Niagara Falls Case Study Niagara falls lays to the south of Toronto on the border with America. The average depth of the water below Niagara Falls is 170 ft and is as deep as its walls are high. The massive volume of water that flows over the falls causes the water to appear green in colour. The water that flows over Niagara Falls comes from Lake Erie which is one of the four great lakes of America. In excess of 5 billion gallons or over 2 trillion litres of water per Hour rushes over the edge of the Falls. This water going over the falls flows down the Niagara River into Lake Ontario and then into the Saint Lawrence River which is 300 miles away. Continuing further North-East , the water finally flows into the Atlantic Ocean over 1000 miles away The governments of America and Canada control the surrounding area most of which is now parkland and conservational areas so as to keep the area attractive to tourists. 44% of tourists to Canada visit Niagara Falls which is roughly 13.4 million people annually .The falls were formed 12,000 years ago as the retreating glaciers exposed the Niagara escarpment, thus permitting the waters of Lake Erie to flow north, to Lake Ontario. This was at the end of the last ice age The escarpment has been gradually eroded back toward Lake Erie, a process that has formed the Niagara Gorge 7 miles long . The Horseshoe Falls is eroding upstream at a faster rate than the American Falls because of the greater volume of water passing over it. Ice accumulates during the winter in the Maid of the Mist pool. The river may become bridged by this ice mass of up to 70 ft above water level. The force of the ice weighs down and erodes the banks and islands as well as bridges such as the honeymoon bridge which collapsed in 1938. .A great rock slide occurred in 1954 at the American Falls and formed a huge talus slope at its base.
