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Lake Hartwell is a man-made reservoir bordering Georgia and South Carolina on the Savannah, Tugaloo, and Seneca Rivers. Lake Hartwell is one of the southeast's largest and most popular recreation lakes. The lake is created by Hartwell Dam located on the Savannah River seven miles (11 km) below the point at which the Tugaloo and Seneca Rivers join to form the Savannah. Extending up the Tugaloo and up the Seneca at normal pool elevation, the lake comprises nearly 56,000 acres (230 km²) of water with a shoreline of . The entire Hartwell "Project" contains 76,450 acres (309 km²) of land and water. I-85 bisects Hartwell Lake and makes the area easily accessible to visitors.〔 ==Background== The Flood Control Act of 17 May 1950 authorized the Hartwell Dam and Reservoir as the second unit in the comprehensive development of the Savannah River Basin. The estimated cost was $68.4 million based on 1948 price levels and preliminary designs. The original project provided for a gravity-type concrete dam long with earth embankments at either end, which would be long on the Georgia side and long on the South Carolina side. The long dam was to be topped with a roadway wide. The main dam was to consist of two non-overflow concrete sections on the right and left banks and long, respectively; a gravity-type concrete spillway long equipped with 12 tainter gates 26 feet by 40 feet in the channel; and a powerhouse on the South Carolina side of the river. Full power pool was designed to be 660 feet above mean sea level. At this elevation, the reservoir would extend up the Savannah River to the confluence of the Tugaloo and Seneca Rivers; 41 miles up the Tugaloo to within approximately 2 miles of the existing Yonah Dam; 27 miles up the Seneca to the mouth of the Little River, South Carolina; 2 miles up the Little River to the Newry site; and 7 miles up the Keowee to the Old Pickens site. The reservoir would cover 56,500 acres and would involve the relocation of 3 sections of railroad totaling 2 miles, the raising of 2 railroad bridges, construction of 6 sections of new state high- ways totaling 19.6 miles and 9 sections of county roads totaling 12.7 miles, the construction of 9 new bridges and the raising of 4 existing bridges, and the relocation of 2 power transmission lines. Construction of the Hartwell project took place from 1955 and was completed in 1963. And construction of the dam started in 1955 and was finished in 1959. Lake Hartwell is named for the American Revolutionary War figure Nancy Hart. Nancy Hart lived in the Georgia frontier, and it was her devotion to freedom that has helped make her name commonplace in the Georgia upcountry. A county, city, lake, state park and highway among others, bear her name.〔(【引用サイトリンク】url=http://www.sas.usace.army.mil/lakes/hartwell/hart.html )〕 The Droughts and water levels of Lake Hartwell 1989 was the first year the lake hit a level 3 dropping to its lowest level during the drought that year. 2008 was the second time the lake hit a level 3. In the year of 2008, due to severe drought in the southeastern United States, the lake dropped to over below its normal water level in December 2008. This revealed old highways that were typically underwater, exposed islands that are usually topped with buoys to warn boaters, and left some boat shells sitting on dry land. The Lake reached it lowest level, , on December 9, 2008. The highest lake elevation was , reached on April 8, 1964. Overall the average lake elevation is .〔 As of the first of October 2010, the lake was back up to just over . This rebound in lake level is due to releases from the lake being suspended for a month ending April 10, 2009 in an effort to return Lake Hartwell to normal elevations. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Lake Hartwell」の詳細全文を読む スポンサード リンク
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