Pacific Northwest Hydrography

Framework Clearinghouse

Hydrologic Unit Boundary

Data Dictionary

Physical Data Model

Version 1.1

*Prepared by the*

*Washington and Oregon*

*Hydrography Framework*

*Technical Work Groups*

*September 28, 2004*

Table of Contents

[Section 1 -- Hydrologic Unit Layer Description
1](#__RefHeading___Toc31005049)

[Hydrologic Unit Layer Description 2](#__RefHeading___Toc31005050)

[Polygon Attribute Tables: Hydrologic Unit Polygons
3](#__RefHeading___Toc31005051)

[Hydrologic Unit Boundary Polygon Attributes
3](#refheading___toc31005052)

[Hydrologic Unit Boundary HUC1 Region Attribute
10](#refheading___toc31005053)

[Hydrologic Unit Boundary HUC2 Region Attributes
11](#refheading___toc31005054)

[Hydrologic Unit Boundary HUC3 Region Attributes
12](#refheading___toc31005055)

[Watershed Boundary HUC5 Region Attributes
14](#refheading___toc31005056)

[Hydrologic Unit Boundary HUC6 Region Attributes
15](#refheading___toc31005057)

[Hydrologic Unit Boundary HUC7 Region Attributes
16](#refheading___toc31005058)

[Hydrologic Unit Boundary HUC8 Region Attributes
16](#refheading___toc31005058)

[Arc Lines Description 18](#__RefHeading___Toc31005059)

[Arc Attribute Table: Hydrologic Unit Polygons
19](#__RefHeading___Toc31005060)

[]{#__RefHeading___Toc31005049 .anchor}Section 1 -- Hydrologic Unit
Layer Description

The purpose of the Hydrologic Unit Boundaries dataset is to
simultaneously maintain an index representing Level One (1) through
Eight (8) Hydrologic Unit Boundaries. This dataset is intended as a tool
for water-resource management and planning activities, particularly for
site-specific and localized studies, which require the amount of detail
provided by a large-scale map. The Hydrologic Unit Boundaries coverage
contains attributes for polygons, arcs and eight Arc/Info regions.
Hydrologic Unit delineations are closed polygons that encompass all area
draining toward the lowest point (called pour point) in the polygon.

To better classify hydrologic units, the dataset is divided into
separate size classifications called "Levels" or "Fields," which define
drainage areas of specific size within a network of hydrologic units.
The largest classification of this kind is called a 1st Level hydrologic
unit (also referred to as Region). An example of a 1st Level hydrologic
unit 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 Level units can be subdivided into smaller
2nd Level units, which can be further subdivided into 3rd Level units
and so on. These divisions currently may continue until much smaller 8th
Level units are reached. The methods for delineating these units are
based on the Interagency Guidelines on Delineation of Hydrologic Unit
and Subwatershed Hydrologic Unit Boundaries
(<http://wwwga.usgs.gov/gis/iag.html>).

Several nested hydrologic unit boundaries have been incorporated to
create this geospatial dataset, which allow for mapping to the 8th
Level. The dataset was developed by delineating the boundary lines on
1:24,000 base maps and digitizing the delineated lines. Digital
Elevation Model data was used in part of the process to establish
preliminary boundaries. The Hydrologic Unit Code attached to each
delineated polygon is linked to the attribute data, which can contain
information on area in acres, non-contributing area, state(s) the
Hydrological Unit (HU) falls within, name for 5th and 6th level HU, 5th
and 6th level code for downstream hydrologic unit and hydrologic unit
modifications. Each line has attributes that describe the HU level
(1-6), originating source for that line and a metadata ID number that
links the line to its associated metadata file.

The following procedures were used to produce this dataset:

-   Hydrologic units were incorporated into this dataset from an
    aggregate of pre-existing HU's.

-   A number of new Hydrological Unit Boundaries were delineated using
    flow lines and basins computed from 10- and 30-meter horizontal
    resolution Digital Elevation data based on flow derived from the
    elevation grid to determine potential pour points.

-   The DEM data is derived from hypsography represented on 1:24000 USGS
    topographic quadrangles.

-   Additional hydrography data was used as a template to control
    pourpoint locations for the delineated HU's.

Examples have been listed for all attributes where possible, as have all
relevant attribute domains. For those instances where domains are
sequential unique whole numbers that are automatically generated, this
value has been omitted.

Maintenance Coverage versus Distribution Coverage

Two separate coverages exist for the Hydrologic Unit Layer dataset: the
publicly distributed coverage (referred hereafter as Distribution) and
the maintenance coverage (referred hereafter as Maintenance).

The Distribution coverage is available to all users for query and
analysis purposes and includes the Polygon Attribute Table, the Arc
Attribute Table and all region feature classes, e.g. PATHUC1 -- PATHUC8.
The Distribution coverage uses the following naming convention:
HU_BOUNDARY. This dataset can be downloaded at
[**http://hydro.reo.gov**](http://hydro.reo.gov/).

The Maintenance coverage is to be checked out for editing purposes using
the Interim HU Guidelines and includes the Polygon Attribute and Arc
Attribute Tables only. The Maintenance coverage uses the following
naming convention: HU\<mm/dd/yy\>, e.g. HU082203. This dataset and the
interim HU Guidelines can be downloaded at
[**http://hydro.reo.gov**](http://hydro.reo.gov/).

[]{#__RefHeading___Toc31005050 .anchor}Hydrologic Unit Layer Description

![](media/image1.jpeg){width="6.492361111111111in"
height="3.8381944444444445in"}

Example Explanation: When delineating 7th level units, all units within
a given 6th level unit have the same first 12 digits.

Starting at the uppermost end of the drainage, the first 7th level
hydrologic unit would be assigned the code "01" for the 13th and 14th
digits. When combined with the 6th level code, the full Hydrologic Unit
Code in the above example would be 17100203020901XX. The next downstream
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 level units have not been
delineated in this area.

For a full description of layer attributes, please see the "Pacific
Northwest Hydrologic Unit Boundaries Dataset Standards" document located
at

[**http://hydro.reo.gov/hu_edit_guidelines.html**](http://hydro.reo.gov/hu_edit_guidelines.html).

[]{#__RefHeading___Toc31005051 .anchor}**Polygon Attribute Tables:
Hydrologic Unit Polygons**Table Name: HU_BOUNDARY.PAT

(Distribution Coverage Name)

**HUMM/DD/YY.PAT**

Example: HU082203.PAT

(Maintenance Coverage Name)

[]{#refheading___toc31005052 .anchor}Hydrologic Unit Boundary Polygon
Attributes

+--------------------------------+-------------------------------------+
| **[ITEM NAME]{.underline}**    | **[ITEM DEFINITION]{.underline}**   |
+--------------------------------+-------------------------------------+
| AREA                           | 8,18,F,5                            |
+--------------------------------+-------------------------------------+
| PERIMETER                      | 8,18,F,5                            |
+--------------------------------+-------------------------------------+
| HU_BOUNDARY#                   | 4,5,B                               |
|                                |                                     |
| (or HU\<mmddyy\>#)             |                                     |
+--------------------------------+-------------------------------------+
| HU_BOUNDARY-ID                 | 4,5,B                               |
|                                |                                     |
| (or HU\<mmddyy\>-ID)           |                                     |
+--------------------------------+-------------------------------------+
| ACRES                          | 14,14,N,4                           |
+--------------------------------+-------------------------------------+
| HUC_NUM                        | 16,16,C                             |
+--------------------------------+-------------------------------------+
| HUC_TYPE                       | 8,8,C                               |
+--------------------------------+-------------------------------------+
| REGION_NAME                    | 30,30,C                             |
+--------------------------------+-------------------------------------+
| SUBREGION_NAME                 | 30,30,C                             |
+--------------------------------+-------------------------------------+
| BASIN_NAME                     | 30,30,C                             |
+--------------------------------+-------------------------------------+
| SUBBASIN_NAME                  | 30,30,C                             |
+--------------------------------+-------------------------------------+
| WATERSHED_NAME                 | 80,80,C                             |
+--------------------------------+-------------------------------------+
| SUBWAT_NAME                    | 80,80,C                             |
+--------------------------------+-------------------------------------+
| CATCHMENT_NAME                 | 80,80,C                             |
+--------------------------------+-------------------------------------+
| SUBCATCH_NAME                  | 80,80,C                             |
+--------------------------------+-------------------------------------+
| OLD_HUCNUM                     | 16,16,C                             |
+--------------------------------+-------------------------------------+
| STATES                         | 12,12,C                             |
+--------------------------------+-------------------------------------+
| NCONTRIB_DA                    | 12,12,N,4                           |
+--------------------------------+-------------------------------------+
| DS_HUC5                        | 10,10,C                             |
+--------------------------------+-------------------------------------+
| DS_HUC6                        | 12,12,C                             |
+--------------------------------+-------------------------------------+
| HUC_MOD                        | 80,80,C                             |
+--------------------------------+-------------------------------------+
| COMMENTS                       | 100,100,C                           |
+--------------------------------+-------------------------------------+
| REGION\*                       | 2,2,C                               |
+--------------------------------+-------------------------------------+
| SUBREGION\*                    | 4,4,C                               |
+--------------------------------+-------------------------------------+
| BASIN\*                        | 6,6,C                               |
+--------------------------------+-------------------------------------+
| SUBBASIN\*                     | 8,8,C                               |
+--------------------------------+-------------------------------------+
| WATERSHED\*                    | 10,10,C                             |
+--------------------------------+-------------------------------------+
| SUBWAT\*                       | 12,12,C                             |
+--------------------------------+-------------------------------------+
| CATCHMENT\*                    | 14,14,C                             |
+--------------------------------+-------------------------------------+
| SUBCATCH\*                     | 16,16,C                             |
+--------------------------------+-------------------------------------+
| FIRST_FIELD\*                  | 2,2,C                               |
+--------------------------------+-------------------------------------+
| SECOND_FIELD\*                 | 2,2,C                               |
+--------------------------------+-------------------------------------+
| THIRD_FIELD\*                  | 2,2,C                               |
+--------------------------------+-------------------------------------+
| FOURTH_FIELD\*                 | 2,2,C                               |
+--------------------------------+-------------------------------------+
| FIFTH_FIELD\*                  | 2,2,C                               |
+--------------------------------+-------------------------------------+
| SIXTH_FIELD\*                  | 2,2,C                               |
+--------------------------------+-------------------------------------+
| SEVENTH_FIELD\*                | 2,2,C                               |
+--------------------------------+-------------------------------------+
| EIGHTH_FIELD\*                 | 2,2,C                               |
+--------------------------------+-------------------------------------+

*\* designates a Redefined Item*

**AREA**

Area of the feature in coverage units, value is assigned by the
software.

**PERIMETER**

Perimeter of the feature in coverage units; value is assigned by the
software

**HU_BOUNDARY# (or HU\<mmddyy\>#)**

An internal feature identifier; value is assigned by software.

