NFIP Maps

Flooding poses a significant threat to communities across the United States, leading to substantial property damage and economic loss. To mitigate these risks, the Federal Emergency Management Agency (FEMA) administers the National Flood Insurance Program (NFIP), which provides flood insurance and promotes sound floodplain management practices.

A cornerstone of the NFIP is the development and utilization of flood maps. These maps are essential tools for identifying flood hazards, assessing risk, and guiding both development and insurance decisions.

Purpose and Importance

Flood maps serve multiple critical functions:

• Risk Identification: They delineate areas susceptible to flooding, highlighting regions with varying levels of flood risk.
• Regulatory Guidance: Local governments rely on flood maps to enforce building codes and land-use regulations aimed at minimizing flood damage.

By providing a visual representation of flood-prone areas, flood maps enable property owners, developers, and policymakers to make informed decisions that enhance community resilience against flooding.

Flood Hazard Boundary Maps

Flood Hazard Boundary Maps (FHBMs) serve as preliminary mapping tools in the NFIP, providing a general overview of flood-prone areas within a community. Unlike FIRMs, FHBMs lack detailed topographical and hydrological information, making them less precise for assessing specific flood risks.

They are granted to a community when they enter the Emergency Program. Over time, FHBMs are typically replaced by more detailed FIRMs as additional studies and data collection are completed. While outdated in most areas, FHBMs remain a historical reference for understanding the initial identification of flood-prone regions.

Flood Insurance Rate Maps

Flood Insurance Rate Maps (FIRMs) are critical tools developed by FEMA as part of the National Flood Insurance Program (NFIP). These maps provide detailed, community-specific information about flood hazards, delineating flood zones, Base Flood Elevations (BFEs), and floodways. FIRMs are used to determine flood insurance requirements for properties based on their level of risk. They also help guide local governments in implementing zoning regulations and building codes that minimize flood damage. FIRMs are updated periodically to reflect changes in topography, development, and hydrology, ensuring they provide accurate and actionable data for communities and property owners.

FIRMs incorporate several key elements:

• Flood Zones: These zones categorize areas based on their level of flood risk. For instance, Special Flood Hazard Areas (SFHAs) are regions with a 1% annual chance of flooding, commonly known as the 100-year floodplain. Zones within SFHAs include:
  • Zone AE: Areas subject to inundation by the 1% annual chance flood event, determined by detailed methods.
  • Zone VE: Coastal areas with a 1% or greater chance of flooding and an additional hazard associated with storm waves.
• Base Flood Elevations (BFEs): These indicate the computed elevation to which floodwater is anticipated to rise during a base flood event.
• Floodways: These are channels of rivers or other watercourses and adjacent land areas reserved to discharge the base flood without cumulatively increasing the water surface elevation more than a designated height.

External Resources

• FloodSmart Flood Maps
• FEMA Map Service Center
• Appendix D: Maps

This page contains information about the NFIP. Find more NFIP Resources.