Is there a way to terraform so that scenery that’s already placed in the park will not move due to height displacement?

Just in case I haven't written clearly what I need to know, here’s what I mean. Let’s assume this bamboo deck is a complete structure in a park and I decide after I’ve built this structure that I want to terraform under it.



Here I’ve made a small pond to show what happens. I moved the land down 4m and the bamboo decking above it also moved down 4m. I’m wondering if it’s possible to make adjustments to the terrain without the scenery being displaced like it moved in this image.

Yeah I have that problem too. I don't think any thing can be done about that. That is just the way the game ways made.