The plow will work just fine, but others have used a subsoiler in conjunction with a guide fastened on the back of it to install flexible water lines. Basically the subsoiler opens the ground and the line is fed through a fixture welded to the back of the implement down into the ground as the tractor moves forward. When finished, I think one justs drives over the disturbed ground to flatten it back out.
I'd bet the relevant threads are in the attachments or projects sections, but they might also be in the rural living or related topics. Do a search using subsoiler and water lines and something should turn up.
Sorry, I don't have any direct experience with this approach.