FLORIDA GEOGRAPHIC DATA LIBRARY DOCUMENTATION

TITLE: HYDROLOGIC UNIT BOUNDARIES IN FLORIDA - 12-DIGIT - SEPTEMBER 2015

Geodataset Name:       NHDWBD_HUC12_SEP15
Geodataset Type:       SHAPEFILE
Geodataset Feature:    Polygon
Feature Count:         1853
GENERAL DESCRIPTION:
This data set is a complete digital hydrologic unit boundary layer to the Subwatershed (12-digit) 6th level for the State of Florida. This data set consists of geo-referenced digital data and associated attributes created in accordance with the "FGDC Proposal, Version 1.0 - Federal Standards For Delineation of Hydrologic Unit Boundaries 3/01/02"(http://www.ftw.nrcs.usda.gov/huc_data.html). Polygons are attributed with hydrologic unit codes for 4th level sub-basins, 5th level watersheds, 6th level subwatersheds, name, size, downstream hydrologic unit, type of watershed, non-contributing areas and flow modification. Arcs are attributed with the highest hydrologic unit code for each watershed, linesource and a metadata reference file.
DATA SOURCE(S):                    U.S. Geological Survey, U.S. Environmental Protection Agency, USDA Forest Service, Florida Department of Environmental Protection
SCALE OF ORIGINAL SOURCE MAPS:     24000
GEODATASET EXTENT:                 State of Florida
PUBLICATION DATE: 2015 TIME PERIOD OF CONTENT: 20150910 DOWNLOAD LINK: http://www.fgdl.org/metadataexplorer/explorer.jsp

FEATURE ATTRIBUTE TABLES:

Datafile Name: NHDWBD_HUC12_SEP15.DBF
ITEM NAME WIDTH TYPE
OBJECTID
4 OID
SHAPE
4 Geometry
TNMID
40 String
METASOURCE
40 String
SOURCEDATA
100 String
SOURCEORIG
130 String
SOURCEFEAT
40 String
LOADDATE
36 Date
GNIS_ID
8 Double
AREAACRES
8 Double
AREASQKM
8 Double
STATES
50 String
HUC12
12 String
NAME
120 String
HUTYPE
254 String
HUMOD
30 String
TOHUC
16 String
NONCON_AC
8 Double
NONCON_KM
8 Double
HUTYPE_DSC
20 String
DESCRIPT
120 String
FGDLAQDATE
36 Date
AUTOID
4 Integer
SHAPE.AREA
0 Double
SHAPE.LEN
0 Double

FEATURE ATTRIBUTE TABLES CODES AND VALUES:

Item
Item Description
OBJECTID Internal feature number.

SHAPE Feature geometry.

TNMID (short for The National Map Identification) is a unique 40-character field that identifies each element in the database exclusively. TNMID is an automatically assigned code that stays with each element. When an element is updated or changed, TNMID links the element to the metadata record and documents the change. TNMID is also used to maintain relationship classes in the normalized data model. When an element is deleted or split, TNMID stays with the original element and is not used again. When an element is split, new permanent identifiers are assigned to the resultant parts.

METASOURCE Unique identifier that links the element to the metadata tables. This ID is generated and assigned automatically by the database and remains with the object permanently.

SOURCEDATA A space provided for a brief description of the type of base data used to update or change the current WBD. The WBD In-State Steward completes this field as part of the metadata form

SOURCEORIG The description of the agency that created the base data used to improve the WBD. The WBD In-State Steward completes this field as part of the metadata form.

SOURCEFEAT Like TNMID, SourceFeatureID is a long, unique code. This code identifies the parent of the feature if the feature is the result of a split or merge, and it is automatically generated and assigned

LOADDATE Represents the date when the data were loaded into the official USGS WBD ArcSDE database. The field is the effective date for all feature edits, and it is automatically generated.

GNIS_ID Preassigned numeric field that uses a unique number to relate the name of the hydrologic unit to the GNIS names database. This field is automatically generated in the database.

AREAACRES Common to all polygon feature classes and is calculated at the 12-digit hydrologic unit from the intrinsic area value maintained by the GIS software; therefore, acreage values may vary from user calculations, depending on the projection of the data. North American Albers Equal Area Conic, North American Datum 1983 is the required projection to use for calculation. If the units of the area field are stored in square meters, then use the conversion factor 0.0002471. For example, 40,469,446 square meters multiplied by 0.0002471 = 10,000 acres.

AREASQKM Calculated at the 12-digit hydrologic unit from the intrinsic area value maintained by the GIS software; therefore, the square kilometer values may vary from user calculations, depending on the projection of the data. North American Albers Equal Area Conic, North American Datum 1983 is the default projection.

STATES The States or outlying area attribute identifies the State(s) or outlying areas that the hydrologic unit falls within or touches. The U.S. Census Bureau 1:100,000-scale State layer will be used to establish State boundaries in the derivation process. The two-letter U.S. Postal Service State abbreviation is assigned. If a hydrologic unit crosses into Canada, the two- letter Canada Post abbreviation for the Province is used. If a unit crosses into Mexico, the MX designation is used. If more than one abbreviation is used, they are separated by commas, without spaces, and are sorted in alphabetical order. This field is populated by the In-State Steward at the 12-digit hydrologic unit

HUC12 The HUC12 field is a unique 12-digit hydrologic unit code.

NAME The 16-digit hydrologic unit name refers to the GNIS name for the geographic area in which the hydrologic unit is located

HUTYPE The 10-digit hydrologic unit type attribute is the single- letter abbreviation for Watershed type from the list of official names provided below. Use the single type that most closely describes the 10-digit hydrologic unit (see coastal examples in fig. 10).
S = Standard hydrologic unit An area with drainage flowing to a single outlet point, excluding noncontributing areas. Some examples include true, classic, composite, and remnant hydrologic units (section 3.5.1).

C =  Closed Basin  hydrologic unit   A drainage area where all surface flow is internal (100 percent noncontributing); no overland flow leaves the hydrologic unit through the outlet point (section 3.5.2).

F =  Frontal  hydrologic unit   An area along the coastline of a lake, ocean, bay, etc., that has more than one outlet. These hydrologic units are predominantly land with some water areas at or near the outlet(s) (section 3.5.2).

M =  Multiple Outlet  hydrologic unit   An area that has more than one natural outlet; for example, an outlet located on a stream with multiple channels. This does not include frontal or water hydrologic units, hydrologic units with artificial interbasin transfers, drainage outlets through karst or groundwater flow, or outlets that cross a stream with an island. This code should be used only in rare instances.

W =  Water  hydrologic unit   An area that is predominantly water with adjacent land areas; for example, a lake, estuary, or harbor (section 3.6).

I =  Island  hydrologic unit   An area that is one or more islands and adjacent water (section 3.6.4).


HUMOD The 10-digit hydrologic unit modification attribute is a two-character, uppercase abbreviation(s) for either (1) the type of modification to natural overland flow that alters the natural delineation of a 10-digit hydrologic unit or (2) the special conditions GF-groundwater flow, GL-glacier, IF-ice field, KA- karst, and NC-noncontributing area. The value of the HUMod field helps to indicate where the modification to the 10-digit hydrologic unit is located. If more than one abbreviation is used, then separate them by commas without spaces and list them from most to least predominant. There are future plans to derive this field at the 10-digit unit from the information on the HUMod from the lines and the HUMod at the 12-digit unit upon check in. Once that process is in place the content will be overwritten. Previous versions of this guideline did not provide the same number of modification choices check metadata or contact the principal WBD In-State Steward for more information.
AW = Artificial Waterway A canal, ditch, or drain used to transport surface water that alters the natural flow out of the hydrologic unit. (The previously included designations AD Aqueduct, DD Drainage Ditch, GC General Canal/Ditch, ID Irrigation Ditch, IT Interbasin Transfer, SD Stormwater Ditch, SC Stormwater Canal, and BC Barge Canal have now been grouped into this designation). Withdrawing and receiving hydrologic units should carry this designation, as well as all hydrologic units in which the flow is altered by an artificial waterway.

GF = Groundwater Flow   A special condition, usually in locations with sandy soil, where most of the runoff in a hydrologic unit drains underground.

KA = Karst   A special condition where a hydrologic unit is within an area of, or includes an area of, geologic formations of irregular limestone deposits with sinks, underground streams, or caverns.

MA = Mining Activity   Substatial topographic modification of a hydrologic unit by surface mining; alters the natural flow out of the hydrologic unit.

NC = Noncontributing Area   A naturally formed area that does not contribute surface water runoff to a hydrologic unit outlet under normal conditions; for example, a playa. This does not include groundwater flow.

NM = No Modifications   No modifications are present. Use when no other options with the modification domain have been cited.

OC = Overflow Channel or Flume   An artificial channel built to control excess high flow from a natural channel; alters the natural flow out of the hydrologic unit.

OF = Overbank Flow   A natural condition in which a stream surpasses bankfull stage and the excess flows into a nearby channel draining to a different hydrologic unit (special condition; see example in fig. 18). Both the losing and the receiving hydrologic unit should carry this designation.

PD = Pipe Diversion   A redirection of surface water by a pipeline from one hydrologic unit to another; alters the natural flow out of the hydrologic unit.

RC = Receiving   A hydrologic unit that receives diverted water.

