GIS

Maricopa County AZ GIS tools make it much easier to answer everyday questions about property, flooding, roads, voting locations, and the natural environment. This guide walks through how the county’s Geographic Information System (GIS) works, which official mapping sites are available, what kind of data you can expect to find, and how residents, businesses, and professionals can confidently use these maps and data in their own decisions and projects.

Start with the county GIS hub for maps, imagery, and data

When people talk about “Maricopa County AZ GIS,” they’re usually referring to the county’s central collection of interactive maps, imagery, and spatial data managed by county staff. The county’s GIS program provides mapping, imagery, and geographic analysis services to both residents and internal departments so everyone is working from the same consistent, authoritative location-based information.

A smart first stop is the official GIS Maps page, which serves as a hub connecting you to mapping applications, imagery, data downloads, and help options. You can reach it from the county site or directly through the dedicated GIS Maps page.

What you’ll find through the GIS Maps hub

From that hub, you can move into several key GIS services that the county highlights as “common requests,” including:

Interactive map viewers for parcels, zoning, floodplains, transportation, and more
Imagery resources such as countywide aerial photography
Data request routes for specialized needs
System status alerts so you know if a GIS app is down for maintenance
Feedback channels to report an error or suggest improvements

Behind the scenes, these tools are maintained by the county’s GIS professionals, who coordinate with many departments (Assessor, Flood Control District, Transportation, Elections, Parks, and others) so that the datasets line up with official records and operational systems as closely as possible.

Dive into GIS mapping applications for everyday questions

Most residents don’t need to download raw GIS data. Instead, they use web mapping applications built on top of that data. Maricopa County groups many of these into one place on its GIS mapping applications site, which is designed as a public portal for everyday map use.

Types of GIS mapping applications you can expect

On that portal, apps are organized into categories that reflect common local concerns:

General maps – parcels, overdue property taxes, historical aerial imagery, planning and zoning, survey points, parks and trails, no-fence districts, lake water levels, and waste/recycling facilities

Flood maps – FEMA floodplains, floodplain change studies, rainfall and weather, and model results from technical flood studies

Transportation maps – road information, road closures, long-range system plans, and interactive active-transportation planning tools

Environmental maps – mosquito management, restaurant inspection ratings, air quality, environmental health districts, and related public health mapping

Each application focuses on a specific problem, so you don’t have to sort through layers you don’t need. For example, one app might be dedicated to showing floodplains and elevation certificates, while another focuses only on parks, trails, and amenities.

Use GIS to look up parcels, property lines, and land information

One of the most frequent uses of Maricopa County AZ GIS is to answer property and parcel questions. Whether you’re a homeowner trying to understand your lot, a real-estate professional preparing disclosures, or an engineer checking a site, GIS parcel maps are usually where you start.

Explore properties with the Parcel Viewer

The Assessor’s Office maintains a dedicated Parcel Viewer that lets you visualize parcels across the county. Within this viewer, you can:

Search by parcel number (APN)

Zoom to a specific address or area

Turn layers on or off, such as parcel boundaries, subdivision outlines, township and range lines, and city boundaries

View aerial imagery from many different years, going back decades

Pull up parcel attribute details maintained by the Assessor

Because this viewer is tied directly to the Assessor’s GIS layers, it’s particularly useful when you’re trying to understand how parcels fit together, where approximate lot lines lie in relation to imagery, or how a subdivision is organized.

Understand what parcel GIS data can (and cannot) do

The county emphasizes that parcel GIS maps are designed for general reference only. They are extremely useful for:

Getting a visual sense of parcel shape and approximate location
Seeing how parcels relate to streets, other lots, or physical features
Quickly navigating to the correct parcel to review Assessor information

However, digital parcel lines are not a substitute for a legal survey or title work. If you need a boundary located precisely—for example, for construction or a legal dispute—you still need to rely on recorded documents and, when necessary, licensed surveyors. GIS is a powerful guide, but it is not a legal document by itself.

Tap the GIS Open Data portal for downloads and analysis

If you work with mapping software, perform analysis, or support projects that need countywide data layers, you’ll want to use the county’s GIS Open Data portal. This site is built to let people discover, preview, and download data that the county’s GIS program publishes.

What kinds of GIS datasets are available?

Within the open data portal, you can search and filter datasets by topic, such as:

Parcels and property data – parcel boundaries and related property information

Flood Control District – layers related to floodplains, structures, and projects

Conservation and natural environment – datasets that describe terrain, land conservation, or environmental features

Elections and Recorder’s Office – election-related geographies and recorder data

Special topics – such as school reopening dashboard data and other county initiatives

Many of these datasets are updated on a daily, weekly, or monthly schedule, and the portal notes that frequency so you know how fresh the data is before you use it.

How to use open GIS data responsibly

The county provides clear disclaimers for its open data and maps. In practice, that means:

Treat GIS open data as a powerful reference and analysis tool, not as a substitute for official legal records.

