DIGITAL FLOOD INSURANCE RATE MAP DATABASE, WILSON COUNTY, NORTH CAROLINA
Dataset Identification:
Resource Abstract:
This Flood Insurance Study was produced through a cooperative partnership between the State of North Carolina and FEMA. The
North Carolina Floodplain Mapping Program, through FEMA's Cooperating Technical State (CTS) Initiative, is conducting flood
hazard analyses and producing updated, digital FIRM panels for all North Carolina communities. Additional information regarding
the North Carolina Floodplain Mapping Program and the data collected during the mapping process are available at www.ncfloodmaps.com.
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 the earth's surface using the NC State Plane Coordinate System, North American Datum 1983, Units of Feet. The specifications
for the horizontal control of DFIRM data files are consistent with those required for mapping at a scale of 1:12,000.
Citation
Title DIGITAL FLOOD INSURANCE RATE MAP DATABASE, WILSON COUNTY, NORTH CAROLINA
publication Date
2015-06-02
presentationForm
FEMA-DFIRM-FINAL
cited responsible party
-
publisher
organisation Name
Federal Emergency Management Agency
Contact information
Address
, Washington, DC
cited responsible party
-
originator
organisation Name
North Carolina Foodplain Mapping Program
cited responsible party
-
originator
organisation Name
Federal Emergency Management Agency
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 FIRM in a digital format suitable for use in electronic mapping applications. The
DFIRM database is a subset of the North Carolina Floodplain Mapping Information System (NCFMIS) that serves to archive the
information collected during the FIS. The NCFMIS is available at www.ncfloodmaps.com.
Resource language:
eng; USA
Resource progress code:
completed
Resource Maintenance Information
maintenance or update frequency:
irregular
Constraints on resource usage:
Constraints
Use limitation statement:
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. Requests for adjustment of credit must be made
within 90 days from the date of this shipment from the ordering site.
Constraints on resource usage:
Legal Constraints
use constraint:
otherRestrictions
Other constraints
Use Constraints: The hardcopy FIRM and DFIRM and the accompanying FISs are the official designation of SFHAs and Base Flood
Elevations (BFEs) for the NFIP. For the purposes of the NFIP, changes to the flood risk information published by FEMA may
only be performed by FEMA and through the mechanisms established in the NFIP regulations (44 CFR Parts 59-78). These digital
data are produced in conjunction with the hardcopy FIRMs and generally matches the hardcopy map exactly. However the hardcopy
flood maps and flood profiles are the authoritative documents for the NFIP. Acknowledgement of FEMA and the North Carolina
Floodplain Mapping Program would be appreciated in products derived from these data.
Constraints on resource usage:
Legal Constraints
Access Constraints
otherRestrictions
Other constraints
Access Constraints: None
Spatial representation type code:
vector
Processing environment:
Native Dataset Environment: Original data development environment varies. Finishing of the data is done using ESRI's ArcGIS
software.
Resource extent
Geographic Extent
Geographic Bounding Box
westBoundLongitude
-79.1937
eastBoundLongitude
-76.6620
northBoundLatitude
36.8701
southBoundLatitude
34.5711
Temporal Extent
2015-06-02
point of contact
-
pointOfContact
organisation Name
Federal Emergency Management Agency
position Name Federal Insurance and Mitigation Administration
Contact information
Telephone
Voice 1-877-336-2627
Address
500 C Street, S.W., Washington, District of Columbia, 20472
Country USA
source description
Source Contribution: Location of roads, railroads, bridges, streams, and other physical features.Source Type CD-ROM
representative resolution scale:
Scale denominator: 1200
source citation
Title WILSON COUNTY, NORTH CAROLINA
publication Date
1995-01-01
presentationForm
REMOTE SENSING IMAGE
other Citation Details
Digital Orthophotography provided by Wilson County.
cited responsible party
-
publisher
organisation Name
North Carolina Floodplain Mapping Program
Contact information
Address
, Wilson, NC
cited responsible party
-
originator
organisation Name
Wilson County, NC
Resource extent
Temporal Extent
1995-01-01
source
source description
Source Contribution: Spatial and attribute information for cross sections, floodplain information, BFEs, coastal transects,
general structures, and station start descriptions.Source Type CD-ROM
representative resolution scale:
Scale denominator: 12000
source citation
Title Flood Insurance Study, Wilson County.
