Upper rapids, Niagara Falls
Niagara Falls is divided into the Horseshoe Falls and the American Falls. The Horseshoe Falls drop about 173 feet (53 m). The American Falls drop about 70 feet (21 m) before reaching a jumble of fallen rocks that were deposited by a massive rock slide in 1954. The larger Horseshoe Falls are about 2,600 feet (792 m) wide, while the American Falls are 1,060 feet (323 m) wide. The volume of water approaching the falls depicted in this photos during peak flow season is 202,000 cubic feet per second (5,720 m³/s). By comparison Africa's spectacular Victoria Falls has over 15 million cubic feet (424,750 m³) of water falling over its crest line each minute during the peak of the wet season (250,000 cu ft/7,079 m³ per second). Since the flow is a direct function of the Lake Erie water elevation, it typically peaks in late spring or early summer. During the summer months, 100,000 cubic feet per second (2,832 m³/s) of water actually traverses the Falls, some 90% of which goes over the Horseshoe Falls, while the balance is diverted to hydroelectric facilities. This is accomplished by employing a weir with movable gates upstream from the Horseshoe Falls. The Falls flow is further halved at night, and during the low tourist season in the winter, remains a flat 50,000 cubic feet per second (1,416 m³/s). Water diversion is regulated by the 1950 Niagara Treaty and is administered by the International Niagara Board of Control (IJC). Viewpoints on the American shore generally are astride or behind the falls. The falls face directly toward the Canadian shore. Thus, the most complete views of Niagara Falls are available from the Canadian shoreline.
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