I want to dig a tunnel for some 3" PVC, roughly 5' below grade (12' long). I don't relish lifting the paving stones (again) or digging a trench 5' deep. So I'm wondering how successful the water drills really are? I've read good things, but it seems too good to be true. There's also a chance that the area contains fill with the odd piece of concrete/brick. If I use a 3/4" pipe with couplings I don't imagine I can hope for more than an 1.5" hole?
There's also these bad boys:
But one long enough to do the job would break the budget. I've checked the rental (Toronto) places online, but I haven't seen any yet.
Any words of wisdom on the water drills or better ideas?