RS = Reservoir   A constructed basin formed to contain and store water for future use in an artificial lake; alters the natural flow out of the hydrologic unit.

UA = Urban Area   Heavy modification of hydrologic unit topography by development beyond that described in section  6.4.2.3,  Transportation Feature,  that alters natural flow out of the hydrologic unit.

WD = Withdrawal   A hydrologic unit from which water is diverted.


TOHUC The 12-digit hydrologic unit ToHUC code attribute is the code for the 12-digit hydrologic unit that is downstream from and naturally receives the majority of the flow from another 12-digit hydrologic unit. For special cases when a downstream code cannot be assigned, identify which of these exceptions applies: If a hydrologic unit flows into an ocean or the Gulf of Mexico, then populate this field with the value OCEAN. If a hydrologic unit drains into either Canada or Mexico, then use the appropriate value CANADA or MEXICO. If a hydrologic unit is a closed basin, then populate this field with the value CLOSED BASIN.

NONCON_AC The noncontributing area attribute represents the area, in acres, of hydrologic units that do not contribute to downstream accumulation of streamflow under normal flow conditions (section 3.5.3). If a noncontributing area is on the boundary between two or more hydrologic units, then determine the low point along the noncontributing area boundary, and associate the noncontributing area with the hydrologic unit adjacent to the low point on the boundary. The value is the total acreage of the noncontributing areas within a hydrologic unit. North American Albers Equal Area Conic, North American Datum 1983 is the required projection to use for calculation. If the units of the area field are stored in square meters, then use the conversion factor 0.0002471.

NONCON_KM The noncontributing area attribute represents the area, in square kilometers, of hydrologic units that do not contribute to downstream accumulation of streamflow under normal flow conditions (section 3.5.3). If a noncontributing area is on the boundary between two or more hydrologic units, then determine the low point along the noncontributing area boundary, and associate the noncontributing area with the hydrologic unit adjacent to the low point on the boundary. The value is the total square kilometers of the noncontributing areas within a hydrologic unit. North American Albers Equal Area Conic, North American Datum 1983 is the required projection to use for calculation. If the units of the area field are stored in square meters, then use the conversion factor 0.0002471

HUTYPE_DSC Description based on HUTYPE field. See HUTYPE for more information.

DESCRIPT GeoPlan added field based on NAME

FGDLAQDATE Date GeoPlan acquired from source.

AUTOID Unique ID added by GeoPlan

SHAPE.AREA Area in meters

SHAPE.LEN Perimeter in meters


USER NOTES:
This data is provided 'as is'. GeoPlan relied on the integrity
of the original data layer's topology
This data is provided 'as is' by GeoPlan and is complete to our
knowledge.
GeoPlan relied on the integrity of the attribute information within
the original data.

The Watershed and Subwatershed hydrologic unit boundaries provide a uniquely 
identified and uniform method of subdividing large drainage areas. The smaller sized 
6th level sub-watersheds (up to 40,000 acres) are useful for numerous application 
programs supported by a variety of local, State, and Federal Agencies. This data set 
is intended to be used as a tool for water-resource management and planning 
activities, particularly for site-specific and localized studies requiring a level of detail 
provided by large-scale map information. The dataset will be appended to a larger 
seamless nationally consistant geospatial database as other states complete their 
portion of the watershed boundary dataset.

This data is provided 'as is' and its horizontal positional accuracy
has not been verified by GeoPlan

This data is provided 'as is' and its vertical positional accuracy
has not been verified by GeoPlan

The distributor shall not be held liable for improper or incorrect use of this data, 
based on the description of appropriate/inappropriate uses described in this 
metadata document. It is strongly recommended that this data is directly acquired 
from the distributor and not indirectly through other sources which may have 
changed the data in some way. These data should not be used at scales greater 
than 1:24,000 for the purpose of identifying hydrographic watershed boundary 
feature locations in 7. 5 should be acknowledged as the data source in products 
derived from these data. The 7 Watershed Boundary Dataset is public information 
and may be interpreted by all organizations, agencies, units of government, or 
others based on needs; however, they are responsible for the appropriate 
application of the data. Federal, State, or local regulatory bodies are not to reassign 
to the Natural Resources Conservation Service any authority for the decisions they 
make.  The Natural Resources Conservation Service will not perform any 
evaluations of these maps or purposes related solely to State or local regulatory 
programs. Photographic or digital enlargement of these maps to scales greater than 
that at which they were originally delineated can result in misrepresentation of the 
data.  If enlarged, the maps will not include the fine detail that would be appropriate 
for mapping at the small scale.  Digital data files are periodically updated. Files are 
dated, and users are responsible for obtaining the latest version of the data from the 
source distributor.

