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Lewisville Lake
Lewisville Lake is a reservoir located in North Texas (USA) on the Elm Fork of the Trinity River in Denton County near Lewisville. Originally engineered in 1927 as Lake Dallas, the reservoir was expanded in the 1940s and 50s and renamed Lewisville Lake. It was built for flood control purposes and to serve as a water source for Dallas and its suburbs, but residents also use it for recreational purposes.
==History==
Lewisville Lake is the second lake to impound the waters of the Elm Fork of the Trinity River in this area. The W.E. Callahan Construction Company completed the Garza Dam in 1927 at a cost of $5 million, which created Lake Dallas. The dam was long with a long service spillway. The lake, with its capacity and forty-three miles of shoreline, served as the principal municipal water source for the city of Dallas for 31 years. In the 1940s, a need for increased water storage capacity and additional flood control became apparent. The United States Congress passed the Rivers and Harbors Act of 1945, which called for additional construction in the Trinity River basin. The United States Army Corps of Engineers built the Garza-Little Elm Dam between 1948 and 1954 at cost of $23.4 million. The structure combined Lake Dallas, Hickory Creek, and Little Elm Creek. The long Lewisville Dam was completed in 1955, and the Garza Dam was breached in 1957 to create the new lake, known then as Garza-Little Elm Reservoir and renamed Lewisville Lake. This new lake had one hundred eighty-three miles of shoreline and a capacity.
During construction, members of the Corps of Engineers stumbled upon an archaeological site. In 1956, Wilson W. Crook, Jr. and R.K. Harris announced that Carbon-14(14C) testing on artifacts from the site, including a Paleo-Indian Clovis projectile point, indicated that humans had lived there c. 36,000 BP. This led to much controversy in the archaeological community. It was not until 1978 that the water levels of the lake would go down far enough to access the site once again. Between 1978 and 1980, Dennis Stanford of the Smithsonian Institution performed a more thorough analysis of the site. He concluded that the original dating was probably due to a rare form of cross-contamination and that a date of c. 12,000 B.P. was probably more correct. Still, the site is considered one of the earliest inhabited by humans in the Southwestern United States and Mexico.
The breaching of the Garza Dam and incorporation of Lake Dallas into the Garza-Little Elm reservoir led to confusion concerning the lake's legal name. This was compounded by the Village of Garza renaming itself Lake Dallas. The federal government attempted to rename the lake as Lewisville Reservoir in 1960, only to reverse itself in 1961. The confusion persisted until the mid-1970s when the lake was officially designated Lewisville Lake. In 1991, the city of Denton installed a hydropower facility at Lewisville Dam. The single horizontal S-Shaped Kaplan unit is capable of producing 2893 kilowatts, and is connected to the grid via the Brazos River Distribution Authority.
抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』
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