DRAFT
Pacific
Northwest Regional
Hydrologic
Unit Boundary
Database
Attribute Standards
(1st through 8th Fields)
Updated: February 06, 2001
Mark Koski, Chester Novak,
Ryan Dalton, Marshall Thompson
Bureau
of Land Management - Salem, OR
2. Hydrologic
Unit “Field” Codes - (Required)
3. Hydrologic
Unit Types - (Optional)
4. Hydrologic
Unit Naming Protocol - (Required)
5. Historical
Hydrologic Unit Number - (Required)
7. Non-Contributing
Areas - (Required)
8. Fifth
Field Down Stream Hydrologic Unit - (Required)
9. Sixth
Field Down Stream Hydrologic Unit - (Required)
10. Hydrologic
Unit Modifications - (Required)
1. Hydrologic
Unit Line Level - (Required)
2. Line
Edit Spatial Data Source - (Required)
3. Line
Edit Verification - (Required)
4. Line
Edit Date - (Required)
5. Line
Edit Organization - (Required)
6. Metadata
ID Number - (Required)
DRAFT
Federal Interagency Standard Attribute Tables
Required Attributes for Polygons
(PAT)
Required Attributes for Arcs (AAT)
In general terms, a hydrologic unit can be defined as any geographic area where all water within that area naturally drains to a specific outlet or pour point. To better classify hydrologic units they are commonly divided into size classifications called “Fields”. “Fields” define drainage areas of specific size within a network of hydrologic units. The largest classification of this kind is termed a 1st Field watershed (also called a Region). One example of a 1st Field watershed is the Columbia River Basin Region, which defines the drainage network for the majority of the States of Oregon and Washington. As part of the ranking system, 1st Fields break down into smaller 2nd Fields which can then be further subdivided into 3rd Fields and so on. These divisions may continue until much smaller 8th Fields are reached. Delineation of these divisions is based on the Interagency Guidelines on Delineation of Watershed and Subwatershed Hydrologic Unit Boundaries (http://wwwga.usgs.gov/gis/iag.html).
The purpose of the hydrologic unit boundary dataset is to simultaneously create a complete index of hydrologic unit boundaries representing the boundaries for 1st through 8th Field hydrologic units. This dataset was built to allow users the ability to query hydrologic units as whole polygons or as individual arcs, based on certain historical information. The attribute descriptions contained in this document explain the information that is available in this dataset and how users are to interpret that information.
After much discussion about what to name this new hydrologic boundary dataset, the core OGIC Hydro group decided that that dataset should be named “PNW_HUCvXX”. What does this mean? This new coverage name stands for Pacific Northwest Hydrologic Unit Codes, version <some_number>. The “XX” represents the current “version” number of the coverage. By “versioning” this coverage, users of the data have an easy way to track the coverage and a quickly look for recent updates to their version. This will allow more people to be working with the same, and most recent, dataset. The names of the coverage will actually be named “PNW_HUCv1”, “PNW_HUCv2”, “PNW_HUCv3”, etc. as the versioning process continues.
When inputting information into database
items, all attributes will be added in ALL UPPERCASE format. This will allow for consistency in database
management and querying.
Because hydrologic units are divided into different size categories, each “Field” receives its own two-digit, numeric identification code. The combination of these numeric codes creates a unique identifier for each subdivision. The approach to defining the unit identification code is discussed in detail later in this document.
Note: This item is based on the national interagency
protocol.
This attribute is to be calculated from the internal “Area” attribute.
ITEM NAME WIDTH OUTPUT TYPE
N.DEC EXAMPLE
ACRES 12 12 N 4 26739.2359
As required by the national protocols, hydrologic units of the same “Field” type (for example, all 6th field hydrologic units within a 5th field) must be sequentially numbered, starting from the most upstream unit and progressing downstream.
The structure of this attribute allows each subdivision to be queried by their full or partial hydrologic unit number. Where a specific hydrologic unit has not yet been delineated, the attribute value “XX” shall serve as a placeholder instead of the standard numeric code.
1st 2nd 3rd 4th
5th 6th 7th 8th
17 | 10 | 02 | 03 | 02 | 09 | 02 | XX
ITEM
NAME WIDTH OUTPUT TYPE
N.DEC EXAMPLE
HUC_NUM 16 16 C - 17100203020902XX

Example Explanation: When delineating 7th field sub-watersheds, all 7th
fields within the same 6th field will have the same first 12
digits. Starting at the uppermost end
of the drainage, the first 7th field hydrologic unit would be
assigned the code “01” for the 13th and 14th digits. When combined with the 6th field
code, the full Hydrologic Unit Code in the above example would be 17100203020901XX. The next downstream hydrologic unit would be assigned the code
“02” for its 13th and 14th digits, making its full HUC
code be 17100203020902XX
and so on. The “XX” at the
end of the example tells users that 8th field watersheds have not
yet been delineated in this area. This
coding scheme should be applied when delineating hydrologic units anywhere from
5th through 8th fields.
Based on the need to determine how hydrologic units were
defined, the “hydrologic unit type” class was formed. This attribute allows
users to query hydrologic units by composition type based on its delineation
method. Information is presented as a
running string, similar to the numeric “field” codes. Individual characters of the string represent the formation
characteristics for each hydrologic unit level. Where a hydrologic unit level has not been delineated or the type
has yet to be classified, an “X” will be used as a placeholder. This is an optional attribute that may be
populated for 1st through 8th field hydrologic units
where necessary.
1st
2nd 3rd 4th 5th 6th 7th 8th
T | T | T | T | T | T | C | X
ITEM NAME WIDTH OUTPUT TYPE
N.DEC EXAMPLE
HUC_TYPE 8 8 C -
TTTTTTCX

Standard
values currently include the following:
T “True”, “pure”, or “classic” hydrologic units are land
areas having all the surface drainage within its boundary converging at a
single point.
C “Composite” hydrologic units, or “remnant areas” are
drainage areas typically formed as the residual areas after delineation of classic
watersheds. The most common example of
a remnant area is the small triangular wedge between the boundaries of adjacent
hydrologic units flowing into the same side of another stream.
F “Frontal” hydrologic units are areas that include
multiple, non-convergent rivers.
Frontal units would most likely be related to hydrologic units feeding
into the Pacific Ocean or Columbia River.
X Unclassified
hydrologic units
The following attribute items are intended for officially
recognized names only. The hydrologic
unit name and hydrologic unit “Field” code attributes relate in the following
ways:
1st Field =
Region
2nd Field =
Sub-Region
3rd Field =
Basin
4th Field =
Sub-Basin
5th Field =
Watershed
6th Field =
Sub-Watershed
7th Field =
Catchment
8th Field =
Sub-Catchment
ITEM NAME WIDTH OUTPUT TYPE
N.DEC EXAMPLES
REGION_NAME 30 30 C
- PACIFIC NORTHWEST
SUBREGION_NAME 30 30 C
- OREGON/WASHINGTON COASTAL
BASIN_NAME 30 30 C
- NORTHERN OREGON COASTAL
SUBBASIN_NAME 30 30 C
- ALSEA
WATERSHED_NAME 80 80 C
- UPPER ALSEA RIVER
SUBWAT_NAME 80 80 C
- UPPER NORTH FORK ALSEA RIVER
CATCHMENT_NAME 80 80 C
- RACKS CREEK
SUBCATCH_NAME 80 80 C
-
The
following guidelines should be used when assigning a name to a hydrologic unit
polygon:
Because of the national protocol requirement for sequential
downstream numbering within hydrologic units, there may be instances where the new
hydrologic unit numbers may not be consistent with some historical
hydrologic unit numbers. With the
renumbering of the hydrologic units, a link may be needed to assist users in
identifying hydrologic units based on the historical hydrologic unit numbers.
This attribute should contain the
historical hydrologic unit numbers that were assigned prior to the renumbering
process.
ITEM NAME WIDTH OUTPUT TYPE
N.DEC EXAMPLE
OLD_HUCNUM 16 16 C
- 1710020309XXXXXX
Note: This item is based on the national interagency protocol.
This attribute should include the names of all states that
a particular hydrologic unit falls within.
Use the 2-digit postal code abbreviation and sort the states in
alphabetical order, with a hyphen separating each state.
ITEM NAME WIDTH OUTPUT TYPE
N.DEC EXAMPLE
STATES 12 12 C -
ID-OR-WA
Example Explanation: ID-OR-WA
represents a hydrologic unit that overlaps the Idaho, Oregon, and Washington
borders.
Note: This item is based on the national interagency
protocol.
Drainage areas that do not flow toward the outlet of any
hydrologic unit are considered non-contributing areas. Such areas may be due to glaciated plains
(potholes), enclosed basins, karst topography, playas, cirques, depression
lakes, dry lakebeds, or similar landforms.
Such areas may be large enough to be designated as a sub-division unto
itself. The largest non-contributing
area in the U.S. is the area of the Great Basin in Utah. This closed area is
large enough to be considered as a sub-region hydrologic unit.
If non-contributing areas are
relatively small, or if they are scattered throughout a drainage area, they
should be considered as part of the delineated hydrologic unit. Record the acreage of non-contributing area for
the hydrologic unit down to the smallest mapped hydrologic unit “Field” in the
given subdivision.
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 hydrologic unit adjacent to the low point on the boundary should be
associated with this non-contributing area.
Occasionally, a non-contributing area may be drained (via canal or
pipeline), thus becoming part of a surrounding or adjacent hydrologic
unit. Local investigation in cases of
suspected drainage or diversion might be needed.
Document the criteria used to
delineate non-contributing areas in the metadata file if a significant number
of non-contributing areas are defined.
Include the amount of non-contributing areas within a hydrologic unit as
an attribute of the database. Delineate
non-contributing areas in a consistent manner throughout the state.
ITEM NAME WIDTH OUTPUT TYPE
N.DEC EXAMPLE
NCONTRIB_DA* 12 12 N
4 325.9362
*Based on the Federal Interagency Standards,
this item definition is 4,4,B. It was
recommended we expand the NCONTRIB_DA item definition to allow a higher level
of accuracy.
Note: This item is based on the national interagency
protocol.
This field represents the hydrologic unit (of the same level) receiving the majority of the downstream flow. Outlets created by ditching or other artificial drainage are not to be considered for this field. Where a specific fifth field hydrologic unit has not yet been delineated, the attribute value “XX” shall serve as a placeholder instead of the standard numeric code.
ITEM NAME WIDTH OUTPUT TYPE
N.DEC EXAMPLE
DS_HUC5 10 10 C - 1710020504
Note: This item is based on the national interagency
protocol.
This field represents the hydrologic unit (of the same level) receiving the majority of the downstream flow. Outlets created by ditching or other artificial drainage are not to be considered for this field. Where a specific sixth field hydrologic unit has not yet been delineated, the attribute value “XX” shall serve as a placeholder instead of the standard numeric code.
ITEM NAME WIDTH OUTPUT TYPE
N.DEC EXAMPLE
DS_HUC6 12 12 C
- 171002050403
Note: This item is based on the national interagency protocol. This attribute item directly relates to the attribute item called FLAGS in the national protocol. The item name “FLAGS” was deemed unacceptable based on discussions with the core OGIC Hydro group because it does not imply any intuitive meaning. Therefore the item name FLAGS was replaced with the name Hydrologic Unit Modifications (or HUC_MOD) name.
This attribute should contain information unique to the
hydrologic unit sub-division for a particular record. This may include information on the type of structure, date of
construction or other features that may influence surface water flow.
ITEM NAME WIDTH OUTPUT TYPE
N.DEC EXAMPLE
HUC_MOD 80
80 C -
CANAL
Example Explanation: Possible
examples include canal, ditch, control structure, diversion, etc.
This attribute may include any additional information that
pertains to the hydrologic unit’s polygon history or general characteristics
that cannot be adequately described in previous items.
ITEM NAME WIDTH OUTPUT TYPE
N.DEC EXAMPLE
COMMENT 100 100 C -
WALDO LAKE
Example Explanation: On a map, the feature containing the
value shown above represents Waldo Lake.
HIGHLIGHTED =
From the “Federal Interagency Standards…” protocol
ITEM NAME WIDTH OUTPUT TYPE
N.DEC EXAMPLES
ACRES
12 12 N
4 2187.4971
HUC_NUM 16 16 C -
171002030902XX
HUC_TYPE 8 8 C -
TTTTTCX
REGION_NAME 30 30 C -
PACIFIC NORTHWEST
SUBREGION_NAME 30
30 C -
OREGON-WASHINGTON COASTAL
BASIN_NAME 30 30 C -
NORTHERN OREGON COASTAL
SUBBASIN_NAME 30
30 C -
ALSEA
WATERSHED_NAME 80
80 C -
UPPER ALSEA RIVER
SUBWAT_NAME 80 80 C -
UPPER NORTH FORK ALSEA RIVER
CATCHMENT_NAME 80
80 C -
RACKS CREEK
SUBCATCH_NAME 80
80 C -
OLD_HUCNUM 16 16 C -
171002030902XX
STATES
12 12 C
- ID-OR-WA
NCONTRIB_DA
12 12 N
4 325.9362
DS_HUC5
10 10 C
- 17100200308
DS_HUC6
12 12 C
- 171002030902
HUC_MOD*
80 80 C
- CANAL
COMMENT 100 100 C -
WALDO LAKE
* The information captured in the HUC_MOD field directly relates to the
FLAGS item as shown in the national interagency protocol.
Redefined items used to
match the PAT to previous standard. These items based on data from the “HUC_NUM” item.
ITEM NAME WIDTH OUTPUT TYPE
N.DEC EXAMPLES
REGION 2 2 C - 17
SUBREGION 4 4 C -
1710
BASIN 6 6 C -
171002
SUBBASIN 8 8 C -
17100203
WATERSHED 10 10 C -
1710020309
SUBWAT 12 12 C
- 171002030902
CATCHMENT 14 14 C -
171002030902XX
SUBCATCH 16 16 C -
171002030902XXXX
FIRST_FIELD 2 2 C -
17
SECOND_FIELD 2 2 C -
10
THIRD_FIELD 2 2 C -
02
FOURTH_FIELD 2 2 C -
03
FIFTH_FIELD 2 2 C -
09
SIXTH_FIELD 2 2 C -
02
SEVENTH_FIELD 2 2 C -
XX
EIGHTH_FIELD 2 2 C -
XX
Note: This item is based on the national interagency
protocol.
Because this coverage simultaneously holds boundary lines ranging from 1st to 8th Field hydrologic unit subdivisions, many boundary lines will be shared between different hydrologic unit classifications.
This attribute is used to identify
the hydrologic unit groupings a given line segment belongs to. Primary order will always be given to the
largest hydrologic unit classification of any shared line segment (e.g. when a
hydrologic unit boundary line is shared between a 5th field and a 6th
field, the line will receive a code of 5).
ITEM NAME WIDTH OUTPUT TYPE
N.DEC EXAMPLE
HUC_LEVEL 1 1 I
- 6
Standard values currently include the following:
1 1st
Field Watershed Boundary
2 2nd
Field Watershed Boundary, NOT Shared with a 1st Field
3 3rd
Field Watershed Boundary, NOT Shared with 1st or 2nd
Field
4 4th
Field Watershed Boundary, NOT Shared with 1st - 3rd Field
5 5th
Field Watershed Boundary, NOT Shared with 1st - 4th Field
6 6th
Field Watershed Boundary, NOT Shared with 1st - 5th Field
7 7th
Field Watershed Boundary, NOT Shared with 1st - 6th Field
8 8th
Field Watershed Boundary, NOT Shared with 1st - 7th Field

Example Explanation: In the example
above, line segments that are only coded with the largest hydrologic unit line
type. In cases where a line segment is
simultaneously shared between a 2nd field and a 5th
field, the line is coded with a “2”.
Where a line segment is a 5th,
6th, and 7th field line, the line is given the code of
“5”, and so on. Finally, where 7th
field lines do not share a boundary with a 6th field line AND 8th
fields have not yet been delineated, all line segments are coded with a “7”,
that is until 8th fields are delineated where the same process
described above would be applied.
Note: This item is based on the national interagency
protocol.
This field captures
information related to the original source from which the spatial data was
derived. In determining which code to use, preference should be given to the
primary source employed to derive the boundary line. All line segments should be broken with a node where line sources
change. NOTE: The spatial data SOURCE should not be
confused with the METHOD in which a line was derived.
ITEM NAME WIDTH OUTPUT TYPE
N.DEC EXAMPLE
LINESOURCE
20 20
C - DRG24
Standard values currently include the following:
DRG24 Topographic
Interpretation- USGS 1:24,000 Digital Raster Graphics (DRG)
TVC24 Topographic Interpretation- USGS 1:24,000 Tagged
Vector Contours (TVC)
DEDEM10 Drainage
Enforced 10 meter Digital Elevation Model (Surface modeling)
DEM10 Derived
from 10 Meter Digital Elevation Model (Surface
modeling)
DEM30 Derived
from 30 Meter Digital Elevation Model (Surface modeling)
WODDB Topographic Interpretation- WODDB Contours (BLM)
GPS Global
Position System
DLG USGS
Digital Line Graph
UNK Unknown
Example Explanation: Arcs digitized
through topographic interpretation of USGS 1:24,000 Digital Raster Graphics
(DRG) contours will receive a code of DRG24.
Hydrologic unit boundaries must undergo a series of quality
control checks prior to being accepted as part of the finalized dataset.
This item may be used at a local level to track the
progress of edits as they move towards final certification. Initial draft lines for each segment are
reviewed by the digitizer/local hydrologists then passed on to specialists from
other agencies for further coordination and verification. This attribute provides
a record of each line segments current status in the review process.
ITEM NAME WIDTH OUTPUT TYPE
N.DEC EXAMPLE
LINEVER 1
1 C - 2
Standard values currently
include the following:
* Only
verification levels of 4 and 5 will be included in the regional dataset. Values of 1 through 3 may only be used at a
local level for planning and coordination purposes during the delineation of
new watersheds. Participating
organizations MUST work with other local participating organizations to form
consensus on line verification prior to inclusion in the regional dataset.
This field contains
information about the last date a spatial edit was performed to a given line
segment. The format should be in:
YYYY/MM/DD
ITEM NAME WIDTH OUTPUT TYPE
N.DEC EXAMPLE
LINEDATE 10 10 C
- 2000/11/15
Example Explanation: Arcs entered on
November 15, 2000 will receive a code of 2000/11/15.
Note: This item is based on the national interagency protocol. In the national interagency protocol, an item called “CONTRIB” is designed to capture information regarding “contributing agency(s)”. At this time, there is some uncertainty as to the intent of what the national protocol is trying to maintain in this field. In the meantime, this attribute item will attempt to capture our vision of this information.
This attribute designates the organization who performed
the last spatial edit to a given line segment. Depending on the variety of
sources used, every line segment within a single hydrologic unit could have a
different organization code. The codes
are to be applied to individual line segments, not hydrologic unit polygons.
ITEM NAME WIDTH OUTPUT TYPE
N.DEC EXAMPLE
LINEORG
10 10
C - USBLM-EUG
Standard
values currently include the following:
CLAMS CLAMS
(Coastal Landscape Analysis and Modeling Study)
IRICC Intergovernmental
Resource Information Coordinating Council
LVWFBR Longview
Fiber Company
NMFS National
Marine Fisheries Service
NRCS Natural
Resources Conservation Service
NWIFC Northwest
Indian Fisheries Commission
ODEQ OR
Dept. of Environmental Quality
ODF OR
Dept. of Forestry
REO REO (Regional Ecosystem Office). These are
lines that were created from REO coverage last updated October 1998.
SNPSN Simpson
Timber Company
UNKNOWN Unknown
input organization
USACE U.S.
Army Corps of Engineers
USBLM-BUR U.S.
Bureau of Land Management - BURNS
USBLM-CSB U.S.
Bureau of Land Management - COOS_BAY
USBLM-EUG U.S.
Bureau of Land Management - EUGENE
USBLM-LKE U.S.
Bureau of Land Management - LAKEVIEW
USBLM-MED U.S.
