The Departure of Knowledge is a Dilemma Facing Many Public Power Entities. When longtime superintendents retire, they take with them the only extensive knowledge of a community's electric distribution system.

Over the years, American Municipal Power-Ohio (AMP-Ohio; Columbus, Ohio, U.S.) member communities have expanded or upgraded their distribution systems, sometimes leading to inaccurate, incomplete or outdated paper maps. AMP-Ohio recognized a need to provide its member communities with updated system maps and the opportunity to update the inventory of the system at the same time.

The maps and inventory would not only provide the necessary information about their systems, but they would also provide the utilities with a way to easily update their maps. With an inventory of its distribution systems, AMP-Ohio also could provide an easy way to determine information about its systems for tax purposes, not to mention reinforcing the ability to provide mutual aid and track system improvements.

THE SOFTWARE STEP

In 2001, AMP-Ohio began a program to create, update and provide geographic information systems (GIS) maps for its member communities. AMP-Ohio purchased ArcGIS, a software program developed by ESRI (Redlands, California, U.S.). ArcGIS is a geographical-relational database that takes a geographic representation (a scale model) of an area and then can assign attributes at any point.

AMP-Ohio purchased the software program because there was an apparent need for updated maps, but the cost to many of its member communities was too high. The member communities simply use ArcReader (available as a free download on the ESRI Web site) to view the data and provide updates to AMP-Ohio, which manages the database on behalf of its members.

FROM PAPER TO GIS

The ArcGIS program uses digital orthophotos, which are aerial photographs. These photos form the backbone of the system mapping, because the photos provide a physical depiction of the member community including landmarks and other points of interest.

The digital orthophotos allow AMP-Ohio to identify the locations of poles, structures and other various equipment in the distribution system. The information is then overlaid on the digital orthophotos, allowing AMP-Ohio to store data relative to any specific point on the digital orthophotos. For example, AMP-Ohio can put the location of a single pole on the map and store data, such as what equipment is located on the pole, the size of the conductor, which circuit it's on and other information. The ArcGIS program uses a database that serves as the tool to provide AMP-Ohio with more information than was available from paper maps.

The ArcGIS program also provides a GIS map. AMP-Ohio can customize the database to meet the individual needs of each member community. The community identifies the information on its system to be collected and AMP-Ohio then customizes the database to fit the request. As little or as much detail can be added.

For example, the community can decide it only wants to include a small amount of information about the poles on its system, such as the pole number, height and class. Or, it can decide to add additional information such as a list of all equipment on the pole, phasing and the circuit the pole is on. Information on pole attachments is one piece of data that can be included and seems to have been a great benefit to the member communities, because it provides information about which poles have attachments and what those attachments are.

After AMP-Ohio chose the program that would fit the needs of its member communities, it had to determine a way to collect the field data that would be entered into the ArcGIS program to complete the GIS map. Data collection is an important part of the map creation process.

To reduce costs to its member communities, AMP-Ohio has printed maps of the digital orthophotos and created data-collection sheets. Member communities can have their field collectors use the maps and data sheets to mark the location of poles on the maps. AMP-Ohio can then determine the location of the poles on the maps, because the poles can be clearly seen on the digital orthophotos. The person collecting the data writes all the necessary information about a pole on a data sheet. The data-collection sheet then corresponds to the numbered pole on the maps.

DATA COLLECTION

After the data-collection process was complete, originally AMP-Ohio entered that information into the computer using the ArcGIS program. However, AMP-Ohio found that while collecting data this way worked well for smaller member communities, it was not as convenient for larger ones, so it investigated an alternative way of collecting data and chose to use ESRI's ArcPad.

ArcPad is software for mobile GIS and field mapping applications, using handheld and mobile devices. ArcPad provides field personnel with the ability to capture, analyze and display geographic information. Data collected with the ArcPad can be downloaded into the ArcGIS program and then can be configured to meet each member community's needs.

When all these steps are completed, the entire distribution system is available on the computer, which allows utility personnel to view the system overlaid on an aerial photograph. This, in turn, allows them to view the exact location of all utility structures and what may be near those structures, such as trees and buildings.

Property lines and street centerlines are often included with the digital orthophotos, which can help to solve easement and other rights-of-way problems. It also provides member communities with a quick way to view the inventory of their entire distribution system and allows them to view information about a specific piece of equipment or structure.

Using their computers, AMP-Ohio members can simply click on any specific piece of equipment on their distribution system and instantly be provided with information about that equipment. For example, they can click on a transformer and be provided with information, including kilovolt-amps, size, phasing and voltage.

AMP-Ohio also can include digital photos and specification drawings to be available, so that when the member community clicks on a pole, it can choose to view either the digital photograph or a standard drawing of the pole. Many AMP-Ohio members who use the GIS maps like to include digital photographs, because they provide a visual inventory in addition to the database inventory for complex poles that contain multiple circuits, taps or switches.

USE AND FEATURES

The GIS system mapping allows users to perform various system inventory searches, such as looking for the number of poles on the electric distribution system that have cable and phone attachments. A task that requires counting the poles that have cable attachments can now be completed in a couple of seconds compared to spending a day in the field determining this information. The system inventory can be exported to an Excel file, which allows member communities to standardize their equipment, ease the material process and share information.

The GIS mapping has an available measuring feature that gives users the ability to measure between points on a map. They can measure the span length between poles or measure the distance between a pole and another point, such as the road rights-of-way. This can reduce some field work in estimating the amount of material needed for new construction or for rebuild work.