| Kern County GIS Tax Parcels 2009 Final | |
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Data format: Shapefile File or table name: kernparcels2009final Coordinate system: Lambert Conformal Conic Theme keywords: parcel, apn, ownership, lot, cadastre, cadastral, tax, property, assessment, assessor |
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Abstract:
This feature class contains land parcel boundaries delineated for property tax assessment purposes. Parcels are modeled as planimetric polygons in a seamless fabric comprising the spatial extent of the County of Kern, in the State of California. |
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Metadata elements shown with blue text are defined in the Federal Geographic Data Committee's (FGDC) Content Standard for Digital Geospatial Metadata (CSDGM). Elements shown with green text are defined in the ESRI Profile of the CSDGM. Elements shown with a green asterisk (*) will be automatically updated by ArcCatalog. ArcCatalog adds hints indicating which FGDC elements are mandatory; these are shown with gray text.
This feature class contains land parcel boundaries delineated for property tax assessment purposes. Parcels are modeled as planimetric polygons in a seamless fabric comprising the spatial extent of the County of Kern, in the State of California.
This data is intended to provide a reasonable representation of parcels, as defined for property tax assessment purposes, that can be used easily in a computerized geographic information system. Includes all private (taxable), state utility, and other governmental (tax exempt) land interests listed on the secured tax roll, but does not include segregated mineral rights, mobilehomes, or unsecured taxable entities. This data is not intended to replace the hardcopy assessment maps or any other official or unofficial county maps, and it is not to be construed as portraying legal ownership or divisions of land for purposes of zoning or subdivision law.
Attributes include a parcel identification number and shape areas calculated in square feet and acres. Assessment roll information is available in separate database tables.
Lien Date
Refer to the disclaimer statement in the 'Access Constraints' element of the 'Identification Information' section of this document.
Kern County Assessor
Attn: Jim Isbell
1115 Truxtun Avenue
I can be reached by telephone during the hours of service specified above. If you contact me via mail or e-mail, please include your full name, telephone number, and e-mail address for fastest response. For ordering instructions, please refer to the 'Distribution Information' section of this document.
This dataset was originally compiled by the Kern County Assessor, in May 2001, from two different sources. The Kern Council of Governments provided the VWGIS data for the entire county; the City of Bakersfield provided the original COBGIS data for the metropolitan Bakersfield area, and continues to share data on an ongoing basis.
Attribute values are originally hand-typed into the system during normal daily updates, and are therefore prone to error. APN values are rigorously tested using various procedures designed to detect as many errors as possible, so most errors are corrected before the data is released. Even though it is not possible to guarantee 100% accuracy (due to the nature of the data as well as human factors and process limitations), we are confident that the attributes contained in this dataset are represented with a very high degree of accuracy overall.
APN attribute values are believed to be about 99.99% accurate (or better). They are rigorously tested in several quality-control procedures on a regular basis. The only error type that cannot be detected by our automated quality-control procedures is a rare instance of two parcels having valid APN values reversed. This type of error is extremely rare, but it has been detected on several occasions. The only method of detection (that we know of) is by deliberate human scrutiny of the GIS parcels compared with the official assessor maps. Such scrutiny is too tedious and time-prohibitive to be practical with such a large dataset, therefore the exact number of errors of this type is unknown, and our estimate of accuracy is based on our past experience and frequency of encounters. The 8-digit APN is sufficient to identify any tax parcel, but it lacks the extra check-digit necessary to join/link to the assessor's tax roll database. The 8-digit APN attribute is provided for those users who would like to join/link to their own databases which may be populated only with 8-digit APN values.
The APN9 field is identical to the APN field, with the addition of a 9th digit, a "check-digit" used exclusively by the assessor's tax roll database system. The check-digit is generated using a special hash code algorithm. The purpose of the check-digit is to prevent typographical errors that might be made during data entry operations by the assessor's staff; it has no intrinsic meaning or significance for parcel identification purposes. The APN9 value is exactly as accurate as the APN attribute, since it is derived from the APN attribute. Since the assessor's tax roll database stores all parcel numbers with a check-digit, the APN9 attribute is included with the GIS polygons to facilitate joining/linking. To do this properly, join or link KERNPARCELS.APN9 to PARCELDATA.APN.
Topological integrity (the spatial coincidence of vertices along the edges of adjacent features) is believed to be excellent, although not perfect. All data is maintained as a Line feature class with topology rules enforced. The APN attribute is stored in a centroid (Point) feature class. Geoprocessing tools are used to generate polygons from the lines, which are then spatially joined with the points to transfer the APN attributes to the polygons, which are then tested with a series of Error Detection and Correction (EDC) procedures. EDC is designed to test line integrity, line attributes, point attributes, and line topology before polygons are even created. Then, after polygons are created, the polygons are tested for overlaps, slivers, APN database parity, and centroid parity. There is a specific type of logical topology error that has been observed, but cannot be tested with EDC procedures. This type of error manifests as two adjacent parcels separated by a thin sliver that joins with a road or canal corridor at one end. This type of gap is difficult to find and correct because it does not form a closed loop or boundary, and therefore does not generate a polygon sliver that can be discovered based on its own characteristics or non-parity with other objects. The exact number of such gaps is not known, but is believed to be very small based on our own observations. The width of such a gap is also believed to be very small, likely well under 1 foot per occurrence.
This parcel shapefile is believed to be 100% complete, but completeness is not guaranteed. The assessor's tax roll database is used as the authoritative object in the process of testing the GIS parcel polygons for completeness. Unfortunately, its schema is highly complex, it is inadequately documented, it suffers from certain legacy data conversion issues, and it endures poor data entry standards, resulting in certain ambiguities and limitations in the data. It also contains many different types of taxable entities, including those that correspond to mapped parcel boundaries, but also including business properties and equipment, aircrafts, boats, mobilehomes, and various other entities that are assessed for taxes yet do not correspond to mapped parcel boundaries. Since only a subset of these taxable entities are modeled in this GIS dataset as mapped parcel boundaries, a query has been devised by the assessor's mapping staff to filter the database to produce a suitable recordset that can be subsequently joined/linked to the parcel polygons modeled in this GIS dataset. The query has been reasonably well researched and designed in order to extract all possible records which should theoretically be represented by mapped parcel polygons, but for the reasons stated above we cannot guarantee 100% completeness. After filtering the tax roll database, a two-part "parity test" is performed: The first part compares the tax roll database to the parcel polygons, to detect APN values that exist in the tax roll database but are in fact missing from the polygon dataset. The second part compares the parcel polygons to the tax roll database, to detect polygons having APN values that are invalid (due to data entry errors and APN value changes that failed to get applied). These errors and omissions are then corrected and the parity test is performed again, until all possible corrections have been made and perfect parity is achieved between the parcel polygons and the tax roll database.
Positional accuracy varies by region, usually about 10 feet or better in urban areas, and up to 50 feet (or more) in the mountains and other rural areas where horizontal control is less reliable due to poor availability of geodetic or survey data. Horizontal control is provided primarily by the Public Land Survey System (PLSS) comprised of Townships, Ranges, and Sections. PLSS datasets are provided by the Kern County Department of Engineering and Survey Services (ESS). Parcels are always created and maintained in direct relation to the PLSS control data, which is also subject to errors and inaccuracies, so the accuracy of the parcels can only be as accurate as the section corners that they are tied to. This dataset does not contain any attributes or other indications of positional accuracy. It was compiled by the assessor's staff from two different sources in 2001. Since both of the original data sources contained widespread accuracy problems, some parcels are misrepresented in geometric shape for various reasons. The assessor's staff is continually improving the accuracy and overall data quality. Three essential aspects of accuracy for tax assessment purposes include 1) the number of segments comprising a parcel's boundary and each segment's length and angle according to legally recorded source documents; 2) modification of a parcel's boundary due to encumbrances such as roads, canals, and easements that affect the property owner's fair use of the property; and 3) the position of a parcel boundary relative to benchmark features having known coordinates (such as section corners). The assessor's geodatabase actually contains quality codes which are used by mapping staff in the production process, but those codes are not transferred to this polygon dataset, which is a derivative product. The exact number of parcels that are geometrically misrepresented (shaped incorrectly) is unknown, but approximately 15 percent of the line segments are known to be reasonably accurate and the accuracy of the remaining 85 percent is unknown.
This dataset is planimetric, having no vertical component.
Parcels covering entire county, digitized from scanned photocopies of assessment maps.
Parcels within the Metropolitan Bakersfield 2010 General Plan boundary.
Internal feature number.
ESRI
Feature geometry.
ESRI
Assessor's Parcel Number.
California State Board of Equalization. Assessors' Handbook Section 215.
Assessor's Parcel Number, extended with final check-digit.
California State Board of Equalization. Assessors' Handbook Section 215. Extended by the Kern Integrated Property System.
Assessor's Parcel Number, delimited with hyphens for readability.
California State Board of Equalization. Assessor's Handbook Section 215.
Area of feature in square feet (approximate).
Calculated from feature geometry.
Area of feature in acres (approximate).
Calculated from feature geometry.
State of California. Board of Equalization. Assessors' Handbook Section 215, Assessment Map Standards. Aug. 1992. <http://www.boe.ca.gov/proptaxes/pdf/ah215.pdf>.
Kern County Information Technology Services. Kern Integrated Property System (KIPS). Implemented 1994.
Kern County Assessor
Attn: Jim Isbell
1115 Truxtun Avenue
I can be reached by mail or e-mail, or by telephone during the hours of service specified above.
Refer to the disclaimer statement in the 'Access Constraints' element of the 'Identification Information' section of this document.
Due to our privacy policy, and pursuant to Govt. Code Sec. 6254.21, the Kern County Assessor's Office does not post property owners' names on the Internet. This policy also applies to the GIS Parcel Data. Because of this limitation, the data is available in two different packages: WITH PROPERTY OWNERS' NAMES or WITHOUT. The two packages are otherwise identical in content. Either package can be obtained by anyone, using either of the following methods: 1. DOWNLOAD FOR FREE - WITHOUT PROPERTY OWNERS' NAMES. Download compressed data files from http://www.co.kern.ca.us/gis. Data at this Internet site is available FREE OF CHARGE. As indicated above, property owners' names are not included with the version posted on the public Internet site. If you want property owners' names included, you must order the data directly from the Kern County Assessor's Office as described below: 2. ORDER DIRECT FOR $80 - WITH PROPERTY OWNERS' NAMES. Order the GIS PARCEL DATA from the Kern County Assessor's Office, by mail, e-mail or phone. Available editions are described in the 'Resource Description' section of this document, above. Data may be provided by e-mail as private download links, or by CD-ROM. Send a check or money order in the amount of $80.00, made payable to 'County of Kern'. Shipping and handling are included (there is no additional charge). Credit cards are not accepted. Requests will not be fulfilled until payment is received. If you represent a government agency, the $80 fee may be waived (at our discretion). Send payment to: KERN COUNTY ASSESSOR ATTENTION: MAPPING 1115 TRUXTUN AVENUE BAKERSFIELD, CA 93301
Kern County Assessor
Attn: Jim Isbell
1115 Truxtun Avenue
Refer also to the 'Point Of Contact' element of the 'Identification' section of this document.