Flood Map Change Basics

FEMA's flood maps are an important flood risk assessment tool. Insurance agents use the maps to help homeowners assess their risk and calculate flood insurance premiums. Regulated lenders are mandated to use maps to determine if insurance is required to protect their collateral. States and communities use the data to manage the community's flood risk in such areas as floodplain and wetland management, land and water use, disaster recovery, and evacuation routes.

Even though FEMA uses the best mapping data available, there may be individual properties that are inadvertently placed in a high-risk flood zone, or it's possible that the homeowner has taken measures within NFIP guidelines to raise the structure above the Base Flood Elevation. In these situations, FEMA has a Letter of Map Change (LOMC) process to provide property owners a way to have the flood map revised or amended so that their property's flood risk is accurately represented.