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The Mailing Address Points were created by combining the data from the Assessor's parcels, USPS database and CAMS address points. From the Assessor's parcels, both site and mailing addresses were incorporated. Mailing addresses that are duplicates of the site addresses were excluded. From the USPS database, a tabular database was geocoded and converted to points. Only addresses with multiple units were incorporated. A python script was used to iterate through the address ranges to genereate the units for each address. Only the first 15 unit values were calculated because the mean for the unit count for each record was 13. From the CAMS address points, the addresses are compared against the Assessor and USPS addresses and duplicate addresses were excluded.
The Office of the Assessor maintains assessment records of real and personal property in the County of Los Angeles. Many of these records are available for sale. The data is available in the form of CD-ROM, DVD, hardcopy, and on-line access. The Office of the Assessor also offers a GIS Tax Parcel Base Map.Some layers included (not an exhaustive list):parcel boundary map (shapefile format)local rollLA County wall mappublicly owned parcelssales listunsecured rolland labels (for mailings)A discussion of parcel accuracyOccasionally questions about the spatial accuracy of parcel information come up. In general, it is important to note that the parcels are for tax assessment purposes only, come from many sources, some historical, and are not necessarily survey grade. That said, they are in general extremely reliable.Here is a longer description from Emilio Solano, head of the Assessor Mapping and GIS Services:The very short answer is this: our data is in its majority accurate within a couple of feet, in other cases will not be so accurate.The issue of accuracy when applied to assessor’s data is very subjective. Our data is very accurate if we consider that all the information matches recorded information, we try our best to keep recent data as it was recorded, and older data gets slightly adjusted to match the most recent data. Another factor to consider is that about one third of the total number of new parcels created every year comes from deeds, not subdivision maps, that is, there is not, in the majority of the cases, any new survey data, more likely general descriptions of where the new boundaries should exist, or references to adjacent properties, even calls to documents recorded many years ago, referring to them just by the document number. In those cases we have to consider the intent of the owner when describing the property in the deed.Another couple of factors that have an impact in the accuracy of our data comes from the fact that we assembled this vast amount of information with digital data provided from at least a dozen of cities, Los Angeles, Long Beach, Torrance, etc. plus all the data gathered by LACO DPW in CAD format. We had to compile all that data, rectify it and adjusted as needed, always keeping in mind that the integrity of the data should be maintained by matching RECORDED information. Another factor is that the data was also coming from tens of thousands of individual recordings, it wasn’t as clean cut as when you look at a single subdivision, no matter how big, where every line is clearly identified by a bearing and a distance within a perfectly traced boundary. Our original data sources even go back as far as remainder pieces of land described by Spanish grants and ranchos, section land plus newer surveys.Even though we always input our data based on survey records using COGO tools, whenever possible, a lot of the data is not. Considering all that, our GIS layer is by far, the most accurate data set of its size available anywhere in the county, both in positional accuracy, and conformity to the information provided by legal sources.All that being said, the resulting fact is that, as mark mentioned, in some areas our data will be very accurate, in others it won’t. The most important thing to keep in mind is that given that our responsibility is to reflect property information as recorded, we do not use anything else as a guide, for example we never use an aerial image to change the position of a line just because it doesn’t fall on top of a fence shown on a photo; remember that many people build their fenced, especially the ones made out of concrete blocks, a couple of inches inside the property boundary because is difficult to dig a trench along an existing wooden or wire fence, now multiply those little variances spread out over a 4000+ square miles of land and you will get a picture of what we are up to.That’s why we continually try to stress in anybody using our data that, if they need total accuracy they will need to hire a surveyor to get it. Our 11 by 17 maps are our only official source of information and should only be used for assessment purposes, or in the case of other uses, just for information, to get an accurate idea of how close to the real location a line could be.
The Census Bureau (http://www.census.gov/) maintains geographic boundaries for the analysis and mapping of demographic information across the United States. Every 10 years the Census Bureau counts the population of the United States as mandated by Constitution. The Census Bureau releases the results of this county as demographic data with geographic identifiers so that maps and analysis can be performed on the US population.
There are little more Census Tracts within Los Angeles County in 2020 Census TIGER/Line Shapefiles, compared to 2010.
UPDATED:
1. September 2022: Previous dataset from March 2021 was clipped to County boundary. New dataset retains shoreline census geography in their entirety.
2. December 2022: Aligned census tract boundary with updated city boundary along shoreline/coastal areas, from Malibu to Long Beach. This data also includes Long Beach City water area tract 990300.
CREATED: March 2021
How was this data created?
This geographic file was downloaded from Census Bureau website: https://www2.census.gov/geo/tiger/TIGER2020PL/STATE/06_CALIFORNIA/06037/on February, 2021 and customized for LA County.
Data Fields:
1. CT20 (TRACTCE20): 6-digit census tract number
2. Label (NAME20): Decimal point census tract number
Note:
If you are interested to check original census tract 2020 boundary, review the census block 2020 data (CT20 field).
