Culling With Terrain

I'm just building my scene and I noticed that when two objects intersect, theres a lot of "flashing" and oddities that can occur, esp. in regards to terrain. It's probably something simple that i've failed to RTFM on but never the less if someone could enlighten me it'd be much appreciated :).

So for instance, heres a section of the scene with a few dumpsters that i'm looking to simulate being "buried" in sand a bit. As I approach, the sand seems to translate up/down where it intersects with the dumpsters:


Also, if the terrain is slightly intersecting the bottom of a dumpster it will flicker/flash quite a bit.

Is there a way to tell unity to cull one object in preference to another? I can see just smart object placement to solve the flickering and that's no problem, but watching the terrain "grow" and "shrink" is a little harsh :).

Try reducing the camera's far clip plane as much as possible. From what I can tell the issue might be the result of not enough zbuffer precision.

Using anti-aliasing (Project Settings--> Quality) can help quite a bit for the visual quality too, but not so much for the flickering. Make sure you don't have surfaces which overlap exactly (one polyon is at the exact same place as another poly), this will cause Z-fighting which is probably what you are seeing.

Other than that, follow Erics answer.