Watersheds (HUC8)
Description | Spatial | Data Structure | Data Quality | Data Source | Data Distribution | Metadata
Description
Citation
Title: Watersheds (HUC8)
Originators: John Watermolen, U.S. Geological Survey
Publisher: National Atlas of the United States
Publication place: Reston, VA
Publication date: 20050601
Edition: Version 2.4
Data type: vector digital data
Description
Abstract: 
This map layer contains hydrologic unit boundaries and codes for the United States, Puerto Rico, and the U.S. Virgin Islands. It was revised for inclusion in the National Atlas of the United States of America, and updated to match the streams file created by the USGS National Mapping Division (NMD) for the National Atlas of the United States of America. This is a revised version of the November 2002 map layer.
Purpose: 
These data are intended for geographic display and analysis at the national level, and for large regional areas. The data should be displayed and analyzed at scales appropriate for 1:2,000,000-scale data. No responsibility is assumed by the U.S. Geological Survey or the National Atlas of the United States in the use of these data.
Supplemental information: 
Any use of trade, product, or firm names is for descriptive purposes only and does not imply endorsement by the U.S. Government. Although this Federal Geographic Data Committee-compliant metadata file is intended to document the map layer in nonproprietary form, as well as in ArcInfo format, this metadata file may include some ArcInfo-specific terminology. Hydrologic Unit Code (HUC) areas in this file do not necessarily match those published in Water-Supply Paper 2294 (Seaber et al). The file has finer resolution than the maps used to determine areas published in the Water-Supply Paper. The ArcInfo version of this file contains two additional annotation layers. One layer is called anno.maplabel1, and contains the first six digits for each accounting unit. The labels for Accounting Regions 1 though 9 have a "0" in front of the number. The second layer is called anno.catnum, and contains the last two digits for each cataloging unit. All numbers were checked manually against a 1:2,000,000-scale plot of the data.
Time Period of Data
Date: 20050501
Currentness reference: 
Ground condition
Status
Data status: Complete
Update frequency: As needed
Key Words
Theme:
Keywords: Inland waters
Keyword thesaurus: ISO 19115 Topic Category
Theme:
Keywords: Hydrologic Units, Drainage Basins, Hydrologic Unit Boundaries, Hydrologic Unit Codes, Cataloging Units, Watersheds
Keyword thesaurus: None
Place:
Keywords: Iowa, Georgia, Hawaii, Virgin Islands, Ohio, Illinois, Maryland, Maine, Texas, Puerto Rico, New York, South Dakota, New Jersey, New Hampshire, United States, U.S. Virgin Islands, District of Columbia, Kentucky, Minnesota, Colorado, Louisiana, Florida, Pennsylvania, North Dakota, Nebraska, Nevada, West Virginia, Alabama, Arkansas, Idaho, Rhode Island, Wisconsin, Oregon, Delaware, Virginia, Oklahoma, Washington, Michigan, Missouri, South Carolina, Mississippi, Alaska, Utah, Connecticut, New Mexico, Massachusetts, Wyoming, Kansas, Arizona, Indiana, North Carolina, California, Montana, Vermont, Tennessee
Keyword thesaurus: None
Data Constraints and Credit
Access constraints: 
None
Use constraints: 
None. Acknowledgment of the National Atlas of the United States of America and (or) the U.S. Geological Survey would be appreciated in products derived from these data.
Dataset credit: 
Others who have helped with this map layer and the metadata include Steve Denowski, Greg Allord, Curtis Price, Ken Lanfear and David Lorenz, in addition to other colleagues within the U.S. Geological Survey.
Point Of Contact
Organization: U.S. Geological Survey
Position: CAPP Chief
Phone: 608-238-9333
Fax: 608-238-9334
Email: atlasmail@usgs.gov
Address type: mailing and physical
Address: 
505 Science Dr.
City: Madison
State or Province: WI
Postal code: 53711-1061
Security Information
Security classifiction system: FIPS Pub 199
Security handling: Standard Technical Controls
Cross Reference
Title: State Hydrologic Unit Map (for each State)
Originators: U.S. Geological Survey
Publisher: U.S. Geological Survey
Publication place: Reston, VA
Publication date: unknown
Data type: Map
Data location: <http://water.usgs.gov/GIS/huc.html>
Spatial Reference Information
Horizontal Coordinate System
Coordinate System Details
Geographic coordinate system
Latitude resolution: 1.11111111111111e-006
Longitude resolution: 1.11111111111111e-006
Geographic coordinate units: Decimal Degrees
Geodetic model
Horizontal datum name: D North American 1983
Ellipsoid name: GRS 1980
Semi-major axis: 6378137.0
Denominator of flattening ratio: 298.257222101
Spatial Domain
Below are the western, eastern, northern, and southern geographic limits of data coverage.
