The Digital Flood Insurance Rate Map (DFIRM) Database depicts flood risk information and supporting data used to develop the risk data.  The primary risk classifications used are the 1-percent-annual-chance flood event, the 0.2-percent-annual-chance flood event, and areas of minimal flood risk.  The DFIRM Database is derived from Flood Insurance Studies (FISs), previously published Flood Insurance Rate Maps (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). The file is georeferenced to earth's surface using the Kentucky State Plane North projection and coordinate system.  The specifications for the horizontal control of DFIRM data files are consistent with those required for mapping at a scale of 1:6000.

The FIRM is the basis for floodplain management, mitigation, and insurance activities for the National Flood Insurance Program (NFIP). Insurance applications include enforcement of the mandatory purchase requirement of the Flood Disaster Protection Act, which "... requires the purchase of flood insurance by property owners who are being assisted by Federal programs or by Federally supervised, regulated or insured agencies or institutions in the acquisition or improvement of land facilities located or to be located in identified areas having special flood hazards," Section 2 (b) (4) of the Flood Disaster Protection Act of 1973.  In addition to the identification of Special Flood Hazard Areas (SFHAs), the risk zones shown on the FIRMs are the basis for the establishment of premium rates for flood coverage offered through the NFIP.

The DFIRM Database presents the flood risk information depicted on the DFIRM in a digital format suitable for use in electronic mapping applications.  The DFIRM database is a subset of the Digital FIS database that serves to archive the information collected during the FIS.

FIRM and FIS effective date

Data access is restricted to LOJIC Participants, their Contractors and Licensees only.

LIMITATION OF LIABILITY: The participants of the Louisville/Jefferson County Information Consortium have no indication or reason to believe that there are any inaccuracies or defects of information incorporated in this work and make NO REPRESENTATIONS OF ANY KIND, INCLUDING, BUT NOT LIMITED TO, THE WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR USE, NOR ARE ANY SUCH WARRANTIES TO BE IMPLIED, WITH RESPECT TO THE INFORMATION OR DATA, FURNISHED HEREIN.

The DFIRM Database is made up of several data themes containing both spatial and attribute information.  These data together represent the current flood risk for the subject area as identified by FEMA.

Location and attributes for flood control structures shown on the DFIRM.

FEMA Guidelines and Specifications for Flood Hazard Mapping Partners, Appendix L: Guidance for Preparing Draft Digital Data and DFIRM Databases.

When FEMA revises an FIS, adjacent studies are checked to ensure agreement between flood elevations at the boundaries.  Likewise, flood elevations at the confluence of streams studied independently are checked to ensure agreement at the confluence.  The DFIRM and the FIS are developed together and care is taken to ensure that the elevations and other features shown on the flood profiles in the FIS agree with the information shown on the DFIRM.  However, the elevations as shown on the DFIRM are rounded, whole-foot elevations.  They must be shown so that a profile recreated from the elevations on the DFIRM will match the FIS profiles within one half of one foot.

Data contained in the DFIRM Database files reflect the content of the source materials.  Features may have been eliminated or generalized on the source graphic, due to scale and legibility constraints.   With new mapping, FEMA plans to maintain full detail in the spatial data it produces.  However, older information is often transferred from existing maps where some generalization has taken place.

Flood risk data are developed for communities participating in the NFIP for use in insurance rating and for floodplain management.  Flood hazard areas are determined using statistical analyses of records of river flow, storm tides, and rainfall; information obtained through consultation with the communities; floodplain topographic surveys; and hydrological and hydraulic analysis.  Both detailed and approximate analyses are employed. Generally, detailed analyses are used to generate flood risk data only for developed or developing areas of communities.  For areas where little or no development is expected to occur, FEMA uses approximate analyses to generate flood risk data.  Typically, only drainage areas that are greater than one square mile are studied.