**HU_BOUNDARY-ID (or HU\<mmddyy\>-ID)**

Feature identifier assigned by user. This item is not used but must be
present for the software.

**ACRES**

Area of polygon in GIS acres. This item is to be generated from the
internal ArcInfo item called "Area."

**Example: 34476.917**

**HUC_NUM**

Hydrologic Unit Field Code. In order to identify an area, be it 1st
through Nth Levels, each is assigned the combination of Levels which
comprise it. Starting at the uppermost end of the drainage, the first
7th level hydrologic unit would be assigned the code 01 for the 13th and
14th digits.

**Example: 170102150104XXXX**

**HUC_TYPE**

Hydrologic Unit Types. This item allows users to query hydrologic units
based on composition type. Information is presented as a running string
where each individual character of the string represents the composition
type of a particular unit (e.g.- character number "1" represents the
composition type of a "1st level" unit, character number "2" represents
the composition type of a "2nd level" unit, etc). Where a hydrologic
unit level has not been delineated or the type has yet to be classified,
an "X" serves as a placeholder. This is an optional item that may be
populated for 1st through 8th level units where deemed necessary.

Example: Closed Basin

> **Domain Value: T\
> **Domain Value Definition: True, pure, or \"classic\" hydrologic units
> are land areas having all the surface drainage within its boundary
> converging at a single point.\
> **Domain Value: C**\
> Domain Value Definition:
>
> 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.
>
> **Domain Value: F**\
> Domain Value Definition: 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.\
> **Domain Value: X**\
> Domain Value Definition: Unclassified hydrologic units\
> **Domain Value: S**\
> Domain Value Definition:\
> **Domain Value: R\
> **Domain Value Definition

**REGION_NAME**

1st Field Hydrologic Unit Naming Protocol

**Example: PACIFIC NORTHWEST**

**SUBREGION_NAME**

2nd Field Hydrologic Unit Naming Protocol

**Example: UPPER COLUMBIA**

**BASIN_NAME**

3rd Field Hydrologic Unit Naming Protocol

**Example: SPOKANE**

**SUBBASIN_NAME**

4th Field Hydrologic Unit Naming Protocol

**Example: PRIEST**

**WATERSHED_NAME**

5th Field Hydrologic Unit Naming Protocol

**Example: COLUMBIA RIVER/LYNCH COULEE**

**SUBWAT_NAME**

6th Field Hydrologic Unit Naming Protocol

**Example: SOUTH SALMON RIVER**

**CATCHMENT_NAME**

7th  Field Hydrologic Unit Naming Protocol

**SUBCATCH_NAME**

8th Field Hydrologic Unit Naming Protocol

**OLD_HUCNUM**

Historic Hydrologic Unit Number. Because of the national requirement for
sequential downstream numbering of 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.

**Example: 17020010**

**STATES**

State(s) containing HU polygon. This attribute should include the names
of all states that a hydrologic unit falls within. Use the two-digit
postal code abbreviation and sort the states in alphabetical order with
a coma **??or hyphen??** separating each state.

**Example: ID**

> **Domain Value: OR**\
> Domain Value Definition: Oregon\
> **Domain Value: CA**\
> Domain Value Definition: California\
> **Domain Value: NV**\
> Domain Value Definition: Nevada\
> **Domain Value: ID**\
> Domain Value Definition: Idaho\
> **Domain Value: WA**\
> Domain Value Definition: Washington

**NCONTRIB_DA**

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.

**Example: 325.9362**

**DS_HUC5**

Fifth Level Downstream HUC. This item represents the hydrologic unit
code of the 5th level hydrologic unit receiving the majority of the
downstream flow. Outlets created by ditching or other artificial
drainage are not to be considered.

**Example: 1701021502**

**DS_HUC6**

Sixth Level Downstream Hydrologic Unit Code. This item represents the
hydrologic unit code of the 6th level hydrologic unit receiving the
majority of the downstream flow. Outlets created by ditching or other
artificial drainage are not to be considered.

**Example: 170102150106**

**HUC_MOD**

Hydrologic Unit Modifications- This item should contain information
about hydrologic unit modifications to natural overland flow (that
affect boundary) unique to the 5th or 6th field level unit delineated in
an area of interest.  This may include information on the type of
structure, date of construction or other features that may influence
surface water flow. In the attribute field, identify from most
significant to least significant modification(s).

**Example: SD**

> **Domain Value: SC\
> **Domain Value Definition: Stormwater Canal\
> **Domain Value: BC**\
> Domain Value Definition: Barge Canal\
> **Domain Value: PD**\
> Domain Value Definition: Pipe Diversion\
> **Domain Value: KA**\
> Domain Value Definition: Karst\
> **Domain Value: OC**\
> Domain Value Definition: Overflow Channel\
> **Domain Value: ID**\
> Domain Value Definition: Irrigation Ditch\
> **Domain Value: SD**\
> Domain Value Definition: Stormwater Ditch\
> **Domain Value: CD**\
> Domain Value Definition: Channel Diversion\
> **Domain Value: LE**\
> Domain Value Definition: Levee\
> **Domain Value: OT**\
> Domain Value Definition: Other
>
> **Domain Value: IT**\
> Domain Value Definition: Interbasin Transfer\
> **Domain Value: CB**\
> Domain Value Definition: Closed Basin\
> **Domain Value: NC\
> **Domain Value Definition: Non-Contributing\
> **Domain Value: NM**\
> Domain Value Definition: No Modifications

**COMMENTS**

Any additional information that pertains to the hydrologic unit\'s
history or general characteristics that cannot be adequately described
in previous items.

