While it is important to know and understand your facilities' flood zone designation, it is equally crucial to look at a few related factors. This can lead to a false sense of security because levees are built to protect from a certain level of flooding, not all foreseeable floods.
Many levees are also in disrepair due to limited maintenance budgets and fail before overtopping.
Failed levees create a fast moving wall of water that can lead to catastrophic structural damage vs. lesser damage with a gradual rise of river flood waters. Flood maps must be used with caution, because many existing U. S. flood maps are considered out of date and they only analyze the predominant flood hazard of a community. They do not generally consider areas less than 1 sq. Development and urbanization, which increases water runoff 2 to 6 times over natural terrain, may lead to more severe surface water and riverine flooding. Prior flood history is one of the most important factors in determining an areas susceptibility to flooding.