Tiles question

[Clap]

Hi, i built something in Green Acres with centred, and i placed some water tiles (terrain).
I wanted to know why this tiles are not blocking me?, i mean, i can cast trough them, they are not acting like true water.
Is there a way to solve this? WITHOUT erasing everything   ?
Thanks!

EDIT: aggg i think that default water doesn't block magic cast, so i need to put another kind of tiles. Thanks anyway you can close it