**Example: Waldo Lake**

**REGION**

1st Field Hydrologic Unit Code

**Example:17**

**SUBREGION**

2nd Field Hydrologic Unit Code

**Example:1701**

**BASIN**

3rd Field Hydrologic Unit Code

**Example: 170102**

**SUBASIN**

4th Field Hydrologic Unit Code

**Example: 17010215**

**WATERSHED**

5th Field Hydrologic Unit Code

**Example: 1701021501**

**SUBWAT**

6th Field Hydrologic Unit Code

**Example: 170102150104**

**CATCHMENT**

7th Field Hydrologic Unit Code

**Example: 170102150104XX**

**SUBCATCH**

8th Field Hydrologic Unit Code

**Example: 170102150104XXXX**

**FIRST_FIELD**

2-DIGIT IDENTIFIER

**Example: 17**

**SECOND_FIELD**

2-DIGIT IDENTIFIER

**Example: 01**

**THIRD_FIELD**

2-DIGIT IDENTIFIER

**Example: 02**

**FOURTH_FIELD**

2-DIGIT IDENTIFIER

**Example: 15**

**FIFTH_FIELD**

2-DIGIT IDENTIFIER

**Example: 01**

**SIXTH_FIELD**

2-DIGIT IDENTIFIER

**Example: 04**

**SEVENTH_FIELD**

2-DIGIT IDENTIFIER

**EIGHT_FIELD**

2-DIGIT IDENTIFIER

**Polygon Attribute Tables: Hydrologic Unit Polygons** Table Name:
HU_BOUNDARY.PATHUC1

(Distribution Coverage Only)

The following box lists the attribute items found in the
HU_BOUNDARY.PATHUC1 table. These attributes pertain to region features
depicting Level 1 Hydrologic Units. Attribute definitions already
included in the HU_BOUNDARY.PAT table have been omitted here and should
be referenced in pages 4-7 of this Data Dictionary.

[]{#refheading___toc31005053 .anchor}Hydrologic Unit Boundary HUC1
Region Attribute

  ---------------------------- ------------------------------------------
  **[ITEM NAME]{.underline}**  **[ITEM DESCRIPTION]{.underline}**

  AREA                         8,18,F,5

  PERIMETER                    8,18,F,5

  HUC1#                        4,5,B

  HUC1-ID                      4,5,B

  ACRES                        14,14,N,4

  REGION                       2, 2,C

  REGION_NAME                  30,30,C
  ---------------------------- ------------------------------------------

**HUC1#**

An internal region identifier; value is assigned by software.

**HUC1-ID**

Region identifier assigned by user. This item is not used, nor is it
changed. Presence is required by software.

**Polygon Attribute Tables: Hydrologic Unit Polygons** Table Name:
HU_BOUNDARY.PATHUC2

(Distribution Coverage Only)

The following box lists the attribute items found in the
HU_BOUNDARY.PATHUC2 table. These attributes pertain to region features
depicting Level 2 Hydrologic Units. Attribute definitions already
included in the HU_BOUNDARY.PAT table have been omitted here and should
be referenced in pages 4-7 of this Data Dictionary.

[]{#refheading___toc31005054 .anchor}Hydrologic Unit Boundary HUC2
Region Attributes

  ------------------------------------ ----------------------------------
  **[ITEM NAME]{.underline}**          **[ITEM DEFINITION]{.underline}**

  AREA                                 8,18,F,5

  PERIMETER                            8,18,F,5

  HUC2#                                4,5,B

  HUC2-ID                              4,5,B

  ACRES                                14,14,N,4

  SUBREGION                            4,4,C

  SUBREGION_NAME                       30,30,C
  ------------------------------------ ----------------------------------

**HUC2#**

An internal region identifier; value is assigned by software.

**HUC2-ID**

Region identifier assigned by user. This item is not used, nor is it
changed. Presence is required by software.

**Polygon Attribute Tables: Hydrologic Unit Polygons** Table Name:
HU_BOUNDARY.PATHUC3

(Distribution Coverage Only)

The following box lists the attribute items found in the
HU_BOUNDARY.PATHUC3 table. These attributes pertain to region features
depicting Level 3 Hydrologic Units. Attribute definitions already
included in the HU_BOUNDARY.PAT table have been omitted here and should
be referenced in pages 4-7 of this Data Dictionary.

[]{#refheading___toc31005055 .anchor}Hydrologic Unit Boundary HUC3
Region Attributes

  ------------------------------------- ---------------------------------
  **[ITEM NAME]{.underline}**           **[ITEM DEFINITION]{.underline}**

  AREA                                  8,18,F,5

  PERIMETER                             8,18,F,5

  HUC3#                                 4,5,B

  HUC3-ID                               4,5,B

  ACRES                                 14,14,N,4

  BASIN                                 6,6,C

  BASIN_NAME                            30,30,C
  ------------------------------------- ---------------------------------

**HUC3#**

An internal region identifier; value is assigned by software.

**HUC3-ID**

Region identifier assigned by user. This item is not used, nor is it
changed. Presence is required by software.

**Polygon Attribute Tables: Hydrologic Unit Polygons** Table Name:
HU_BOUNDARY.PATHUC4

(Distribution Coverage Only)

The following box lists the attribute items found in the
HU_BOUNDARY.PATHUC4 table. These attributes pertain to region features
depicting Level 4 Hydrologic Units. Attribute definitions already
included in the HU_BOUNDARY.PAT table have been omitted here and should
be referenced in pages 4-7 of this Data Dictionary.