Bounding Coordinates
In Unprojected coordinates (geographic)
Boundary Coordinate
West -179.133400 (latitude)
East 179.788200 (latitude)
North 71.398050 (longitude)
South 17.674700 (longitude)
Data Structure and Attribute Information
Name and Format
Data type: vector digital data
Native dataset environment: Microsoft Windows 7 Version 6.1 (Build 7601) Service Pack 1; Esri ArcGIS 10.3.1.4959
Overview
Direct spatial reference method: Vector
Attributes of huc2m_layer
Description: 
A subdivision of the Earth, used for the collection and organization of
hydrologic data.  Regions, subregions, accounting units, and cataloging
units are all types of hydrologic units.
Source: 
National Atlas of the United States
Attributes
OBJECTID
Definition: 
Internal feature number.
Attribute values: Sequential unique whole numbers that are automatically generated.
Attribute definition source: 
ESRI
Plytype
Definition: 
A code indicating the classification of offshore polygons.
Attribute domain values
Value Definition
0 
Land, including islands.
Definition Source: 
U.S. Geological Survey
Attribute domain values
Value Definition
2 
Open water.
Definition Source: 
U.S. Geological Survey
Attribute definition source: 
National Atlas of the United States
Huc
Definition: 
The Hydrologic Unit Code.  The code is 8 digits and can be subdivided as
follows:
>Digits   Type
>1-2      Water Resource Region
>1-4      Subregion
>1-6      Accounting Unit
>1-8      Cataloging Unit
>
This is the same as Cat.  There are six polygons in the file with a Huc
of 0; these polygons are not assigned to any hydrologic unit.
Attribute domain range
Range Value
Minimum 1010001
Maximum 21020002
Attribute definition source: 
National Atlas of the United States
Reg_name
Definition: 
The Water Resource Region name.
Attribute value codeset domain
Codeset Description
Name Hydrologic Unit Maps: Seaber, P.R., Kapinos, F.P., and Knapp, G.L.: U.S. Geological Survey Water-supply Paper 2294; 1987
Source 
U.S. Geological Survey
Attribute value codeset domain
Codeset Description
Name Alaska State Hydrologic Unit Map, U.S. Geological Survey map; 1987
Source 
U.S. Geological Survey
Attribute definition source: 
National Atlas of the United States
Map_label
Definition: 
A 6-digit character string of the hydrologic unit code. This was created
to help map production and a zero was added in front of the single digit
regions.
Attribute domain range
Range Value
Minimum 010100
Maximum 210200
Attribute definition source: 
National Atlas of the United States
Sub_name
Definition: 
The Subregion name.
Attribute value codeset domain
Codeset Description
Name Hydrologic Unit Maps: Seaber, P.R., Kapinos, F.P., and Knapp, G.L.: U.S. Geological Survey Water-supply Paper 2294; 1987
Source 
U.S. Geological Survey
Attribute value codeset domain
Codeset Description
Name Alaska State Hydrologic Unit Map, U.S. Geological Survey map; 1987
Source 
U.S. Geological Survey
Attribute definition source: 
National Atlas of the United States
Acc_name
Definition: 
The Accounting Unit name.
Attribute value codeset domain
Codeset Description
Name Hydrologic Unit Maps: Seaber, P.R., Kapinos, F.P., and Knapp, G.L.: U.S. Geological Survey Water-supply Paper 2294; 1987
Source 
U.S. Geological Survey
Attribute value codeset domain
Codeset Description
Name Alaska State Hydrologic Unit Map, U.S. Geological Survey map; 1987
Source 
U.S. Geological Survey
Attribute definition source: 
National Atlas of the United States
Cat_name
Definition: 
The Cataloging Unit name.  Except in Alaska, this includes the State(s)
in which the unit is located. The State name is spelled out except where
the cataloging unit name is very long and the cataloging unit is located
in several States, in which case the State names are abbreviated with
the 2-letter State FIPS code.  Occasionally, State names are truncated
rather than abbreviated.
