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Geographic Information Systems (GIS) is a relatively new technology that
is used in a wide variety of applications such as: transportation, crime
analysis, land management, real estate, environmental impact analysis, flood
control, utilities, terrain modeling, emergency response, and much more. A GIS
consists of any number of various layers of spatial data such as parcels,
streets, district boundaries, utility lines, rivers, or anything that can be
shown by location. This spatial data is linked to tables of information about
the spatial feature, for example, parcels may have a table with an ID number,
ownership information, and an address. The spatial and tabular data combined is
compared, analyzed, and queried to extract information about their
relationships. This information, displayed with a graphical representation
(map), is used for easier comprehension and better decision making for
managers, analysts, technicians, support staff and assistants.
 For
much of its history, the Maricopa County Assessor's Office has had a completely
manual, paper system of mapping. Around 1994, the department implemented a
Computer Aided Drafting (CAD) program to draw all new subdivisions, but left
the older subdivisions on paper. In 1996, a GIS centroid (point) layer was
developed to provide some amount of analysis capabilities. Then around the
beginning of 1998, the office dedicated itself to converting to a completely
digital system. With an average of 35,000 parcel changes each year and being
the fastest growing County in the nation, the Assessor's Office needed a more
efficient, robust system to provide quality service to its customers. After
reviewing several bids from vendors, the department chose Smart Data Strategies
(SDS) to convert all of its paper maps to digital files, a process that was
completed in April of 2002. The office is currently designing several automated
routines and applications to utilize the new digital data. With the new GIS
system, and other ongoing development, the County hopes to:
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Better track
parcel information for more accurate valuations and faster appeals.
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More quickly
capture new parcels and assign Assessor's Parcel Numbers (APNs).
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Speed up the
issuance of building permits for developers and cities.
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Automate tedious
functions that were previously done manually.
- Automatic calculation of
areas
- Revision Block Automation
- Map Output Automation
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Provide easier
access to parcel maps on a PC desktop
- Web Site (Public)
- Customized applications in Visual Basic (Internal)
- ESRI ArcView and Explorer (Internal)
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Utilize spatial
queries, overlay functions and graphics of GIS
- Analysis
- Custom Maps
** All adding up
to a cost savings to the citizens by faster and more accurate service.
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The Maricopa County Assessor's office realizes the enormous costs of
data collection for a GIS system. Therefore, the department is dedicated to
freely sharing all spatial and tabular information as a public record, as long
as it is not to be distributed in any way for commercial sale, resale or profit
by a non-County entity. This open information policy would include, but is not
limited to:
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Private Citizens
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Maricopa County Agencies and
Departments
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Incorporated Cities
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Arizona State Agencies
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Federal Agencies
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Arizona Native American
Communities
Should a
commercial company desire the data for resale or profit, they would need to
purchase that data under the County's data pricing policy.
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 The
Maricopa County Assessor's GIS Mapping office has a wide variety of duties
ranging from assigning parcel numbers for new subdivisions to in-depth spatial
analysis. Here are some of our responsibilities:
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Timely and accurate assignment of Assessor's Parcel Numbers
(APNs) for all new subdivisions. Under a new departmental policy to expedite
the parcel number assignment, in order for jurisdictions to assign permits more
quickly, the office will have an accelerated parcel
number assignment program,
provided certain criteria are met.
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Timely and accurate capture of all new subdivisions in a digital
format. Our office is responsible for producing a digital CAD drawing of all
new subdivisions for use by the public and internal appraisal staff. For the
last several years these drawings have been input using Coordinate Geometry
(COGO). The maps are drawn in MicroStation using the Assessor's
CAD standards.
All assessor parcel maps are standardized versions of the recorded plat map and
are merely a representation of parcel features. While the office makes every
effort for accuracy, these maps are not engineering accurate and should not be
used for applications requiring extreme positional accuracy. Over the past
several years, our jobs have been greatly aided with the help of local
engineering firms and jurisdictions who have been graciously providing us with
digital copies of the recorded plat maps. With digital copies, it is estimated
that the county tax payers save in excess of $90,000 a year when factoring the
time required to draw these same subdivisions by hand. In 1998, the department
processed over 700 new subdivisions in Maricopa County with approximately five
full time technicians.
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Timely and accurate capture of all land splits in a digital
format.
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 The
Maricopa County Assessor's Office uses a wide variety of popular CAD and GIS
software for its cadastral mapping. These products were chosen to fill
specialized mapping functions and, where needed, conversion routines were
written to integrate or utilize the data across different data formats. The
links provided below are not an endorsement of any of these products, but
merely a reference to show the capabilities and uses of the software as it
pertains to GIS mapping.
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SOFTWARE
- Bentley
MicroStation V8 -- A CAD product used for all edits and updates of
parcels.
- ESRI ArcView 9.1
- ESRI ArcInfo 9.1
-- Used for creation of GIS layers, GIS analysis, and quality cartographic
displays.
- Autodesk MapGuide
6.5 -- Used to display the GIS layers on the web site.
- Autodesk Autocad -- The department
uses this CAD product primarily for conversion of some AutoCad files to
MicroStation.
- Windows 2000 and XP -- The operating system.
- Corel Draw 8 -- Used to produce and manipulate raster files for the web and
other displays.
- Oracle 10g -- The main database which houses all of the property data for the
County.
- MySQL 5 -- Web page map annotation database.
- Microsoft Access -- Used for smaller departmental applications of tracking
work.
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HARDWARE
- Map Guide Server - Dell PowerEdge 6600
Dual Xeon 3.0GHz Processors/4MB Cache
4 Gigabyte RAM
876 Gigabytes of storage
Redundant Power Supply
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OUTPUT DEVICES
- Hewlett Packard Design Jet 1055 36" -- Used for large color maps.
- Hewlett Packard Design Jet 750C 36" -- Used for large color maps.
- Xerox 8825 -- High speed, large format plotter for parcel maps. Top
Check the County job board for
any openings!
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