That is pretty cool and quite a feat. I wonder if they could get away with that today, or would all the environmentalists get in too much of an uproar.
Niagra falls is going to move (recede). They've been doing it for miles -- for thousands of years, and they will continue to do so regardless of the efforts of the Corps of Engineers, much as the Mississippi is going to move to the Achafalaya and leave New Orleans high and dry. We can fight nature all we want, but eventually that bitch will win!