Mapping Software

The County is providing a free, web-based, mapping software so that individuals and community groups can participate in the redistricting process. The online software is available for use by the public to prepare and submit Redistricting Plans for the CRC’s consideration. This is a soft launch of the mapping software meant to give members of the public time to learn how to use the tool. We will continue to refine the software to include additional features such as sharing plans among users.

If you would like to report an error or if you are in need of personalized help with the mapping software, please email tle@crc.lacounty.gov. Personalized help is available in English, Spanish, Mandarin, Farsi, Hindi, Korean, and Vietnamese. Interpreters will be provided for additional languages. 

IMPORTANT NOTE:  As required by California State Law (Election Code section 21003 via Assembly Bills 420, 1986, and 2172), the incarcerated population will need to be counted in their last known place of residence. We expect to have these data and final dataset by the end of September 2021. Plans submitted prior to the upload of this final dataset are considered preliminary and not final. The LA County CRC will review and consider preliminary plans (in concept) and final plans submitted by the public. Only submitted plans prepared with the final and full dataset will be considered final. Once the new dataset is uploaded, all working plans will be deleted. We recommend that you save your shapefiles so that you can use them to review with the final dataset with the adjustments for the incarcerated population. It is this dataset that must be used for any official maps. Click here to watch a video from Esri to learn more about exporting and importing shapefiles.

TRAINING: Priti Mathur from ARCBridge will held a free public workshop on “How to Use Redistricting Mapping Software” on Thursday, September 9, 11:00 am (PST). Click here to view the recording.

How to Create and Submit Redistricting Plans

Creating and submitting a map is now possible through a free, web-based, mapping tool developed by Esri. Below are steps and videos to help you get started on developing maps and plans for the Commission to consider:

  1. Click here to access the redistricting mapping tool. Alternatively, copy and paste into your web browser: https://redistricting-lacounty.esriemcs.com/redistricting/index.html.
  2. Click on “Create an account” and enter in your name, email, the username you would like, and a password.
  3. Click “Sign in To Portal for ArcGIS” to log in with your new username and password.
  4. Select which template you would like to start with:
    • Current Supervisorial Districts (2011) – Begin with a map of the current five (5) Supervisorial Districts. This is the suggested template for users who may want to make minor changes to the existing Supervisorial Districts, including moving one community to another bordering Supervisorial District.
    • Blank Template – Begin with a blank template to create and submit a map with five (5) Supervisorial Districts. This is the suggested template for users who may want to make changes that differ substantially from the current Supervisorial Districts.
    • Communities of Interest Template – Begin with a blank template to create and submit a map with one (1) designated area of interest. This is the suggested template for users who want to identify a community or area that should be kept together without having to submit a map with five (5) Supervisorial Districts.
  5. Click the “File” tab to save or open a plan. To save a new plan, click on the “Save As” button to save your new plan. Enter in a file name (e.g., LastName_Date) and description. Click here to watch a video demonstration.
  6. Click the “Learn” tab and read additional details on what each tab can do.
  7. Click the “View” tab and select your preferred display options, including how lines, districts, and names are displayed. Selecting “Show Target Values” under the “View” tab will add a column in your data window with the approximate number of people each district should have. Click here to watch a video demonstration.
  8. Click the “Create” tab to add demographic data and start using tools to draw districts and communities of interest. In this tab, you can select different drawing tools in the “Redistricting” section. This includes drawing tools that select one geography at a time, select multiple geographies by rectangle, select multiple geographies by polygon, or select multiple geographies by line. To designate areas to a certain district, select the “District” drop-down menu in the “Redistricting” section then select the areas you would like to designate to the selected district. You can zoom in to see smaller geographical areas which you can select and assign a district. Click here to watch a video demonstration.
  9. If you would like to view the borders for whole cities and places in the county, explore the “Map Contents” window. You can do this by clicking on the gray triangle button immediately left of the + and – zoom keys in the map window to expand the “Map Contents” area. In this “Map Contents” area, you can add additional layers for Los Angeles County (e.g., Cities and Communities; CVAP) by checking the box next to “LA_County_Reference,” clicking the triangle icon immediately left of the check box for “LA_County_Reference” to expand your options further, then checking the box for the additional layers and lines you would like. Click here to watch a video demonstration.
  10. If you would like to assign whole cities and places to districts, use the “Identify” window. You can do this by clicking on the “Identify” tab at the bottom of the “Map Contents” window discussed in the previous step. Once in the “Identify” window, use the drop-down menu for “Place” to find and select a city or place in Los Angeles County. Click on the “Show” button next to the drop-down menu once you select the place. This will show you your selected city or place on the map. In the “Identify” window, you will be able to see all the demographic information for your selected city or place. To assign the selected city or place to a specific district, select the district you would like the city to under the “Create” tab (see step 8) then click on the “Assign To…” button in the “Identify” window. Click here to watch a video demonstration.
  11. Check the data window below the map window to see if your districts meet the target deviation. Each district should have approximately equal population (approximately 2,002,802 people) with a maximum deviation of 10% (approximately 200,280 people). In this data window, you can also check the racial/ethnic makeup of each district you drew.
  12. Click the “Review” tab to see if your plan meets the requirements for submission. Click on the “Check Integrity” button in the “Analysis” section to run the integrity tests. Your plan must meet all the checks before submitting. If your plan does not meet one or more of the checks, you can click on the “Details” button next to the check to see why your plan did not meet that requirement. Click here to watch a video demonstration on running integrity checks.
  13. Click on the “Share” tab if you would like to share your plan with known colleagues and other members of the public. Click here to watch a video demonstration on how to share a plan. In this tab, you can additionally attach files or include information and comments about your plan. Click here to watch a video demonstration on attaching files and including comments.
  14. Click the “Submit” tab and click “Submit Plan” to submit your finished plan. The plan will only be submitted if it passes the integrity test detailed in step 10.

Additional Tips:

  • Hover your cursor (without clicking) over any button or icon and a small window will appear with a short description on what that button or icon does.
  • Save often by either clicking the “Save” icon in the “File” tab or clicking the floppy disk icon in the top tool bar in orange.
  • You can change the basemap by clicking on the “Create” tab then the “Basemap” button under the “Map” section. This will allow you to change the underlying map. Options include a topographic map and streets map.
  • You can zoom in and out by using your mouse wheel or clicking on the + and – icon on the top left corner of your map screen.
  • You can use the “Identify” tool under the “Create” tab to examine specific geographies (e.g., blockgroups) and assign them individually to specific districts. Click here to watch a video demonstration.
  • You can use the “Select by Attributes” under the “Create” tab to identify geographies that meet certain criteria (e.g., racial/ethnic percentage makeup) to then designate to specific districts. You can use the “Select by Location” tool under the “Create” tab to specify locations (e.g., neighborhoods) you can select to designate to specific districts. Click here to watch a video demonstration.
  • If you would like to export your map to your local computer, you can do so by clicking the “File” tab then clicking the “Export.” You can export your map and plan as different file types, including as an image, fixed text format, or shapefile. Click here to watch a video demonstration on exporting and importing fixed text format files. Additional instructions here. Click here to watch a video demonstration on exporting and importing shapefiles.
  • In the “Review” tab, you can generate reports to examine various data points, such as voting age population breakdown. Click here to watch a video demonstration on generating reports.
  • For more help or if you have additional questions, please email tle@crc.lacounty.gov

Additional Resources: