Tax lots - ArcSDE version
1.1 Citation
Originator Metro Data Resource Center
Publication date 1990
Title Tax lots
1.2 Description
Abstract Tax lots, right-of-way outlines and tax account numbers as represented on county tax assessor hard copy maps. Each tax lot is a polygon with an associated tax lot number which is the "hook" to the county tax assessor's tabular data base. Selected items from each County Assessor's file are included.  In Clackamas and Washington counties, the tax lot spatial features are maintained by the counties and delivered to Metro on a quarterly basis.  The taxlots covering the City of Portland are maintained by the city and sent to Metro quarterly. The remainder of Multnomah County is maintained by the County.
Purpose All data associated with the taxlot shape files are compiled by Metro from existing records created and maintained by county Assessment and Taxation offices. Care should be taken in the use and interpretation of these data. Not all columns are fully populated by the assessor. For example, the landuse and prop_code columns are useful for producing generalized land-use maps, but are not considered reliable for parcel specific applications. Field verification has not been done.
Supplemental information Layer Files/Legends: Landval.avl - draws land value in 4 classes
Bldgval.avl - draws building value in 4 classes
Totalval.avl - draws total value in 4 classes
bldgsqft.avl - draws building sq. ft. in 4 classes
Yearblt.avl - draws year built in 4 classes
Landuse.avl - shades each land use in a different color
The ArcInfo coverage also includes polygons which are not taxlots, e.g. streets, railroad rights-of-way and water bodies.  The coverages are tiled by section.  Coverages include line attributes (not available as shapefile or SDE layer).
1.3 Time period of content Current
Last Dataset Update Date 2013-09-01 22:18:57.0
1.4 Status
Progress Complete
Maintenance/Update Frequency Quarterly
1.5 Spatial domain
Description Clackamas, Multnomah and Washington counties in Oregon.
West bounding coordinate -123.47121656
East bounding coordinate -121.65053671
North bounding coordinate 45.82618832
South bounding coordinate 44.85462409
1.6 Keywords
Theme keyword thesaurus None
Theme keyword Taxlots, tax lots, parcels, assessor, cadastral
Place keyword thesaurus None
Place keyword Portland, Clackamas County, Multnomah County, Washington County, Oregon
1.7 Access Constraints None
1.8 Use Constraints These data are sold under the agreement that the user may use the data in its business activity and for no other purpose whatsoever.
User shall not allow access to the data by any other person or organization, unless authorized in writing by the Metro DRC or,
if the other party is a contractor providing services to a government requiring usage of the data in order to provide contractual services.<br>
User shall not duplicate the data except for the following:<br>
(1) User may make one backup copy of the data, and<br>
(2) User may translate the data into other formats and/or media.<br>
For full product purchase agreement that accompanies these data, please see
1.10 Browse graphic
Browse graphic file name taxlot.gif
Browse graphic file description Sample tax lot plot shaded by assessor's building value. The street names are also shown.
Browse graphic file type GIF
1.13 Native data set environment Software/hardware: ArcInfo 8.2 on NT workstation.<br>ArcSDE 8.2 on Compaq Alpha 4100.  Tru64 5.0 OS.
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2.4 Horizontal positional accuracy

Varies depending on location.  When the taxlot layer was started in 1988, the standard was +/- 10 feet in urban areas, except Beaverton and Tigard's planning areas which were +/- 5 feet accuracy.  In 2003, Oregon Department of Revenue prepared the <a href="">Cadastral Data Content Standard</a> that specifies horizontal accuracy.  The standard specifies the majority of taxlot lines in areas of urban density to be within 2 feet accuracy.  In the remaining urban growth boundary, taxlot line work is to be within 5 feet.  Taxlots on farmland are to be +/- 10 feet accuracy, and on resource land, +/- 40 feet accuracy.  The three counties have brought much of this layer into compliance with the ODOR standard.  As of June 30, 2003, the following locations meet the standard:  Hillsboro, Lake Oswego, Molalla, all of Multnomah County, Oregon City, east Sherwood, southeast Tualatin, and West Linn.
2.5 Lineage
Process step
Process description Portland General Electric (PGE) purchased aerial orthophotography with 10 foot horizontal control and digitized street center lines, tax lots and street names. This layer was produced on a CAD system as a visual background to their electrical system.
Process date 1980 (approx.)
Process step
Process description Metro converted the PGE line work to polygons and added tax account numbers. David Evans and Associates was contractor. Beaverton, Oregon City and Tigard planning areas were improved to +/- 5 feet accuracy. Oregon Dept. of Revenue and Multnomah County Assessor provided CAD drawings of the area east of 42nd Ave. which had been entered using coordinate geometry and existing control from the cities and county.  This original RLIS dataset contained 553 sections.
