Is there a way to edit some details on a procedurally generated planet?

Example - I had a terra generated, but now I just want to add a lake here, and a river there, etc, to the procedurally generated terrain without necessarily changing anything else..... just a few small edits.

thanks;

Small edits are impossible in fully procedural terrain. You may adjust river parameters, but this changes all rivers on the whole planet. This is how procedural generation works.