Description: This layer represents current city boundaries within Los Angeles County. The Los Angeles County Department of Public Works provides the most current shapefiles representing city boundariesand city annexationson the Los Angeles County GIS Data Portal. True, legal boundaries are only determined on the ground by surveyors licensed in the State of California. Numerous records are freely available at the Land Records Informaitonwebsite, hosted by the Department of Public Works.Principal attributes include:CITY_NAME: represents the city's name.CITY_TYPE: may be used for definition queries; "Unincorporated" or "City".FEAT_TYPE: identifies the feature that each polygon represents:Land - This value is used for polygons representing the land masses, if you want to see only land features on your map.Pier - This value is used for polygons representing piers along the coastline. One example is the Santa Monica Pier.Breakwater - This value is used for polygons representing man-made barriers that protect the harbors.Water - This value is used for polygons representing navigable waters inside the harbors and marinas.3NM Buffer - This value is used for polygons representing the three seaward nautical miles within the cities' limits, per the Submerged Lands Act.POPULATION: Information in this field is supplied by Mark Greninger (mgreninger@cio.lacounty.gov).Reference Date: 2013
Copyright Text: This data is maintained by the Los Angeles County Department of Public Works. Contacts: James Kulbacki, 626-458-7113, JKulbacki@dpw.lacounty.gov; Thierno Diallo, 626-458-6920, tdiallo@dpw.lacounty.gov; Michael Maung, 626-458-7078, mmaung@dpw.lacounty.gov
Description: This layer contains the 2011 Official Supervisorial District Boundary for the County of Los Angeles, drawn at the parcel level, per Assessor parcels and the County Cadastral Landbase.Supplemental Information: Adopted September 27, 2011 – Another entry on this portal includes redistricting information from the Districts’ adoption in 2011, along with boundaries drawn at the TIGER street map level. Per Sec. 21500 of the California Elections Code, Supervisor District boundaries are adjusted following each decennial federal census. Published in the County Code under Title 1, Chapter 1.08, boundary descriptions are based on census tracts and city boundaries at the time of adoption.Metes and Bounds descriptions were prepared by the Department of Public Works.2010 Census Blocks provide more information and GIS data downloads on this portal. Census tracts listed in the County Code correspond to the first six digits of the GIS attribute CTCB10.City Boundaries and City Annexations provide current and historical legal city boundary information on this portal.
Copyright Text: Thierno Diallo
Geographic Information Manager
County of Los Angeles
Department of Public Works Survey/Mapping and Property Management Division
Description: 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.
Copyright Text: Emilio Solano
Los Angeles County
Assessor
500 W Temple Street
Los Angeles, CA 90012
esolano@assessor.lacounty.gov
Description: The CSA project was developed to provide a common geographic boundary for reporting departmental statistics for unincorporated areas to the Board of Supervisors. The CIO and the LA County Enterprise GIS group worked with the Los Angeles County Board of Supervisors Unincorporated Area and Field Deputies to establish names that reflect as best as possible the general name preferences of residents and historical names of areas. A Board Motion will establish these area names as “Board Approved.” CSAs differ from the more informal “Community” geographies because:They are primarily focused on broad statistics and reporting, not mapping of communities.They represent board approved geographies comprised of Census block groups split by cities.They must cover the entire unincorporated CountyThere can be no holes or overlapping areasThe CSAs originally were created using Census Block Groups split by cities (e.g. "Split Block Groups") as a geographic building block. These boundaries are subsequently updated as needed based on city's annexation/deannexation records. In the City of Los Angeles, the LA City Neighborhood file was overlaid on the Block Groups and boundaries assigned using the centroid of the block group - therefore, while the names of the CSAs in LA City match the neighborhood file, the boundaries are not the same.Additionally, CSAs are to be named according to the following recommended naming conventions:All names will be assumed to begin with “Unincorporated” (e.g. Unincorporated El Camino Village) for the unincorporated areas. They will not be part of the Statistical Geography 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))Data Fields:CITY_TYPE: Incorporated cities or unincorporated areasLCITY: Name of incoprporated citiesCOMMUNITY: Unincorporated community names and LA City neighborhood names.
Copyright Text: Los Angeles County Enterprise GIS (eGIS)
egis@isd.lacounty.gov
Description: Water Purveyor Service Area boundaries which also contain the contact information of the water companies.
Copyright Text: Los Angeles County Department of Public Works
Survey/Mapping and Property Management Division
Francis Calasanz
(626) 458-3542
Waterworks Division
Michael Roach
(626) 300-3343
Data Updated by Htoon Chao/Viki Yip
NOTE: Los Angeles County Department of Public Works Waterworks Division only maintains areas that are covered by waterworks districts.
