The high-water mark is the mark indicating the highest level water has reached on a particular structure or home. In our case, it was about 56 inches. In the picture above, our son is standing on his tip-toes to point to the height of the water during one of our worst flooding episodes.
“Know Your Line: Be Flood Aware” FEMA, along with 7 other federal agencies, has recently developed a high-water mark initiative designed to illustrate the high-water mark in areas prone to flooding. The idea is to illustrate, by posting signs, to residents of a community the flooding history for a particular location so they can take the necessary steps to protect themselves from future flooding. To date a handful of communities across the USA are participating in this initiative.
In the picture below it highlights a high water mark for flooding that took place during Hurricane Sandy in New York City.
For more information on high-water lines in terms of flooding see here.