In places like Minneapolis, it’s dumped in places next to or actually in the rivers. It’s kind of cool watching dump trucks drop loads of snow off a high bridge. I believe it’s done when necessary in the Northeast as well.
They used to have trucks in NYC that they would drop the snow into, and it would use the heat from the engine to melt the snow and drain it right into the sewers.
That was a while ago. Dont know if they still have them.