Sometimes when it's been really dry and I need to dig a post hole I just run the garden hose on the spot for awhile. Or just dump a 5 gal. bucket of water if the hose don't reach. I add more water as I go deeper if needed. Around here ground water starts filling the hole after about a foot or so.
Top of the mornin to ye! And a happy St. Paddy’s day to ye all!