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Great Lakes Coastal Information

This page provides information about FEMA's ongoing floodplain mapping work in the coastal areas adjacent to the Great Lakes. The primary audience for this page are communities and residents in the Great Lakes coastal area, as well as others interested in lake coast flood analysis.

Map of the Great Lakes Coastal area, including the states of Minnesota, Wisconsin, Illinois, Indiana, Michigan, and Ohio in FEMA Region 5, Pennsylvania in FEMA Region 3, and New York in FEMA Region 2.

FEMA has initiated a coastal analysis and mapping study to produce updated Flood Insurance Rate Maps (FIRMs) for coastal counties along the Great Lakes. In partnership with U.S. Army Corps of Engineers (USACE) Detroit District and the Engineer Research and Development Center (ERDC), FEMA conducted a comprehensive analysis of storm and high water events within the Great Lakes Basin. The study uses the latest scientific methods and the best available data to comprehensively depict flood hazards along the lakeshore. The new flood risk information will be used to increase the understanding of local flood risk, facilitate mitigation efforts, and improve local community resilience to flood losses (life, property, and business) along the Great Lakes.

The most severe flood events on the Great Lakes occur when high lake levels are combined with strong winds that drive waves onshore. When large waves are paired with elevated lake levels, the waves are able to reach farther onshore, erode the backshore, and potentially reach developed lakefront areas. Whether wave hazards reach development depends on local conditions—for instance, the bluffs are high enough in many areas to limit the wave effects to the bluff face. However, in other areas, the bluff or shore protection structures may be overtopped or waves may pass over inundated, low-lying areas. FEMA’s flood hazard studies are conducted in accordance with published standards and associated guidance, which presents recommended approaches to meet the standards. See the Coastal Flood Hazard Analysis and Mapping Guidance page for information on coastal study guidance resources.

The updated Flood Insurance Studies and FIRMs produced for Great Lakes communities will identify Coastal High Hazard Areas, labeled Zone VE on the map. Like Zones A and AE, Zone VE is used for an area subject to the hazards associated with a 1-percent-annual-chance flood. However, the Zone VE designation is used to differentiate Coastal High Hazard Areas from other Special Flood Hazard Areas. Coastal High Hazard Areas (Zone VE) are areas that are exposed to powerful waves during large flood events. Identifying the areas where wave hazards are expected to be particularly strong is critical for flood risk awareness because waves have the potential for causing significant structural damage to buildings.  

To obtain information on the coastal study being conducted for all of the Great Lakes, please visit the Great Lakes Coastal Flood Study website.

For general information about the FEMA Regional offices responsible for managing the Great Lakes coastal flood studies, please visit the following websites:

For More Information

  • Find answers to many of your questions by visiting our Coastal Frequently Asked Questions page.

  • The Coastal Flood Risk Resources page, organized by resource type, contains links to useful fact sheets, flyers, brochures, and other helpful documents produced by FEMA, other Federal agencies, State agencies, Water Management Districts, and other entities.

Last Updated: 
06/05/2020 - 08:47