1. Introduction

The U.S. Geological Survey (USGS) in Portland, in cooperation with Bonneville Power Administration, the Northwest Power Planning Council, and other Federal and state agencies and NW Indian Tribes produced a 1:100,000-scale River Reach data layer for the Pacific Northwest in the early 1990s. The Pacific Northwest (PNW) River Reach Files are a geo-referenced river reach data layer that encompasses the Columbia River Basin within the conterminous United States, the coasts of Oregon and Washington, Puget Sound in Washington, the Klamath and Goose Lake Basins in southern Oregon and the Bear Lake Basin in southeastern Idaho. The system is basically a 1:100,000 scale enhancement of the pre-existing 1:250,000 scale EPA River Reach File 2 (RF2).

This process was a primary task of the PNW River Reach Project because these reach identifiers are an integral hydrologic component in a regional rivers and fisheries information system now known as StreamNet (formerly the Coordinated Information System (CIS) and the Northwest Environmental Database (NED)). StreamNet is an ongoing effort by federal, state, and tribal organizations within the region to compile reach and stream specific information pertinent to the Region’s fish and wildlife resources in Oregon, Idaho, Washington, and Montana. The PNW Reach Files carry the U.S. Environmental Protection Agency's (US EPA) river reach numbers. The system was transferred over to the StreamNet project at Pacific States Marine Fisheries Commission (PSMFC) in early 1997 for maintenance, enhancement, and distribution. PSMFC is also the lead contractor responsible for supervising the integration and conversion of the PNW Reach Files into the new National Hydrography Dataset.

1.1 Methodology The PNW River Reach Files were constructed using ARC/INFO versions 4.0 and 5.0. A unique conflation algorithm was developed by the USGS that transferred the reach identifiers from the RF2 to the new 1:100,000-scale hydrography. The 1:100,000-scale hydrography were constructed from scanned 1:24,000 and 1:63,000-scale separates and then edited. Most, but not all hydrographic features found on these two larger scale products will be found in the PNW Reach Files. The PNW Reach Files are a linked stream network. ARC:NETWORK utilities were used on the Reach Files to provide attribute information that would allow a user to perform directional routing upstream or downstream from a given starting point using either a GIS or by using items, such as UPLINK1,2,3 PNTR# and DOWNLINK found in the Arc Attribute Table. Water body features such as lakes, reservoirs, defined wetlands, double-banked streams, and others were moved to a separate 'banks' coverage and represented in the Reach File with centerlines and tributary connectors arcs. Reach files are organized by USGS hydrologic unit codes (HUCs - also known as cataloging units) and are designed to provide users with a 1:100,000-scale reach structure for performing various types of hydrologic applications. Every reach in the Reach File has been assigned a unique but stable reach identifier (17 character river reach number comprised of the 8 digit HUC, the 4 digit segment number (SEG), and the 5 digit reach mile point). New reaches in the system were numbered starting with SEG = 500 providing a unique way to locate all new arcs in the system. The following is a generalized list of procedures followed to construct the PNW River Reach Files. The USGS Open File report mentioned in the .DOC will include all of the processing macros written to assist in the Reach File development.

Generalized procedures for constructing 100K scale Reach Files

   1.  Read 100K hydrography DLG's for each map into GIS.

   2.  Edgematch north and west edges of each map to adjacent 100K quads.

   3.  CLIP each 100K quad with adjusted Hydrologic Unit boundary.

   4.  APPEND clipped quad pieces together.

   5.  Correct internal node errors using automated snapping.

   6.  Remove non-attributed pseudo nodes.

   7.  Copy polygons to Waterbody coverage.

   8.  Edit out double-banked streams, shorelines,and braided areas and

       put into Water bodies coverage.

   9.  Add centerlines through waterbodies and wide streams and connector

       arcs from centerlines to tributaries.

   10. Create Trace coverage from EPA Reach File.

   11. Edit Trace, correcting stream names and topologic structure where

   12. Adjust Trace segment endpoints to align with corresponding 100K

       endpoint.

   13. CONFLATE (Transfer) Trace-ID from Trace reaches to corresponding

       reaches in 100K coverage.

   14. Make check plots to verify results of conflation.

   15. Transfer EPA extended attributes (SEG, LEVEL, SEQNUM, FLAG) to

       100K reaches.

   16. Assign unconflated 100K reaches a provisionary reach code.

   17. Move provisionary codes to SEG.

   18. Add State, County, and quad boundary items to reaches in 100K-scale

       Reach File.

