Major Transmissions Systems in New Mexico

Founded in 1917, Public Service Company of New Mexico (PNM) is the state’s largest electricity and natural gas provider. PNM is a subsidiary of PNM Resources, an energy holding company based in Albuquerque, New Mexico.

Major Transmissions Systems in New Mexico represents the latest in a series of electric and gas system maps produced by PNM. The earliest was a set of commercially published street maps with electric and gas lines hand drawn in colored pencil. Dated from approximately 1910 to 1930, these maps, contained in a leather-bound notebook, were recently rediscovered in a dusty file cabinet in the basement, subsequently scanned, and digitally archived. Subsequent maps were hand lettered and airbrushed, and later Leroy lettering and adhesive graphics were followed by hand drafting on U.S. Geological Survey basemaps. PNM’s first GIS-based system map was completed in ArcView 3. Reflecting advances in GIS technology as well as data quality, this 2005 version of PNM’s system map was completed in ArcGIS 9 with the supporting data residing in geodatabases served by ArcSDE.

While building on the legacy of previous system maps, many challenges were faced in producing this map. As an important reference tool used by many of the departments and divisions found in a modern energy company, a transmission system map also finds use by other utilities, investors, energy speculators, and public regulation agencies. As such, the map must convey complex, detailed, and multifaceted data in a manner understandable to a wide audience. A balance between geospatial accuracy, cartographic clarity, and system connectivity was attempted with large-scale insets that were deemed necessary to convey the spiderweb of transmission lines in urban areas.

Data concerning other companies’ facilities was traded, cajoled, borrowed, and scrounged by countless phone calls, e-mails, Web searches, and news articles. In addition, the ever-changing nature of the data was a big challenge as new lines were constructed and new generation facilities were brought online along with corporate mergers, acquisitions, and name changes. Given that, the published map was outdated the day after it left the presses. However, because of the flexibility of the underlying geodatabase, the information conveyed on this map will always be kept current and will be reflected on the next version of the map.