Attribute value codeset domain
Codeset Description
Name Hydrologic Unit Maps: Seaber, P.R., Kapinos, F.P., and Knapp, G.L.: U.S. Geological Survey Water-supply Paper 2294; 1987
Source 
U.S. Geological Survey
Attribute value codeset domain
Codeset Description
Name Alaska State Hydrologic Unit Map, U.S. Geological Survey map; 1987
Source 
U.S. Geological Survey
Attribute definition source: 
National Atlas of the United States
Huc2
Definition: 
The number of the Water Resource Region.  This is also the first two
digits of the Hydrologic Unit Code and is the same as Reg.  A region is
one of 21 major geographic areas within the U.S. or Caribbean area which
contains either the drainage area of a major river or the combined
drainage area of a series of rivers.
Attribute domain range
Range Value
Minimum 1
Maximum 21
Attribute definition source: 
National Atlas of the United States
Huc4
Definition: 
The number of the Subregion.  This is also the first four digits of the
Hydrologic Unit Code and is the same as Sub. A subregion is a
subdivision of a region and includes the area drained by a river system,
a reach of a river and its tributaries in that reach, a closed basin, or
a group of streams forming a coastal drainage area.  There are 222
subregions.
Attribute domain range
Range Value
Minimum 101
Maximum 2102
Attribute definition source: 
National Atlas of the United States
Huc6
Definition: 
The number of the Accounting Unit.  This is also the first six digits of
the Hydrologic Unit Code and is the same as Act.  The accounting units
nest within or are equivalent to the subregions.  There are 352
accounting units.  If the last two digits of this number are 00, the
accounting unit and subregion are the same.
Attribute domain range
Range Value
Minimum 10100
Maximum 210200
Attribute definition source: 
National Atlas of the United States
Reg
Definition: 
The number of the Water Resource Region.  This is also the first two
digits of the Hydrologic Unit Code, and is the same as Huc2.  A region
is one of 21 major geographic areas within the U.S. or Caribbean area
which contains either the drainage area of a major river or the combined
drainage area of a series of rivers.
Attribute domain range
Range Value
Minimum 1
Maximum 21
Attribute definition source: 
National Atlas of the United States
Sub
Definition: 
The number of the Subregion.  This is also the first four digits of the
Hydrologic Unit Code and is the same as Huc4.  A subregion is a
subdivision of a region and includes the area drained by a river system,
a reach of a river and its tributaries in that reach, a closed basin, or
a group of streams forming a coastal drainage area.  There are 222
subregions.
Attribute domain range
Range Value
Minimum 101
Maximum 2102
Attribute definition source: 
National Atlas of the United States
Acc
Definition: 
The number of the Accounting Unit.  This is also the first six digits of
the Hydrologic Unit Code and is the same as Huc6.  The accounting units
nest within or are equivalent to the subregions.  There are 352
accounting units.  If the last two digits of this number are 00, the
accounting unit and subregion are the same.
Attribute domain range
Range Value
Minimum 10100
Maximum 210200
Attribute definition source: 
National Atlas of the United States
Cat
Definition: 
The number of the Cataloging Unit.  This is the same as Huc.  A
cataloging unit is currently the smallest element in the hierarchy of
hydrologic units, and represents part or all of a surface drainage
basin, a combination of drainage basins, or a distinct hydrologic
feature.  There are 2,264 cataloging units.  If the last two digits of
this number are 00, the cataloging unit and accounting unit are the
same.  Cataloging units may also be referred to as watersheds.  There
are 6 polygons in the file with a Cat of 0; these polygons are not
assigned to any hydrologic unit.
Attribute domain range
Range Value
Minimum 1010001
Maximum 21020002
Attribute definition source: 
National Atlas of the United States
Cat_num
Definition: 
The number of the Cataloging Unit.  This is a redefined Huc or Cat
number changed into a character string.
Attribute domain range
Range Value
Minimum 1010001
Maximum 21020002
Attribute definition source: 
National Atlas of the United States
SUBNUM
SE_ANNO_CAD_DATA
AREA
LEN
POLYS_AREA
POLYS_LEN
SHAPE
Definition: 
Feature geometry.
Attribute values: Coordinates defining the features.
Attribute definition source: 
ESRI
Shape_Length
Definition: 
Length of feature in internal units.
Attribute values: Positive real numbers that are automatically generated.
Attribute definition source: 
Esri
Shape_Area
Definition: 
Area of feature in internal units squared.
Attribute values: Positive real numbers that are automatically generated.
