This page contains FEMA guidance on how flood studies are performed and how flood hazard maps are prepared for coastal areas. These guidance documents are intended to help maintain consistency throughout the regions on hazard flood studies and flood hazard maps. The page is intended for FEMA staff, FEMA contractors and mapping partners that are involved in these vital study and mapping activities.
Guidelines and Specifications
- 2012 Draft Guidelines and Standards for the Great Lakes
- 2007 Guidance for Atlantic and Gulf Coasts of the United States
- 2005 Guidance for Pacific Coast of the United States
- 2002 and 2003 Guidance for Wave Elevation Determination and V Zone Mapping
- Other Coastal Flood Hazard Technical Resources
- Other Resources
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As part of its administration of the National Flood Insurance Program (NFIP), the Federal Emergency Management Agency (FEMA) prepares flood hazard maps that delineate flood insurance risk zones and Base (1-percent-annual-chance) Flood Elevations in coastal areas of the United States. These areas are among the most densely populated and economically important areas in the United States. Coastal areas are subject to a variety of natural processes that result in significant hazards and risks to public safety and property along the nation's coastlines, including extreme conditions of storm surge flooding, waves, erosion, rainfall and wind.
In an effort to maintain consistency in how flood studies are performed and how flood hazard maps are prepared for coastal areas, FEMA has issued the guidance documents summarized below for use by the FEMA staff, FEMA contractors and mapping partners that are involved in these vital study and mapping activities.
The Draft Guidelines and Specifications for Coastal Studies Along the Great Lakes issued on May 8, 2012, was open for public review until July 7, 2012. This section D.3 of Appendix D of Guidelines and Specifications for Flood Hazard Mapping Partners provides guidelines, procedures and standards for performing coastal flood hazard analyses and delineating coastal flood hazard areas for the Great Lakes coastlines in the United States. Please submit comments to FEMA-GS@fema.dhs.gov by July 7, 2012.
In February 2007, FEMA issued Atlantic Ocean and Gulf of Mexico Coastal Guidelines Update , which supersedes the version of Appendix D, Section D.2, Wave Elevation Determination and V Zone Mapping: Gulf of Mexico and Atlantic Ocean that appeared in the April 2003 version of the Guidelines. The new guidelines incorporated the coastal methodology recommendations from FEMA Procedure Memorandum 37: Protocol for Atlantic and Gulf Coast Coastal Flood Insurance Studies in FY05 , issued on August 1, 2005. Additionally, the new guidelines included a new methodology for the calculation of wave setup, incorporated the FEMA criteria for evaluating coastal structures, provided guidance for redelineating coastal flood hazard zones and clarified requirements for intermediate data submittals for FEMA-contracted studies. Guidance for the use of the Wave Height Analysis for Flood Insurance Studies, Version 4.0 and RUNUP, Version 2.0, programs are provided in Section D.2.7, Overland Wave Propagation and in Section D.2.8, Wave Runup and Overtopping, respectively.
Phase 1 Summary Report for Coastal Flood Hazard Analysis and Mapping for the Pacific Coast of the United States documents the results of a project to evaluate existing FEMA procedures for delineating coastal flood hazard areas in three major coastal regions of the United States—the Atlantic, Gulf and Pacific—and to develop new guidelines and procedures for the Pacific coastal region. The goal of this project was to incorporate recent advances in the sciences and in coastal engineering into a recommended approach for improved coastal flood hazard mapping, based on an understanding of local and regional coastal processes.
The resulting document, Guidelines for Coastal Flood Hazard Analysis and Mapping for the Pacific Coast of the United States, provides guidelines, procedures and standards for performing coastal flood hazard analyses and delineating coastal flood hazard areas and flood insurance risk zones for the Pacific coast of the United States for inclusion as Appendix D, Section D.4, Wave Elevation Determination and V Zone Mapping: Pacific Ocean, of the Guidelines. This section focuses on the Pacific coast from the U.S.-Mexico border to the U.S.-Canada border and does not address hazards in Alaska, Hawaii or other Pacific islands.
In March 1993, FEMA compiled the Wave Elevation Determination and V Zone Mapping Guidelines to specify technical policies and procedures to be employed in the preparation of coastal flood studies and restudies for the NFIP. The Wave Elevation Determination and V Zone Mapping Guidelines provided unified instructions on the application of the methodologies used to determine the coastal flooding elevation hazards documented in Flood Insurance Study reports and on the delineation of coastal flood elevations and hazards on Flood Insurance Rate Maps.
In February 2002, FEMA superseded the Wave Elevation Determination and V Zone Mapping Guidelines by including appropriate information in the Guidelines and Specifications for Flood Hazard Mapping Partners (Guidelines) - Appendix D: Guidance for Coastal Flooding Analyses and Mapping. Guidance for coastal flood hazard analysis on the Great Lakes was also included in Appendix D, Section D.3, Wave Elevation Determination and V Zone Mapping: Great Lakes. FEMA included the content of the February 2002 version of Appendix D, without significant changes, in the April 2003 version of the Guidelines.
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