i placed the small ones in deli cups and the larger ones in pillowcases (spent almost $200 on those), then placed them in plastic tubs and stacked them in my center hallway. i live on the third floor, so flooding isn't a big issue. as for water, if it looked like it was going to hit really hard, i would have filled a bathtub up with water. otherwise, they can go a few days w/o water with no ill effects.
however, the smarter thing to do is have a big cargo vehicle that you can load them all into and then get the hell out.