New PRELIMINARY Coastal Flood Maps

Coastal Flood Maps, otherwise known as Flood Insurance Rate Maps (FIRMs) are used to determine the minimum elevation needed for construction to reduce the chances of flooding, as well as construction methods required in certain zones.

Monroe County Building Department looks over the newly released maps


The County has hired a consultant to analyze how flood risks are changing in Unincorporated Monroe County based on the provided studies using updated information and the best available science and technology.  The technical consultant will also be reviewing the maps and modeling conducted by FEMA and is prepared to appeal any of the maps that do not appear to be correct.  

June 2020 Consultant Presentation

  1. Karl Bursa

    Senior Administrator, Floodplain
    Phone: 305-453-8759

  2. Mary Wingate

    Chief of Floodplain Regulatory Operations
    Phone: 305-289-2866


On December 27, 2019, the Federal Emergency Management Agency (FEMA) released new PRELIMINARY coastal flood maps to Monroe County staff. These maps, after a multi-year study of Monroe County’s coastal flood risks and an extensive vetting process, will eventually replace the current flood maps which are based on 30-plus-year-old studies.

While FEMA has emphasized that these are only PRELIMINARY maps, Monroe County wants to ensure all residents and business owners are aware of the potential for a change in flood risk for their property so that they can be more proactive in reducing their flood risk. 


  • FEMA FIRM PRELIMINARY Mapping tool  (NOTE: Use in Chrome Browser for optimum user experience)  Click in the FIRM Panel section where the property is located to view the popup containing a link to the Draft Map (PDF) or search by property address in the top left-hand corner.
  • FEMA PRELIMINARY Map Service Center - Select State (FL), County (Monroe County) to get to the webpage listing various area maps. Warning maps on the site are very large and may take several minutes to open/download.

MapAnnotation2 2020-01-16 113634

IMPORTANT: These maps don’t show an additional difference in elevation due to a change in mapping standards between the old and new proposed flood maps (datum NGVD29-> NAVD88). This means that all NGVD29 elevations (e.g., BFE, Lowest Floor Elevation) need to be converted to NAVD88. While there is no set conversion factor, as it varies throughout Monroe County, on average there is -1.5 foot conversion. To account for this change, ON AVERAGE you should add +1.5 foot to any apparent increase. For example, if your building was in an AE-8 flood zone and is still shown in an AE-8 zone, then it actually experienced an increase of 1.5 feet. Another example, if your building was in an AE-6 flood zone and is proposed to be in an AE-9 zone, the increase appears to be three-feet.  However, the actual increase would be 4.5 feet.

To convert one vertical datum to another, visit the ArcGIS SFWMD Elevation Conversion: NGVD29 to NAVD88 mapping toolFor more information on vertical datums, read FEMA’s fact sheet at

Previous X-Zone Buildings

Structures removed from the X-zones didn’t previously have a flood level associated with them, so this mapping standard difference wouldn’t be relevant.


Visit the FEMA Flood Map Service Center and search by property address.  


To emphasize that flood risks are changing and to make sure property owners understand this is coming, Monroe County Building Department will be requiring owner’s to sign a form with permits that acknowledge the issuance of these new PRELIMINARY coastal flood maps and the fact that these maps may indicate a future change to the required elevation of a building currently being permitted. 

Building Department Permit Application with new signature page 3 -1

This is intended to help homeowners understand that what they might be proposing to build today, under the existing flood maps, could become non-conforming after the maps are changed, thereby making their flood risk and insurance costs greater. Owners should think about designing their improvements to meet the proposed PRELIMINARY maps to assure they are addressing potential future risk.


During the week of January 27, 2020, FEMA held Community meetings throughout the Keys, offering the public an opportunity to view and comment in person on the proposed PRELIMINARY Flood Insurance Rate Maps. Following this, Monroe County, through its Consultant, examined the maps and the accompanying Flood Insurance Studies provided by FEMA.

The COVID-19 Pandemic impacted FEMA’s original timeline for Monroe County’s Map Review and Adoption Process, setting the entire process back approximately 3 months. FEMA is now in the process of preparing a notice for advertisement in the Federal Register. FEMA is anticipating FR publication late summer or early fall. Once the federal register notice is published, legal notices will be sent to local newspapers announcing this publication. The second legal notice in the newspapers will mark the beginning of the 90-Day Appeal and Comment period. At this point in time, anyone wishing to comment or appeal the maps as they are proposed may communicate their intentions to FEMA, along with any supporting documentation they feel supports their case.

Once FEMA reviews and processes all appeals, they will publish the final FIRMS. The Final FIRMs will most likely become effective sometime in 2021-2022.

When that happens, the county will formally adopt the maps by ordinance and the maps will be used when reviewing permits; and the final maps will establish what a finished floor elevation needs to be and determine building and site design requirements to reduce future risk of flooding. New lender requirements may go into effect along with flood insurance requirements, as well as changes in flood insurance rates as a result of map changes.


Any community or individual property owner can appeal proposed changes to flood hazard information or comment on other information included on the preliminary flood hazard maps, also known as Flood Insurance Rate Maps (FIRMs) and the preliminary Flood Insurance Study (FIS) report.  

Per FEMA, an appeal must be based on data and documentation showing the proposed flood hazard information shown on the preliminary FIRM or in the FIS report is scientifically or technically incorrect. Appellants need to demonstrate better methodologies, assumptions or data exists and provide alternative analyses that incorporate those methodologies, assumptions, or data if appropriate. The results must show an overall change in the flood hazard information shown on the preliminary FIRM and/or in the FIS report.

Formal appeals of the Preliminary Maps to areas in Unincorporated Monroe County must be submitted to FEMA through Monroe County.   An Appeal application required for submittal with all proposed Appeals to the Preliminary Flood Maps may be downloaded when available HERE. These Appeals will have a $170 application fee and a $5,000 deposit required to be submitted as part of the application.  The $5,000 deposit will be held in escrow and the money from this deposit will be used on an as-required basis by the County’s consultant in marshaling the individual appeal.  At the conclusion of the appeal, any remainder of the deposit will be returned to the Applicant.   

Additional information regarding FEMA Appeals to Preliminary FIRMS and the Appeals process may be found at: 

FEMA Appeal Process


The following diagram shows the tentative process timeline provided by FEMA for the Draft Maps, Preliminary Maps, and Final Maps:



For more information about the FEMA mapping process, email or call 305-453-8759.

To learn more about flood insurance, talk to your insurance agent or visit