Assessor Parcels from the 2014 Tax Roll are now available for download!
The Office of the Assessor (click here for their website) maintains assessment records of real and personal property in the County of Los Angeles, as well as a GIS Tax Parcel Base Map. The Assessor has recently changed its policies and will be releasing a number of datasets publicly over time. They will be available here, as well as on the County’s Open Data Portal (click here to learn more). To access the Property Assessment Information System, where you can search for properties and see maps and imagery, go to the PAIS website.
Data Download
The 2014 Parcels with associated Tax Roll information can be downloaded by clicking on the link below. Due to the size (over 500 MB), this is a zipped file geodatabase in ESRI format. For API access and other downloads, the Open Data Portal will enable that once it is rolled out mid-March.
Click here to download the 2014 Parcels.
Data for Purchase
The Assessor still maintains a few datasets for sale, including the full parcel dataset. The Assessor Data Sales Page has the list of data.
Methodology
At the end of every year, the Assessor finalizes the “Tax Roll,” which is the list of parcels that are sent to the Treasurer/Tax Collector, and to whom tax bills are sent. This process is called “roll closure.” Changes due to sales, splits, and other parcel changes are tracked from that point forward, but are not included in the 2014 Tax Roll file.
The Assessor Mapping Unit is updating parcel boundaries and creating new parcel numbers as changes occur (over 30,000 per year). The mapping unit tends to be ahead of the parcel data files, so there may be parcel boundaries with new parcel ID numbers that are not represented (yet) in the tax roll file. In those cases a user will find that the parcel boundary does not have associated Tax Roll information.
Some data notes
- Property Address Information – Note that because government owned properties are not taxed, the Assessor does not maintain property address information for many of these properties.
- Property Value – the best field is most likely Roll_totLandImp, which is the combined Land and Improvement Value. Exemptions are included in the netTaxableValue_LandImp_lessREXHOX field.
- Use Code – Use Codes provide valuable information about the general use of the property. Click here for the Use Code Reference
- Boundary Description fields – Note that this is NOT a legal description – it is a description used by the Assessor to provide information about the boundaries. Note as well that there are cases where there will be information on the last line, but not on line 1.
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.
