I attempted to make artic installation/structure over water and this is what I got, zero sprites but it does look blocky. I don't know if any one has done this yet...
[attachmentid=5324]
sorry for the weird picture, my sc doesn't work so I had to use paint and cut the picture out.

EDIT:
dang I should have turned the grid off, now it looks really blocky!
Use the bridge's end terrain to blend the terrain into the snow, yes turn the grid off next time.
if u can get it to blend in with the snow itll be awesome!
It wouldn't blend well because the bridge tiels are different from the structure tiles, so it's just switch the side in which the bloxkiness was at. It's a neat idea, perhaps you could try elevated heights of the terrain on the water.
its really blocky , that would be really nice if it blended with the snow , buy nice try and keep up the good work

ok hears some additions, I think I made it worse though

. I was finding it really hard to blend the dirt with the structure...
bottom part
[attachmentid=5330]
top part
[attachmentid=5331]
Its not too bad, like everyone said it is blocky. You actually might need some sprites though if its impossible to blend every single block. I dunno

1) Turn off the grid
2) I think it was fine the way before, with that second picture you just messed it up by making way too many of those bridge things.
3) It's blocky around the edges
Ya it looks ok, but it's hard to see when you have the grid on. It really blocky, but the concept is nice, i like the ramp goind down out of the bridge, but you should of continued the dirt a little more so you don't see to blocky dirt part.
Kudos for NOT using sprites. Sprites are the easy way out. I know there's ways to combine tiles from unlikely sources (look around in doodads) to blend things. It takes a bit of experimentation and creativity, though.