Process date 1989-90
Process step
Process description Metro converted 436 rural sections to polygon coverages and added tax account numbers. David Evans and Associates was contractor.  Tax assessor hard copy maps were scanned and registered to PGE base maps.
Process date 1991 approx.
Process step
Process description Washington Co. rural taxlot linework created by Washington Co. using assessor maps.
Process date 199301
Process step
Process description Washington County began maintaining this layer within their boundaries.
Process date 199301 approx.
Process step
Process description Metro converted the coverage from NAD27 to NAD83 and from single to double precision.
Process date 199401
Process step
Process description Clackamas County began maintaining this layer within their boundaries.
Process date 1995 approx.
Process step
Process description Multnomah Co. rural taxlot linework created by Metro using 1:24000 USGS quad for control.
Process date 199507
Process step
Process description Oregon Dept. of Revenue and Multnomah County Assessor provided tax lot CAD drawings of the remaining areas of the city of Portland.  This data was entered using coordinate geometry and existing control.  The city of Portland converted the CAD drawings to ARC/INFO format and furnished the information to Metro.
Process date 199706
Process step
Process description A major upgrade was completed in Multnomah County.  The taxlots for Portland were re-mapped and updated. The horizontal positional accuracy was spatially corrected.<br>
Columns storing X and Y coordinates of each taxlot were added, mainly for use by programmers.
Process date 199710
Process step
Process description Clackamas County is gradually improving the horizontal ground control of the map by registering the map to the 1996 Spencer B. Gross digital orthophotography.  The photography has ground control of +/- 5 feet.
Process date 1998
Process step
Process description In Multnomah County, the "TLID" field was changed to be the "state ID number" instead of the account number (R number). This made Multnomah County consistent with the other two counties. In cases where the state ID number was not available, the R number was supplied. Since the state ID number is wider in Multnomah County, the TLID field was changed to 15 characters wide instead of 12.<br>
The Multnomah County portion was projected to NAD83/91 projection (also known as HPGN).
Process date 199801
Process step
Process description A field called "Rno" was added to the taxlots shapefile. Earlier the Multnomah County "R number" was used in the "Tlid" field. The "R number" is now in its own field for those users who still need it.
Process date 199804
Process step
Process description In Washington County, the technique used to populate OWNER2, OWNER3 and OWNERADDR was improved. Previously the address could appear in OWNER2, OWNER3 or OWNERADDR (depending on the first available field). Now all the address information is in OWNERADDR.
Process date 199807
Process step
Process description This layer was reprojected to the NAD83/91 projection (also known as HPGN) as part of a conversion of all RLIS map layers.
Process date 199807
Process step
Process description Multnomah County Assessment and Taxation updated their computer system and are now using a new format for the tax lot identifier (TLID). Since the beginning of RLIS Lite, Metro has used the county's format for taxlot number, so we converted to the new 16-character number used by the county.<br>
EXAMPLE: (^ represents a space). 1S2E06AB^^^00100. If the quarter section or quarter-quarter section letters are not used, a space is used as a place holder. There are three additional spaces following the quarter-quarter section letter. The 5-digit tax lot number uses leading zeros as place holders if the number is less than 10000.<br>
Landuse data for Multnomah County was extracted from a new field, and may look slightly different than previous releases.
Process date 200001
Process step
Process description The TLID format for Multnomah County was changed to be consistent with the format used by the Assessor. The 3 spaces between township, range, section and the taxlot id number was changed to 2 spaces and a hyphen.<br>
Y2K issues required that the SALEDATE field be changed from a numeric field formatted YYMM to a character field formatted YYYYMM.
Process date 200011
Process step
Process description Projection information (.prj file), compatible with ArcGIS 8.1, was added to the layer.
Process date 20010715
Process step
Process description Incorporated Clackamas County COGO-ed taxlot data for Lake Oswego and West Linn.
Process date 20011031
Process step
Process description Add XML metadata compatible with ArcCatalog 8.1
Process date 20011031
Process step
Process description Clackamas County replaced data with COGO'ed areas in Lake Oswego and West Linn to Willamette River.
Process date 2002
Process step
Process description Positional adjusts to taxlots per COGO data by County Surveyor in portions of Urban Washington County - (primarily Northern Hillsboro/Beaverton, SW Tigard and Sherwood).
Process date 2002 ongoing
Process step
Process description Clackamas County replaced data in Oregon City with COGO'ed sections.