Attribute definition source: 
Esri
Attributes of Hydrologic Unit Boundary (described by HUCS00L020.AAT or Hucs00l020.dbf)
Description: 
A boundary between hydrologic units.
Source: 
National Atlas of the United States
Attributes
Shape
Definition: 
The representation of the entity in the data.
Attribute domain values
Value Definition
Polyline 
1-dimensional element that surrounds a 2-dimensional element.
Definition Source: 
ESRI GIS software
Attribute definition source: 
National Atlas of the United States
Fnode# or Fnode_
Definition: 
Internal sequence number of the from-node.
Attribute domain range
Range Value
Minimum 1
Maximum 9039
Attribute definition source: 
National Atlas of the United States
Tnode# or Tnode_
Definition: 
Internal sequence number of the to-node.
Attribute domain range
Range Value
Minimum 1
Maximum 9039
Attribute definition source: 
National Atlas of the United States
Lpoly# or Lpoly_
Definition: 
Internal sequence number of the left polygon.
Attribute domain range
Range Value
Minimum 1
Maximum 5348
Attribute definition source: 
National Atlas of the United States
Rpoly# or Rpoly_
Definition: 
Internal sequence number of the right polygon.
Attribute domain range
Range Value
Minimum 1
Maximum 5347
Attribute definition source: 
National Atlas of the United States
Length
Definition: 
The length of the line in coverage units.  In the distributed file,
coverage units represent decimal degrees.
Attribute domain range
Range Value
Minimum 0.000
Maximum 6.143
Attribute definition source: 
National Atlas of the United States
US_HUCS_ALB# or Hucs00m020
Definition: 
Internal feature number.
Attribute domain range
Range Value
Minimum 1
Maximum 11576
Attribute definition source: 
National Atlas of the United States
US_HUCS_ALB-ID (Included in Export format file only.)
Definition: 
User-assigned feature number.
Attribute domain range
Range Value
Minimum 1
Maximum 11576
Attribute definition source: 
National Atlas of the United States
Bndtype
Definition: 
The code number describing the location or type of the hydrologic unit
boundary.  Boundaries occur between hydrologic units and between onshore
and offshore parts of the same hydrologic unit.
Attribute domain values
Value Definition
0 
Coastline or International Boundary separating offshore and onshore
parts of the same hydrologic unit.
Definition Source: 
U.S. Geological Survey
Attribute domain values
Value Definition
2 
Land and occasionally water boundary between two Water Resource
Regions.
Definition Source: 
U.S. Geological Survey
Attribute domain values
Value Definition
4 
Land and occasionally water boundary between two Subregions.
Definition Source: 
U.S. Geological Survey
Attribute domain values
Value Definition
6 
Land and occasionally water boundary between two Accounting Units.
Definition Source: 
U.S. Geological Survey
Attribute domain values
Value Definition
8 
Land and occasionally water boundary between two Cataloging Units.
Definition Source: 
U.S. Geological Survey
Attribute definition source: 
National Atlas of the United States
Error_type
Definition: 
A code indicating the type of conflict between the streams file and the
hydrologic unit boundary.
Attribute domain values
Value Definition
0 
No conflict exists.
Definition Source: 
U.S. Geological Survey
Attribute domain values
Value Definition
4 
There was an error in the streams file.  The hydrologic unit
Boundary was not changed.
Definition Source: 
U.S. Geological Survey
Attribute domain values
Value Definition
5 
There was a conflict between the NMD streams data and the
1:500,000-scale Hydrologic Unit Boundaries map.  The hydrologic unit
boundary was changed to agree with the streams.
Definition Source: 
U.S. Geological Survey
Attribute definition source: 
National Atlas of the United States
SDTS Feature Description
Spatial data transfer standard (SDTS) terms
Feature class
Type: GT-polygon composed of chains
Count: 2259
Data Quality and Accuracy Information
General
Logical consistency report: 
Polygon and chain-node topology are present. All polygons are labeled and were tested by using the ArcInfo command labelerrors. All polygons were checked for closure and intersections by using the ArcInfo intersecterr command. The file is clean.
Completeness report: 
This file contains hydrologic unit boundaries and codes for all 50 States, Puerto Rico, and the U.S. Virgin Islands. Boundaries and codes are included for regions, subregions, accounting units, and cataloging units.
Attribute Accuracy
Attribute accuracy report: 
The arc attributes were manually checked by assigning unique line weights and colors to the values, and then plotting the data. The plots were then compared to the source. The polygon attributes were checked by comparing a 1:2,000,000-scale plot to the source. The attribute accuracy is estimated at 99%.
