FEMA Flood Insurance Rate Maps and Map Revisions

Special Flood Hazard Areas (SFHAs) are areas located within the 100-year floodplain, defined as any area that has a one percent chance of flooding in any given year.  Smaller scale floods (50-year and 10-year) have a greater chance of occurring in any given year and can also pose a significant flood hazard to persons and property in close proximity to channels and streams. Additionally, floods larger than the mapped 100-year event can occur.

Flood Insurance Rate Maps (FIRMs)

The FEMA Flood Insurance Rate Maps (FIRMs) are the official maps showing the community’s Special Flood Hazard Areas. These maps are utilized as the basis for local floodplain management regulations and mitigation efforts, to assess flood risk, and to determine if flood insurance is required for structure(s) on a property.  Although these maps are not property specific (e.g., no lot boundaries), by using the major roads and flooding sources for reference, users can get an idea of the flood risks in their area.

These maps are available to view online at the FEMA Map Service Center and on SanGIS. The Map Service Center site has an address search feature that allows a user to find the correct FIRM panel using their address in an on-line search tool.  Paper copies of the FIRMs are available at County library branches and at the Flood Control Counter at the County’s Operation Center Annex at 5201 Ruffin Road, San Diego.

For additional assistance with using a FIRM, please contact the FEMA Map Information eXchange (FMIX) by phone at 1-877-FEMA-MAP (1-877-336-2627); or by e-mail at FEMAMapSpecialist@riskmapcds.com. You can also visit  http://www.floodmaps.fema.gov/fhm/fmx_main.html, or contact the San Diego County Department of Public Works – Flood Control Counter staff at (858) 694-2055.

Letters of Map Amendment and Revision (LOMA/LOMR)

In some cases, a lender determines that a property is in the Special Flood Hazard Area (SFHA), or 100-year floodplain, and requires the owner to purchase flood insurance.  If the property owner wishes to dispute the fact that they are in the SFHA, they can apply for a Letter of Map Amendment (LOMA) or a Letter of Map Revision Based on Fill (LOMR-F), if fill placement is the basis of the request.

You may also access tutorials designed to assist in the preparation of these forms at https://www.fema.gov/national-flood-insurance-program-flood-hazard-mapping/letter-map-change. These tutorials will guide you through the application and provide tips on filling out the forms.

Upon receiving a completed application, FEMA reviews property-specific information and makes a final flood zone determination for the property.  Once an application is received with all the required supporting data, the LOMA or LOMR-F is normally issued within 60 days.  If the LOMA or LOMR-F removes the SFHA designation from the property, it can then be presented to the lender as proof that there is no Federal flood insurance requirement for the property.  Bear in mind that even though a LOMA or LOMR-F may remove the Federal requirement for flood insurance, a lender retains the prerogative to require flood insurance.

Allowable Use of Map Revisions Based Upon Fill

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If you have questions or would like additional information, 
call the County Stormwater hotline at 1(888) 846-0800
or e-mail us at watersheds@sdcounty.ca.gov

Report a Stormwater Violation On-Line

If you see a County storm drainage system in need of maintenance, contact the County Department of Public Works Field Operations staff at (619) 443-1260 weekdays or contact the Stormwater Hotline at 1(888) 846-0800.  For after-hours emergencies contact (858) 565-5262. 

Department of Public Works
Flood Control
5510 Overland Ave., Suite 410, MS O326
San Diego,  CA  92123,  USA
(858) 495-5318           Fax: (858) 495-5263