This jam didn't result in any damage and I have seen bigger jams but I felt safe enough next to this one that I could take the video. Things can change quickly in a jam and where one minute there was water flowing through a hole, the next it is clogged with ice, and then water backs up and a head is created. If you are observing ice flows do so with caution and preferably from a distance.
Just as a note on the video, what caught my attention first was the fact that there was a tire floating on an ice sheet. I observed the flow for about 15 minutes and the tire remained on the ice for the entire time. No doubt it will end up in the Bay of Fundy.