How Well Did FEMA's Maps Predict Sandy's Flooding?
When Superstorm Sandy struck New York and New Jersey last year, the accuracy of FEMA’s flood-risk maps for the area varied widely. In some cases, the data behind the maps dated as far back to the 1970s. The maps help guide development and set flood insurance rates, so many property owners were left unprepared for the flooding. Click a county below to see more about FEMA’s data for that county, including the age of its maps and how well they predicted Sandy’s extent. | Related story »
Notes: In certain places on this map, Sandy was such a rare storm that FEMA could not necessarily have predicted all of the areas that would flood. This explains some, but not all, of the variation in these scores. However, areas with newer maps using newer technology predicted the flood extents far more accurately overall. Also, a FEMA official told ProPublica that the accuracy of the inundation maps may vary from location to location, but overall it represents a “very accurate overall depiction of the extent of flooding from Sandy.” Read our methodology »
Sources: FEMA National Flood Hazard Layer, FEMA Modeling Task Force (MOTF) Hurricane Sandy Impact Analysis