Niagara Falls consists of Horseshoe Falls and the American Falls. Due to several years of rocks falling in, between the year 1931 and 1954, the American Falls faced erosion, which if not prevented would have resulted in the permanent extinction of the American Falls. With resulting public outcry and protests to save the American Falls, the United States Army Corps of Engineers (USACE) – Buffalo district was encumbered with the immense responsibility of dewatering the American Falls for repairs. Taking up this historic challenge, a cofferdam was constructed, that took 3 days after working in two 11-hour shifts, resulting in cutting off of the flow of the Falls from 60,000 gallons per second to one-fourth of its capacity of 15,000 gallons per second.
This gigantic effort, comprising 1,264 truck loads, carrying 27,800 tons of sand and earth, was carried out to fill the cofferdam. Another minor discovery, which emerged from the De-watering Project, was that of a dead-body of a woman, which would never have been possible if the American Falls had been in full-flow. The woman was wearing a gold band, with the tragic inscription ‘forget me not’ on the inside.
Rochester Shale, a type of rock, which started crumbling due to the de-watering project, was a major concern for the geologists who wanted to carry out tests. Pipes totaling 800 feet of length and approximately six inch diameter were laid to moisten the shale.
The motive behind the endeavor to pull off such a huge feat was to conduct tests to prevent further erosion and test the structural integrity of the American Falls. Having planned through all the tests, and having implemented their staggering efforts, USACE estimated that the work will be completed by 1972. A battery of tests consisting of chemical analysis of the rocks, microscopic inspections, and several other tests were conducted accumulating large amounts of engineering, geological, and other data.
After an effort of more than 5 years, the International Joint Commission in 1975 concluded that 385,000 tons of Talus had accumulated at the base of American Falls, and had resulted in reduction of waterfall from 100 feet to 45 feet, while the depth of the Talus ranged from 25 feet to 50 feet.
As per the consensus taken from the public, there was to be no noticeable change in the appearance of American falls. But, it was accepted that there would always be some risk involved in the viewing of falls owing to continued erosion around the Falls.
The important lesson that the effort taught the engineers, and which is also a lesson for all humanity, is that everything has a life span and nothing escapes mortality. May it be flesh and blood humans, or even a stupendous spectacle for humanity such as the Niagara Falls. As is well said, that change is inevitable, and so is the mere existence of everything. It is an important question to be asked that whether something is too big to fall such as the American Falls, or something is too small to rise, like the Talus which over the years caused near extinction of American falls. The dewatering of Niagara Falls in 1969 is abject lesson in the Power of Human effort as compared to the might of Powerful Nature.