U.S. Department of Agriculture, Natural Resources Conservation Service
2001
Connecticut Watershed Boundary Dataset Poly
vector digital data
Fort Worth, TX
U.S. Department of Agriculture, Natural Resources Conservation Service
Initially entitled ct_hu12_geo83, this dataset was renamed NRCS Watershed Boundary Dataset Poly when it was converted to the Connecticut State Plane Coordinate System (NAD 83) for use by the State of Connecticut, Department of Environmental Protection in 2005.
http://www.lighthouse.nrcs.usda.gov/gateway/gatewayhome.html
This data set is a digital hydrologic unit boundary layer that is at the Subwatershed (12-digit) level. The original data set was developed by delineating the boundary lines on base USGS 1:24000 scale topographic quadrangle, and digitizing the delineated lines. Digital Raster Graphics (DRG) images were used for edits to the data layer.
This data set consists of geo-referenced digital map data and attribute data. The spatial data are in a statewide coverage format and include complete coverage of the entire state of Connecticut, and small parts of surrounding states. The hydrologic unit ID code attached to each delineated polygon is linked to the attribute data.
The Watershed and Subwatershed hydrologic unit boundaries provide a uniquely identified and uniform method of subdividing large drainage areas. These smaller sized hydrologic units (up to 250,000 acres) are useful in many programs supported by the Natural Resources Conservation Service and others.
2001
publication date
As needed
-73.737982
-71.646339
42.233967
40.939104
None
Hydrologic Units
Watershed Boundary Dataset
Subwatersheds
WBD
Watersheds
Counties and County Equivalents of the States of the United States and the
New England
Connecticut
USGS Topographic Map Names Data Base
Northeastern United States
None
The U.S. Department of Agriculture, Natural Resources Conservation Service, should be acknowledged as the data source in products derived from these data.
This data set is to be used as a primary reference source. This is public information and may be interpreted by organizations, agencies, units of government, or others based on needs; however, they are responsible for the appropriate application. Federal, State, or local regulatory bodies are not to reassign to the Natural Resources Conservation Service any authority for the decisions they make.
Photographic or digital enlargement of these maps to scales greater than that at which they were originally delineated can cause 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.
U.S. Department of Agriculture, Natural Resources Conservation Service
GIS Specialist
mailing address
344 Merrow Road
Tolland
Connecticut
06084-3917
USA
860-871-4011
202 720 7808 (Office of Public Affairs)
860-871-4054
http://www.cteco.uconn.edu/metadata/dep/browsegraphic/watershedboundarydatasetfullview.gif
Full view of Connecticut Watershed Boundary Dataset polygon and line features.
GIF
http://www.cteco.uconn.edu/metadata/dep/browsegraphic/watershedboundarydatasetdetailviewhuc12.gif
Detailed view of Connecticut Watershed Boundary Dataset polygon and line features. Watersheds are labeled with the 12-digit Hydrologic Unit Code (HUC12).
GIF
http://www.cteco.uconn.edu/metadata/dep/browsegraphic/watershedboundarydatasetdetailviewhuc10.gif
Detailed view of Connecticut Watershed Boundary Dataset polygon and line features. Watersheds are labeled with the 10-digit Hydrologic Unit Code (HUC10).
GIF
http://www.cteco.uconn.edu/metadata/dep/browsegraphic/watershedboundarydatasetdetailviewhuc8.gif
Detailed view of Connecticut Watershed Boundary Dataset polygon and line features. Watersheds are labeled with the 8-digit Hydrologic Unit Code (HUC8).
GIF
These data are maintained by the State of Connecticut using ArcGIS software developed by Environmental Systems Research Institute (ESRI) in a Microsoft Windows operating system environment.
Polygon identifiers are visually checked with the DRG backdrop and compared with other available information, such as tables of basins with their codes.
Certain node/geometry and topology (GT) polygon/chain relationships are collected or generated to satisfy topological requirements. (The GT-polygon corresponds to a hydrologic unit or a portion of a hydrologic unit at the edge of a quadrangle sheet.) Some of these requirements include: chains must begin and end at nodes, left and right GT-polygons are defined for each chain element and are consistent throughout. The tests of logical consistency are performed using vendor software. All internal polygons are tested for closure with vendor software. All data are checked for common boundary lines (i.e., adjacent polygons with the same label).
Subwatershed and Watershed naming conventions differ from the newest standard specifications by being more descriptive of the stream reach which the hydrologic unit encompasses. This was done to minimize confusion in areas where tributary stream names are similar. Other attributes have been added to further clarify location within New England. Subwatershed boundaries were delineated outside the state border in order to complete hydrologic units which straddled the border.
The accuracy of these maps is generally based on the contour information of corresponding DRGs. The differences in positional accuracy between the hydrologic unit boundaries and their digitized map locations is unknown.
Hydrologic unit boundaries generally were digitized within 0.01 inches of their locations on the digitizing source. Edge match locations are exact because the data were extracted from a New England-based hydrologic units layer which had been electronically edge-matched.
USDA-Natural Resources Conservation Service
2001
Subwatersheds for Connecticut
Statewide coverage
Tolland, Connecticut, USA
Natural Resources Conservation Service
24000
paper; USGS Digital Raster Graphics
1969
1984
varies
NRCS
map delineation
Map delineation on paper topographic quads.
CT DEP
Unknown
Map digitizing
CT DEP
Unknown
Digitizing begins on NRCS Subwatersheds layer
NRCS
1997
Data layer attribution, editing, review by CT NRCS and DEP personnel, USGS
NRCS
1997
Delineation of New York hydrologic unit boundaries for units that cross border
NRCS
1998
Edge match with Massachusetts: both arcs and attributes
NRCS
1999
Edge match with available New York data (watershed level only), including digitizing of new hydrologic unit boundaries where necessary to complete all polygons which straddle state border.
NRCS
1999
Edge match with Rhode Island: both arcs and attributes
NRCS
2000
Review and editing/combining of smaller subwatersheds to better meet National Standard
NRCS, DEP
2000
Attribute edits to update layer to newest Hydrologic Unit Digitizing Standard
NRCS
2001
Metadata creation
NRCS
2001
Reprojection to UTM NAD83
NRCS
2001
Submission for National Review and Certification
NRCS
2001
Conversion to Connecticut State Plane Coordinate System - Using ArcGIS 9.1 software, the polygon feature shapefile component to the Watershed Boundary Dataset for Connecticut (ct_hu12_geo83.shp) obtained from the NRCS ftp site was projected from geographic coordinates to the Connecticut State Plane Coordinate System of 1983 (NAD83) and named Watershed_Boundary_Dataset_Poly.shp. Where necessary, excluded the AREA and PERIMETER attributes from both the Shapefile and Attribute Entity portion of the metadata because these attributes are only maintained by ArcInfo software with data in ArcInfo Coverage format. Also deleted line and node feature attribute definitions from the metadata prepared by NRCS because they do not describe polygon features. For cartographic purposes, made an ArcView 3 Legend file and ArcMap Layer file.
NRCS
20051130
State of Connecticut, Department of Environmental Protection
Howie Sternberg
Vector
GT-polygon composed of chains
194
Lambert Conformal ConicLambert Conformal Conic41.20000041.866667-72.75000040.833333999999.999996499999.999998
coordinate pair
0.000250
0.000250
survey feet
North American Datum of 1983
Geodetic Reference System 80
6378137.000000
298.257222
North American Vertical Datum of 1988
unknown
meters
Implicit coordinate
Connecticut Watershed Boundary Dataset Poly
Attribute field (item) names need to be spelled exactly as shown and in the order specified. Required attributes must be populated unless fields are optional, in those cases, leave the field blank. The attribute schema is illustrated for Environmental Systems Research Institute (ESRI) software1. If another software is being used other than ArcInfo or ArcView, please follow the ArcInfo format. For field width in ArcView, please create the fields according to the width specified under "Output" in the descriptions below. All the fields listed below are required in each state dataset, but, a state may add additional fields to their own dataset. If there are any questions, contact the National Cartography & Geospatial Center for assistance.
Federal Standards for Delineation of Hydrologic Unit Boundaries - FGDC Proposal, Version 1.0
HU_12_TYPE
Populate this field with the hydrologic unit type from the list provided that most closely identifies the subwatershed. Use any of the one digit abbreviations in uppercase that is provided in the list.
Federal Standards for Delineation of Hydrologic Unit Boundaries - FGDC Proposal, Version 1.0
Federal Standards for Delineation of Hydrologic Unit Boundaries, FGDC Proposal, Version 1.0
Please refer to the Entity and Attribute Overview for valid values and definitions
Shape
Feature geometry.
ESRI
Coordinates defining the features.
HUC_8
A unique 8-digit code from the USGS map series "Hydrologic Unit Maps". Use the existing code for the sub-basin where the subwatershed resides; do not change this code. The same number should be used in every record that pertains to a subwatershed that resides within the same 8-digit sub-basin.
Federal Standards for Delineation of Hydrologic Unit Boundaries - FGDC Proposal, Version 1.0
Federal Standards for Delineation of Hydrologic Unit Boundaries, FGDC Proposal, Version 1.0
Please refer to the Entity and Attribute Overview for valid values and definitions
HUC_10
This field provides a unique 10-digit code for each watershed. Add two digits to the end of the existing 8-digit code, therefore resulting in a 10-digit number. This same number should be used in every record that pertains to a subwatershed that resides within the same 10-digit watershed.
Federal Standards for Delineation of Hydrologic Unit Boundaries - FGDC Proposal, Version 1.0
Federal Standards for Delineation of Hydrologic Unit Boundaries, FGDC Proposal, Version 1.0
Please refer to the Entity and Attribute Overview for valid values and definitions
HUC_12
This field provides a unique 12-digit code for each subwatershed. Add two digits to the end of the existing 10-digit code, therefore creating a 12-digit number.
Federal Standards for Delineation of Hydrologic Unit Boundaries - FGDC Proposal, Version 1.0
Federal Standards for Delineation of Hydrologic Unit Boundaries, FGDC Proposal, Version 1.0
Please refer to the Entity and Attribute Overview for valid values and definitions
ACRES
Area of subwatershed including non-contributing areas calculated to acres as a whole number, no decimals. The "Acres" field needs to be calculated from the "Area" field.
Federal Standards for Delineation of Hydrologic Unit Boundaries - FGDC Proposal, Version 1.0
Federal Standards for Delineation of Hydrologic Unit Boundaries, FGDC Proposal, Version 1.0
Please refer to the Entity and Attribute Overview for valid values and definitions
STATES
The "States" field needs to include the names of all state(s) that the subwatershed falls within. Use the 2-digit postal abbreviation in upper case and sort the state(s) in alphabetical order. If using more then one abbreviation, separate with a comma with no space after the comma.
Federal Standards for Delineation of Hydrologic Unit Boundaries - FGDC Proposal, Version 1.0
Federal Standards for Delineation of Hydrologic Unit Boundaries, FGDC Proposal, Version 1.0
Please refer to the Entity and Attribute Overview for valid values and definitions
NCONTRB_A
Drainage areas that do not flow toward the outlet of any hydrologic unit are considered non-contributing. If a non-contributing area is on the boundary between two or more hydrologic units, determine the low point along the non-contributing area boundary. The non-contributing area should be associated with the hydrologic unit adjacent to the low point on the boundary. This attribute should be the total of the non-contributing areas within a hydrologic unit calculated in acres.
Federal Standards for Delineation of Hydrologic Unit Boundaries - FGDC Proposal, Version 1.0
Federal Standards for Delineation of Hydrologic Unit Boundaries, FGDC Proposal, Version 1.0
Please refer to the Entity and Attribute Overview for valid values and definitions
HU_10_DS
Populate this field with the 10-digit code of the 5th level hydrologic unit that is receiving the majority of the flow from the watershed that the 6th level HU falls within. Outlets created by ditching or other artificial drainage are not to be considered for this field. If the 5th level HU empties directly to the ocean and not to another hydrologic unit, the word, "ocean", is used in this field.
Federal Standards for Delineation of Hydrologic Unit Boundaries - FGDC Proposal, Version 1.0
Federal Standards for Delineation of Hydrologic Unit Boundaries, FGDC Proposal, Version 1.0
Please refer to the Entity and Attribute Overview for valid values and definitions
HU_10_NAME
This field is for officially recognized names only. Populate this field by following the directions in subsection 6.3 "Watershed and Subwatershed Naming Protocol". Populate this field with the identical name for all 6th level hydrologic units that fall within the same 10-digit HU. The name used to attribute the watershed should be used only once within a 4th level unit.
Federal Standards for Delineation of Hydrologic Unit Boundaries - FGDC Proposal, Version 1.0
Federal Standards for Delineation of Hydrologic Unit Boundaries, FGDC Proposal, Version 1.0
Please refer to the Entity and Attribute Overview for valid values and definitions
HU_10_MOD
This field should identify any type of modifications to natural overland flow present in the 10-digit watershed. In the attribute field, identify from most significant to least significant modification(s). Use one or more of the following abbreviations in uppercase to identify your modification(s). If using more then one abbreviation, separate with a comma with no space after the comma.
Federal Standards for Delineation of Hydrologic Unit Boundaries - FGDC Proposal, Version 1.0
Federal Standards for Delineation of Hydrologic Unit Boundaries, FGDC Proposal, Version 1.0
Please refer to the Entity and Attribute Overview for valid values and definitions
HU_10_TYPE
Populate this field with the hydrologic unit type from the list provided that most closely identifies the watershed. Use any of the one-digit abbreviations in uppercase that is provided in the list.
Federal Standards for Delineation of Hydrologic Unit Boundaries - FGDC Proposal, Version 1.0
Federal Standards for Delineation of Hydrologic Unit Boundaries, FGDC Proposal, Version 1.0
Please refer to the Entity and Attribute Overview for valid values and definitions
HU_12_DS
Populate this field with the 12-digit code of the 6th level hydrologic unit that is receiving the majority of the flow from the subwatershed. Outlets created by ditching or other artificial drainage are not to be considered for this field. If the 6th level HU empties directly to the ocean and not to another hydrologic unit, the word, "ocean", is used in this field.
Federal Standards for Delineation of Hydrologic Unit Boundaries - FGDC Proposal, Version 1.0
Federal Standards for Delineation of Hydrologic Unit Boundaries, FGDC Proposal, Version 1.0
Please refer to the Entity and Attribute Overview for valid values and definitions
HU_12_MOD
This field should identify any type of modifications to natural overland flow present in the 12-digit subwatershed. In the attribute field, identify from most significant to least significant modification(s). Use one or more of the following abbreviations in uppercase to identify your modification(s). If using more than one abbreviation, separate with a comma with no space after the comma.
Federal Standards for Delineation of Hydrologic Unit Boundaries - FGDC Proposal, Version 1.0
Federal Standards for Delineation of Hydrologic Unit Boundaries, FGDC Proposal, Version 1.0
Please refer to the Entity and Attribute Overview for valid values and definitions
Sequential unique whole numbers that are automatically generated.
OBJECTID
Internal feature number.
ESRI
Sequential unique whole numbers that are automatically generated.
SHAPE
Feature geometry.
ESRI
Coordinates defining the features.
HU_12_NAME
This field is for officially recognized names only. Populate this field by following the directions in subsection 6.3 "Watershed and Subwatershed Naming Protocol". The name used to attribute the subwatershed should be used only once within a 5th level unit.
Federal Standards for Delineation of Hydrologic Unit Boundaries - FGDC Proposal, Version 1.0
Federal Standards for Delineation of Hydrologic Unit Boundaries, FGDC Proposal, Version 1.0
Please refer to the Entity and Attribute Overview for valid values and definitions
SHAPE.area
SHAPE.len
Hydrologic Unit delineations are closed polygons that encompass all area draining toward the lowest point (called outlet) in the polygon. Because of nominal sizes for the different hydrologic unit levels (Watershed (40,000 to 250,000 acres) and Subwatershed (3,000 minimum, generally 10,000 to 40,000 acres)), some polygons do not include all areas up to the drainage divide but all areas to one or more other upstream hydrologic units. A unique hydrologic unit code is used to identify each
hydrologic unit. The Watershed hydrologic unit codes start with the 8-digit Subbasin (Cataloging Unit) number that contains the Watershed. Likewise the Subwatershed hydrologic unit codes start with the 10-digit Watershed number that contains the Subwatershed.
A map unit symbol uniquely identifies each closed polygon. Each symbol is linked to a hydrologic unit code. The uniqueness of hydrologic unit codes while applying to hydrologic units does not carry over to polygons. Small islands offshore in coastal and lakeshore areas or in river deltas are given the same code as adjacent hydrologic units on the mainland.
Attribute data associated with a hydrologic unit code includes:
non-contributing area (acres);
names for each level of nesting (region, subregion, basin, subbasin, watershed and subwatershed);
codes for hydrologic units immediately downstream;
name of town where subwatershed outlet occurs;
information about type of subwatershed or watershed;
reference to human-caused modifications to stream flow within the watershed;
notes concerning delineation of hydrologic unit boundary.
Description of attributes by field from the Federal Standards for Delineation of Hydrologic Unit Boundaries
1) .pat attributes
Huc_8 : Eight Digit Hydrologic Unit Code - (REQUIRED)
A unique 8-digit code from the USGS map series "Hydrologic Unit Maps". Use the existing code for the sub-basin where the subwatershed resides; do not change this code. The same number should be used in every record that pertains to a subwatershed that resides within the same 8-digit sub-basin.Numbers were assigned in an upstream to downstream fashion. Where no downstream/upstream relationship could be determined numbers were assigned in a clockwise fashion.
Huc_10: Ten Digit Hydrologic Unit Code - (REQUIRED)
This field provides a unique 10-digit code for each watershed. Add two digits to the end of the existing 8-digit code, therefore resulting in a 10-digit number. This same number should be used in every record that pertains to a subwatershed that resides within the same 10-digit watershed.Numbers were assigned in an upstream to downstream fashion. Where no downstream/upstream relationship could be determined numbers were assigned in a clockwise fashion. It should be noted that the polygons that cross into Idaho were numbered by Idaho and are not consistent with the above methods. Affected huc_8s include: 17040202, 17040204 and 17040104.
Huc_12: Twelve Digit Hydrologic Unit Code - (REQUIRED)
This field provides a unique 12-digit code for each subwatershed. Add two digits to the end of the existing 10-digit code, therefore creating a 12-digit number.Numbers were assigned in an upstream to downstream fashion. Where no downstream/upstream relationship could be determined numbers were assigned in a clockwise fashion. It should be noted that the polygons that cross into Idaho were numbered by Idaho and are not consistent with the above methods. Affected huc_8s include: 17040202, 17040204 and 17040104.
Acres: Acres - (REQUIRED)
Area of subwatershed including non-contributing areas calculated to acres as a whole number, no decimals. The "Acres" field needs to be calculated from the "Area" field.
States: States - (REQUIRED)
The "States" field needs to include the names of all state(s) that the subwatershed falls within. Use the 2-digit postal abbreviation in upper case and sort the state(s) in alphabetical order. If using more then one abbreviation, separate with a comma with no space after the comma.
Ncontrb_a: Non-Contributing Area - (FIELD REQUIRED, ATTRIBUTES OPTIONAL)
Drainage areas that do not flow toward the outlet of any hydrologic unit are considered non-contributing. If a non-contributing area is on the boundary between two or more hydrologic units, determine the low point along the non-contributing area boundary. The non-contributing area should be associated with the hydrologic unit adjacent to the low point on the boundary. This attribute should be the total of the non-contributing areas within a hydrologic unit calculated in acres.
Hu_10_ds: Fifth Level Downstream Hydrologic Unit Code - (FIELD REQUIRED, ATTRIBUTES OPTIONAL)
Populate this field with the 10-digit code of the 5th level hydrologic unit that is receiving the majority of the flow from the watershed that the 6th level HU falls within. Outlets created by ditching or other artificial drainage are not to be considered for this field. If an HU flows into an ocean or the Gulf of Mexico populate this field with "OCEAN" and if a HU flows into one of the Great Lakes use the term "LAKE". If a HU flows across international borders use "CANADA" or "MEXICO" depending on which country the HU drains into. If an HU is a closed basin, then populate this record with the term "CLOSED BASIN".
Hu_10_name: Fifth Level Hydrologic Unit Name - (FIELD REQUIRED, ATTRIBUTES OPTIONAL)
This field is for officially recognized names only. Populate this field by following the directions in subsection 6.3 "Watershed and Subwatershed Naming Protocol". Populate this field with the identical name for all 6th level hydrologic units that fall within the same 10-digit HU. The name used to attribute the watershed should be used only once within a 4th level unit. Some 10-digit HU were assigned the huc_10 number when no GNIS name was identified on the DRG-Es.
Hu_10_mod: Fifth Level Hydrologic Unit Modifications - (REQUIRED)
This field should identify any type of modifications to natural overland flow that alters the location of the hydrologic unit boundary for a 10-digit watershed. In the attribute field, identify from most significant to least significant modification(s). Use one or more of the following abbreviations in uppercase to identify your modification(s). If using more then one abbreviation, separate with a comma with no space after the comma.
SC - Stormwater Canal
ID - Irrigation Ditch
IT - Interbasin Transfer
BC - Barge Canal
SD - Stormwater Ditch
PD - Pipe Diversion
CD - Channel Diversion
NC - Non-Contributing
KA - Karst
LE - Levee
NM - No Modifications
OC - Overflow Channel
DM - Dam at outlet or HU boundary
OT - Other
Hu_10_type: Fifth Level Hydrologic Unit Type - (REQUIRED)
Populate this field with the hydrologic unit type from the list provided that most closely identifies the watershed. Use any of the one-digit abbreviations in uppercase that is provided in the list.
S - "Standard" hydrologic unit - Any land HU with drainage flowing to a single outlet point, excluding non-contributing areas. This includes areas or small triangular wedges between adjacent HU's that remain after classic hydrologic units are delineated. Some examples include "true", "classic", "composite", and "remnant" hydrologic units.
C - "Closed Basin" hydrologic unit - A drainage area that is 100% non-contributing. This means all surface flow is internal, no overland flow leaves the hydrologic unit through the outlet point.
F - "Frontal" hydrologic unit - Areas along the coastline of lakes, oceans, bays, etc. that have more than one outlet. These HU's are predominantly land with some water areas at or near the outlet(s).
W - "Water" hydrologic unit - Hydrologic units that are predominantly water with adjacent land areas, ex. lake, easturies, harbors.
I - "Island" hydrologic unit - A hydrologic unit that is one or more islands and adjacent water out to the toe of the shore face.
U - "Unclassified" hydrologic unit - A hydrologic unit that can't be defined or doesn't fit into one of the types that have been listed.
Hu_12_ds: Sixth Level Downstream Hydrologic Unit Code - (FIELD REQUIRED, ATTRIBUTES OPTIONAL)
Populate this field with the 12-digit code of the 6th level hydrologic unit that is receiving the majority of the flow from the subwatershed. Outlets created by ditching or other artificial drainage are not to be considered for this field. If a HU flows into an ocean or the Gulf of Mexico populate this field with "OCEAN" and if a HU flows into one of the Great Lakes use the term "LAKE". If a HU flows across international borders use "CANADA" or "MEXICO" depending on which country the HU drains into. If an HU is a closed basin, then populate this record with the term "CLOSED BASIN".
Hu_12_name: Sixth Level Hydrologic Unit Name - (FIELD REQUIRED, ATTRIBUTES OPTIONAL)
This field is for officially recognized names only. Populate this field by following the directions in subsection 6.3 "Watershed and Subwatershed Naming Protocol". The name used to attribute the subwatershed should be used only once within a 6th level unit. Some 10-digit HU were assigned the huc_12 number when no GNIS name was identified on the DRG-Es.
Hu_12_mod: Sixth Level Hydrologic Unit Modifications - (REQUIRED)
This field should identify any type of modifications to natural overland flow that alters the location of the hydrologic unit boundary for a 12-digit subwatershed. In the attribute field, identify from most significant to least significant modification(s). Use one or more of the following abbreviations in uppercase to identify your modification(s). If using more than one abbreviation, separate with a comma with no space after the comma.