Verify anything that will go into legal documents or binding decisions by checking with the originating office (for example, Assessor, Recorder, or Flood Control District).

Expect that there may be occasional errors or omissions due to how data is collected, processed, or updated.

For classrooms, community projects, or general planning, this open data portal is an excellent way to bring Maricopa County AZ GIS into your own mapping software and explore patterns across the county.

Check flood risk and water projects with GIS flood maps

Flooding and drainage are major concerns in the desert, especially when new development is planned near washes or rivers. The county’s GIS flood maps help residents and professionals understand where flood risks exist and how they are managed.

Review FEMA floodplains and elevation certificates

The Flood Control District supports a dedicated Floodplains and Elevation Certificates viewer. This application allows you to:

View effective FEMA 100-year floodplains within the county
Identify areas where elevation certificates are available
Zoom to a specific property or area of interest
See how floodplains relate to parcels, streets, and other features

This is especially important when you’re:

Evaluating a property purchase in or near a flood-prone area
Preparing documentation for insurance or mortgage underwriting
Planning development that might affect drainage or require mitigation

Again, GIS helps you visualize the situation quickly, but final determinations should rely on official flood studies, FEMA maps, and professional review.

Use GIS to understand flood studies and projects

Beyond floodplains, the county’s flood-related GIS tools also show:

Active and completed flood control projects
Model outputs from two-dimensional flood studies
Historical and current rainfall and weather data used to support decisions

For engineers and planners, these layers give important context for how flood risk has been studied and managed. For residents, they offer reassurance that flood control infrastructure and planning are guided by detailed geographic analysis.

Navigate road information, closures, and long-range planning

Transportation is another area where Maricopa County AZ GIS is heavily used. Road ownership can be complex, construction closures move around, and long-range planning involves many moving parts. GIS mapping makes this information easier to understand.

Track road closures with interactive GIS maps

When you need to know whether a road is open or how construction might affect your route, the county’s Road Closures map provides interactive information. With that application, you can:

Pan and zoom across the county to see where closures are in effect
Click on specific segments to view details about the closure
Understand how a closure interacts with nearby intersections and detours

Because it’s map-based, you can easily see the broader context—something that’s harder to visualize from a simple written list of closures.

See the bigger picture with transportation GIS layers

Transportation GIS tools, including long-range transportation system and active-transportation planning maps, help:

Show which roads the county maintains
Identify key corridors for growth and investment
Collect public comments about bicycle and pedestrian needs

These applications give residents a voice in planning, while staff use GIS analysis to weigh competing priorities, evaluate safety, and coordinate with other infrastructure.

Explore parks, trails, and recreation amenities with GIS

Parks and trails are another popular entry point into Maricopa County’s mapping system. GIS allows the Parks & Recreation Department to show not just park locations, but also individual trail segments, amenities, and even trail surfaces.

How recreation mapping helps residents

With GIS-based parks and trails maps, you can:

Find a regional park or trail system near you
Explore trail loops, elevation profiles, and access points
Identify trailheads, parking, restrooms, and other amenities
Understand how regional trails like the Maricopa Trail connect across the county

Because these maps are constantly updated as new trails are built or rerouted, they provide more current information than a static printed map on its own.

Use environmental health and air quality GIS tools

Maricopa County also uses GIS to support public health and environmental protection. Map viewers help residents quickly see whether a location is near certain facilities or areas of concern.

Examples of environmental GIS applications

Environmental mapping tools include viewers that:

Show mosquito trap and treatment locations so residents can understand control efforts

Display restaurant inspection ratings across the county, allowing you to explore licensed facilities on a map rather than searching one by one

Present current air quality information and locations of air quality facilities

Show environmental health districts and office locations to clarify which team covers a specific site

These applications demonstrate how GIS supports transparency: instead of reading long tables or lists, users can inspect the same data in a visual, geographic format.

Turn GIS into a civic tool for elections and voting

Location is central to elections: where you vote, which districts you’re in, and which jurisdictions have elections at any given time all depend on geography. Maricopa County Elections relies on GIS to provide clear, accurate information to voters.

Find voting locations with an elections GIS map

The Where to Vote locator uses GIS to show:

In-person voting locations and secure drop boxes
Hours of operation and site details
Ballot replacement centers during certain elections

By entering an address, voters can see options near them instead of reading through long lists. Because the sites change depending on the election, the map is especially helpful for staying current.

How GIS supports election transparency

Beyond the voting location map, election-related GIS is also used to:

Display election results geographically
Support reprecincting and redistricting work
Provide data to cities and towns that rely on county election support

These uses help demonstrate how Maricopa County AZ GIS is woven into the civic process, not just infrastructure and land management.

Rely on survey control and land records through GIS

Surveyors, engineers, and planners need more than parcel lines: they need control points and detailed land records that underpin measurements and designs. The county maintains GIS tools specifically for that audience.

