There is a way, but it involves upgrading that pier to a dock, building around the tile with the dock, and then demolishing the dock and rebuilding the pier on the same tile, but on the other bank, and then building next to that.
I have not experimented to learn exactly why and how it works. I play without reloading, and this happened mostly by accident. But it worked in .992 for sure. I think that the river tile was a turn in the river.