See the green tower in the foreground? That the observation tower at the park in Niagara Falls, New York. About 450 years ago the first European saw the Falls and it didn’t look like it does today.
First the amount of water crashing over the crest of the Falls was about 5 times the amount. Imagine the thundering sound of the Falls. But maybe even more important, there was only one falls and it was located basically where that green tower is located. In the 450 years since first seen by a European, the Falls has gouged itself back to where it now is located.
Since 1969, we have controlled the flow, to decrease the erosion, so now the Falls moves back about a foot a year.