Access land survey points and control information

The Land Survey Points application allows users to view and work with survey control data managed by the Maricopa County Department of Transportation. Through this tool, professionals can:

Locate primary and secondary control points
Explore public land survey system (PLSS) corners and their status
Download or export survey data for further use
See how survey control relates to parcels, roads, and public land ownership

Because survey control underlies so many other datasets, keeping this information accessible in GIS form helps maintain consistency across the county’s mapping efforts.

Understand the limits of survey GIS data

As with other GIS tools, the county emphasizes that survey-related maps and data are provided with disclaimers. Users are reminded that:

Datasets may contain errors due to original sources or processing
The data is provided without warranty and should be independently verified
Commercial reuse is restricted without proper agreements where applicable

Professional users should treat GIS survey data as a strong starting point, then confirm critical measurements through standard surveying practice.

Connect GIS data across departments and services

One of the strengths of Maricopa County AZ GIS is how many departments rely on it. The same base maps, imagery, and address data can support:

Assessing and taxing property
Planning and regulating land development
Designing, operating, and maintaining transportation infrastructure
Managing floodplains and drainage projects
Supporting elections and voter outreach
Protecting public health and the environment
Managing parks, trails, and recreational amenities

By centralizing GIS services, the county avoids conflicting maps and duplicated effort. Residents benefit from consistent location information, no matter which department they’re dealing with.

Know how Maricopa County describes GIS data accuracy

Across the various viewers and portals, Maricopa County repeats a consistent message about GIS data:

Maps and data are designed for general reference.

They are not a substitute for a title report, official survey, or other legal documents.

There may be delays between when a change happens and when it appears on the map.

Users are responsible for verifying information before relying on it for legal or financial decisions.

In many applications, the county also notes that users agree to indemnify the county from claims related to the use of the information. While that sounds formal, the practical takeaway is simple: use GIS to understand patterns, locations, and context, then confirm important details directly with the relevant office.

Get help or share feedback with the county’s GIS teams

Because GIS is used across so many departments, the county offers multiple ways to connect with GIS-related staff:

The GIS Maps hub points to mapping applications, system status alerts, and feedback forms.

The open data portal provides contact information for enterprise GIS support.

The staff directory includes a specific entry for Geographic Information Systems within the Office of Enterprise Technology.

If you notice something that looks wrong on a map, or if you need help understanding how to use an application, reaching out through these official channels is the best way to get accurate guidance from the teams that manage Maricopa County AZ GIS.

GIS-related departments and offices

Geographic Information Systems – 301 S 4th Ave, Phoenix, AZ 85003 – Phone: (602) 506-7116

Office of Enterprise Technology – 301 S 4th Ave, Phoenix, AZ 85003 – Phone: 602-506-4357

Maricopa County Assessor’s Office – Phone: (602) 506-3406

Maricopa County Elections – 510 S. 3rd Ave, Phoenix, AZ 85003 – Phone: 602-506-1511

Maricopa County – 301 West Jefferson Street, Phoenix, AZ 85003 – Main Line: 602-506-3011

Maricopa County GIS FAQs

How do I get to the official county GIS maps hub online?

Start by bookmarking the county’s central GIS Maps page, which pulls together mapping apps, imagery, data request forms, and system status messages in one place. From this hub you can jump straight into commonly used tools like map viewers, imagery consortium information, and feedback forms for reporting issues with layers or apps. Visit the county’s GIS Maps hub whenever you need an authoritative starting point for any county mapping question.

Where can I download county GIS datasets for my own mapping projects?

If you work with desktop GIS or need raw layers, use the county’s GIS Open Data portal. There you can search by topic—such as parcels, flood control, conservation, or elections—and download data in formats compatible with common mapping software. The portal notes how frequently each dataset is updated, and the disclaimer reminds users to treat these layers as reference information and to double-check anything that will be used in legal documents, permits, or contracts.

What official web maps should I use for everyday property, flood, and transportation questions?

The county groups its public web maps on the GIS Mapping Applications page. From there you can open focused apps for parcels and overdue property taxes, FEMA floodplains and elevation certificates, rainfall and weather, road closures, transportation system planning, mosquito management, restaurant inspections, and air quality. Each app is built around a specific task, so you can quickly jump into the viewer that matches your question instead of turning dozens of layers on and off yourself.

How do I look up a specific parcel and see what surrounds it?

For detailed parcel-level questions, use the Assessor’s Parcel Viewer. You can search by parcel number or address, turn parcel and subdivision boundaries on and off, and overlay recent aerial imagery to understand how a lot fits with nearby streets, washes, or other development. The viewer includes a caution that parcel lines are approximate and may not match recorded documents exactly, so it’s helpful for orientation and research but not a replacement for a survey or title work.

Can I check my voting location and election maps through the county’s GIS?

Yes. Maricopa County Elections provides a dedicated Where to Vote locator that uses GIS to show in-person voting locations and ballot drop boxes based on your address. The map reflects which locations are open for a specific election and lets you filter by voting option, so you can quickly see what’s available near you. For more advanced election mapping—such as results or redistricting information—you can navigate from the elections site into additional map viewers and data pages referenced there.