   19. Compute sinuosity for each reach.

   20. Block man-made waterways, braided reaches, and other features

       determined as not part of the basin network by calculating

       their LENGTH item to negative.

   21. Determine allocation centers. Usually mouth of basin.

   22. ALLOCATE from centers.

   23. WRITEALLOCATION ROUTING results to Reach File Arc Attribute Table.

   24. Use DIRECTION item to flip reaches to flow in a downstream direction

   25. Calculate PNTR# to internal record number of Arc Attribute Table

   26. Unblock previously blocked arcs.

   27. Calculate river mile for allocated reaches.

   28. Compute upstream linkage. INFO program.

   29. Order attributes in Reach Files and Water bodies coverage for

       consistency among Files.

   30. Check Reach File using checking programs.

   31. Manually add  Northwest Power Planning Council reach codes, stream

       names and river miles.

   32. Run final check programs

   33. Archive Reach Files.

   34. Distribute to states for review.

1.2 New Features

PSMFC has, via the StreamNet project, made several major enhancements in the PNW River Reach file which are now incorporated in the system. The major enhancement has been the addition of a new attribute which allows the for the development and use of a stream based routing system.

The impetus and methodology for deriving the new stream based identifier was developed by an interagency committee that was formed under the President’s 1993 Forest Plan. The Interorganizational Resource Information Coordinating Council (IRICC), comprised of representatives from federal, state, tribal, and local entities, was tasked with developing data standards that could be used across agency boundaries that would facilitate implementation of the Forest Plan. They recognized that for stream related data, a comprehensive and regionally standard hydrologic system was necessary to ensure that data could be readily collected and shared between agencies. They further recognized that the utility of such a system would be greatly enhanced if a method for identifying a given stream within the hydrologic coverage was available. After looking at the various options available in the region, the IRICC group officially adopted the PNW Reach File system as the base hydrologic layer and developed a new attribute called the Longitude/ Latitude ID (LLID) for use in uniquely identifying streams.. This attribute consists of the longitude and latitude of the mouth of the stream. All reaches (or arcs) that comprise a given stream were to be assigned a unique LLID. Longitude would precede latitude to conform with standard x,y ordering. The code will be 13 characters long, with 7 for decimal degrees of longitude and 6 for decimal degrees of latitude, with implied decimal points.

After the IRICC decision, a fast track effort was put in place to add the new LLID field to the PNW Reach File and this effort is largely complete (all streams in OR and WA, all named streams in ID and MT). In the PNW Reach File a stream is defined a series of contiguous arcs comprising a waterway with identical values in the FEAT_NAME field. Only arcs representing the transport path of water (stream, braided stream, some canals, and centerlines and connector arcs within lakes and reservoirs) with a SAVENEG value of NO were included. For features that were unnamed, stream ID’s were applied visually using best professional judgment.

StreamNet has used the new LLID as the basis for building a regionally consistent stream routing system. By using this routing system, one can exploit the benefits of ArcInfo’s dynamic segmentation, including the use of event tables for data collection and sharing. We believe this is a significant enhancement to the reach file which will greatly facilitate its use.

Other enhancements made include the addition of an open water name field (OW_NAME) that has been populated, where possible, with the name of the reservoir or lake in which the centerline of a given stream lies. The FEAT_NAME field is then reserved for the name of the stream or river. Three additional fields were added in order to facilitate more straightforward use and queries of the USGS minor code fields. We found that the population of these fields (MINOR1, MINOR2, MINOR3) by all of the various entities who worked on the reach file over the years was inconsistent making it very difficult to find certain arc types (for example, all centerline arcs within reservoirs). By generalizing the minor coding into 3 new fields (PRIMARY, SECONDARY, and DESCRIPTOR) we feel we have added some new flexibility in finding certain reach types.

The PRIMARY attribute is non-null item that provides a generalized description of the arc type.

Codes, description and approximate arc counts are shown here:

Code
	

Description
	

Count

101
	

Reservoir
	

2178

199
	

Island
	

68

200
	

Shoreline (Pacific Coast)
	

1283

412
	

Stream
	

247402

413
	

Braided Stream
	

8324

414
	

Ditch or canal
	

14342

415
	

Aquaduct
	

395

416
	

Flume
	

13

417
	

Penstock
	

9

418
	

Siphon
	

100

420
	

Wash or ephemeral drain
	

25

421
	

Lake or pond
	

6558

The SECONDARY attribute is non-null item that differentiates between a normal 1-d feature (code 0), centerlines (999), and pigtails (990), as well as several misc. circumstances.

