Is the canal right next to the L&N train bridge really private?

Was fishing the L&N train bridge recently, and then after wanted to go through a canal/cut right next to it and saw it was marked private. I know that many places are private but I was really confused how the land that holds the bridge could be privately owned.

The canal I am talking about can be seen in these google maps screenshot:



It is in the bottom left of the picture right under the bridge. On each side of the entrance are two private property signs.

Does a private citizen really own the land that holds the bridge and the marsh on the other wise that google cals 'catfish point'?