Hydrologic Unit Boundary HUC4 Region Attributes

  --------------------------------- -------------------------------------
  **[ITEM NAME]{.underline}**       **[ITEM DEFINITION]{.underline}**

  AREA                              8,18,F,5

  PERIMETER                         8,18,F,5

  HUC4#                             4,5,B

  HUC4-ID                           4,5,B

  ACRES                             14,14,N,4

  SUBBASIN                          8,8,C

  SUBBASIN_NAME                     30,30,C
  --------------------------------- -------------------------------------

**HUC4#**

An internal region identifier; value is assigned by software.

**HUC4-ID**

Region identifier assigned by user. This item is not used, nor is it
changed. Presence is required by software.

**Polygon Attribute Tables: Watershed Polygons** Table Name:
HU_BOUNDARY.PATHUC5

(Distribution Coverage Only)

The following box lists the attribute items found in the
HU_BOUNDARY.PATHUC5 table. These attributes pertain to region features
depicting Level 5 Hydrologic Units. Attribute definitions already
included in the HU_BOUNDARY.PAT table have been omitted here and should
be referenced in pages 4-7 of this Data Dictionary.

[]{#refheading___toc31005056 .anchor}Watershed Boundary HUC5 Region
Attributes

  ---------------------------------- ------------------------------------
  **[ITEM NAME]{.underline}**        **[ITEM DESCRIPTION]{.underline}**

  AREA                               8,18,F,5

  PERIMETER                          8,18,F,5

  HUC5#                              4,5,B

  HUC5-ID                            4,5,B

  ACRES                              14,14,N,4

  WATERSHED                          10,10,C

  WATERSHED_NAME                     80,80,C

  DS_HUC5                            10,10,C
  ---------------------------------- ------------------------------------

**HUC5#**

An internal region identifier; value is assigned by software.

**HUC5-ID**

Region identifier assigned by user. This item is not used, nor is it
changed. Presence is required by software.

**Polygon Attribute Tables: Hydrologic Unit Polygons** Table Name:
HU_BOUNDARY.PATHUC6

(Distribution Coverage Only)

The following box lists the attribute items found in the
HU_BOUNDARY.PATHUC6 table. These attributes pertain to region features
depicting Level 6 Hydrologic Units. Attribute definitions already
included in the HU_BOUNDARY.PAT table have been omitted here and should
be referenced in pages 4-7 of this Data Dictionary.

[]{#refheading___toc31005057 .anchor}Hydrologic Unit Boundary HUC6
Region Attributes

  -------------------------------- --------------------------------------
  **[ITEM NAME]{.underline}**      **[ITEM DEFINITION]{.underline}**

  AREA                             8,18,F,5

  PERIMETER                        8,18,F,5

  HUC6#                            4,5,B

  HUC6-ID                          4,5,B

  ACRES                            14,14,N,4

  SUBWAT                           12,12,C

  SUBWAT_NAME                      80,80,C

  DS_HUC6                          12,12,C
  -------------------------------- --------------------------------------

**HUC6#**

An internal region identifier; value is assigned by software.

**HUC6-ID**

Region identifier assigned by user. This item is not used, nor is it
changed. Presence is required by software.

**Polygon Attribute Tables: Hydrologic Unit Polygons** Table Name:
HU_BOUNDARY.PATHUC7

(Distribution Coverage Only)

The following box lists the attribute items found in the
HU_BOUNDARY.PATHUC7 table. These attributes pertain to region features
depicting Level 7 Hydrologic Units. Attribute definitions already
included in the HU_BOUNDARY.PAT table have been omitted here and should
be referenced in pages 4-7 of this Data Dictionary.

[]{#refheading___toc31005058 .anchor}Hydrologic Unit Boundary HUC7
Region Attributes

  ---------------------------------- ------------------------------------
  **[ITEM NAME]{.underline}**        **[ITEM DEFINITION]{.underline}**

  AREA                               8,18, F, 5

  PERIMETER                          8,18,F,5

  HUC7#                              4,5,B

  HUC7-ID                            4,5,B

  ACRES                              14,14,N,4

  CATCHMENT                          14,14,C

  CATCHMENT_NAME                     80,80,C
  ---------------------------------- ------------------------------------

**HUC7#**

An internal region identifier; value is assigned by software.

**HUC7-ID**

Region identifier assigned by user. This item is not used, nor is it
changed. Presence is required by software.

**Polygon Attribute Tables: Watershed Polygons** Table Name:
HU_BOUNDARY.PATHUC8

(Distribution Coverage Only)

The following box lists the attribute items found in the
HU_BOUNDARY.PATHUC8 table. These attributes pertain to region features
depicting Level 8 Hydrologic Units. Attribute definitions already
included in the HU_BOUNDARY.PAT table have been omitted here and should
be referenced in pages 4-7 of this Data Dictionary.

Watershed Boundary HUC8 Region Attributes

  ------------------------------- ---------------------------------------
  **[ITEM NAME]{.underline}**     **[ITEM NAME]{.underline}**

  AREA                            8,18,F,5

  PERIMETER                       8,18,F,5

  REOHUC_V13#                     4,5,B

  REOHUC_V13-ID                   4,5,B

  ACRES                           14,14,N,4

  SUBCATCH                        16,16,C

  SUBCATCH_NAME                   80,80,C
  ------------------------------- ---------------------------------------

**HUC8#**

An internal region identifier; value is assigned by software.

**HUC8-ID**

Region identifier assigned by user. This item is not used, nor is it
changed. Presence is required by software.

[]{#__RefHeading___Toc31005059 .anchor}**Arc Lines Description**

![](media/image2.jpeg){width="6.488194444444445in"
height="3.847916666666667in"}

Example Explanation: In the example above, line segments that are only
coded with the largest hydrologic unit line classification. In cases
where a line segment is simultaneously shared between a 2nd level and a
5th level units, the line is coded with a "2." Where a line segment is
shared between a 5th, 6th, and 7th level units, the line is given the
code of "5", and so on. When 8th level units are eventually delineated,
the same process described above should be applied.

This coverage is in a regions (ESRI) format; therefore, this coverage
simultaneously holds boundary lines ranging from 1st through 8th level
hydrologic units, many boundary lines are shared between different
hydrologic unit classifications.

[]{#__RefHeading___Toc31005060 .anchor}**Arc Attribute Table: Hydrologic
Unit Polygons** Name: HU_BOUNDARY.AAT

(Distribution Coverage Name)

**HUMM/DD/YY.AAT**

Example: HU082203.AAT

(Maintenance Coverage Name)

*Arc Attribute Table:*

+--------------------------------------+-------------------------------+
| **[ITEM NAME]{.underline}**          | **[ITEM                       |
|                                      | DEFINITION]{.underline}**     |
+--------------------------------------+-------------------------------+
| FNODE#                               | 4,5,B                         |
+--------------------------------------+-------------------------------+
| TNODE#                               | 4,5,B                         |
+--------------------------------------+-------------------------------+
| LPOLY#                               | 4,5,B                         |
+--------------------------------------+-------------------------------+
| RPOLY#                               | 4,5,B                         |
+--------------------------------------+-------------------------------+
| LENGTH                               | 8,18,F                        |
+--------------------------------------+-------------------------------+
| HU_BOUNDARY#                         | 4,5,B                         |
|                                      |                               |
| (or HU\<mmddyy\>#)                   |                               |
+--------------------------------------+-------------------------------+
| HU_BOUNDARY --ID                     | 4,5,B                         |
|                                      |                               |
| (or HU\<mmddyy\>-ID)                 |                               |
+--------------------------------------+-------------------------------+
| HUC_LEVEL                            | 1,1,I                         |
+--------------------------------------+-------------------------------+
| LINESOURCE                           | 20,20,C                       |
+--------------------------------------+-------------------------------+
| LINEVER                              | 1,1,C                         |
+--------------------------------------+-------------------------------+
| LINEDATE                             | 10,10,C                       |
+--------------------------------------+-------------------------------+
| LINEORG                              | 10,10,C                       |
+--------------------------------------+-------------------------------+
| METADATA_ID                          | 1,1,I                         |
+--------------------------------------+-------------------------------+
| COMMENTS                             | 100,100,C                     |
+--------------------------------------+-------------------------------+

**FNODE#**

An internal node identifier; value is assigned by software.

**TNODE#**

An internal node identifier; value is assigned by software.

**LPOLY#**

An internal polygon identifier; value is assigned by software.

**RPOLY#**

An internal polygon identifier; value is assigned by software.

**LENGTH**

Length of feature in coverage units; value is assigned by software.

**Example: 1 meter**

**HU_BOUNDARY# (or HU\<mmddyy\>#)**

An internal arc identifier; value is assigned by software.

**HU_BOUNDARY-ID (or HU\<mmddyy\>-ID)**

Arc identifier assigned by user. This item is not used, nor is it
changed. Presence is required by software.

**HUC_LEVEL**

This item is used to identify the hydrologic unit groupings a given line
segment belongs to. This item is used to identify the hydrologic unit
groupings a given line segment belongs to. Primary order is always 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 level
unit and a 6th level unit, the line receives a code of 5).

**Example: 5**

> **Domain Value: 1\
> **Domain Value Definition: 1st Level Unit Boundary\
> **Domain Value: 2**\
> Domain Value Definition: 2nd Level Unit Boundary, NOT Shared with a
> 1st Level Unit Boundary\
> **Domain Value: 3**\
> Domain Value Definition: 3rd Level Unit Boundary, NOT Shared with 1st
> or 2nd Level Unit Boundary\
> **Domain Value: 4**\
> Domain Value Definition: 4th Level Unit Boundary, NOT Shared with
> 1st - 3rd Level Unit Boundary\
> **Domain Value: 5**\
> Domain Value Definition: 5th Level Unit Boundary, NOT Shared with
> 1st - 4th Level Unit Boundary\
> **Domain Value: 6**\
> Domain Value Definition: 6th Level Unit Boundary, NOT Shared with
> 1st - 5th Level Unit Boundary\
> **Domain Value: 7**\
> Domain Value Definition: 7th Level Unit Boundary, NOT Shared with
> 1st - 6th Level Unit Boundary\
> **Domain Value: 8**\
> Domain Value Definition: 8th Level Unit Boundary, NOT Shared with
> 1st - 7th Level Unit Boundary

**LINESOURCE**

Information related to the original spatial data source from which the
boundary line was derived. This item captures information related to the
original spatial data source from which the boundary line was derived.
In determining which code to use, preference should be given to the
primary source employed to determine the boundary lines position. All
line segments should be broken with a node where line sources change.
The linesource domain value is case sensitive and must be entered in
lowercase.

