Nice blockout! I would suggest choosing your rendering system first, then set up the ground shader to work within it. For example, in Unity I would use a layered shader, and paint a mask where the water would be on the concrete. And add some clumps of dirt as geometry.
@Fabi_G nice plausible solution and yes slightly larger examples do display stands/footings as that concept depicts + a few with 'trolley' wheels attached for navigating broken ground.