What to do with propane canisters?

[VeniceInlet]

I am in a low elevation that could flood in a major storm. I've been wondering what I should do with the three grill-sized propane canisters I keep around for cooking. I know to disconnnect them and tightly turn them off, but I also know I'm not supposed to store them in a garage or shed.

So here's my question: Where do I put them if I were to evacuate? I can just see them floating away like little bombs, waiting to be punctured by other debris.

[bosag]

Well, we buried ours about 3 ft under, altho during jeanne, I didnt do a very good job and one of them popped out of the ground and floated around the back yard (fenced in)

[Alladin]

Just tie a rope to the tanks and secure the other end to a tree. 20 lb. LPG tanks are very safe, they have a pressure relief valve to prevent any explosion.

I think it highly unlikely that hurricane debris would puncture a propane tank under any circumstance.