**Example: drg24**

> **Domain Value: drg24\
> **Domain Value Definition: USGS 1:24,000 Digital Raster Graphics
> (DRG)\
> **Domain Value: tvc23**\
> Domain Value Definition: USGS 1:24,000 Tagged Vector Contours (TVC)\
> **Domain Value: dem10**\
> Domain Value Definition: Derived from 10 Meter Digital Elevation Model
> (Surface modeling)\
> **Domain Value: dem30**\
> Domain Value Definition: Derived from 30 Meter Digital Elevation Model
> (Surface modeling)\
> **Domain Value: dlg**\
> Domain Value Definition: USGS Digital Line Graph\
> **Domain Value: ortho**\
> Domain Value Definition: orthophotography
>
> **Domain Value: unk**\
> Domain Value Definition: Unknown

**LINEVER**

Line Edit Verification. Indicates which level in a series of quality
control checks the hydrologic boundary has undergone prior to being
accepted as part of the finalized dataset. \* Only verification levels
of 4 and 5 are included in the regional dataset. This item may be used
in local offices to track the progress of edits as organizations
delineate new hydrologic units and move toward regional and national
certification of those units.

**Example: 2**

> **Domain Value: 1\
> **Domain Value Definition: Initial Draft Line\
> **Domain Value: 2**\
> Domain Value Definition: Line accuracy certified by local hydrologist\
> **Domain Value: 3**\
> Domain Value Definition: Line accuracy certified by ALL local
> participating organizations\
> **Domain Value: 4**\
> Domain Value Definition: Line accuracy certified by Pacific Northwest
> stewards\
> **Domain Value: 5**\
> Domain Value Definition: Line accuracy certified by National stewards

**LINEDATE**

Date that the last line edit was performed. This item is used to record
the last date a spatial edit was performed to a given line segment. The
format should be in: YYYY/MM/DD.

**Example: 2002/11/15**

**LINEORG**

The organization who performed the last spatial edit to a given line
segment. This item 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 may
have a different organization code. The codes are to be applied to
individual line segments, not hydrologic unit polygons. The Lineorg
domain value is case sensitive and must be entered in lowercase.

