Drawing Communities in DRA

Alec Ramsay
Dave’s Redistricting
6 min readApr 6, 2021

For a long time in DRA you have been able to overlay the images of communities of interest (COI) drawn in other tools — such as Districtr, Representable, or California’s DrawMyCACommunity — on maps drawn in DRA (see Using Custom Overlays).

Though the process was cumbersome, you have also been able to draw maps in DRA that represented communities & overlay them on other maps using the same mechanism (see Creating Communities of Interest).

We’ve now streamlined the process of drawing communities & adding them to maps in DRA.

Creating a New Community

Communities are now first-class entities in DRA on par with maps — you can now create & build communities in exactly the same manner as maps.

Next to the New Map button on the toolbar in the list of maps there’s now a New Community control.

When you click on it, you see a new community dialog.

New Community dialog

As with creating a new map, you give the community a name and pick the state it is in. For a community though, the name is the label for the community that will show up on the map (when you want it to).

  • Plan Type — This is preset to Community.
  • Shape Count — This is analogous to the number of districts in a regular map. It is preset to one, as most communities are defined by one contiguous shape.
  • Description — This briefly describes the community.

Press the Apply button to create the empty community map. Then you can paint the community just as you would a district, using all the DRA tools you know & love.

The Background Map is turned on by default to help you identify features & locate your community.

You can change the color for the community shape in Map Settings, so it won’t conflict with district colors. Below the Shape Count field, there will be an entry for the community (analogous to a district), and you can change the color in the Color column. You can also use the opacity setting to control the opacity of the community when it is overlaid on another map.

Adding Landmarks

You can also now add landmarks to maps, using the new Add Landmark tool to the left of the Pan hand on the toolbar. This is especially handy when you’re drawing a community of interest.

To add a landmark to a map or community, you first click on the Landmark tool and then click on the map where you want to add the landmark. A dialog comes up that lets you name and describe the landmark.

You can also edit the latitude & longitude which will change the location of the landmark. This lets you find the coordinates of a place — e.g., using Google Maps or Wikipedia, etc. — copy them, and then paste them into the Lat/Lng field. Using this approach, you can click anywhere on the map and then paste in the coordinates of the landmark.

After you have created a landmark, you can click on it to edit it or delete it.

There is a new “Landmarks” checkbox in the Overlays pane that toggles landmarks on & off on both the map.

Note: You can add landmarks before you draw districts or communities too! There’s no precedence or ordering.

Finding Communities

You can also now filter maps by type, using the new Plan column in list view. Maps show as one of the following types:

  • 2010
  • 2020/Congress
  • 2020/Upper
  • 2020/Lower
  • 2020/COI
  • 2020/Other

If you want to find all the communities for a state, you can filter maps like this:

As with regular maps, you can use the Label feature to tag communities so that they’re easy to find.

Overlaying a Community

You can now overlay communities on maps in two ways. As before, you click the gear icon in the Custom Overlays panel.

This will bring up a dialog that lets you both add images of communities (layers) or communities (maps) drawn in DRA.

Adding Layers

To add a layer to your map that is the image of a community imported from another tool, click on Add Layers. This will bring up the Pick Layers dialog described in Using Custom Overlays.

Note: You can now include Point features in your GeoJSON overlays.

Adding Communities

To add a community to your map that is a map of the community drawn in DRA, click on Add Maps. This will bring up a map picker.

The search box will be pre-filtered to show the communities that you have created for the map’s state. You can find communities that others have drawn using the Published and Official controls or by changing the search criteria directly (see Filtering & Sorting Maps).

Note: The overlay for a community is generated with some latency (~15–30 seconds) after editing the community map. The overlay for a community will track changes to the community map, but there will be some latency in seeing the latest version.

Select the community you want to add to your map and press Pick. It will show up as an overlay in the Custom Overlays panel where you can toggle the lines, fill, and label as with layer images and now landmarks as well.

The community will be overlaid on your map making it easy to see, for example, whether or not districts split the community.

Note: You can also pick a map that is not a community to overlay on your map, e.g., if you have a map that shows the outlines of previous districts or you incumbent addresses.

Sharing a Community

You can share communities with other DRA users, just like regular maps (see Sharing & Publishing Maps).

You can also export the definition of a community as a block-assignment file (CSV) or a shape (GeoJSON) which lets you submit the community to a commission or use it in another tool (see Exporting Maps).

You can create an image of your community, using the feature described in Creating Map Images.

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Alec Ramsay
Dave’s Redistricting

I synthesize large complex domains into easy-to-understand conceptual frameworks: I create simple maps of complex territories.