Waste Collection Service Area depicts the boundaries of the Solid Waste Collection Service Areas of different waste haulers.
Waste Collection Service Area depicts the boundaries of the Solid Waste Collection Service Areas of different waste haulers.
This layer contains the 2021 Official Supervisorial District Boundary for the County of Los Angeles, per Assessor parcels and the Department of Public Works' City/Community boundaries.
Implemented: 3/4/2022 (Refer to Use Limitations Section)
Last Updated: 7/26/2022: Removed small sliver between SD3 and SD5 .
Updated: 5/11/2022: Updated to match parcel boundaries in water areas of southeast Long Beach.
Supplemental Information: Adopted December 15, 2021 - The County of Los Angeles Citizens Redistricting Commission’s Redistricting Plan adjusting the Official Supervisorial District Boundary for the County of Los Angeles pursuant to Elections Code Sections 21530 et seq. See Resolution No. 2021-04, Resolution of the County of Los Angeles Citizens Redistricting Commission Adopting a Redistricting Plan for the Los Angeles County Supervisorial Districts pursuant to Elections Code Section 21530 et seq.and Resolution No. 2021-05, Resolution of the County of Los Angeles Citizens Redistricting Commission Adopting a Redistricting Report for the Los Angeles County Supervisorial Districts pursuant to Elections Code Section 21534, subd. (d)(3).
Per Sec. 21531 of the California Elections Code, Supervisorial District boundaries in the County of Los Angeles are adjusted in the year following the year in which the decennial federal census is taken.
Published in the County Code under Title 1, Chapter 1.08, are boundary descriptions for the Supervisorial Districts.
This layer contains Legal City boundaries within Los Angeles County. The Landbase is jointly maintained by the Los Angeles County Assessor and the Los Angeles County Department of Public Works.The Los Angeles County Department of Public Works provides the most current shape file of these city boundaries for download at its https://egis-lacounty.hub.arcgis.com/datasets/la-county-city-boundaries/explore?location=34.153321%2C-118.083123%2C9.49.
Note: This boundary layer will not line up with the Thomas Brothers® city layer.
Principal attributes include:
CITY_NAME: represents the city's name.
CITY_TYPE: may be used for definition queries; "Unincorporated" or "City".
FEAT_TYPE: contains the type of feature each polygon represents:
Land - Use this value for your definition query if you want to see only land features on your map.
Pier - One example is the Santa Monica Pier. Man-made features may be regarded as extensions of the coastline.
Breakwater - Examples include the breakwater barriers that protect the Los Angeles Harbor.
Water - Polygons with this attribute value represent internal navigable waters. Examples of internal waters are found in the Long Beach Harbor and in Marina del Rey.
3NM Buffer - Per the Submerged Lands Act, the seaward boundaries of coastal cities and unincorporated county areas are three nautical miles (a nautical mile is 1852 meters) from the coastline.
Last Updated: December 2022
This product is for information purposes and should not be used for legal, engineering, or survey purposes. County assumes no liability for any errors or omissions.
In 2014 and 2015, The LA County Enterprise GIS team under the Geographic Information Officer worked with the Unincorporated Area Deputies and Field Deputies of each Board Office to establish names that reflect the desires of residents.
CSAs differ from the more informal Community geographies because:
They are focused on broad statistics and reporting, not mapping of communities.
They represent board approved names assigned to Census block groups and city boundaries.
They cover the entire unincorporated County (no gaps).
There are not overlapping areas.
Additionally, CSAs use the following naming conventions:
All names are assumed to begin with Unincorporated (e.g. Unincorporated El Camino Village) which will not be part of the CSA Name (so the name of the Statistical Area would be El Camino Village).
Names will not contain “Island.” Beginning each name with Unincorporated will distinguish an area from any surrounding cities. There may be one or more exceptions for certain small areas (e.g. Bandini Islands)
A forward slash implies an undetermined boundary between two areas within a statistical geography (e.g. Westfield/Academy Hills or View Park/Windsor Hills)
Certain established names may include hyphens (e.g. Florence-Firestone)
Aliases may be defined in parentheses (e.g. Unincorporated Long Beach (Bonner/Carson Park))
The original set of names were derived from community names used in the 2011 Redistricting process, chosen with the assistance of the Board of Supervisors.
Updates:
(1) 2023 January: Updated layer schema to include feature type (“FEAT_TYPE”) field, which can be one of land, water, breakwater, or pier (consistent with the City Boundaries layer).
(2) 2022 December: CSA data was updated to incorporate the “Tesero Del Valle” annexation to the city of Santa Clarita. Unincorporated Valencia is now completely annexed to the City of Santa Clarita. In addition to land area, this data also includes other feature types such as piers, breakwater and water area.
(3) 2022 September: CSA data was updated to match with city boundaries along shoreline/coastal area and minor boundary adjusted in some other areas.