Access curated resources to help you understand and navigate FEMA flood risk requirements. These materials are designed for engineers, planners, developers, and property owners working with flood hazard information.
FEMA Official Resources
FEMA Flood Map Service Center
Access official Flood Insurance Rate Maps (FIRMs), floodplain boundaries, and study documentation.
Visit Resource →FEMA Guidance Documents
Technical guidelines, standards, and specifications for flood hazard mapping and analysis.
Visit Resource →LOMC Application Portal
Submit Letters of Map Change (LOMA, LOMR, LOMR-F) and track application status online.
Visit Resource →National Flood Insurance Program
Program information, regulations, and community participation requirements.
Visit Resource →Modeling & Analysis Tools
HEC-RAS
USACE's Hydrologic Engineering Center River Analysis System for hydraulic modeling.
Visit Resource →HEC-HMS
Hydrologic Modeling System for simulating watershed precipitation-runoff processes.
Visit Resource →USGS StreamStats
Web-based tool for streamflow statistics and watershed characteristics.
Visit Resource →NOAA Precipitation Data
Precipitation frequency estimates and Atlas 14 data for hydrologic analysis.
Visit Resource →Key Concepts & Terminology
Base Flood Elevation (BFE)
The computed elevation to which floodwater is anticipated to rise during the base flood (1% annual chance flood). Used to determine flood insurance rates and building elevation requirements.
Floodway
The channel of a river or stream and adjacent land areas that must be reserved to discharge the base flood without cumulatively increasing the water surface elevation by more than one foot.
Letters of Map Change (LOMC)
Official revisions to FEMA flood maps, including LOMAs (Letter of Map Amendment) for property-specific changes and LOMRs (Letter of Map Revision) for studies affecting larger areas.
Special Flood Hazard Area (SFHA)
Areas subject to inundation by the 1% annual chance flood, shown on FIRMs as zones beginning with the letter A or V. Mandatory flood insurance purchase requirements apply in these areas.
Regulatory Floodway
The portion of the floodplain required to convey flood flows. Development within the floodway is restricted to prevent increases in flood elevations.
Common FEMA Forms
- MT-1 Form: Elevation Certificate - Documents building elevation for flood insurance and regulatory purposes
- MT-2 Form: Floodproofing Certificate - Certifies non-residential structures are floodproofed
- LOMA Application: Request map amendment to remove property from Special Flood Hazard Area
- LOMR Application: Request map revision based on new hydrologic/hydraulic studies
- Conditional Letter: Pre-construction approval for map changes based on proposed conditions
Need Expert Guidance?
BaseFlood Engineering can help you navigate these resources and apply them to your specific project needs.
Contact UsDisclaimer: This page provides links to external resources for informational purposes. BaseFlood Engineering is not responsible for the content of external sites. Always verify information with official FEMA sources and consult with qualified professionals for project-specific guidance.