|
The Ocoee Whitewater Center, near Ducktown, Tennessee, United States, was the canoe slalom venue for the 1996 Summer Olympics in Atlanta,〔(1996 Summer Olympics official report. ) Volume 1. p. 542.〕〔(1996 Summer Olympics official report. ) Volume 3. p. 164.〕 and is the only in-river course to be used for Olympic slalom competition. A 1,640 foot (500 m) stretch of the Upper Ocoee River was narrowed by two-thirds to create the drops and eddies needed for a slalom course. Today, the course is watered only on summer weekends, 34 days a year, for use by guided rafts and private boaters. When the river has water, 24 commercial rafting companies take more than 750 raft passengers through the course each day. No longer used for slalom, the hanging slalom gates have been permanently removed. Because the river is dry most of the year, the Center, now operated by the U.S. Forest Service, also serves as a site for hiking, mountain biking, conferences, weddings, and receptions. It receives about 300,000 visitors a year.〔http://www.fs.fed.us/r8/ocoee/aboutUs.shtml〕 ==Design and construction== Since most Olympic host cities are located far from usable whitewater, canoe slalom is a relatively recent addition to the Olympic games. The first two Olympic canoe slalom venues were canals built around dams on small rivers in nearby mountains: Augsburg Eiskanal for the 1972 Munich Games, and Segre Olympic Park for the 1992 Barcelona Games. The 1996 Atlanta Games produced the third such venue by modifying the then-dry streambed of the Upper Ocoee River. As the only in-river Olympic venue, it had the greatest water volume, the highest drop, and the steepest slope. The more recent Olympic venues, built closer to their host cities, rely entirely on pumped water and use smaller concrete channels designed to minimize the energy cost of running the pumps. Levees built along the shore of the Ocoee River, and covered with natural rock, reduced its width from to , which is still twice the width of most artificial whitewater channels. Even at this reduced width, for the water surface to have the desired dynamics the streamflow needed to be , which is two or three times greater than the flow of most artificial whitewater channels. The proposed river modifications were tested on a 1-to-10 scale model, with water, constructed outdoors near the base of Ocoee Dam #1, at . Despite the fact that the Ocoee is watered by rainfall and gravity, the energy cost of putting water in the river is high in terms of sacrificed electricity production. The Upper Ocoee, the section of the river between Dam #3 and its powerhouse, is normally dewatered except during flood control releases, usually during the winter and spring. Lake water is taken by tunnel and penstock, at the rate of , to the power house lower than the lake surface. This water flow and vertical drop generate 23 megawatts of electricity. Any water in the river must come directly from the dam and bypass the power house. The Olympic Games dam release of represented an electricity sacrifice of 31 megawatts, and today's recreational releases of represent an electricity sacrifice of 35 megawatts, or $2100/hour at 6¢/kilowatt-hour.〔 http://tva.gov/news/keytopics/power_prices.htm TVA Power Prices, retrieved July 3, 2015〕 The popular rafting industry generates enough revenue to partially compensate the Tennessee Valley Authority for lost electricity, but slalom athletes need a cheaper place to practice. In 2006, the U.S. National Whitewater Center was built in Charlotte, North Carolina, with an Olympic-standard whitewater course watered by three half-megawatt pumps. 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「Ocoee Whitewater Center」の詳細全文を読む スポンサード リンク
|