Discover the Waters of Lake Tahoe Illustrated by Peter Grosshauser Waters of the Lake Tahoe Region .. 2 Reservoirs of History . 4 Water in Lake Tahoe .. 6 Using Lake Tahoe’s Water .. 8 Clarity . .10 Aquatic Invasive Species . 12 Take Action for Lake Tahoe .. 14 Activity Booklet 1 Truckee River Water- shed Nevada Lake 1 Waters of the Lake Tahoe Region Tahoe Located on the border between Nevada and California, Lake Tahoe is known for its California clear, deep, blue water. Whether you live near Lake Tahoe or are among the nearly 3 million people who visit this special area every year, you will find much to explore. Through the activities in this booklet, let’s use water science to Discover the Waters of Lake Tahoe. Up from the Depths Visualize how deep Lake Tahoe really is! YOU WILL NEED: • A staircase (can be small, like steps to a porch) iSTOCK.COM/MariuszBlach • Pencil • Measuring tape Water In, Water Out Lake Tahoe StatS • Calculator • Lake Tahoe’s maximum depth is 1,645 feet (501 m). Water enters Lake Tahoe from sixty-three tributaries (streams DIRECTIONS: • Lake Tahoe is the second-deepest lake in the United States (Oregon’s Crater that contribute to a larger 1. Find a staircase at your house or school. How many times Lake is more than 1,900 feet [579 m] deep) and the eleventh-deepest lake in body of water). They flow into do you think you would need to climb these stairs to the world. the lake from the surrounding • Lake Tahoe is twenty-two miles (35 km) long and twelve miles (19 km) wide. mountains, which form the equal the deepest spot in Lake Tahoe (1,645 feet, 501 m)? Lake Tahoe Basin (a basin Write your estimate here. __________ • The volume of the water in Lake Tahoe would cover the entire state of is the land area from which 2. Measure the height of one of the stairs in inches and California in 1.2 feet (37 cm) of water, or the state of Nevada in 1.7 feet water drains into a lake). The (52 cm) of water. Lake Tahoe Basin is part of the record. __________ inches larger Truckee River watershed • If Lake Tahoe were emptied, it would take approximately 600 years for water 3. Climb the staircase, counting each step as you go. Record from rain and snow to refill it. (an area of land where all of the water that is under it or the number of stairs. ________ stairs • The surface of Lake Tahoe is about 6,225 feet (1,897 m)—more than a mile— drains off of it goes into the 4. Multiply the height of one stair by the total number of above sea level. same place). stairs to calculate the height of the staircase in inches. • Lake Tahoe is recognized internationally for its outstanding clarity and ________ inches x ________ stairs = ________ inches extraordinary beauty. What’s in a Name? 5. To calculate the height of the staircase in feet, divide Lake Tahoe got its name from a mispronunciation of the your answer from above by 12. __________ feet Washoe Tribe’s word for “lake,” 6. Now, divide Lake Tahoe’s depth by the height of the Da ow (dah-oh). Washoe people staircase in feet to calculate how many times you would have lived near Lake Tahoe for thousands of years. Every spring have to climb it to equal Lake Tahoe’s depth. the Washoe return to the lake 1,645 feet/ ________ feet = _________ staircase climbs to fish and celebrate its life- 7. Compare your answer to your estimate. Can you climb giving waters and the start of the growing season. the stairs that many times? Statue of Liberty Statue of Liberty 305.5 feet (93 m) Lake Tahoe Lake 1,645 feet (501 m) Eiffel Tower 1,063 feet (324 m) Empire State Building 2 1,250 feet (381 m) 2 Option: Measure using the metric system (100 cm = 1 m). 3 Learning from the Past People now realize human activities can negatively affect water quality. Reservoirs of History Environmental restoration (returning it to good condition), conservation (careful management) and protection (keeping it safe from harm) are Lake Tahoe’s waters and land have Timeline important for Lake Tahoe’s future. supported people for thousands of Millions of years ago, faulting (shifting rocks) and volcanic eruptions created years. Review the timeline to learn how a deep valley that was then filled by precipitation and melting glaciers over people’s use of the land has affected the thousands of years. Change the Land, Change the Water Approximately 11,200 years ago lake’s water over time. MAP KEY First evidence of humans in the area. See how the ways we use the land can affect our water. Forest: green Approximately 7,000 BCE through 1840 YOU WILL NEED: WORD LIST: The Washoe and the Pyramid Lake Paiute 1844 The first European Americans Lake: blue • Colored