publication Date
2005-12-02
presentationForm
mapDigital
other Citation Details
This Flood Insurance Study was produced through a cooperative partnership between the State of North Carolina and FEMA. The
North Carolina Floodplain Mapping Program, through FEMA's Cooperating Technical State (CTS) Initiative, is conducting flood
hazard analyses and producing updated, digital FIRM panels for all North Carolina communities. A more detailed description
of the areas studied and the engineering methods used can be found in sections 4.0 and 5.0 of the accompanying Flood Insurance
Study report. Additional information regarding the North Carolina Floodplain Mapping Program and the data collected during
the mapping process are available at www.ncfloodmaps.com.
cited responsible party
-
publisher
organisation Name
North Carolina Floodplain Mapping Program
Contact information
Address
, Raleigh, NC
cited responsible party
-
originator
organisation Name
North Carolina Floodplain Mapping Program
Resource extent
Temporal Extent
2005-12-02
source
source description
Source Contribution: Grid of DFIRM panels.Source Type CD-ROM
representative resolution scale:
Scale denominator: 12000
source citation
Title WILSON COUNTY, NORTH CAROLINA, Digital Flood Insurance Rate Map
publication Date
2005-12-02
presentationForm
mapDigital
other Citation Details
Grid of FIRM panels created for this Flood Insurance Study.
cited responsible party
-
publisher
organisation Name
North Carolina Floodplain Mapping Program
Contact information
Address
, Raleigh, NC
cited responsible party
-
originator
organisation Name
North Carolina Floodplain Mapping Program
Resource extent
Temporal Extent
2005-12-02
source
source description
Source Contribution: National Geodetic Survey reference points (bench marks).Source Type CD-ROM
representative resolution scale:
Scale denominator: 24000
source citation
Title Geodetic bench marks
publication Date
2004-01-01
presentationForm
mapDigital
other Citation Details
The National Geodetic Survey (NGS) serves as the Nation's depository for geodetic data in the National Spatial Reference System.
These geodetic data include bench marks and other control points that provide the base of reference for latitude, longitude,
height, scale, orientation, and gravity measurements used throughout the United States.
cited responsible party
-
publisher
organisation Name
National Geodetic Survey
Contact information
Address
, Silver Spring, MD
cited responsible party
-
originator
organisation Name
National Geodetic Survey
Resource extent
Temporal Extent
2004-01-01
source
source description
Source Contribution: North Carolina Geodetic Survey reference points (bench marks).Source Type CD-ROM
representative resolution scale:
Scale denominator: 24000
source citation
Title Geodetic bench marks
publication Date
2004-01-01
presentationForm
mapDigital
other Citation Details
The North Carolina Geodetic Survey (NCGS) is the lead agency in North Carolina responsible for the coordination of geodetic
activities among State agencies. NCGS coordinates the development, adoption, and promotion of: (a) classification standards
of content, format, and accuracy for geodetic data and (b) standards and specifications for geodetic surveying techniques
and technologies for use by all State agencies and, encourages their use by non-state agencies. NCGS disseminates information
on technological improvements for collecting geodetic data and coordinates the plans and requirements for geodetic activities
of State agencies. The NCGS Geodetic Survey Section establishes precisely located monuments on the North Carolina Grid System
and Bench Marks referenced to a vertical datum (NGVD 1929 and NAVD 1988). The Geodetic Survey Section establishes and maintains
the official survey base of the state of North Carolina to support mapping, boundary determination, property delineation,
infrastructure development, resource evaluation surveys, and scientific applications.
cited responsible party
-
publisher
organisation Name
North Carolina Geodetic Survey
Contact information
Address
, Raleigh, NC
cited responsible party
-
originator
organisation Name
North Carolina Geodetic Survey
Resource extent
Temporal Extent
2004-01-01
source
source description
Source Contribution: Base map surface water features.Source Type CD-ROM
representative resolution scale:
Scale denominator: 12000
source citation
Title WILSON COUNTY, NORTH CAROLINA, Digital Flood Insurance Rate Map
publication Date
2005-12-02
presentationForm
mapDigital
other Citation Details
Base map surface water features digitized from Digital Orthophotos.
cited responsible party
-
publisher
organisation Name
North Carolina Floodplain Mapping Program
Contact information
Address
, Raleigh, NC
cited responsible party
-
originator
organisation Name
North Carolina Floodplain Mapping Program
Resource extent
Temporal Extent
2005-12-02
source
source description
Source Contribution: Grid of USGS 7.5-Minute Series Topographic Maps.Source Type CD-ROM
representative resolution scale:
Scale denominator: 24000
source citation
Title 7.5-Minute Quadrangle Grid
publication Date
1999-01-01
presentationForm
mapDigital
other Citation Details
Grid of USGS 7.5-Minute Series Topographic Maps.
