Darren Landro, age 11, of Williamsport, Pa., for his question:
CAN NIAGARA FALLS BE TURNED OFF?
Next to the world famous Niagara Falls are two important vacation and industrial cities: Niagara Falls, Ontario, Canada, with a population of about 67,000, and Niagara Falls, New York, with a population of about 85,000. The falls and the hydroelectric facilities located in and near these two cities provide the greatest single natural source of water power in North America.
Niagara Falls and the Niagara River together form one of the world's most beautiful waterways. The spot is a tourist's dream come true. It is also the honeymooners' paradise.
The Niagara River connects Lake Erie and Lake Ontario.
All of the Great Lakes except Lake Ontario empty into this 35 mile long river. About 200,000 tons of water a minute pass through a steep walled gorge where the Niagara Falls are located.
The water divides into two streams. The larger one goes over a rocky ledge of Niagara limestone on the Canadian side and forms the famous Horseshoe Falls. The smaller stream forms the American Falls. Horseshoe Falls is 158 feet high and 2,600 feet wide. The American Falls is 167 feet high and about 1,000 feet wide.
Although the water continues to flow day after day and year after year, there is definitely a way to turn part of the falls off. Man did just that in 1969.
Worried about the amount of erosion and perhaps hoping to find a way to prevent further sloughing off of the rock, the United States Army engineers built a dam in 1969 that would and did temporarily stop the flow of water over the American Falls.
The water is flowing again now and scientists say it will continue to fall over the cliffs for many hundreds of years to come.
The ledge of Horseshoe Falls is being worn away by erosion at the rate of about three feet each year. Cutting action on the American Falls is slower since there is not as much flow.
About 80,000 tons of rock fell from the face of the American Falls in 1931 with another 185,000 tons falling in 1954.
Niagara Falls was created after the last great ice sheet withdrew from this part of the continent about 20,000 years ago.
In 1885, the New York state government established Niagara Falls Park on the United States side. A year later all the land on the Canadian side of the falls became Queen Victoria Park. Four observation towers give visitors great views of the falls.
In 1962, one of the world's largest hydroelectric facilities, a $720 million power plant that can produce 2,190 million kilowatts, was built at the falls by the United States. Canada completed a gigantic plant in 1958.