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Coastal Flood Risk Studies

The coastal Flood Insurance Rate Map (FIRM) update process starts with the "discovery" phase, during which FEMA meets with coastal communities, state representatives, and other stakeholders to share data and collaboratively determine needs and identify the best path forward.

A coastal FIRM update is generally conducted along the entire state coastline or across an entire lake basin (i.e., for the Great Lakes). This approach saves technical and data-gathering resources over the traditional county-by-county FIRM update approach. In addition to providing more accurate flood risk information, these studies make efficient use of tax dollars by generating new data that can be used to support other studies on coastal erosion, land-use planning, estuaries/wildlife habitat, and other coastal topics. Given the size and scope of these studies, a multitude of partners and communities work in cooperation toward a common goal. 

After a study is conducted, preliminary FIRMs and Flood Insurance Study (FIS) reports are distributed to each community involved. Information about the analysis used to create the new preliminary FIRMs is included in the FIS reports to provide transparency to the community and enable them to evaluate the technical approach and the science behind the study.

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Learn more about the steps involved in producing updated coastal flood risk information and maps.

Regulatory vs. Non-Regulatory Products

The FIRM is referred to as a "regulatory product” of the study, meaning that the FIRM is used to determine who must buy flood insurance and where floodplain development ordinances apply. Under the Risk MAP program, additional "non-regulatory” Flood Risk Products may also be included to help communities and property owners plan for resilience. Examples of Flood Risk Products include a coastal depth grid (which shows how deep the water would be during the 1-percent-annual-chance flood at any given location) and tools that identify the areas where the risk is greater than on the previous map, wave heights and severity of flooding, and erosion risk determinations.

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Visit the Flood Risk Products page for more on these and other products.

After issuing the Preliminary FIRM, FEMA Regional Offices will usually hold formal coordination meetings with community officials and open houses for the public to explain changes to the FIRM, answer questions, and obtain feedback. Preliminary FIRMs are available for viewing online through FEMA’s Flood Map Service Center.

Appeal Period

Afterward, a 90-day appeal period will be initiated. During this time, the community and others may appeal the proposed flood hazard information by submitting scientific or technical data that proves the flood hazard information shown on the preliminary FIRM and/or FIS report is erroneous. Please note that all comments or appeals to FIRMs should be submitted through the community; therefore, contact your community officials with any concerns.

At the end of the 90-day appeal period or after all appeals have been resolved, FEMA will issue a Letter of Final Determination (LFD) establishing that the flood hazard information is final. The LFD initiates a six-month compliance period during which the community must adopt or amend its floodplain management regulations to reflect the updated flood hazard information shown on the FIRM and FIS report.

The FIRM and FIS report will become effective following the 6-month compliance period. At that time, flood insurance will be required for structures that are shown on the FIRM in a Special Flood Hazard Area (SFHA) and carry a mortgage backed by a federally regulated lender. The final FIRM will be available at a community’s local map repository and online through FEMA’s Flood Map Service Center.

Risk MAP for Your Community

To learn about the progress of your community’s coastal mapping project, please visit the Risk MAP pages. There you can find an interactive map that allows users to zoom in, locate their community, and click to learn about the project status (i.e., timeframe for their preliminary and effective maps). A browser plug-in may be required to use this tool. 

If your community participates in the National Flood Insurance Program, paper copies of the FIRMs and FIS reports are on file at your local Community Map Repository, usually located in the planning and zoning office. Please contact a FEMA Map Information eXchange Map Specialist to determine the location of your Community Map Repository or to ask additional questions about a project status.