Code
	

Description
	

Count

0
	

N/A
	

249925

202
	

Closure Line (water-water)
	

1202

204
	

Apparent Limit
	

13

990
	

Connector Arc
	

8955

998
	

Added arc to connect lines at map boundaries
	

383

999
	

Centerline
	

20219

The DESCRIPTOR attribute is non-null item that provides additional information about the arc. For example, a primary type of 200 (shoreline) may have a descriptor of 116 (bay).

Code
	

Description
	

Count

0
	

N/A
	

171565

105
	

Inundation area
	

46

111
	

Marsh- wetland- swamp- bog
	

1008

116
	

Bays- estuaries- gulfs- oceans- seas
	

1451

601
	

Underground
	

193

602
	

Overpassing
	

50

603
	

Elevated
	

6

604
	

Tunnel
	

44

610
	

Intermittent
	

105399

614
	

Dry
	

7

617
	

Underpassing
	

928
  	  	 

A new minor code was added in Version 2.3 of the 100k Reach Files. Named MINOR5, it is found in the .dat file associated with the ARC/INFO exported coverages, and related to the .aat files through the RRN attribute. MINOR5 is a number describing a reach's order within a route, meaning that the reach most downstream of all members of a route has a value MINOR5 = 1, and for the most upstream reach MINOR5 = (n) where n is the total number of reaches comprising the route. The other reaches have MINOR5 values increasing relative to their order from the confluence reach. This attribute can be used to rebuild routes in the correct direction, as well as to navigate the reaches to determine up and downstream linking.

1.3 Descriptors:


River Reach File, Hydrography, Catalog Unit, Hydrologic Unit, 100K-scale, LLID


2. PNW Reach File Applications

2.1 Intended use of data

Many different types of GIS analysis can be performed on the Reach Files. These might include buffering around reaches, stream network routing, basin characteristics analysis or dynamic segmentation. Furthermore, the system provides an ideal environment for storing, organizing, and displaying stream related fisheries and habitat data.

2.2 Limitations of data
The PNW River Reach Files were compiled from 1:100,000-scale Digital Line Graphs for hydrography, which were constructed from scanned 1:24,000 and 1:63,000-scale separates and then edited. The county boundaries coverage was at 1:500,000-scale. This lower resolution may have caused some reaches to be incorrectly coded for COUNTY and COUNTY-2. Not all stream reaches have been named. None of the water body features were named or coded with a unique identifier. Stream ID’s (LLID) have only been assigned to named streams in Oregon, Washington, Idaho, and Montana, and unnamed streams in Oregon and Washington.

3. PNW River Reach File Data Dictionary

3.1 STR100-PNW.AAT


Following is a description of attributes for a given reach in the Arc Attribute Table:

File name: [PNWRRF].AAT

ATTRIBUTE NAME  DESCRIPTION

------------------------------------------------------------------------------

FNODE#          ARC attribute - downstream node number

TNODE#          ARC attribute - upstream node number

LPOLY#          ARC attribute - identifies polygon number to the left of

                the arc when polygon topology has been computed.

RPOLY#          ARC attribute - identifies polygon number to the right of

                the arc when polygon topology has been computed.

LENGTH          Arc length in feet.


STR100-PNW# ARC attribute - internal record number.
STR100-PNW-ID ARC attribute - assignable User-ID number
MAJOR1 NMD DLG base category identifier. 50 identifies feature as
hydrography.
MINOR1 NMD feature classifier. 412 identifies the feature as a stream
999 was used to indicate artificial features such as center-
MINOR2 NMD feature classifier. Descriptive code of 610 identifies
the featurestream, (412) as intermittent.
MINOR3 NMD feature classifier. Rarely used for hydrography. Code
of 111111 was used to indicate outlet reach for the basin,
888888 indicated headwater reach.
HUC 8 digit USGS Hydrologic Unit Code number.
SEG Reach segment number.
RMI River Mile marker. Distance in miles. Lowest reach of each unique
SEG number has an RMI value of 00.00.
FEAT_NAME Hydrographic feature name. Sources for stream names were from

