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Keywords: Dams
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- Abstract: Dams have negative impacts on the plants and animals that have adapted to the specific movement of natural rivers and streams. Dams also cause temperature changes, erosion, and movement of sediment that are deadly to many organisms.
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- Abstract: The Gold Rush, positive for California in so many ways, had a devastating effect on the state's environment. Many of these problems were directly related to gold-mining technology. The process of hydraulic mining, which became popular in the 1850s, caused irreparable environmental destruction. Two images show California's largest hydraulic mine ? Malakoff Diggings, in Nevada County ? in action. (Malakoff Diggings is now a state park and open to visitors.) Dams (such as the English Dam in Nevada County, shown in one photograph), which were constructed to help supply water to the mines during the dry summer months, changed the course of rivers. The sediment washed away by hydraulic mining clogged riverbeds and lakes, threatening agriculture throughout the Central Valley. Conflicts over water arose between mining and farming interests. Hydraulic mining essentially came to an end in 1884 with the Sawyer Decision, legislation passed to resolve this conflict. The mining industry also needed a great deal of wood, both to fuel the boilers at the mines and to build extensive canal systems. This demand for lumber helped create the logging industry. California's forests had plenty of trees to log, many quite large. The lithograph "The Stump and Trunk of the Mammoth Tree of Calaveras" depicts a society ball at which 32 people danced on the stump of a giant sequoia tree. Photographer Carleton E. Watkins was well known for his images of the grand views of the West. He was the first to capture Yosemite on film, and helped shape how people throughout the country and the world viewed California. He took many of the broad landscape photos in this group. Watkins also made use of the new technology of the day to create stereoscopic views, including the image of the Malakoff Diggings. There are also several Daguerreotypes in this topic. They include a portrait of John A. Sutter (at whose mill gold was first discovered); miners at work; miners with equipment; and general scenes of mining operations.
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- Abstract: This BioBulletin Web site takes an in-depth look at the power of dams to sustain and destroy life near rivers, and the process and results of setting dammed rivers free. The site includes text, videos, photographs, and interviews with key scientists.
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- Abstract: In this video segment from PEEP and the Big Wide World, children figure out how to control the flow of water so it supplies two dams.
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