What does this mapping application do?

It runs inside a web browser, shows street map and aerial map of the City of Gaithersburg, and displays basic information about properties (parcels) within the City.


The mapping application contains information and data compiled and processed by the City and third parties. The City makes no representation or warranty that the information contained in the data is accurate, true or correct. In using the Data, you understand and agree that the information contained therein is subject to error, and cannot be relied upon without verification or site inspection.

You understand and agree that your use of the data presented in the mapping application is at your sole risk. The information is made available on an "as is" and "as available" basis without any warranties of any kind, whether express or implied, including without limitation, implied warranties of merchantability, fitness for a particular purpose, and non-infringement. Should there be an error, inaccuracy, or other defect in the Data, you assume the full liability for and cost of correcting any such error, inaccuracy or defect.

How do I zoom in or zoom out of the map?

  • You can zoom in or zoom out the map by clicking +/- buttons on the map.
  • If you are using a smart device such as iPad, you can pinch-zoom in and out using your fingers.
  • If you are using a device with a wheel mouse, you can scroll up or down to zoom in and out.
  • If you are using a desktop PC, you can press Shift while you draw a box to zoom in, and press Shift + Ctrl while you draw a box to zoom out.

How do I view details about a property (parcel)?

  • If you already know the location on the map:
    Zoom to the area where the property is located by zooming and panning. Once you see the property of your interest, click (or tap with finger) the property. An information window will show up.
  • If you know the address of the property:
    Simply start typing the address in the address input box. Once your address shows up as a candidate, click the address. The map will automatically zoom to the property, and an information box will show up. If no matching City address is found, check your street number, street name, and street type.

How is this mapping application built?

This application was built in-house using the City’s GIS system. All the GIS data is stored within the City’s GIS database, and being served out as ArcGIS server services. ESRI's ArcGIS Server JavaScript API was used to build a web mapping application.

What if I find an error, have a suggestion or question about the application?

Please click "Contact Us" button and send us an email! We would love to hear from you.

Tell me about the data used in this application.

There are many data layers and several map services that comprises this application.

Aerial Map

The City acquires a new aerial imagery in every 2 - 3 years. The current imagery is from 2017 and has a 3 inch resolution. Users can zoom to 1:288 scale without the image becoming pixelated.

Street Map

Since rendering a dynamic and complex map takes a long time, we cache images for street map. Due to the nature of serving out static, pre-cached images, sometimes the street map doesn't reflect the most up-do-date information we have in the system.

Information Window

GIS data layers utilized in the information window come from several sources.

GIS Data Layers
Address Maintained by the City staff.
Parcel (tax account)The parcel (property) boundary information is maintained by the City staff, while the attribute information comes from State Department of Assessments & Taxation (SDAT).
Zoning Maintained by the City staff. The boundary between different legal land use zone areas (zoning), as defined in Chapter 24 of the City of Gaithersburg Code.
Neighborhood Maintained by the City staff. City staff, including members of Neighborhood Services and the Planning Division, developed critera to place each tax parcel within a staff-defined "neighborhood" boundary. The critera used included reference to legal subdivisions, utilizing community association areas, recognizing historic districts and areas of the City that were historically considered as a "neighborhood," and staff knowledge.
Enterprise Zone State-designated tax incentive zone in Gaithersburg, MD. More information is available in State's Department of Commmerce web page.
Recycling Day Maintained by the City staff. The information window shows recycling pick-up date for eligible residents. Please visit the City's recycling program page for details.
City Election Maintained by the City staff. Please visit City's elections page for details.
School Districts The current data shows the information for 2020 - 2021 School year obtained from Montgomery County Public Schools (MCPS). The MCPS boundary information contained in the mapping application is subject to change. Please verify school assignments with MCPS boundary line at (240)314-4710.