First Street's new flood map tool suggests FEMA has estimated 8.7 million properties with a 1% flood risk while they suggest it to be higher at 14.6M.
First Street notes that they use risks such as heavy rainfall, include areas of the country FEMA hasn't mapped and they factor current climate data.
In a statement, FEMA said: “The FEMA Flood Insurance Risk Maps and First Street Foundation maps do not conflict with each other; rather they complement one another by depicting different types of risk. Users should explore the differences between the maps to build a more comprehensive understanding of flood risk.”
Its data also includes projections of how each property’s flood risk might change over the next three decades based on climate models.
Use the link to add your current address or the property you are considering to purchase: