Actually, I was pondering that question in a more general sense yesterday after watching one of the video lectures on the Shakeout website. Or maybe on one of the other videos I linked to...I forget. Anyway, I heard the factoid that in a really big earthquake, the ground can shift side to side at 6 feet per second. If you've ever seen those security camera photos of the Kobe earthquake, you'll know what that's like. Just look at this video clip. That's insane! And in the truly big quakes, the ground can keep moving for many looooong minutes.

As long as your water containers won't bang into something sharp enough to puncture them, or have something nearby that could fall on top of them, I would imagine that they should be OK (I think this is basically the kind of question you're asking, right TeacherRO?). I keep my Aquatainers out in the garage, next to one wall. I should probably rig up a rope or strap that goes around the jugs and holds them against the wall to keep them from scooting across the floor or repeatedly bashing against my car door like a gang of hooligans after a football match.