If the person owns both sides of the stream and has deeded ownership of the stream bottom then they can prevent you from wading the stream. It looks like they know the law as they indicate that you can float the stream in that area. That's what case law has established, that the surface of the water is available for recreational use by the public. (unless it's a private lake or pond where the water is completely surrounded by private property)

The Audubon property on the Pomperaug River in Southbury is like that. They own both sides and the river bottom so they can prevent people from wading that stretch of the river, but they can't prevent kayaks, canoes or float tubes from using the water surface as the waters upstream and downstream are open to public use.

We had the same situation on a section of the upper Farmington River. A homeowner had deeded ownership of the river bottom halfway across the river. Due to that, he could prevent people from wading in "his" section of the river. He couldn't prevent them from floating or boating on the surface.