SC - Stormwater Canal
ID - Irrigation Ditch
IT - Interbasin Transfer
BC - Barge Canal
SD - Stormwater Ditch
PD - Pipe Diversion
CD - Channel Diversion
NC - Non-Contributing
KA - Karst
LE - Levee
NM - No Modifications
OC - Overflow Channel
DM - Dam at outlet or HU boundary
OT - Other
Hu_12_type: Sixth Level Hydrologic Unit Type - (REQUIRED)
Populate this field with the hydrologic unit type from the list provided that most closely identifies the subwatershed. Use any of the one digit abbreviations in uppercase that is provided in the list.
S - "Standard" hydrologic unit - Any land HU with drainage flowing to a single outlet point, excluding non-contributing areas. This includes areas or small triangular wedges between adjacent HU's that remain after classic hydrologic units are delineated. Some examples include "true", "classic", "composite", and "remnant" hydrologic units.
C - "Closed Basin" hydrologic unit - A drainage area that is 100% non-contributing. This means all surface flow is internal, no overland flow leaves the hydrologic unit through the outlet point.
F - "Frontal" hydrologic unit - Areas along the coastline of lakes, oceans, bays, etc. that have more than one outlet. These HU's are predominantly land with some water at or near the outlet(s).
W - "Water" hydrologic unit - Hydrologic units that are predominantly water with adjacent land areas, ex. lake, easturies.
I - "Island" hydrologic unit - A hydrologic unit that is one or more islands and adjacent water out to the toe of the shore face.
U - "Unclassified" hydrologic unit - A hydrologic unit that can't be defined or doesn't fit into one of the types that have been listed.
ArcInfo (.pat) and ArcView Polygon Format
Item name Width Output Type (ArcView) N.Dec. Example
Huc_8 8 8 C - 01080201
Huc_10 10 10 C - 0108020103
Huc_12 12 12 C - 010802010310
Acres 8 12 F N 0 026739
States 11 11 C - KS,MO,OK
Ncontrb_a 8 12 F N 0 357
Hu_10_ds 10 10 C - 1710020504
Hu_10_name 80 80 C - Upper Blue River
Hu_10_mod 20 20 C - CB,NC,ID
Hu_10_type 1 1 C - S
Hu_12_ds 12 12 C - 171002050402
Hu_12_name 80 80 C - Drift Creek-Big Bear River
Hu_12_mod 20 20 C - SD,KA,PD
Hu_12_type 1 1 C - C
2) .aat attributes
Hu_level: Hydrologic Unit Level - (REQUIRED)
This field provides the means to create cartographically pleasing maps. Populate this field with the highest hydrologic unit level (smallest number) for the line (arc) represented by the record. Record the level using numbers 1 through 6 representing each level with 1 being the highest and 6 the lowest level. An example would be if a line represents a region, subregion, basin, subbasin, watershed, and subwatershed boundary, then this cell would be populated with a 1 (Region). Example two would be if a line is a subbasin, watershed, and subwatershed boundary, then the cell would get a 4 (Subbasin). Use one of the levels provided in the list below.
Level Digit# Name
1 2 Region
2 4 Subregion
3 6 Basin
4 8 Subbasin
5 10 Watershed
6 12 Subwatershed
Linesource: Line Spatial Data Source - (REQUIRED)
The Linesource should indicate the base map source(s) used to delineate at 1:24,000 scale. Populate the field using one of the standardized code(s) listed below in uppercase. If using more than one code, separate with a comma with no space after the comma.
