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GIS Mapping in Maryland

ALLEGANY COUNTY, MD - Allegany County lies in the western panhandle of Maryland and has a high proportion of development along the floodplain because most of the land lies on steep slopes. In January 1996, following a heavy snowfall and subsequent rapid thaw and heavy rains, severe flooding along the Georges-Wills Creek basin occurred. Eight months later, Hurricane Fran further damaged the area with the resultant flooding in the same locations. In the aftermath of these two Presidential Declared Disasters, a Hazard Mitigation Plan was developed that highlighted the need for basic floodplain boundary information and other government and emergency services related data.


Geographic Information System (GIS) capabilities were determined to be the most cost effective and comprehensive data storage medium available for use by a wide variety of data end-users. Because of the wide range of data required, decisions were made to concentrate on a reference base upon which all other data "layers" would relate: street boundaries.


The most accurate presentation was to digitize aerial photographs provided by the Maryland Department of Planning and then extract data layers readable by ARCVIEW, a GIS software. This was the first step in a comprehensive Hazard Identification and Risk Assessment process initiated by Allegany County. Project Impact funds ($100,000) were joined with Allegany County funding ($100,000) to complete one-half of the entire county.


The data are being used by the State Highway Administration to provide baseline road references for the re-issuance of Flood Hazard Insurance Rate Maps presently being completed in the Georges Creek area. This information will be the basis for decision making on a wide range of planning issues being addressed by not only the Project Impact sub-committees but also the State, regional and county planning bodies. The digitized data are presently being formatted by the Allegany County Planning Commission for presentation to Project Impact sub-committees.


Standard Homeowner's insurance policies do not cover flood damage. The National Flood Insurance Program makes Federally backed flood insurance available to homeowners, renters, and business owners in participating communities.

Last updated June 3, 2020