Process date 20021101
Process step
Process description Multnomah County began maintaining taxlots within their boundaries.  In the past, Multnomah County's taxlots were maintained by the city of Portland and Metro (Metro maintained land outside the city).  The taxlots will be more accurate since this layer will be maintained by the cartographers in the Assessment & Taxation office.  This quarter, the county provided taxlots for the rural portion of the county.
Process date 200302
Process step
Process description <b>Tax Lots, multi-part features</b> - The tax lot layer now supports multi-part features, a feature that is composed of more than one physical part but only references one set of attributes in the database. Previously two or more polygons could represent one tax lot, e.g. tax lots that cross roads. When you select a multi-part tax lot, both parts of the tax lot will be selected, but only one row in the attribute table.<br>
<b>Tax Lots, multiple database records</b> - Multiple county assessor database records for a single tax lot are now included as a separate point data layer. These records previously were not included in RLIS Lite. The primary record is included as a row in the taxlot database and all the records are included in a new point data layer called TL_MANY. TL_MANY includes all attributes that are on the taxlot data layer and an additional attribute called TLID_LONG. TLID_LONG, also known as the state_id or map tax lot number, uniquely identifies each multiple record.
Process date 200304
Process step
Process description Over the past eighteen months, Multnomah County gradually took over maintenance of taxlots.  Metro now receives all taxlot shapes and A&T data directly from the county.
Process date 200407
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3.2 Direct spatial reference method Vector
3.3 Point and vector object information
SDTS point and vector object type Polygon
Point and vector object count 602170
3.4 Raster object information
Raster object type NA
Row count
Column count
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4.1 Horizontal Coordinate System
Grid coordinate system name State plane coordinate system 1983.
SPCS zone identifier 5076
Planar distance units International feet
Horizontal datum name North American Datum of 1983/1991 (HPGN)
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5.2 Overview description Related data files and field descriptions follow:
Table Name Column Name Column Type Column Width Sample Domain Value Definition
TAXLOTS_METRO -- -- -- -- Tax lot attributes provided by the three county assessors.
X_COORD Integer 4 --
Y_COORD Integer 4 --
TLID String 16 --
RNO String 10 --
OWNERSORT String 5 --
OWNER1 String 32 --
OWNER2 String 35 --
OWNER3 String 35 --
OWNERADDR String 35 --
OWNERCITY String 30 --
OWNERZIP String 10 --
SITESTRNO Integer 4 --
SITEADDR String 35 --
SITECITY String 15 --
LANDVAL Numeric 8 --
BLDGVAL Numeric 8 --
TOTALVAL Numeric 8 --
BLDGSQFT Integer 4 --
A_T_ACRES Numeric 8 --
YEARBUILT Integer 2 --
PROP_CODE String 3 --
LANDUSE String 3 --
TAXCODE String 7 --
SALEDATE String 6 --
SALEPRICE Numeric 8 --
COUNTY String 1 --
OWNERSTATE String 2 --
SITEZIP String 10 --
JURIS_CITY Integer 15 --
GIS_ACRES Numeric 8 --
STATECLASS Numeric 4 --
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6.1 Distributor
Contact organization Metro Data Resource Center
Address 600 NE Grand Ave.
City Portland
State or province OR
Postal code 97232
Contact voice telephone 503 797-1742
Contact facsimile telephone 503 797-1909
Contact electronic mail address
6.3 Distribution liability The information in this file was derived from digital databases on Metro's GIS. Care was taken in the creation of this file.  Metro cannot accept any responsibility for errors, omissions, or positional accuracy.  There are no warranties, expressed or implied.
6.4 Standard order process
Digital transfer information
Format name Shapefile - Hourly fee will be charged for conversion
Transfer size Approx. 350 MB (199709)
Digital transfer options:
Online option
Network resource name
Access instructions Metro can place data on its FTP site on request.  In most cases, a fee for the data will be charged.  Call 503 797-1742 or email for instructions.
Offline option
Offline media CD-ROM
Recording format ISO9660 (DOS, Unix, or Macintosh)
Fees See RLIS a la carte at Coverages: 1-50 sections - $54.00; 51-150 sections - $34.00; Over 150 sections - $22.00; Regional coverage - call for current pricing.
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7.1 Metadata date 20130901
7.4 Metadata contact
Contact person Alan Holsted
Contact voice telephone 503 797-1594
Contact facsimile telephone 503 797-1909
Contact electronic mail address
7.5 Metadata standard name FGDC Content Standards for Digital Geospatial Metadata
7.6 Metadata standard version 19940608
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