Federal Emergency Management Agency

Modeling and Mapping Non-Accredited Levees: Understanding the Zone D

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Cover photo for the document: Modeling and Mapping Non-Accredited Levees: Understanding the Zone D

The Federal Emergency Management Agency (FEMA) defines Zone D as an area of possible, but undetermined, flood hazard. Historically, FEMA has not used Zone D behind levees, however, given uncertainties in the impact a non-accredited levee system may have on flood hazards, it will be used in some situations. The new levee analysis and mapping procedures will be coupled with the Zone D designation to reflect possible flood risks behind certain non-accredited levee systems.

This fact sheet summarizes the use of the Zone D designation in the Levee Analysis and Mapping Procedures.

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Icon for file of type application/pdfModeling and Mapping Non-Accredited Levees: Understanding the Zone D
436.37KJuly 1, 2013
Icon for file of type application/pdfModeling and Mapping Non-Accredited Levees: Understanding the Zone D
479.79KSeptember 12, 2013
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