2016 Redistricting Reference Data


In February of 2016, an extra legislative session was held to comply with a court order which required the General Assembly to redraw the 1st and 12th congressional districts. All information on this page corresponds with the redistricting database compiled by the General Assembly for that effort.

A large amount of reference data is used to draw political districts. That data can be divided into two main groups: numeric and geographic. The numeric component includes items such as population and election results. The geographic component includes features such as roads, rivers, and political boundaries that can be graphically displayed as features on a map.

The numeric data matches up with the geographic data at several different levels. The main levels of interest in district drawing are counties, voting tabulation districts (VTDs), and census blocks. These three main levels have a nesting relationship. In other words, counties are comprised of VTDs that, in turn, are comprised of census blocks. Each level covers the entire territory of the state, such that there is no point within the state's boundaries that cannot be assigned to each of the three levels.

Population Data - by April 1st of the year following each decennial census, the US Census Bureau provides Public Law 94-171 data to each of the states. This data corresponds with block level geography, the lowest level tabulated by the Census Bureau, and that at which districts are ultimately defined. For the 2016 congressional redraw, only total population and total voting age population values were used from this dataset.

Election Returns Data - provided by the State Board of Elections. Election results from twenty statewide contests are included in this database, coming from the 2008 through 2014 general elections.

Complete numeric datasets, as processed for use in the General Assembly's redistricting system, are linked below for download. The field key is required to interpret the field headings. See the data processing notes document for technical details. The "block level keys" table is useful for establishing relationships between the different geographic levels. The numeric data is also appended to each of the corresponding geographic layers, available for download in the following section. Note that the General Assembly's redistricting system is census block-based. All data items therefore have to reconcile to that lowest level of geography. Although election returns are available at all geographic levels, they are most reliable at the VTD and county levels since the original data was VTD-based.

The geographic data in the General Assembly's redistricting system is based on the 2010 TIGER/Line Shapefiles provided by the US Census Bureau. Below are links to various statewide layers derived from that dataset. These files are intended for use with Geographic Information System (GIS) software. Layers are projected in NC State Plane, NAD83, meters.

Tab-Delimited Text (*.tab) is a simple text format consisting of values separated by tabs. It is easily imported into spreadsheet and database programs, with each line of the file corresponding to a table row, and each item in a line corresponding to a table column. It can also be viewed with text editor programs such as NotePad or WordPad, provided the file isn't too large.

Access Database (*.accdb). This is a database format used by Microsoft Access, starting with Access 2007.

File Geodatabase. This is a spatial data format created by ESRI. File geodatabases contain geographic layers and are used with geographic information system (GIS) software. Each geodatabase is comprised of a directory with a ".gdb" extension containing a large number of individual files.

ZIP. Due to large size, some of the files linked from this site have been compressed or "zipped". In addition to native support in some operating systems, a variety of commercial and open source programs exist that can extract ".zip" files.