Bureau of Land Management - MEDFORD
USBLM-OSO U.S.
Bureau of Land Management - OREGON STATE OFFICE
USBLM-PNV U.S.
Bureau of Land Management - PRINEVILLE
USBLM-RSB U.S.
Bureau of Land Management - ROSEBURG
USBLM-SLM U.S.
Bureau of Land Management - SALEM
USBLM-VAL U.S.
Bureau of Land Management - VALE
USBR U.S.
Bureau of Reclamation
USBPA U.S.
Bonneville Power Administration
USEPA-R10 U.S.
Environmental Protection Agency - Region 10
USFS-DES U.S.
Forest Service - DESCHUTES
USFS-FRE U.S.
Forest Service - FREMONT
USFS-KAL U.S.
Forest Service - KALMATH
USFS-MAL U.S.
Forest Service - MALHEUR
USFS-MTH U.S.
Forest Service
- MT HOOD
USFS-OCH U.S.
Forest Service - OCHOCO
USFS-ROG U.S.
Forest Service - ROGUE RIVER
USFS-R6 U.S.
Forest Service - REGION SIX SUPERVISORS OFFICE
USFS-SIS U.S.
Forest Service - SISKIYOU
USFS-SIU U.S.
Forest Service - SIUSLAW
USFS-SIX U.S.
Forest Service - SIX RIVERS
USFS-UMA U.S.
Forest Service - UMATILLA
USFS-UMP U.S.
Forest Service - UMPQUA
USFS-WAL U.S.
Forest Service - WALLOWA WHITMAN
USFS-WIL U.S.
Forest Service - WILLAMETTE
USFS-WIN U.S.
Forest Service - WINEMA
USFWS U.S.
Fish and Wildlife Service
USGS U.S.
Geological Survey
USGS-NMD U.S.
Geological Survey - National Mapping Division
USNPS U.S.
National Park Service
WEYHSR Weyerhaeuser
Company
Example Explanation: Arcs provided
by the Eugene District BLM office would receive a code of USBLM-EUG.
Note: This item is based on the national interagency
protocol.
The definition for Metadata ID has not yet been
created. The purpose of this item is to
conform to attribute standards that are expected from the national interagency
protocol when they are complete. At
this time, there is no need to populate this item.
ITEM NAME WIDTH OUTPUT TYPE
N.DEC EXAMPLE
METADATA_ID 1 1 I -
(record sequence number)
This attribute may include any additional information that
pertains to the boundary line’s history or general characteristics that cannot
be adequately described in previous items.
ITEM NAME WIDTH OUTPUT TYPE
N.DEC EXAMPLE
COMMENT 100
100 C - STILL NEEDS VERIFICATION
HIGHLIGHTED =
From the “Federal Interagency Standards…” protocol
ITEM NAME WIDTH OUTPUT TYPE
N.DEC EXAMPLES
HUC_LEVEL **
1 1 I - 5 (highest level HUC associated)
LINESOURCE
20 20 C
- DRG24
LINEVER 1 1 C -
3 (level of verification)
LINEDATE 10 10 C -
2000/11/15
LINEORG 10 10 C -
USFS-WIL (organization id)
METADATA_ID
1 1 I - (record sequence number)
COMMENT 100 100 C -
STILL NEEDS VERIFICATION
** The information captured in the HUC_LEVEL field directly relates to
the HU_LEVEL item as shown in the national interagency protocol.
ITEM NAME WIDTH OUTPUT TYPE N.DEC
HUC_8 8
8 C -
HUC_10 10
10 C -
HUC_12 12
12 C -
ACRES 4
4 B -
STATES 12
12 C -
NCONTRIB_DA 4 4 B
-
HU-10_DS 12 12 C
-
HU-10_NAME 80 80
C -
HU-12_DS 12 12 C
-
HU-12_NAME 80 80 C
-
FLAGS 80
80 C -
ITEM NAME WIDTH OUTPUT TYPE N.DEC
HUC_LEVEL
1 1 I -
LINESOURCE 20 20 C
-
METADATA_ID 1 1 I
-
CONTRIB 50 50 C
-