USEPA 1:250,000 scale Trace graphic files, 1:100,000-scale

manuscripts, and NMD Geographic Names database.
Additional stream names were added from available map

resources.
FEAT_SRC Source of hydrographic feature.
A1 - Origin of feature was from NMD 1:100,000-scale DLG,
A2 - digitized from 1:100,000-scale manuscript,
A9 - manually added feature using GIS editor.
B1 - Origin was from NMD 1:24,000-scale DLG,
B2 - feature was digitized from 1:24,000-scale manuscript,
* note: these codes can be expanded to include features
obtained from larger scale maps or GPS acquired data.
STATE Predominant state that a particular reach falls within.
STATE-2 Second most predominant state a particular reach falls
within.
COUNTY Predominant county a particular reach falls within.
COUNTY-2 Second most predominant county a particular reach falls
within.
QUAD100 Predominant 1:100,000-scale quad a particular reach falls
within.
QUAD100-2 Second most predominant quad particular reach falls within .
QUAD75 Predominant 1:24,000-scale quad a particular reach falls
within.
QUAD75-2 Second most predominant quad a particular reach falls
within .
CEN Node number of allocation center a reach was allocated from.
Non -Allocated reaches have a CEN value of 0.
Results from ALLOCATE can be displayed in ARCPLOT.
CUMLENGTH Cumulative length of arcs traversed from any allocation
center.
DNARC Down arc. The internal record number (cover#) of the
previously allocated arc.
PNTR# A record of the order of the Arc Attribute Table at the time
SAVENEG Flag item that preserves a record of the features that were
blocked prior to ALLOCATION.
Value of 1 means a feature has been blocked.
SINUOUS Ratio of the true distance of a reach over its straight line
UHUC1 Hydrologic Unit Code number of the first upstream reach for
a particular reach.
UPNTR1 Pointer number (PNTR#) of first upstream reach.
UHUC2 Hydrologic Unit Code number of the second upstream reach for
a particular reach.
UPNTR2 PNTR# of second upstream reach.
UHUC3 Hydrologic Unit Code number of the third upstream reach for
a particular reach.
UPNTR3 PNTR# of third upstream reach
UFLAG Flag item to indicate the presence of a fourth upstream
reach for a particular reach. If true, UFLAG is set to 1.
DHUC Hydrologic Unit Code number of downstream reach.
DPNTR PNTR# of downstream reach.
CSEG Northwest Power Planning Council (NPPC) added reach code.
CRMI River mile designation assigned to NPPC reaches.
CNAME Stream name of NPPC reaches.
RRN Unique River Reach Number
LLID Item used to group arc’s into distinct routes based on
FEAT_NAME (see discussion above)
OW_NAME open water feature name of centerline arcs within large
water bodies (see discussion above)
PRIMARY aggregation of minor codes (see discussion above)
SECONDARY aggregation of minor codes (see discussion above)
DESCRIPTOR aggregation of minor codes (see discussion above)

------------------------------------------------------------------------------

Following is a list of items contained in the water body Polygon Attribute and Arc Attribute Tables:

File name: BANKS-PNW.PAT

ITEM            DESCRIPTION

AREA            ARC attribute. Area of a polygon in map units.

PERIMETER       ARC attribute. Perimeter of a polygon in map units.

BANKS-PNW#      ARC attribute. Polygon internal number.

BANKS-PNW-ID    ARC attribute. User assignable polygon-ID number.

MAJOR1          NMD category code. Value of 50 indicates hydrography

MINOR1          NMD feature code identifier.

MINOR2          NMD feature code identifier

MINOR3          NMD feature code identifier.

HUC             Hydrologic Unit Code

------------------------------------------------------------------------------
File name:BANKS-PNW.AAT

ITEM            DESCRIPTION

FNODE#          ARC attribute. From-node number.

TNODE#          ARC attribute. To-node number.

LPOLY#          ARC attribute. Polygon to left of arc in F-T node direction.

RPOLY#          ARC attribute. Polygon to right of arc in F-T node direction.

LENGTH          ARC attribute. Length of arc in map units.

BANKS-PNW#      ARC attribute. Arc internal number.

BANKS-PNW-ID    ARC attribute. User assignable arc -ID number.

MAJOR1          NMD category code.

MINOR1          NMD feature code identifier.

MINOR2          NMD feature code identifier.

MINOR3          NMD feature code identifier.

