Whenever we replaced or put in a new water line, we ran the plastic water pipe through a 4-inch drainage tile. Doing so allows us to replace a water line very easily without having to do any digging. It also makes it much easier to detect leaks in the water line, since the water will run out of the tile into our dry well. Make sure the dry well is drained because groundwater will also make its way into the 4-inch tiles.
Where the water line comes up into a building, write on the wall the length of the pipe in case it needs to be replaced someday. When replacing a water line, connect the new line to the old, and have someone pull out the old while someone else pushes in the new line. When trying to push a new line through an empty 4-inch tile, tape a golf ball to the end of the water line so it won't catch on the corrugations of the tile.