer these questions. E N 1. A large tributary enters the Sacramento River right in the city of Sacramento. What is the T name of that tributary? ____________________ W 2. Name another tributary of the Sacramento River: _____________________ O R K 3. Name two cities upstream of Sacramento on the American River. S H a. _____________________ b. _____________________ E E 4. Name two towns downstream of Sacramento. T a. _____________________ b. _____________________ 5. Name the two cities that sit on opposite sides of the Feather River. a. _____________________ b. _____________________ 6. ________________ water supports more forms of life. circle one: Clean Polluted 7. Describe how a watershed works. Include the words: streams, runoff, ocean, downhill. 10 Name:_______________________ S Watershed Crossword & Wordsearch T U ACROSS D 2. Makes up less than E 1% of the Earth's water N 4. Water that runs off T the land 7. Runoff flows in this direction W 9. The land connected O by the water flowing R through it 10. The largest river in K the Sacramento S River Watershed H DOWN 1. Rain or snow E 3. To dry up E 5. Opposite of T downstream 6. Final destination of water in the Word list: watershed, downhill, upstream, ocean, Sacramento River, evaporate, Sacramento River stream, freshwater, precipitation, runoff 8. Creek or river.