Today, part of the removable river was moved about 20 inches, creating a temporarily access hatch together with a huge mess:
There is much work to be done to figure out a way to hide the hatch, make it reasonably accessible so it is not as much of a PIA as my original hard to move, removable river, and to add the finishing scenery and decorating.
As usual, I will report back to you folks as I continue with this saga. Arnold