What are these foundations at Niagara Falls?

[Heywood Jannockitov]

I saw a special on PBS not too long ago. Very interesting. They indicated that the flow over the falls is significantly less than in 1900, due to diversions, tunnels, power, etc.

Yes, most definitely. I have an old aerial photo I'll have to scan - it's in a book, that shows a progression of lines depicting the edge of the Horseshoe falls at different stages over the course of about 200 years. As you say, the flow has been cut so much that the rate of erosion has been reduced from about 3 feet per year to probably a few inches. The Toronto Power discharge tunnel was designed so that sections would break away as the gorge erodes upstream.

 

[Robert_in_NY]

I was told about the flow of water being diverted at night and how you can see it in the morning if you look early enough. I just haven't had a chance to see it yet but hopefully I will this month still.