Positional Accuracy
Horizontal accuracy report: 
The accuracy of the original map layer was checked by comparing the digital files to several data sources. First, both the line work and the polygon labels were checked against the source compilation. No digitization errors were found during this phase. Next, the hydrologic unit boundaries were compared to the 1970 1:2,000,000-scale DLG stream file and the 1:500,000-scale Hydrologic Unit Maps. Plots containing both the streams and the hydrologic unit boundaries were made at a scale of 1:2,000,000. Hydrologic unit boundary intersections were checked, as well as problem areas such as points where streams crossed hydrologic unit boundaries on the plot but not on the hydrologic unit map. More than 400 errors were found. All errors that could be corrected were corrected. The remaining errors could not be corrected because the streams were in error rather than the hydrologic unit boundaries. Finally, the hydrologic unit boundaries were plotted at 1:2,000,000 scale and compared to the NMD 1998 1:2,000,000-scale hydrologic data set. Any discrepancies were addressed by reference to either the 1:500,000-scale or the 1:100,000-scale maps. The exceptions to this were the hydrologic unit boundaries for Alaska, Hawaii, Puerto Rico, and the U.S. Virgin Islands. The Alaska boundaries were checked on a 1:2,500,000-scale plot but not modified, because the boundaries cross glaciers, and it is difficult to distinguish flow from the glaciers. The Hawaii hydrologic unit boundaries were not reviewed because each island represents a cataloging unit. The Puerto Rico and U.S. Virgin Islands boundaries were not plotted but were reviewed on-screen using a 1:1,000,000 hydrologic map layer created for the 1991 National Water Summary. The horizontal positional accuracy of the data matches the positional accuracy of the original compilation.
Data Source and Process Information
Data Sources
Data source information
HUCS10
Title: Hydrologic Unit Codes map
Originators: U.S. Geological Survey
Publisher: U.S. Geological Survey
Publication place: Reston, VA
Publication date: 19860101
Edition: Version 1.0
Data type: Map
Map scale denominator: 0
Media: None
Source contribution: 
Intermediate digital file.
Date: 19860101
Currentness reference: 
Publication date
HUCmaps
Title: State Hydrologic Unit Maps (for each State)
Originators: U.S. Geological Survey
Publisher: U.S. Geological Survey, Office of Water Data Coordination
Publication place: Reston, VA
Publication date: unknown
Data type: Map
Data location: <http://water.usgs.gov/GIS/huc.html>
Map scale denominator: 500
Media: None
Source contribution: 
Linework for the map layer.
Beginning date: 19740101
Ending date: 19870101
Currentness reference: 
Publication date
DLGCO
Title: 1:2,000,000 County Boundaries
Originators: U.S. Geological Survey
Publisher: U.S. Geological Survey
Publication place: Reston, VA
Publication date: 19890101
Data type: Map
Map scale denominator: 0
Media: None
Source contribution: 
Determination of boundaries for identification of offshore and onshore areas.
Date: 19890101
Currentness reference: 
Publication date
HUCAKmap
Title: Alaska State Hydrologic Unit Map
Originators: U.S. Geological Survey
Publisher: U.S. Geological Survey
Publication place: Reston, VA
Publication date: 19870101
Data type: Map
Data location: <http://water.usgs.gov/GIS/huc.html>
Map scale denominator: 0
Media: None
Source contribution: 
The source contributed line work and names for hydrologic units in Alaska.
Date: 19870101
Currentness reference: 
Publication date
Seaber
Title: Hydrologic Unit Maps
Originators: Seaber, Paul R.
Knapp, George L.
Kapinos, F. Paul
Series name: Water-Supply Paper
Series identification: 2294
Publisher: U.S. Geological Survey
Publication place: Reston, VA
Publication date: 19870101
Data location: <http://water.usgs.gov/GIS/huc.html>
Media: hardcopyPaper
Source contribution: 
Cataloging unit names for all States except Alaska.
Date: 19870101
Currentness reference: 
Publication date
HUCS23
Title: 1:2,000,000-Scale Hydrologic Unit Boundaries
Originators: U.S. Geological Survey
Publisher: U.S. Geological Survey
Publication place: Reston, VA
Publication date: 20021101
Edition: Version 2.3
Data type: Map
Map scale denominator: 0
Media: None
Source contribution: 
Spatial and attribute information.