**Example: usblm-eug**

> **Domain Value: bcmelp**
>
> Domain Value Definition: British Columbia Ministry of Environment
> Lands and Parks
>
> **Domain Value: caspam**
>
> Domain Value Definition: California Sierra Province Area Management
>
> **Domain Value: calwater**
>
> Domain Value Definition: The California Interagency Watershed Mapping
> Committee
>
> **Domain Value: clams**
>
> Domain Value Definition: Coastal Landscape Analysis and Modeling Study
>
> **Domain Value: coclrkwa**
>
> Domain Value Definition: Clark County WA
>
> **Domain Value: cokingwa**
>
> Domain Value Definition: King County WA
>
> **Domain Value: copierwa**
>
> Domain Value Definition: Pierce County WA
>
> **Domain Value: cosnohwa**
>
> Domain Value Definition: Snohomish County WA
>
> **Domain Value: cospokwa**
>
> Domain Value Definition: Spokane County WA
>
> **Domain Value: cothurswa**
>
> Domain Value Definition: Thurston County WA
>
> **Domain Value: coyakwa**
>
> Domain Value Definition: Yakima County WA
>
> **Domain Value: ctyolywa**
>
> Domain Value Definition: City of Olympia WA
>
> **Domain Value: ctyseawa**
>
> Domain Value Definition: City of Seattle WA
>
> **Domain Value: ctyvanwa**
>
> Domain Value Definition: City of Vancouver WA
>
> **Domain Value: id**
>
> Domain Value Definition: Idaho
>
> **Domain Value: lvwfbr**
>
> Domain Value Definition: Longview Fiber Company
>
> **Domain Value: nwifc**
>
> Domain Value Definition: Northwest Indian Fisheries Commission
>
> **Domain Value: ordeq**
>
> Domain Value Definition: OR Dept. of Environmental Quality
>
> **Domain Value: ordf**
>
> Domain Value Definition: Oregon Dept. of Forestry
>
> **Domain Value: ordwr**
>
> Domain Value Definition: Oregon Dept. of Water Resources
>
> **Domain Value: orit**
>
> Domain Value Definition: Oregon Institute of Technology
>
> **Domain Value: psrc**
>
> Domain Value Definition: Puget Sound Regional Council
>
> **Domain Value: raynr**
>
> Domain Value Definition: ITT Rayonier
>
> **Domain Value: reo**
>
> Domain Value Definition: HUC 5 lines used as a starting basis
>
> **Domain Value: smpsn**
>
> Domain Value Definition: Simpson Timber Company
>
> **Domain Value: titan**
>
> Domain Value Definition: Titan Geospatial
>
> **Domain Value: unknown**
>
> Domain Value Definition: Unknown or unclassified input organization
>
> **Domain Value: usace**
>
> Domain Value Definition: U.S. Army Corps of Engineers
>
> **Domain Value: usblm**
>
> Domain Value Definition: U.S. Bureau of Land Management
>
> **Domain Value: usblm-bns**
>
> Domain Value Definition: U.S. Bureau of Land Management - Burns
> District
>
> **Domain Value: usblm-cby**
>
> Domain Value Definition: U.S. Bureau of Land Management - Coos Bay
> District
>
> **Domain Value: usblm-eug**
>
> Domain Value Definition: U.S. Bureau of Land Management - Eugene
> District
>
> **Domain Value: usblm-lak**
>
> Domain Value Definition: U.S. Bureau of Land Management - Lakeview
> District
>
> **Domain Value: usblm-med**
>
> Domain Value Definition: U.S. Bureau of Land Management - Medford
> District
>
> **Domain Value: usblm-oso**
>
> Domain Value Definition: U.S. Bureau of Land Management - Oregon State
> Office
>
> **Domain Value: usblm-pri**
>
> Domain Value Definition: U.S. Bureau of Land Management - Prineville
> District
>
> **Domain Value: usblm-rsb**
>
> Domain Value Definition: U.S. Bureau of Land Management - Roseburg
> District
>
> **Domain Value: usblm-slm**
>
> Domain Value Definition: U.S. Bureau of Land Management - Salem
> District
>
> **Domain Value: usblm-spo**
>
> Domain Value Definition: U.S. Bureau of Land Management - Spokane
> District
>
> **Domain Value: usblm-val**
>
> Domain Value Definition: U.S. Bureau of Land Management -- Vale
> District
>
> **Domain Value: usbor**
>
> Domain Value Definition: U.S. Bureau of Reclamation
>
> **Domain Value: usbpa**
>
> Domain Value Definition: U.S. Bonneville Power Administration
>
> **Domain Value: usepa**
>
> Domain Value Definition: U.S. Environmental Protection Agency
>
> **Domain Value: usepa-r10**
>
> Domain Value Definition: U.S. Environmental Protection Agency - Region
> 10
>
> **Domain Value: usfs**
>
> Domain Value Definition: U.S. Forest Service
>
> **Domain Value: usfs-col**
>
> Domain Value Definition: U.S. Forest Service - Colville NF
>
> **Domain Value: usfs-des**
>
> Domain Value Definition: U.S. Forest Service - Deschutes NF
>
> **Domain Value: usfs-fre**
>
> Domain Value Definition: U.S. Forest Service - Freemont NF
>
> **Domain Value: usfs-gip**
>
> Domain Value Definition: U.S. Forest Service - Gifford Pinchot NF
>
> **Domain Value: usfs-gstc**
>
> Domain Value Definition: U.S. Forest Service - Geospatial Service and
> Technology Center
>
> **Domain Value: usfs-kla**
>
> Domain Value Definition: U.S. Forest Service - Klamath NF
>
> **Domain Value: usfs-mal**
>
> Domain Value Definition: U.S. Forest Service - Malheur NF
>
> **Domain Value: usfs-mbs**
>
> Domain Value Definition: U.S. Forest Service - Mt. Baker-Snoqualmie NF
>
> **Domain Value: usfs-mth**
>
> Domain Value Definition: U.S. Forest Service - Mt. Hood NF
>
> **Domain Value: usfs-och**
>
> Domain Value Definition: U.S. Forest Service - Ochoco NF
>
> **Domain Value: usfs-oka**
>
> Domain Value Definition: U.S. Forest Service - Okanogan NF
>
> **Domain Value: usfs-oly**
>
> Domain Value Definition: U.S. Forest Service - Olympic NF
>
> **Domain Value: usfs-sis**
>
> Domain Value Definition: U.S. Forest Service - Siskiyou NF
>
> **Domain Value: usfs-siu**
>
> Domain Value Definition: U.S. Forest Service - Siuslaw NF
>
> **Domain Value: usfs-six**
>
> Domain Value Definition: U.S. Forest Service -- Six Rivers NF
>
> **Domain Value: usfs-uma**
>
> Domain Value Definition: U.S. Forest Service - Umatilla NF
>
> **Domain Value: usfs-ump**
>
> Domain Value Definition: U.S. Forest Service - Umpqua NF
>
> **Domain Value: usfs-waw**
>
> Domain Value Definition: U.S. Forest Service - Wallowa-Whitman NF
>
> **Domain Value: usfs-wen**
>
> Domain Value Definition: U.S. Forest Service - Wenatchee NF
>
> **Domain Value: usfs-wil**
>
> Domain Value Definition: U.S. Forest Service - Willamette NF
>
> **Domain Value: usfs-win**
>
> Domain Value Definition: U.S. Forest Service - Winema NF
>
> **Domain Value: usfws**
>
> Domain Value Definition: U.S. Fish and Wildlife Service
>
> **Domain Value: usgs**
>
> Domain Value Definition: U.S. Geological Survey
>
> **Domain Value: usgs-nmd**
>
> Domain Value Definition: U.S. Geological Survey - National Mapping
> Division
>
> **Domain Value: usnmfs**
>
> Domain Value Definition: U.S.National Marine Fisheries Service
>
> **Domain Value: usnps**
>
> Domain Value Definition: U.S. National Park Service
>
> **Domain Value: usnrcs**
>
> Domain Value Definition: Natural Resources Conservation Service
>
> **Domain Value: wadfw**
>
> Domain Value Definition: Washington Department of Fish and Wildlife
>
> **Domain Value: wadnr**
>
> Domain Value Definition: Washington State Department of Natural
> Resources
>
> **Domain Value: wadot**
>
> Domain Value Definition: Washington Department of Transportation
>
> **Domain Value: waecy**
>
> Domain Value Definition: Washington Department of Ecology
>
> **Domain Value: weyhsr**
>
> Domain Value Definition: Weyerhaeuser Company

**METADATA_ID**

Metadata ID is a code that identifies which metadata file applies to the
arc. In many cases, there is 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.

**Example: Record Sequence Number**

**COMMENTS**

This item may include any additional information that pertains to the
hydrologic unit's history or general characteristics that cannot be
adequately described in previous items.

Example: STILL NEEDS VERIFICATION