Description: These are the jurisdictions covered by the four Road Maintenence District tree crews. It was derived from the Road Maintenance District boundary layer as the tree units cover the same areas as the road crews although there is only one tree unit per each of the 4 MDs, whereas there can be many road crew RDs per MD. To create the layer all of the RDs in each MD were merged into one multi-featured polygon. This layer is used in the Service Locator and The Works App.
Description: This data is not for tax collection purposes. It is used to expedite Road Maintenance operations. This data is typically updated to coincide with city annexations. The most current data is available for public downloading at the Los Angeles County GIS Data Portal. See http://egis3.lacounty.gov/dataportal/2011/01/27/los-angeles-county-road-maintenance-district-boundary/
Copyright Text: If any questions, contact Thierno Diallo (tdiallo@dpw.lacounty.gov)
Description: The Los Angeles County Waterworks Districts boundary layer was created by the GIS and Mapping Unit of the Waterworks Division from the legal descriptions of the initial formations of the Districts and updated with subsequent annexations (additions to) and detachments (subtractions from) of the Districts. The boundaries are used internally for analysis and planning and are used by the general public to find the Water Utility for their property when accessing the Service Locator on the Public Works website.
Copyright Text: Los Angeles County Public Works
Waterworks Division
Michael Roach (626) 300-3343 Data updated by Htoon Chao / Viki Yip
Information Technology Division
John Halaka
(626) 458-4125
Description: The US Congressional Districts layer contains polygons for US Congressional Districts. The source for the information in this layer is the Los Angeles County Registrar/Recorder's Precinct Information File (PIF), The boundries are based on the 2010 Census as provided by the California Secretary of State in 2011.
Copyright Text: Los Angeles County - Registrar-Recorder/County Clerk
Geographic Information Systems Section
_GIS@rrcc.lacounty.gov
Description: The State Assembly Districts layer contains polygons for 2010 California State Assembly Districts. The source for the information in this layer is the Los Angeles Registrar/Recorder's Precinct Information File (PIF),The boundaries are based on the 2010 Census as provided by the California Secretary of State in 2011.Where boundaries are defined by streets, water, city boundaries, or other features, those arc segments are copied to the districts layer, so that the boundaries and other layer features match perfectly.
Description: The State Senate Districts layer contains polygons for California State Senate Districts. The source for the information in this layer is the Los Angeles County Registrar/Recorder's Precinct Information File (PIF), The boundaries are based on the 2010 Census as provided by the California Secretary of State in 2011.Where boundaries are defined by streets, water, city boundaries, or other features, those arc segments are copied to the districts layer, so that the boundaries and other layer features match perfectly.
Description: LA City Council Districts as adopted by Final Ordinance 2012 No. 182168. This data was provided by the City of Los Angeles.These boundaries are legally accurate as specified by the Los Angeles City Bureau of Engineering.Updated December 2013.
Copyright Text: Randy Price
Division Manager
City of Los Angeles
Bureau of Engineering
Description: The CSA project was developed to provide a common geographic boundary for reporting departmental statistics for unincorporated areas to the Board of Supervisors. The CIO and the LA County Enterprise GIS group worked with the Los Angeles County Board of Supervisors Unincorporated Area and Field Deputies to establish names that reflect as best as possible the general name preferences of residents and historical names of areas. A Board Motion will establish these area names as “Board Approved.” CSAs differ from the more informal “Community” geographies because:They are primarily focused on broad statistics and reporting, not mapping of communities.They represent board approved geographies comprised of Census block groups split by cities.They must cover the entire unincorporated CountyThere can be no holes or overlapping areasThe CSAs originally were created using Census Block Groups split by cities (e.g. "Split Block Groups") as a geographic building block. These boundaries are subsequently updated as needed based on city's annexation/deannexation records. In the City of Los Angeles, the LA City Neighborhood file was overlaid on the Block Groups and boundaries assigned using the centroid of the block group - therefore, while the names of the CSAs in LA City match the neighborhood file, the boundaries are not the same.Additionally, CSAs are to be named according to the following recommended naming conventions:All names will be assumed to begin with “Unincorporated” (e.g. Unincorporated El Camino Village) for the unincorporated areas. They will not be part of the Statistical Geography 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))Data Fields:CITY_TYPE: Incorporated cities or unincorporated areasLCITY: Name of incoprporated citiesCOMMUNITY: Unincorporated community names and LA City neighborhood names.
Copyright Text: Los Angeles County Enterprise GIS (eGIS)
egis@isd.lacounty.gov
