the strain gauge probably wouldnt help with the seals but if the seals flexed before they let go, it might help. But if you think about it after, what are you going to do anyways if the alarm goes off?! that is 1500GALLONS, thinking about it after doesnt really help to have the alarm. pretty much if she is going to break, then she'll break and there is nothing we can do about it
just like the other guy said, make sure you insurance knows and you are covered. Even 100GAL of saltwater running down inside your walls will do extreme damage to your house.