The Florida Geographic Data Library is a collection of Geospatial Data
compiled by the University of Florida GeoPlan Center with support from
the Florida Department of Transportation. GIS data available in FGDL is
collected from various state, federal, and other agencies (data sources)
who are data stewards, producers, or publishers. The data available in
FGDL may not be the most current version of the data offered by the
data source. University of Florida GeoPlan Center makes no guarantees
about the currentness of the data and suggests that data users check
with the data source to see if more recent versions of the data exist.

Furthermore, the GIS data available in the FGDL are provided 'as is'.
The University of Florida GeoPlan Center makes no warranties, guaranties
or representations as to the truth, accuracy or completeness of the data
provided by the data sources. The University of Florida GeoPlan Center
makes no representations or warranties about the quality or suitability
of the materials, either expressly or implied, including but not limited
to any implied warranties of merchantability, fitness for a particular
purpose, or non-infringement. The University of Florida GeoPlan Center
shall not be liable for any damages suffered as a result of using,
modifying, contributing or distributing the materials.

A note about data scale: 

Scale is an important factor in data usage.  Certain scale datasets
are not suitable for some project, analysis, or modeling purposes.
Please be sure you are using the best available data. 

1:24000 scale datasets are recommended for projects that are at the
county level.
1:24000 data should NOT be used for high accuracy base mapping such
as property parcel boundaries.
1:100000 scale datasets are recommended for projects that are at the
multi-county or regional level.
1:125000 scale datasets are recommended for projects that are at the
regional or state level or larger.

Vector datasets with no defined scale or accuracy should be
considered suspect. Make sure you are familiar with your data
before using it for projects or analysis. Every effort has been
made to supply the user with data documentation. For additional
information, see the References section and the Data Source Contact
section of this documentation. For more information regarding
scale and accuracy, see our webpage at:
http://geoplan.ufl.edu/education.html

REFERENCES:
https://pubs.usgs.gov/tm/11/a3/pdf/tm11-a3.pdf

DATA LINEAGE SUMMARY:
GeoPlan Center downloaded the NHD GeoDatabase from the Florida Department 
of Environmental Protection in May 2016. The data was exported to shapefile 
and defined with the FGDL Albers projection file.

This data was originally produced by U.S. Geological Survey in cooperation with 
U.S. Environmental Protection Agency, USDA Forest Service, and other Federal, 
State and local partners. The Florida Data Stewards (FDEP) then update the data. 

After exporting GDB feature classes to shapefile using ArcGIS 10.3.1, the 

NONCONTRIBUTINACRES renamed to NONCON_AC
NONCONTRIBUTINGSQKM renamed to NONCON_KM
HYTYPE_DSC added based on HUTYPE domain text values
Upcased all fields
DESCRIPT field added based on NAME field
FGDLAQDATE added based on date downloaded from source
Renamed GDB feature class from WBDHU12 to nhdwbd_huc12_sep15.shp
based on most recent date in field LOADDATE

Metadata was derived using instructions from here:
http://nhd.usgs.gov/wbd_metadata.html

Attribute definitions were taken from here:
https://pubs.usgs.gov/tm/11/a3/pdf/tm11-a3.pdf
Process Date: 20160630

MAP PROJECTION PARAMETERS:

Projection                          ALBERS
Datum                               HPGN
Units                               METERS
Spheroid                            GRS1980
1st Standard Parallel               24  0  0.000
2nd Standard Parallel               31 30  0.000
Central Meridian                   -84 00  0.000
Latitude of Projection's Origin     24  0  0.000
False Easting (meters)              400000.00000
False Northing (meters)             0.00000

DATA SOURCE CONTACT (S):

Name:
Abbr. Name:
Address:


Phone:

Web site:
E-mail:
Contact Person:
         Phone:
        E-mail:
Florida Department of Environmental Protection (FDEP) OTIS/GIS Section
FDEP
2600 Blair Stone Rd, MS 6520
Tallahassee, FL
32399-2400


http://www.dep.state.fl.us/gis/datadir.htm GIS.Librarian@dep.state.fl.us

FGDL CONTACT:
Name:                   FLORIDA GEOGRAPHIC DATA LIBRARY
Abbr. Name:             FGDL
Address:                Florida Geographic Data Library
                        431 Architecture Building
                        PO Box 115706
                        Gainesville, FL  32611-5706
Web site:               http://www.fgdl.org

Contact FGDL: 

      Technical Support:	        http://www.fgdl.org/fgdlfeed.html
      FGDL Frequently Asked Questions:  http://www.fgdl.org/fgdlfaq.html
      FGDL Mailing Lists:		http://www.fgdl.org/fgdl-l.html
      For FGDL Software:                http://www.fgdl.org/software.html