FEMA Preliminary Flood Maps

New Flood Maps are Not in Effect

FEMA published preliminary flood maps. The preliminary flood maps FEMA proposed will replace the current Flood Insurance Rate Maps. Islamorada engaged the technical consulting firm Woods Hole Group to analyze FEMA's work and appeal the preliminary maps. Islamorada and individual property owners had the opportunity to appeal the preliminary maps in the 90-day appeal period that began on March 19, 2021. All appeals were submitted prior to June 17, 2021, which was the last day of the 90-day appeal period. Currently, the preliminary maps are in FEMA’s review and comment period.  When all appeals have been resolved, FEMA will give the Village six months' advance notice before the new maps become effective. In the coming months, FEMA will complete its review of all comments and appeals and publish the final Flood Insurance Rate Maps (FIRMs). The final FIRM effective date is TBA.

Background

The Preliminary Coastal Flood Maps for Florida Keys municipalities and Monroe County were released in late 2019. The release was followed by Public Flood Risk Open Houses throughout Monroe County in January 2020 to ensure all Monroe County residents had the opportunity to review and discuss the Preliminary Flood Insurance Rate Maps (FIRMs) with coastal mapping experts.

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. The new maps are based upon the best and most recent available data as well as the most advanced possible modeling software.

These flood hazard determinations are used to meet the floodplain management requirements of the NFIP and are used to calculate the appropriate flood insurance premium rates for new buildings built after the FIRM and FIS report became effective.

Once effective, the FIRM and FIS report will be used by insurance agents and others to calculate appropriate flood insurance premium rates for new buildings and the contents of those buildings. Property owners are advised to be aware of the potential for a change in flood risk and required flood elevations for their property. The new FIRMs may assist individuals to make informed decisions about maintenance or modification to existing structures on their property as well for making decisions concerning potential new construction.

Following staff review of the maps, technical consulting firm Woods Hole Group was hired by Monroe County and Islamorada to analyze how flood risks are changing based on studies and the best available science and technology. When all appeals have been resolved, FEMA will give the Village six months advance notice before the new maps become effective.

Once the final FIRMs are effective, they will be used to determine the minimum elevation needed for construction to reduce the chances of flooding as well as the construction methods required in certain zones. For additional information about the new preliminary coastal flood maps and the FEMA process to publish the final FIRMs, Please visit Monroe County Flood Maps.

View Islamorada Preliminary Flood Maps

View Interactive FEMA Preliminary Flood Maps for Monroe County

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. (Information from Monroe County website. For more information, please visit South Florida Water Management District.)

To convert one vertical datum to another, visit the ArcGIS SFWMD Elevation Conversion: NGVD29 to NAVD88 mapping tool. 

Islamorada property owners may send questions to Flood managers.