cited responsible party
-
publisher
organisation Name
ESRI
Contact information
Address
, Redlands, CA
cited responsible party
-
originator
organisation Name
U.S. Geological Survey
Resource extent
Temporal Extent
1999-01-01
source
source description
Source Contribution: Spatial and attribute information for benchmarks established during the Flood Insurance Study.Source
Type CD-ROM
representative resolution scale:
Scale denominator: 12000
source citation
Title Contractor Established Benchmarks
publication Date
2013-04-16
presentationForm
mapDigital
other Citation Details
Contractor Established Benchmarks
cited responsible party
-
publisher
organisation Name
North Carolina Floodplain Mapping Program
Contact information
Address
, Raleigh, NC
cited responsible party
-
originator
organisation Name
North Carolina Floodplain Mapping Program
Resource extent
Temporal Extent
2013-04-16
source
source description
Source Contribution: Spatial and attribute information for cross sections, floodplain information, BFEs, general structures,
and station start descriptions.Source Type CD-ROM
representative resolution scale:
Scale denominator: 6000
source citation
Title Physical Map Revision, Wilson County, NC
publication Date
2013-04-16
presentationForm
mapDigital
other Citation Details
This Flood Insurance Study was produced through a cooperative partnership between the State of North Carolina and FEMA. The
North Carolina Floodplain Mapping Program, through FEMA's Cooperating Technical State (CTS) Initiative, is conducting flood
hazard analyses and producing updated, digital FIRM panels for all North Carolina communities. A more detailed description
of the areas studied and the engineering methods used can be found in sections 4.0 and 5.0 of the accompanying Flood Insurance
Study report. Additional information regarding the North Carolina Floodplain Mapping Program and the data collected during
the mapping process are available at www.ncfloodmaps.com.
cited responsible party
-
publisher
organisation Name
Federal Emergency Management Agency
Contact information
Address
, Washington, DC
cited responsible party
-
originator
organisation Name
Federal Emergency Management Agency
Resource extent
Temporal Extent
2013-04-16
source
source description
Source Contribution: Location of roads, railroads, bridges, streams, and other physical features.Source Type CD-ROM
representative resolution scale:
Scale denominator: 2400
source citation
Title Wilson County Digital Orthoimagery
publication Date
2007-02-18
presentationForm
REMOTE SENSING IMAGE
other Citation Details
Digital Orthophotography provided by Wilson County.
cited responsible party
-
publisher
organisation Name
Wilson County,NC
Contact information
Address
, Wilson, NC
cited responsible party
-
originator
organisation Name
Wilson County,NC
Resource extent
Temporal Extent
2007-02-18
source
source description
Source Contribution: Spatial and attribute information for political entities (counties, municipalities) and military and
Native American lands.Source Type CD-ROM
representative resolution scale:
Scale denominator: 12000
source citation
Title Political Boundaries
publication Date
2008-08-05
presentationForm
mapDigital
other Citation Details
Political boundaries shown on the DFIRM were provided by Wilson County, NC.
cited responsible party
-
publisher
organisation Name
North Carolina Floodplain Mapping Program
Contact information
Address
, Raleigh, NC
cited responsible party
-
originator
organisation Name
Wilson County, NC
Resource extent
Temporal Extent
2008-08-05
source
source description
Source Contribution: Spatial and attribute information for transportation features including roads, railroads and airports.Source
Type CD-ROM
representative resolution scale:
Scale denominator: 12000
source citation
Title Transportation Features
publication Date
2008-08-05
presentationForm
mapDigital
other Citation Details
Transportation features were derived from data provided by Wilson County, NC.
cited responsible party
-
publisher
organisation Name
North Carolina Floodplain Mapping Program
Contact information
Address
, Raleigh, NC
cited responsible party
-
originator
organisation Name
Wilson County, NC
Resource extent
Temporal Extent
2008-08-05
source
source description
Source Contribution: Spatial and attribute information for base map surface water features.Source Type CD-ROM
representative resolution scale:
Scale denominator: 6000
source citation
Title Surface Water Features
publication Date
2013-04-16
presentationForm
mapDigital
other Citation Details
Base map surface water features digitized from Digital Orthophotos.
cited responsible party
-
publisher
organisation Name
North Carolina Floodplain Mapping Program
Contact information
Address
, Raleigh, NC
cited responsible party
-
originator
organisation Name
North Carolin Floodplain Mapping Program
Resource extent
Temporal Extent
2013-04-16
source
source description
Source Contribution: Location of roads, railroads, bridges, streams, and other physical features.Source Type CD-ROM
representative resolution scale:
Scale denominator: 2400
source citation
Title Wilson County Digital Orthoimagery
publication Date
2009-02-18
presentationForm
REMOTE SENSING IMAGE
other Citation Details
Digital Orthophotography provided by Wilson County.