------------------------------------------------------------------------------
Following are the Item format tables for the Reach File and associated coverages.
Datafile name: [PNWRRF].AAT

44 ITEMS: STARTING IN POSITION 1
COL ITEM NAME WDTH OPUT TYP N.DEC ALTERNATE NAME
1 FNODE# 4 5 B -
5 TNODE# 4 5 B -
9 LPOLY# 4 5 B -
13 RPOLY# 4 5 B -
17 LENGTH 4 12 F 3
21 STR100-PNW# 4 5 B -
25 STR100-PNW-ID 4 5 B -
29 MAJOR1 6 6 I -
35 MINOR1 6 6 I -
41 MINOR2 6 6 I -
47 MINOR3 6 6 I -
53 HUC 8 8 I -
61 SEG 4 4 I -
65 RMI 5 5 N 2
70 FEAT_NAME 60 60 C -
130 FEAT_SRC 2 2 I -
132 STATE 4 4 C -
136 STATE-2 4 4 C -
140 COUNTY 15 15 C -
154 COUNTY-2 15 15 C -
170 QUAD100 26 26 C -
196 QUAD100-2 26 26 C -
222 QUAD75 25 25 C -
247 QUAD75-2 25 25 C -
272 CEN 4 5 B -
276 CUMLENGTH 4 12 F 2
280 DNARC 4 5 B -
284 PNTR# 4 5 B -
288 SAVENEG 1 1 I -
289 SINUOUS 5 5 N 2
294 UHUC1 8 8 I -
302 UPNTR1 5 5 I -
307 UHUC2 8 8 I -
315 UPNTR2 5 5 I -
320 UHUC3 8 8 I -
328 UPNTR3 5 5 I -
333 UFLAG 1 1 I -
334 DHUC 8 8 I -
342 DPNTR 5 5 I -
347 CSEG 3 3 I -
350 CRMI 5 5 N 2
355 CNAME 30 30 C -
385 RRN 17 17 C -
402 LLID 13 13 C -
415 OW_NAME 60 60 C -
475 PRIMARY 6 6 I -
481 SECONDARY 6 6 I -
487 DESCRIPTOR 6 6 I -

------------------------------------------------------------------------------
Datafile name: BANKS-PNW.PAT
8 ITEMS: STARTING IN POSITION 1
COL ITEM NAME WDTH OPUT TYP N.DEC ALTERNATE NAME
1 AREA 4 12 F 3
5 PERIMETER 4 12 F 3
9 BANKS-PNW# 4 5 B -
13 BANKS-PNW-ID 4 5 B -
17 MAJOR1 6 6 I -
23 MINOR1 6 6 I -
29 MINOR2 6 6 I -
35 MINOR3 6 6 I -
40 HUC 8 8 I -
------------------------------------------------------------------------------
Datafile name: BANKS-PNW.AAT
11 ITEMS: STARTING IN POSITION 1
COL ITEM NAME WDTH OPUT TYP N.DEC ALTERNATE NAME
1 FNODE# 4 5 B -
5 TNODE# 4 5 B -
9 LPOLY# 4 5 B -
13 RPOLY# 4 5 B -
17 LENGTH 4 12 F 3
21 BANKS-PNW# 4 5 B -
25 BANKS-PNW-ID 4 5 B -
29 MAJOR1 6 6 I -
35 MINOR1 6 6 I -
41 MINOR2 6 6 I -
47 MINOR3 6 6 I -
------------------------------------------------------------------------------
Datafile name: STR-CNTRS.PAT
15 ITEMS: STARTING IN POSITION 1
COL ITEM NAME WDTH OPUT TYP N.DEC ALTERNATE NAME
1 AREA 4 12 F 3
5 PERIMETER 4 12 F 3
9 STR-CNTRS# 4 5 B -
13 STR-CNTRS-ID 4 5 B -
17 NODE# 4 5 B -
21 CAPACITY 4 12 F 2
25 IMPED-LIMIT 4 12 F 2
29 IMPED-DELAY 4 12 F 2
33 LINE-SYMBOL 4 5 B -
37 MAXIMUM-IMPED 4 12 F 2
41 AVERAGE-IMPED 4 12 F 2
45 ARCS-ALLOCATED 4 5 B -
49 UTILIZED 4 12 F 2
53 ALLOCATED 4 12 F 2
57 POINT-SYMBOL 4 5 B -

* Note: Items are NETWORK:ALLOCATION default, units are in meters
==============================================================================
==============================================================================

Map projection parameters for PNW Reach Files:

	PROJECTION LAMBERT

	UNITS FEET

	DATUM NAD27

	SPHEROID CLARKE1866


	1st Standard Parallel		42  20 0.000

	2nd Standard Parallel		48  40 00

	central meridian		-117  00 0.00

	lat org				41  00 0.00

	easting				914401.82880

	northing			0.0

