By Jessica Wyland, Esri
As bark beetles silently kill hundreds of thousands of acres of towering trees in the U.S. and Canada, Flathead Electric Cooperative (FEC) operators are growing concerned about what this infestation means to its members in rural Montana. Dead trees along an electric distribution line represent a distinct fire hazard and power outage threat.
In 2007, the U.S. Forest Service blamed the beetles for killing 3.9 million acres of trees in Colorado, Montana, Wyoming, Oregon, Idaho, Utah and Washington.
“Our aim in general is to stay ahead of problem areas by keeping track of the trees that grow near utility equipment and lines,” said Steve Quigley, vegetation supervisor at FEC. “Because of the beetle infestation, stretches of the electric distribution line that were previously clear of tree interference could become a concern. Here in our service area, the “Ëœbeetle kill’ has been minimal compared to some of our neighbors to the north such as British Columbia, Canada, and in the south such as Helena and Deer Lodge National Forests.”
FEC serves more than 60,000 metered customers throughout northwest Montana, ranging from Glacier National Park just west of the Continental Divide to Libby near the Idaho border. Understandably, tracking tree health is a major concern for FEC. It is also a difficult endeavor. Much of FEC’s 2,000 miles of overhead line runs through dense conifer forests that provide limited access to field crews.
“Our top priority is the safety of our members and employees who live and work near our facilities,” Quigley said. “We are also very concerned about the reliability of our service. So, we appreciate that ArcGIS technology from Esri gives us the ability to keep track of any new developments in the study of the bark beetle infestation.”
Albeit a major threat, the bark beetle problem is just one of the many issues the right-of-way management department deals with using ArcGIS.
“We rely on ArcGIS to help us spot problem areas and to be pro-active rather than reactive,” Quigley said. “GIS has become a primary tool in assisting us in the effort to stay ahead of potential tree problems that may be developing in certain areas and minimize the effect they can have on our power-flow reliability.”
Getting Better All the Time
Quigley joined FEC in 1999. Since then, he has recorded all vegetation management activities—from planning to completion—in a Microsoft Excel spreadsheet and on large paper maps.
“The whole process was becoming very cumbersome and inefficient,” Quigley said. “The spreadsheets have been a great method for storing the data, but it became apparent to me that there were better tools available. Technology had arrived that could also digitally preserve the information recorded on the paper maps.”
Quigley recognized the value of GIS technology and the many ways it could most benefit the co-op. The opportunity to collaborate with Gayle Chvilicek, a member of the FEC GIS/mapping department, opened up possibilities to use the valuable information Quigley had collected.
“It was the collection of data from the previous 10 years in the spreadsheet format that set the pattern for the fields within the feature classes,” Chvilicek said. “This data, and the format it was in, worked fantastic with the geo-coding function of the ArcGIS software. It enabled us to capture the history of where problem trees had been and create a foundation from which to build the new feature classes.”
Chvilicek said the utility stays in “develop mode,” with weekly and monthly appointments set aside for discussion of new ideas and a review of ideas they are currently testing. Staff continues looking for new ways GIS can help improve and stream-line processes.
“GIS is helping us ask better questions,” Quigley said. “In many cases because of the birds-eye-view GIS gives us, it is prompting us to identify other information that can help us in the future with tasks such as establishing system trims and more accurate maintenance cycles.”
Data Here, There and Everywhere
After conducting many interviews with Quigley, and using the aforementioned pattern established from spreadsheets, Chvilicek set up the feature classes and the fields within. The symbols, with their meaning corresponding to the field “Job Type,” were designed and assigned, then used to track the progress of work from beginning to end. Each symbol was associated with a service order number which contained the written instructions regarding each service call.
The feature class titled “System Trims” is digitized using line segments to represent the route where large sections of overhead power lines have been inspected and trimmed. The digitized lines are assigned a color to represent the year of the examination and tree trimming, with a label displaying the field with the service order number connected to it.
Another type of feature class which digitizes with points rather than lines was used to set up the other five feature classes. Most frequently used is the “Master Jobs” feature class. In this feature class, the symbols correspond to the field titled “Job Type” indicating what kind of problem the tree created.
For instance, trees that have an immediate potential to cause harm are marked as “Danger Trees” and removed in short order. The abbreviation “DT” is typed into the field, which produces the visible symbol to represent “Service Order Complete—Danger Tree Removed.” Using the identify icon to click on the “DT” symbol, information is made visible in a pop-up. This pop-up contains data from the other fields in the feature class such as “Date Completed,” “Service Order Number” and other customer information.
A category within the field titled “Job Type” is “Cycle Buster.” The abbreviation “CB” indicates a tree or group of trees that grows faster than other trees in the area. Owners are generally more agreeable to the idea of removing or replacing a tree once utility staff can show how frequently the tree needs to be trimmed in order to keep it away from power lines, and that the obvious result is increased cost.
Another of the feature classes using points is the “Chip Sites” class, which is designed to help crews find the locations where arrangements were made in advance for wood chips to be dumped. The fields within this feature class pertain to location addresses and site details. This can lead to big savings in travel expenses when working in remote areas.
Seasonally, the utility relies on a feature class called “Tree Replacements.” The fields within this feature class are designed to track existing agreements to replace tall, fast growing trees (“Cycle Busters”) with low, maturing, “No Trim” trees. After the tree has been replaced, one of the fields can indicate that the agreement is complete, which turns the symbol from red to green.
Come Together with GIS
Since the company moved its vegetation management information to its GIS, there have been many benefits including more accurate information of the service area and customer data. Quigley can now access that data, along with other useful tools on a laptop. This saves time and travel, especially when work takes him to more remote areas for investigations and inspections. Published maps with selected feature classes are included and updated weekly.
In the office, Quigley is able to create paper maps for tree crews with notes and comments to assist them. The “Master Jobs” feature class shows data for previous years and allows the utility to see what needs to be done as well as what type of problem trees are in a particular area. The “Outages” feature class tracks outages caused by trees. An unusual number of outages in an area would serve as a flag to warrant further investigation.
“These outages could be the result of many trees which have died and are beginning to topple into the line as a result of beetle infestation,” Quigley said. “Many outages in an area caused by trees could also indicate that it is time to set up a system trim, possibly sooner than it was scheduled.”
GIS allows the utility to identify patterns and detect problems areas. This helps direct tree crews to the most important needs first and in many cases, take care of the situation before it becomes a costly problem.
“GIS technology is an important factor in improving our ability to be proactive in our efforts to be aware of areas where trees have the greatest potential to damage equipment or disrupt service,” Chvilicek said. “With GIS we are better equipped to make the best informed decisions and formulate the best strategies to keep our crews focused and working safely and efficiently while maintaining reliability of service.”
Jessica Wyland is a writer for Esri covering GIS in the utilities industry.
MORE INSIGHT AT HTTP://POWER-GRID.COM
Gather more information online by going to the website and typing “right of way” into the search engine. You’ll find:
- “Building a Transmission Line in Southeast Alaska” by the Southeast Alaska Power Agency and Dryden & LaRue,
- “Information Critical to Vegetation Management Programs” by Paul S. Hurysz,
- “Resolving Discrepancies with the NERC Facilities Ratings Methodology” by Paul Richardson,
- And more.
Visit http://power-grid.com for all the details.
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