Description: This layer offers the anticipated floodplain boundaries however, the data shown are in the process of being reviewed and adopted by FEMA and a given community. Changes to the Preliminary boundaries may occur before official map adoption. Use this layer with caution. The effective regulatory floodplain should be used for conducting all official floodplain determinations until such time the preliminary floodplain is reviewed and adopted by FEMA and a given community. It is reasonable to assume that preliminary floodplain boundaries are more accurate than the Q3, but the Q3 may better represent the current regulatory Flood Insurance Rate Map (FIRM) when verified by using the paper FIRM. Last Updated: 8/31/2017
Description: This Digital Flood Insurance Rate Map (D-FIRM) database presents the flood risk information depicted on Maryland's Flood Insurance Rate Maps (FIRMs) in a digital format suitable for use in electronic mapping applications. The primary risk classifications used are the 1-percent-annual-chance flood event (100-year storm), the 0.2-percent-annual- chance flood event (500-year storm), and areas of minimal flood risk. The DFIRM Database is derived from Flood Insurance Studies (FISs), FIRMs, flood hazard analyses performed in support of the FISs and FIRMs, and new mapping data, where available. The FISs and FIRMs are published by the Federal Emergency Management Agency (FEMA). This D-FIRM database contains up to date information as of the publish date, however FEMA continuously makes updates including adoption of new and revised maps. When FEMA makes updates they will be reflected immediately in FEMA's Map Service Center; MDE will soon after reflect those updates on mdfloodmaps.net. The specifications for the horizontal control of DFIRM data files are consistent with those required for mapping at a scale of 1:12,000.Last Updated: 5/14/2025