Redistricting—whether school districts, voting precincts, or city council districts—is a balancing act. Every change made to one district affects at least one other district. The City of Long Beach has developed an award-winning redistricting application using ArcView GIS that not only has made the redistricting process more rapid but allows officials to consider new factors and to easily create maps for consensus building and publication notification.

The Long Beach City Charter requires the City to evaluate City Council district composition every five years and adjust district boundaries to reflect changes in population. The goal is to create districts that do not deviate more than 5 percent from a predetermined ideal population mix. Prior to the use of GIS, the redistricting process was a tedious one requiring two to five months. Census block data was kept in an Excel spreadsheet. Blocks affected by boundary changes had to be identified, and the new areas were mapped and color coded by hand. Processing a simple boundary change could require a week. The time and effort involved in creating just one scenario severely limited the number of possible what-if situations that could be explored.

In 1995, the City decided to find a better way to perform redistricting. "This time around we knew GIS could do it," says Tina Dickinson, GIS manager for the City of Long Beach. The City started using GIS in 1981. Currently 10 major departments and many subdepartments use GIS. Each department is responsible for maintaining its own data and has one to three staff members with GIS training. The Central Management Department supports all GIS efforts in the City. This Department provides programming support for MapObjects and ArcView GIS applications and ensures that data standards are maintained.

Dickinson wrote the redistricting application, which displays linked bar and pie charts and a table as well as a map, entirely in ArcView GIS. The application consists of scripts and buttons that are added to the interface. The actual coding and testing took approximately 40 hours including revisions to accommodate additional functionality requested by users. Not only does the application vividly and instantly illustrate the effects of boundary changes on the population for the subject district, but it also shows the effects on all other districts in the City.

For the first time, the effect of boundary changes on the ethnic composition of districts can be determined. This aspect of redistricting could not be done using manual methods. This functionality is important because the City may not make or destroy a district with a majority of minority residents.

The GIS staff set up training sessions for council members and their aides. Within a half hour, council members and their staffs were able to be productive with the application. Previously, aides had done most of the work required for developing scenarios using manual methods. The redistricting application is so easy to use that each of the nine council members sat down in front of the screen and devised and modified redistricting scenarios. In addition to integrating guidelines for the ideal district population distribution, the application applies certain constraints. No council members can change district boundaries so that another council member's residence is removed from his or her district.

Dickinson describes the real value in using the redistricting application in terms of flexibility and the ability to explore many more options. "We had never been able to do many what ifs. It took too much time to do one scenario. At most we produced four. Now each of the nine council members can do five plans and modify them as many times as they want."

The real-time visual feedback council members received from the application allowed them to explore options rapidly and to generate maps so that consensus with other council members could be arrived at quickly. Instead of taking up to five months to hash out new district boundaries, a workable redistricting plan was created and adopted within two weeks. The maps needed for public notification of the redistricting were also easy to generate.

Dickinson sees the potential for using the redistricting application to solve other population-related problems. She has used it to help the Police Department determine the reporting district boundaries for call-for-service requests.

The benefits of this application have been recognized outside the City of Long Beach. In 1997, the redistricting application won an achievement award in the public works, general services, parks and recreation category from Public Technology, Inc. (PTI), a nonprofit technology research, development, and commercialization organization for cities and counties in the United States.