Can you turn the falls off?
Well, it is definitely not easy however it is possible. In 1969 to study the erosion of the falls a dam was built to bypass water from the United States to Canada. Wow, what a site that would have been. I imagine it attracted a lot of geologists.
Hey, I'm going to the DTube meet-up and would love to meet some people here who are going to let me know in the comments. And a special thanks to 