Address Points

Current data date: June 2012 – we will be releasing new versions of this data periodically.

This dataset contains address points from the Countywide Address Management System, a collaborative program between the County’s Registrar/Recorder, Chief Information Officer, Public Works Department, Department of Regional Planning, and many local cities [...]]]>

Address Points

Current data date: June 2012 – we will be releasing new versions of this data periodically.

This dataset contains address points from the Countywide Address Management System, a collaborative program between the County’s Registrar/Recorder, Chief Information Officer, Public Works Department, Department of Regional Planning, and many local cities to manage addresses and street centerlines for the purposes of geocoding and cartography.

What this data is (and isn’t)

This dataset contains the best available information, with close to 3 million primary and secondary addresses in the County of Los Angeles.   It does NOT include information about every unit, suite, building, and sub-address.  With probably over 7 million addresses, we have a ways to go.

Description

This dataset includes over 2.9 million individual points for addresses in the County.  Data has been compiled from best available sources, including city databases, LA County Assessor parcels, and the County’s House Numbering maps.  Please see the Source field for information.

Street Name information has been split into multiple fields to support the County’s specifically designed geocoders – please see the entry on LA County Specific Locators and Matching rules for more information.

Multi-address Parcels

Some of our data sources (LA City, LA County, for example) have mapped each individual address in their city.  These may also show unit information for an address point.  A property with multiple addresses will show a point for each address.  For some cities where this has not happened, the data source is the Assessor, where the primary address of the property may be the only address shown.  We invite cities and sources with more detailed information to join the CAMS consortium to continue to improve the data.

Legal vs. Postal Cities

Many users confuse the name the Post Office delivers main to (e.g. Van Nuys, Hollywood) as a legal city (in this case Los Angeles), when they are a postal city.  The County contains 88 legal cities, and over 400 postal names that are tied to the zipcodes.  To support useability and geocoding, we have attached the first 3 postal cities to each address, based upon its zipcocode.

For a full list of zipcode to postal city correlations, see this file: zipcodexxpostalcities (zipped .dbf file)

Download the data

•  Data Download in ESRI Shapefile Format (123 Mb): lacounty_address_points.zip (zipped shapefile)

Importantly, it includes the zoning codes for each city, their general plan codes, and a generalized general plan code developed by SCAG to support regional analysis. This information was consolidated by [...]]]> This dataset was developed in 2009 by the Southern California Association of Governments (SCAG) to provide a Countywide zoning and general plan information.

Importantly, it includes the zoning codes for each city, their general plan codes, and a generalized general plan code developed by SCAG to support regional analysis.  This information was consolidated by SCAG, with QAQC done by local jurisdictions.

Download the data

• Zoning Shapefile (640 Mb zip file).  Please take care when downloading: zoning_countywide.zip (shpped shapefile)
• SCAG Land Use Codes (.dbf file that can be joined on the scag_gp_co field): scag_land_use_codes.zip (zipped dbf file)
• For a detailed description of the land use codes, download the Land Use Code Descriptions (word file)

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.

Click here for their Data Sales – General Information page.

Click here for their Price List.

Some layers included (not an exhaustive list):

• parcel boundary map (shapefile format)
• local roll
• LA County wall map
• publicly owned parcels
• sales list
• unsecured roll
• and labels (for mailings)

A discussion of parcel accuracy

Occasionally 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.