Date: 19981001
Currentness reference: 
Ground condition
HUCS22
Title: 1:2,000,000-Scale Hydrologic Unit Boundaries
Originators: U.S. Geological Survey
Publisher: U.S. Geological Survey
Publication place: Reston, VA
Publication date: 20020101
Edition: Version 2.2
Data type: Map
Map scale denominator: 0
Media: None
Source contribution: 
Spatial and attribute information.
Date: 19981001
Currentness reference: 
Ground condition
HUCS21
Title: 1:2,000,000-Scale Hydrologic Unit Boundaries
Originators: U.S. Geological Survey
Publisher: U.S. Geological Survey
Publication place: Reston, VA
Publication date: 20010401
Edition: Version 2.1
Data type: Map
Map scale denominator: 0
Media: None
Source contribution: 
Spatial and attribute information.
Date: 19981001
Currentness reference: 
Ground condition
HUCS20
Title: 1:2,000,000-Scale Hydrologic Unit Boundaries
Originators: U.S. Geological Survey
Publisher: U.S. Geological Survey
Publication place: Reston, VA
Publication date: 19990401
Edition: Version 2.0
Data type: Map
Map scale denominator: 0
Media: None
Source contribution: 
Spatial and attribute information.
Date: 19981001
Currentness reference: 
Ground condition
NAHydro
Title: Hydrography Features of the United States (linear)
Originators: U.S. Geological Survey
Publisher: U.S. Geological Survey
Publication place: Reston, VA
Publication date: 19980101
Data type: Map
Map scale denominator: 0
Media: None
Source contribution: 
Coastline information
Beginning date: 19850101
Ending date: 19980101
Currentness reference: 
Ground condition
RF1
Title: Reach File Version 1.0 Alpha
Originators: U.S. Environmental Protection Agency
Publisher: U.S. Environmental Protection Agency
Publication place: Washington, DC
Publication date: 19750101
Data type: Map
Media: None
Source contribution: 
Information on flow between cataloging units.
Date: 19750101
Currentness reference: 
Publication date
HUCS111
Title: Hydrologic Unit Codes map
Originators: U.S. Geological Survey
Publisher: U.S. Geological Survey
Publication place: Reston, VA
Publication date: 19940101
Edition: Version 1.1.1
Data type: Map
Map scale denominator: 0
Media: None
Source contribution: 
Intermediate digital file.
Date: 19940101
Currentness reference: 
Publication date
HUCS11
Title: Hydrologic Unit Codes map
Originators: U.S. Geological Survey
Publisher: U.S. Geological Survey
Publication place: Reston, VA
Publication date: 19920101
Edition: Version 1.1
Data type: Map
Map scale denominator: 0
Media: None
Source contribution: 
Intermediate digital file.
Date: 19920101
Currentness reference: 
Publication date
DLGHY
Title: 1:2,000,000 DLG Hydrography
Originators: U.S. Geological Survey
Publisher: U.S. Geological Survey
Publication place: Reston, VA
Publication date: unknown
Map scale denominator: 0
Media: None
Source contribution: 
Location of streams for accuracy testing.
Beginning date: 19720101
Ending date: 19800101
Currentness reference: 
Publication date
NAStates
Title: State Boundaries of the United States
Originators: U.S. Geological Survey
Publisher: U.S. Geological Survey
Publication place: Reston, VA
Publication date: 19980101
Data type: Map
Map scale denominator: 0
Media: None
Source contribution: 
Coastline information
Beginning date: 19720101
Ending date: 19980101
Currentness reference: 
Ground condition
Process Steps
Process step information
Process Step 1
Process description: 
The original hydrologic unit boundaries file (HUCS10) was created through the following steps: >a) 1:2,000,000-scale stable-base map plots of drainage (streams) and >the latitude/longitude grid were obtained from the USGS National >Mapping Division (NMD). These plots were in the Lambert Conformal >Conic projection, and used 1:500,000-scale State base map projection >parameters. Fifteen sections were plotted using 1970 National Atlas >1:2,000,000-scale sectional boundaries. > >b) Individual State 1:500,000-scale hydrologic unit maps in the Lambert >Conformal Conic projection were photoreduced to 1:2,000,000. > >c) Hydrologic unit boundaries were compiled and the edges were matched >on scale-stable 1:2,000,000 plots. The boundaries were combined with >the streams plots for digitizing. > >d) The hydrologic unit boundaries were digitized by Automated Datatron, >Hyattsville, MD, which digitizes materials on contract for NMD. > >e) Digital data from Automated Datatron was converted to an ArcInfo >coverage, then checked and corrected. > >f) A detailed, annotated list was compiled, listing locations where >hydrologic unit boundaries and streams were coincident, or where >1:2,000,000-scale DLG streams were in error. Wherever possible, >conflicts and errors were resolved.