The DFIRM Database consists of countywide raster and study area vector files and associated attributes produced in conjunction with the hard copy FEMA Flood Insurance Rate Map (FIRM).  The published effective FIRM and DFIRM maps are issued as the official designation of the SFHAs.  As such they are adopted by local communities and form the basis for administration of the NFIP.  For these purposes, they are authoritative.  Provisions exist in the regulations for public review, appeals and corrections of the flood risk information shown to better match real world conditions.  As with any engineering analysis of this type, variation from the estimated flood heights and floodplain boundaries is possible.  Details of FEMA's requirements for the FISs and flood mapping process that produces these data are available in the Guidelines and Specifications for Flood Map Production Coordination Contractors.  Attribute accuracy was tested by manual comparison of source graphics with hardcopy plots and a symbolized display on an interactive computer graphic system.

Independent quality control testing of FEMA's DFIRM database was also performed.

To obtain more detailed information in areas where Base Flood Elevations (BFEs) and/or floodways have been determined, users are encouraged to consult the Flood Profiles and Floodway Data and/or Summary of Stillwater Elevations tables contained within the FIS report that accompanies this DFIRM database.  Users should be aware that BFEs shown in the S_BFE table represent rounded whole-foot elevations.  These BFEs are intended for flood insurance rating purposes only and should not be used as the sole source of flood elevation information.  Accordingly, flood elevation data presented in the FIS report must be used in conjunction with the DFIRM for purposes of construction and/or floodplain management.  The 1-percent-annual-chance water-surface elevations shown in the S_XS table match the regulatory elevations shown in the FIS report.

The DFIRM Database consists of study area raster and vector files and associated attributes produced in conjunction with the hardcopy FEMA DFIRM.  The published effective FIRM and DFIRM are issued as the official designation of the SFHAs.  As such, they are adopted by local communities and form the basis for administration of the NFIP.  For these purposes, they are authoritative.  Provisions exist in the regulations for public review, appeals and corrections of the flood risk information shown to better match real world conditions.  As with any engineering analysis of this type, variation from the estimated flood heights and floodplain boundaries is possible.  Details of FEMA's requirements for the FISs and flood mapping process that produces these data are available in the Guidelines and Specifications for Flood Map Production Coordination Contractors.  Horizontal accuracy was tested by manual comparison of source graphics with hardcopy plots and a symbolized display on an interactive computer graphic system.

Independent quality control testing of FEMA's DFIRM database was also performed.

The DFIRM Database consists of countywide raster and vector files and associated attributes produced in conjunction with the hardcopy FEMA FIRM.  The published effective FIRM and DFIRM maps are issued as the official designation of the SFHAs.  As such they are adopted by local communities and form the basis for administration of the NFIP.  For these purposes, they are authoritative.  Provisions exist in the regulations for public review, appeals and corrections of the flood risk information shown to better match real world conditions.  As with any engineering analysis of this type, variation from the estimated flood heights and floodplain boundaries is possible.  Details of FEMA's requirements for the FIS and flood mapping process that produces these data are available in the Guidelines and Specifications for Flood Map Production Coordination Contractors.  Vertical accuracy was tested by manual comparison of source graphics with hardcopy plots and a symbolized display on an interactive computer graphics system.

Independent quality control testing of FEMA's DFIRM database was also performed.

Downloadable Data

No warranty expressed or implied is made by FEMA regarding the utility of the data on any other system nor shall the act of distribution constitute any such warranty.  FEMA will warrant the delivery of this product in a computer-readable format, and will offer appropriate adjustment of credit when the product is determined unreadable by correctly adjusted computer input peripherals, or when the physical medium is delivered in damaged condition.  Request for adjustment of credit must be made within 90 days from the date of this shipment from the ordering site.

Data requests must include the full name of the community or county and the FIRM panel number(s) or the 7.5- minute series quadrangle sheet area(s) covered by the request.

Printed workmaps that match this data set are available from FEMA at the Map Service Center, cited above.