TOPO24 - Delineation from hardcopy 1:24,000 scale topographic maps
TOPO25 - Delineation from hardcopy 1:25,000 topgraphic maps, only Alaska and Caribbean
TOPO63 - Delineation from hardcopy 1:63,360 topographic maps, only Alaska and Caribbean
DRG24 - Delineation from 1:24,000 scale Digital Raster Graphics
DRG25 - Delineation from 1:25,000 Digital Raster Graphics, only Alaska and Caribbean
DRG63 - Delineation from 1:63,360 Digital Raster Graphics, only Alaska and Caribbean
DEM10 - Derived from 10 meter Digital Elevation Model
DEM30 - Derived from 30 meter Digital Elevation Model
NED30 - Derived from 30 meter National Elevation Dateset Model
EDNA30 - (formally NED-H), derived from 30 meter Elevation Derivatives for National
Applications
BATH"scale" (ex. BATH24) - Interpreted from NOAA 1:24,000 scale bathymetric data
HYPSO"scale" (ex. HYPSO24)- Delineated from 1:24,000 scale contour data
ORTHO"scale" (ex. ORTHO12) - Interpreted from 1:12,000 scale Ortho-imagery
DEDEM10 - Drainage enforced 10 meter Digital Elevation Model
DEDEM30 - Drainage enforced 30 meter Digital Elevation Model
GPS - Derived from Global Positioning System
LIDAR - Derived from LIDAR
IFSAR - Derived from IFSAR data
OTH - Other
UNK - Unknown
All other reference and source maps not listed should be noted in the metadata.
Meta_id: Metadata ID Number - (REQUIRED)
Metadata ID is a code that identifies which metadata file applies to the arc. In many cases there will only be one metadata file. However, in some cases more than one metadata file may be created to identify different groups and/or procedures used to produce the lines. These separate metadata files may be identified for each separate arc. The metadata ID should be a 4-character code starting with the 2-letter state postal code, followed by a 2-digit sequence number. For example "OK01", "ID02", etc.
ArcInfo Line (.aat) Attribute Format
Item name Width Output Type N.Dec. Example
Hu_level 1 1 I - 6
Linesource 20 20 C - DEM30,DRG24,GPS
Meta_id 4 4 C - OK01
Federal Geographic Data Committee. 2001. Federal Standards for Delineation of Hydrologic Unit Boundaries. June 12, 2001 Draft with emailed amendments to certain polygon and arc attribute structure.
U.S. Department of Agriculture, Natural Resources Conservation Service, National Cartography and Geospatial Center
mailing address
P.O. Box 6567
Fort Worth
Texas
76115
U.S.
817 334 5559
817 334 5469
Connecticut Watershed Boundary Dataset Poly
Although these data have been processed successfully on a computer system at the U.S. Department of Agriculture, no warranty expressed or implied is made by the agency regarding the utility of the data on any other system, nor shall the act of distribution constitute any such warranty. The U.S. Department of Agriculture will warrant the delivery of this product in 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.
Neither the U.S. Department of Agriculture, nor any of its agencies are liable for misuse of the data, nor is it liable for damage, transmission of viruses, or computer contamination through the distribution of these data sets.
The United States Department of Agriculture (USDA) prohibits discrimination in its programs on the basis of race, color, national origin, sex, religion, age, disability, political beliefs and marital or familial status. (Not all prohibited bases apply to all programs.) Persons with disabilities who require alternative means for communication of program information (Braille, large print, audio tape, etc.) should contact the USDA Office of Communications at (202) 720-5881 (voice) or (202) 720-7808 (TDD).
To file a complaint, write the Secretary of Agriculture, U.S. Department of Agriculture, Washington, D.C. 20250, or call (202) 720-7327 (voice) or (202) 720-4107 (TDD). USDA is an equal opportunity employer.
Arc Interchange File
20010712
non-compressed
spatial and keys
3.423
http://www.lighthouse.nrcs.usda.gov/gateway/gatewayhome.html
8 mm cartridge tape
2.3
gigabytes
tar
1/4-inch cartridge tape
150
megabytes
tar
The charge for one data set is $XX.XX. A data set is one hydrologic unit boundary area in full quadrangle format and includes both spatial and attribute data.
Call or write to organization listed under Distributor. Spatial line data are in DLG-3 optional format. Digital line graph files contain area records. A conversion legend is provided for each digital line graph file. Hydrologic unit codes and information concerning the hydrologic unit area are available in a companion ASCII attribute file.
10 working days
20010712
2002
U.S. Department of Agriculture, Natural Resources Conservation Service
GIS Specialist
GIS Specialist
mailing address
344 Merrow Road
Tolland
Connecticut
06084-3917
(860) 871-4011
(860) 871-4054
FGDC Content Standards for Digital Geospatial Metadata
FGDC-STD-001-1998
local time
http://www.esri.com/metadata/esriprof80.html
ESRI Metadata Profile