Process date: unknown
Process Step 2
Process description: 
HUCS11 was created by modifying and correcting the HUCS10 file in ArcInfo, and combining it with a 1:2,000,000-scale U.S. counties file to identify onshore and offshore areas. Other county attributes were excluded. This process was done in ArcInfo, and used a fuzzy tolerance of 2 meters. A small part of the original map, which laid on top of part of the Canadian Great Lakes, was deleted. The attributes were renamed and expanded.
Process date: 19920101
Process Step 3
Process description: 
A HUCs_2M.TRACE file was created from the River Reach 1 (rf1) coverage, which includes a pointer to the next downstream segment of each reach. The resulting file was added to INFO, along with an index created using the INDEX_HUC.AML. These files are included in HUCS111 only and are not in the distributed version of the Hydrologic Unit Boundaries map layer.
Process date: 19940101
Process Step 4
Process description: 
Using ArcInfo, HUCS111 was compared with the most recent 1:2,000,000- scale streams file created by the USGS National Mapping Division (NMD) for inclusion in the National Atlas of the United States of America. Where a stream crossed a hydrologic unit boundary, the boundary was compared to the 1:500,000-scale State hydrologic unit map (Seaber). If a stream and hydrologic unit boundary intersection could not be resolved by this comparison, the USGS 1:100,000-scale topographic quadrangles were used. All corrected hydrologic unit boundaries were given a value of 5 for the Error_type attribute. The boundaries were changed by moving vertices to include the stream in the appropriate hydrologic unit. All editing was done on-screen. This step happened May 22, 1998 and November 10, 1998. The Region, Subregion, Accounting unit, and Cataloging unit names from Seaber were added to the map layer and spot-checked. Cataloging unit names for Alaska were added from the Alaska Hydrologic Unit Map (HUCAKmap). Values for BNDTYPE were determined from the bounding polygons using INDEX_HUC.AML. The attributes Error_type, Reg_name, Map_label, Cat_Name, and Cat_num were added to the file. Two annotation layers were also added to the coverage. One layer is called anno.maplabel1, which shows the first six digits for each accounting unit. The labels for accounting Regions 1 though 9 have the "0" in front of the number. The second annotation layer is anno.catnum, and this layer has the last 2 digit codes for each cataloging unit. All numbers were checked manually on a 1:2,000,000-scale plot of the data set. The cataloging unit names were spot-checked. The file was modified to agree with the official National Atlas coastline (NAStates) The ArcInfo coverage was exported to create the shapefiles and SDTS files.
Process date: 19980101
Process Step 5
Process description: 
The HUCS20 file was modified and corrected in ArcInfo. Two Hydrologic unit codes were corrected. The first error was in western Illinois, Region 07, Subregion 08, Accounting unit 01, where cataloging unit 04 was incorrectly tagged 07. The second error was in northeastern Missouri, Region 07, Subregion 11, Accounting unit 00, Cataloging unit 01, where the subregion was incorrectly tagged 10. Misspelled names in sub_name, acc_name, and cat_name were corrected. The file was exported to create new shapefiles and SDTS files.
Process date: 20010101
Process Step 6
Process description: 
The HUCS21 file was modified and corrected in ArcGIS. One Hydrologic Unit code was corrected in Oregon. Region 17, Subregion 07, Accounting unit 03, Cataloging unit 01 had all user-defined attribute items incorrectly valued as Region 17, Subregion 09, Accounting unit 00, Cataloging unit 05.
Process date: 20020101
Process Step 7
Process description: 
The HUCS22 file was modified and corrected in ArcGIS. One cataloging unit name was corrected in Oregon. Region 17, Subregion 10, Accounting unit 02, Cataloging unit 03 had the attribute CAT_NAME incorrectly valued as Wilson-Trusk-Nestuccu, Oregon. It was corrected to Wilson-Trask-Nestucca, Oregon.