cited responsible party
-
publisher
organisation Name
Wilson County,NC
Contact information
Address
, Wilson, NC
cited responsible party
-
originator
organisation Name
Wilson County,NC
Resource extent
Temporal Extent
2009-02-18
AbsoluteExternalPositionalAccuracy
name Of Measure Horizontal Positional Accuracy Report
evaluation Method Description
The DFIRM Database consists of countywide vector files and associated attributes produced in conjunction with the hardcopy
FEMA FIRM. 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 Hazard Mapping Partners. For streams restudied by detailed and limited
detail methods, the 1% and 0.2% annual chance floodplains were delineated using flood elevations determined at each cross
section. Between cross sections, the boundaries were interpolated using topographic data acquired using airborne LIDAR. This
LIDAR data was acquired during the winter 2000-2001 flying season. The topographic data satisfies a vertical root-mean- square
error (RMSE) accuracy standard of 20cm (1.3 feet accuracy at the 95% confidence limit) for coastal areas and 25 cm (1.6 feet
accuracy at the 95% confidence limit) for non-coastal areas of the State. These data could be contoured at roughly a 2- foot
vertical contour interval. All elevations were referenced to the NAVD 88 and reflect orthometric heights. Variably spaced,
bare-earth digital topographic data in ASCII point file format were combined with imagery (either flown concurrently with
the LIDAR data or using existing digital orthophotos) to establish a Triangulated Irregular Network (TIN) of digital elevation
points, which include selected breaklines to be used for hydraulic modeling. Furthermore, a uniformly spaced sampling of the
TIN resulted in uniformly spaced Digital Elevation Models (DEMs), with 20 ft x 20 ft post spacing, which was generated in
multiple file formats. For coastal floodplains, after analyzing wave heights along each transect, wave elevations were interpolated
between transects. Various source data were used in the interpolation, including topographic data described above. 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.
AbsoluteExternalPositionalAccuracy
name Of Measure Vertical Positional Accuracy Report
evaluation Method Description
The DFIRM Database consists of countywide vector files and associated attributes produced in conjunction with the hard copy
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 FISs and flood mapping process that produces these
data are available in the Guidelines and Specifications for Flood Hazard Mapping Partners. For streams restudied by detailed
and limited detail methods, the 1% and 0.2% annual chance floodplains were delineated using flood elevations determined at
each cross section. Between cross sections, the boundaries were interpolated using topographic data acquired using airborne
LIDAR. This LIDAR data was acquired during the winter 2000-2001 flying season. The topographic data satisfies a vertical root-mean-
square error (RMSE) accuracy standard of 20cm (1.3 feet accuracy at the 95% confidence limit) for coastal areas and 25 cm
(1.6 feet accuracy at the 95% confidence limit) for non-coastal areas of the State. These data could be contoured at roughly
a 2- foot vertical contour interval. All elevations were referenced to the NAVD 88 and reflect orthometric heights. Variably
spaced, bare-earth digital topographic data in ASCII point file format were combined with imagery (either flown concurrently
with the LIDAR data or using existing digital orthophotos) to establish a Triangulated Irregular Network (TIN) of digital
elevation points, which include selected breaklines to be used for hydraulic modeling. Furthermore, a uniformly spaced sampling
of the TIN resulted in uniformly spaced Digital Elevation Models (DEMs), with 20 ft x 20 ft post spacing, which was generated
in multiple file formats. For coastal floodplains, after analyzing wave heights along each transect, wave elevations were
interpolated between transects. Various source data were used in the interpolation, including topographic data described above.
Vertical 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.
Completeness Commission
evaluation Method Description
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.
Completeness Omission
evaluation Method Description
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.
ConceptualConsistency
measure Description
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
FIRM 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 FIRM. However, the elevations as shown on the FIRM are rounded
whole-foot elevations. They must be shown so that a profile recreated from the elevations on the FIRM will match the FIS profiles
within one half of one foot.
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.
notes: This metadata was automatically generated from the FGDC Content Standards for Digital Geospatial Metadata standard (version
FGDC-STD-001-1998) using the 2012-06-20T17:21:00 version of the FGDC RSE to ISO 19115-2 transform.
Metadata contact
-
pointOfContact
individual Name MipHelp
organisation Name
Federal Emergency Management Agency
position Name Federal Insurance and Mitigation Administration
Contact information
Telephone
Voice 1-877-336-2627
Address
500 C Street, S.W., Washington, District of Columbia, 20472
Country USA