Advantages and Disadvantages of Flood Warnings and Preparation?

A: This gives People Time to move their Possessions Upstairs or even Evacuate, reducing the Damage that the Flood will Cause D: This does Nothing to Prevent Floods. Some People may not even be Able to access the Warnings. Making the Buildings more Protected is Expensive and People may be Shocked from a False Sense of Security [Their House will be in Ruins even with Protection]