Process date: 20021101
Process Step 8
Process description: 
The HUCS23 file was modified and corrected in ArcGIS. Cataloging unit 03050201 had the attribute CAT_NAME incorrectly valued as Copper, South Carolina. It was corrected to Cooper, South Carolina. HUC 1103 Sub_name was incorrectly valued as Middel Arkansas. It was corrected to Middle Arkansas. The codes and all attributes in the following basins were corrected: Cataloging unit 9030006 corrected from 9030004, Cataloging unit 12100204 corrected from 12100303, and Cataloging unit 17060206 corrected from 17060203.
Process date: 20050501
Data Distribution Information
General
Distribution liability: 
Although these data have been processed successfully on a computer system at the U.S. Geological Survey, no warranty expressed or implied is made by the U.S. Geological Survey regarding the utility of the data on any other system, nor shall the act of distribution constitute any such warranty.
Distribution Point of Contact
Organization: Earth Science Information Center, U.S. Geological Survey
Phone: 1-888-ASK-USGS (1-888-275-8747)
Instructions: 
In addition to the address above there are other ESIC offices throughout the country. A full list of these offices is at <http://ask.usgs.gov/esic_index.html>.
Address type: mailing
Address: 
507 National Center
City: Reston
State or Province: VA
Postal code: 20192
Metadata Reference
Metadata Date
Last updated: 20240110
Future metadata review date: 20141021
Metadata Point of Contact
Organization: U.S. Geological Survey
Position: CAPP Chief
Phone: 608-238-9333
Fax: 608-238-9334
Email: atlasmail@usgs.gov
Address type: mailing and physical
Address: 
505 Science Dr.
City: Madison
State or Province: WI
Postal code: 53711-1061
Metadata Access
Metadata security information:
Classifcation system: None
Classification: Unclassified
Handling information: 
None
Metadata Standards
Standard name: FGDC Content Standard for Digital Geospatial Metadata
Standard version: FGDC-STD-001-1998
Time convention: local time
FGDC Plus Metadata Stylesheet
Stylesheet: FGDC Plus Stylesheet
File name: FGDC Plus.xsl
Version: 1.7
Description: This metadata is displayed using the FGDC Plus Stylesheet, which is an XSL template that can be used with ArcGIS software to display metadata. It shows metadata elements defined in the Federal Geographic Data Committee (FGDC) standard and the ESRI Profile of the Content Standard for Digital Geospatial Metadata (ESRI Profile). This stylsheet is in the public domain and may be freely used, modified, and redistributed. It is provided "AS-IS" without warranty or techical support.
Instructions: Click the title on the top of the page to toggle opening and closing all metadata content sections. Or tab to individual sections by clicking the section links listed horizontally below the title. Section names are centered and shown in white with a blue background. Click on a section name (e.g. Description) to open and close all section content, or individually click terms listed on the left (Status, Key Words, etc.) to individually open and close section content items. Note, some section content items (Citation, Description, etc.) are intentionally opened by default due to their importance.
Key features: Supports W3C DOM compatible browsers such as IE6, Netscape 7, and Mozilla Firefox. Metadata content organized into sections that expand and collapse. Click on title to toggle opening and closing all content (metadata sections). Page header includes menu links that tab to invidual metadata sections. Page footer links to http://www.fgdc.gov/ web site. Ignores metadata XML elements that contain all whitespace (spaces, carriage returns, tabs, line feeds, etc). Over 40 metadata elements are parsed to respect line breaks introduced by metadata author to either start a new line or a new paragraph, depending on number of consecutive line breaks and white space characters present. Over 40 metadata elements are searched for internal URL strings (that contain a "://" or "www.") and converts each one to a hypertext link. Browse graphic image and description displayed together on same page if image is JPG, JPEG, GIF, PNG, or BMP. Other browse graphic file types such as PDF popup in separate window. Enumerated attribute domain values listed in HTML table, which can be opened and closed. All FGDC metadata elements supported. FGDC Process Steps include full descriptions of each Data Source Used and Produced as long as the value of Process Step's Source Citation Used (srcused) and Source Citation Produced (srcprod) metadata element match a Data Source Citation (srccitea) metadata element value. All ESRI metdata elements supported except for Binary elements used to include thumbnail image. Includes ESRI Geoprocessing History, ESRI Feature Terms, ESRI Geometric Network, ESRI Subtype, ESRI Relationship Class, ESRI Topology, and ESRI Raster elements. Topology rules are named and described as shown on the ESRI topology_rules_poster.pdf included with ArcGIS software.
Download: FGDC Plus Stylesheet is available from the ArcScripts downloads at www.esri.com.
Federal Geographic Data Committee
NEPAssist: Metadata