Metadata: Top of Bank

Top of Bank

Category Hydro
Feature Dataset Name STAND-ALONE
Database Type SDE
Originator City of Portland
Bureau Bureau of Planning and Sustainability
Publication Date 05/18/2010
Abstract Lines representing top-of-bank of major rivers and streams in the Portland region (where mapped). River top of bank derived from 2014 LiDAR using an automated mapping method explained in the process steps below. River top of bank will be completely mapped by early 2017. Columbia Slough top of bank derived from visual interpretation of aerial photos and 2007 LiDAR data. Mapping will be expanded over time using LiDAR data and field surveys.

Purpose For locating top-of-bank in the Portland region
Supplemental Information Refer to the City of Portland Zoning Code definitions for a definition of top of bank, and how it is measured.
Last Dataset Update 05/04/2020 13:43
Last Source Update 05/04/2020 07:13
Maintenance/Update Frequency As needed
Extent City of Portland
Data Type Vector
Shape Type Poly Line
Feature Count 239
Horizontal Position Accuracy Mapped using LiDAR digital elevation model (DEM) and, where manually identified, aerial photos as reference. Refer to the LiDAR data and aerial photo metadata for specific information about horizontal accuracy.
Horizontal Position Accuracy Link Neither
Progress Complete
North Bounding Coordinate 729081.39895013
South Bounding Coordinate 676519.185039371
East Bounding Coordinate 7696976.957021
West Bounding Coordinate 7617373.25853018
Theme Keyword(s) top-of-bank, streams, rivers
Theme Keyword Thesaurus None
Place Keyword(s) Portland, Multnomah County, Washington County, Clackamas County, Oregon
Place Keyword Thesaurus None
Access Constraints Available for Public Use
Use Constraints These data are distributed under the terms of the City of Portland Data Distribution Policy. Care was taken in the creation of this data but it is provided "as is".

The City of Portland cannot accept any responsibility for errors, omissions, or positional accuracy.
Source Dataset Type File Geodatabase
Output Geodatabase EGH_Public
Distribution Grid: State plane coordinate system 1983(91).
Units: International feet
Datum: North American Datum of 1983/1991 (HPGN)
Liability: The information in this file was derived from digital databases on the City of Portland GIS. Care was taken in the creation of this file. The City cannot accept any responsibility for errors, omissions, or positional accuracy. There are no warranties, expressed or implied.
Format: Shapefile or File Geodatabase Feature Class - Data will be provided via City of Portland FTP Site.
Online Resource:
Online Instructions: City of Portland Public/Open Data is distributed via the PortlandMaps Open Data Site - Data not available on the PortlandMaps Open Data site can be requested by contacting the City of Portland CGIS Group -
Transfer Size: varies
SPCS Zone Identifier: 5076
Kevin Martin
503 823-7710
503 823-7800
1900 SW 4th Avenue, Suite #7100
Portland, OR 97201

City of Portland - BPS
503 823-7700
503 823-7800
53223.png 311.76Kb X
01/01/2010 Manual mapping of top of bank (Columbia Slough)
Top of bank in parts of the Columbia Slough was manually mapped by the Bureau of Environmental Services in 2010 using the 2005 LiDAR DEM, the 2005 LiDAR hillshade, and 2010 6" aerials as reference. This mapping will eventually be updated with results from the automated mapping method.
02/01/2016 Automated mapping of top of bank
Top of bank was mapped using the 2014 LiDAR digital elevation model (DEM), the LiDAR-derived ordinary high water line, and a geoprocessing script that automatically identifies top of bank based on the Zoning Code definition of top of bank. The script also removes "Noise" in the raw mapping output by applying several generalization tools to the raw output.

The mapping script is available upon request.

Attribute Tables & Domains

Table Description
Table Jurisdiction
Column Sort Column Name Column Alias Column Type Column Size Domain Value(s) Column Description
A unique software ID for each polygon. May change when data is modified.
1 SOURCE Reference Source String 60
Field Survey Mapped based on GPS information or other data collected in a field survey X
LIDAR DEM Visually mapped based on information derived from 2005 LiDAR data X
LIDAR-Derived Mapped using an automated method based on the Zoning Code definition of top of bank. Refer to the lineage section above for a description of the processing steps.
The reference source for the mapped top-of-bank
1 SOURCE_REF Reference Source Details String 30
2014 LiDAR data Source is the 2014 3' resolution LiDAR digital elevation model (DEM)
2005 LiDAR Data Source is 2005 3' resolution LiDAR digital elevation model (DEM) and hillshades
Any additional reference information regarding the mapping source (LiDAR flight date, survey information, etc.)
1 MODIFIER Modified By String 15
BES City of Portland Bureau of Environmental Services X
BPS City of Portland Bureau of Planning & Sustainability X
Metro Metro X
Last organization to edit the top-of-bank lines
1 MOD_NAME Modifier Name String 15
Initials of the last person to edit the top-of-bank line
1 MOD_DATE Modification Date Date 8
Date of the last modification
1 CREATED_BY Created By String 50
Name of the organization that originally created the top-of-bank line. Same domain as the "MODIFIER" attribute
1 CREATEDATE Creation Date Date 8
Date the top-of-bank line was originally created.
1 FIELD_DATE Field Date Date 8
Date of any field visit or survey.
1 REVIEW Flag for Review? String 5
Indicates whether the top-of-bank line needs further review (i.e., the mapped location is approximate).
1 NOTES NOTES String 150
Any notes related to the top-of-bank line
1 IS_TOB Is TOB? String 5
"True" indicates the line represents a top-of-bank; all other lines are used to create polygon features for modeling purposes.