Regulation and responsibility in case of natural extreme event, the precautionary principle

To prevent the occurrence of risks as floods, new juridical answers have been elaborated, especially after 1995. The principle of precaution, which is still lacking in precision, is more and more influent on the decision making. The public actors have to comply with the attitude of precaution and new specific mechanisms and ditties. This kind of evolution largely explains the changes in the administrative and penal liability.