It's very fashionable to decry things we don't understand. Dowsing clearly works; my father called the local dowser in for his house in a remote part of SW Ireland. I watched him walk back and forth across the land, rods twitching, and eventually he hacked his heel down and said to "drill here" and we'd get "water for a family of five and to spare". Drill he did, we dropped down a remote-control DanFoss pump, and sucked on an aquifer that never failed, even in the drought years.
OK, they guy knew all the land thereabouts: he lived locally. Maybe he just knew the exact path of every underground watercourse in the neighborhood, but I doubt it. As a scientist, I want replicability of the observation (no problem here: he and several others do this for a living: no charge unless the water flows), and I'd like an explanation of why (none yet)...but equally I refuse to dismiss a phenomenon simply because it has no explanation yet. If we did that we'd still be living in the dark because we couldn't explain sunlight.
... they also have ground requirements much closer to 'airport with atypically long runway'
If that's what they need then the Irish government should look at creating a spaceport near Shannon, which has a gigantic runway,suitable both for the frequent US military stopovers to and from the Middle East, and (I was told) for the Shuttle, should an emergency ever have arisen requiring a landing in Europe if Edwards or elsewhere was unavailable. But that may just be local pride