pencils or markers erosion, filter, Land Changes = Water Changes tribes live in harmony with the land and arrive at Lake Tahoe. forest fire, water for about 8,000 years and DIRECTIONS: If uncontrolled, forest fires, logging and Wetland: yellow impervious, 1859–1900 Sixty percent of Tahoe's forests The three maps below tell a story of the Lake Tahoe Basin through grazing may disturb (alter the natural 1,000 years, respectively. logging, protect, are clear-cut to support the Comstock mines different times in history. Color each map according to the map key. condition) soils and cause erosion (the breaking Logging: brown restoration, 1913 Some Lake Tahoe landowners work to in nearby Virginia City, Nevada. Use the information on page 4 and the word list at right to fill in the down and washing away of land surfaces). establish Lake Tahoe as a national park, but wetlands Urban: gray blanks beneath each map below to see how land use has affected there are too many homes and businesses. Lake Tahoe's water over time. O EN Forest Fire: red erosion R 1960s Urbanization of Lake Tahoe explodes, EVADA- including development of the Tahoe Keys. N F O Y T Half of the Upper Truckee Marsh (Tahoe's I S largest wetland) is filled with soil. , UNIVER , S N O I CT LLE CO IAL O Urbanization (the construction of buildings C EN PE R and roads) introduces impervious surfaces S EVADA- N (materials that don’t F O Y 1968 Dr. Charles Goldman starts measuring T LAKE TAHOE LAKE TAHOE LAKE TAHOE I allow precipitation S clarity. Through 1971, annual Lake Tahoe to soak in). Runoff BEFORE 1840 APPROXIMATELY TODAY , UNIVER , S clarity averaged 97 feet. N 1840-1970 O (precipitation flowing I CT off these surfaces) LLE CO IAL 1969 The United States Congress approves washes pollutants (excess C PE sediment or chemicals) S an agreement between California and Nevada to work together to jointly manage to the lake. 1997 Lowest annual average clarity on record Lake Tahoe and create the Tahoe Regional at 64 feet. President Clinton visit sparks Planning Agency. Environmental Improvement Program to impervious surface restore and protect Lake Tahoe. 2007 The Angora Forest Fire burns almost five square miles (13 km2), including 254 homes. Wetlands (marshy areas) and riparian areas 2008 Asian clam, an aquatic invader, (land along the edge of a waterbody) filter is identified. A boat inspection pollutants from water. Removing or damaging program is established to prevent Map 1 Map 2 Map 3 the further introduction and spread these natural filters allows more pollutants to Early people Tree removal from ____________ of forests slows of aquatic invasive species. X enter the lake. U VEILLE __________________________ erosion of soil into Lake Tahoe. 2011 Landmark water clarity restoration plan M ________________ no wetland /JI known as the Lake Tahoe TMDL is adopted by COM wetland . the trees and wetlands, leads to ____________________ Urbanization creates more ____________ the States of California and Nevada oto PH keeping Lake Tahoe clean. surfaces where water can’t soak in. Dirty water and approved by the U.S. Environmental tock of soil, which flows into Lake Protection Agency. ©IS flows off these surfaces and into Lake Tahoe. _____________________ Tahoe. 2013 Lake clarity continues decade-long Removal of wetlands, a natural ____________, naturally filter the water flowing trend of stabilization, indicating means more soil enters Lake Tahoe. Removal of Present You can help continue the into Lake Tahoe. efforts to restore and protect trees from ____________ results in erosion of Lake Tahoe may be working. restoration, conservation and protection 44 of Lake Tahoe! soil, which flows into Lake Tahoe. 5 Water in Lake Tahoe WARMER Let’s take a look at how water makes its way COLDER COLDER into Lake Tahoe and examine some interesting 6 Lake Mixing features of the lake. 5 Although Lake Tahoe is located at a high 4 Rain and Snow elevation where winters MIXING are relatively cold and Water enters Lake Tahoe from precipitation (rain and 3 long, the lake does not freeze snow). The lake covers nearly 40 percent of the basin, so over in the winter. During the much of that rain and snow falls directly on it. From the 2 summer, water near the Summer: Sun warms surface water. Winter: Cold temperatures cause surface water surrounding land, runoff (water from rain and melting 1 surface warms while to cool, sink and mix with the water below. snow) flows into streams and directly into the lake. deeper waters remain cooler. In fall and winter, surface water Precipitation can also soak into the ground (infiltrate) Inches cools again.