A Partnership of UConn and Eversource

Eversource Energy Center



Mapping Tree Risk

Connecticut enjoys a ranking among the top 13 states in the nation for its forested land area spanning 55 percent of the State, with additional areas enjoying the beauty of urban tree canopies. Within these diverse environments, including open space and conservation areas, Eversource maintains nearly 17,000 miles of overhead electric distribution lines in 149 Connecticut cities and towns.

With the use of 3-D measurements obtained by aircraft-mounted laser technology, images of the earth’s surface, including tree heights, locations, and forest density, are obtained to enable a birds-eye view of roadside tree conditions, as well as potential travel hazards.

UConn’s research enables a proactive assessment to determine areas where trees have the potential to endanger power lines or public safety. Trees prone to failure during storm conditions will be included in Eversource’s vegetation management efforts to ensure the reliable delivery of electricity.

For the majority of eastern and northwestern Connecticut towns (86), we are using aerial laser technology to show tree proximity to power lines. And we are taking an even closer look by leveraging the laser technology in Greenwich, Connecticut, as part of our 3-D imaging for modernization study, capturing greater detail with 20-100 points of data in each square meter of land space. In addition, the 3-D image data becomes an input to our Outage Prediction Modeling reflecting local tree conditions.

Eversource also works closely with towns to develop sustainable and storm-resistant forest designs, partnering with local communities to maintain the region’s character and preserving nature’s beauty for generations to come.


  • Connecticut ranks 13 in the nation in terms of percent forest cover and fourth in terms of population density.
  • Fifty five percent of Connecticut is currently considered forest and an additional 20 percent of Connecticut is covered by urban tree canopies. 
  • Trees growing in wetlands, rocky or shallow soils have shallow roots and are prone to uprooting.
  • Trees in rocky or shallow soils have shallow roots and are prone to uprooting.
  • The forests in Connecticut today began growing in the late nineteenth century after agricultural land was abandoned and large-scale charcoal production ceased.
  • Connecticut’s forest today is taller, more expansive, and more mature than it was at the time when much of today’s utility infrastructure was built.
  • Forest cover has greatly expanded in Connecticut over the past 100 years in a largely unmanaged manner, resulting in many cases in tall thin trees.
  • New or recently trimmed forest edges may be less stable until the newly exposed trees adjust to the greater wind exposure.
  • Eversource trims around all power lines in its service area once every four years.

Goals & Project Updates

The purpose of this research is to help the public and utility companies most optimally manage their roadside trees and forests to increase storm resistant trees thereby reducing weather-related power outages as well as allow the UConn Outage Prediction Model to make better predictions of outages during storm events. The specific goals for this project are to map locations where tree failures could pose a threat to power lines, determine what environmental factors make trees more prone to failure during storm conditions, and create a map showing the risk of tree failure at any given location within the state (the risk for a given area will be based on the number of trees within striking distance of utility lines).

The locations of trees posing a potential threat to power lines have been mapped for about two thirds of Connecticut.

Eversource’s vegetation management and outage records are being used to identify the characteristics of areas that have had power outages in the past, and these characteristics will be used to identify similar areas which have the potential for outages in the future.

Preliminary maps of trees in proximity to utility infrastructure have been shown to improve predictions of storm-related power outages.

The accuracy of utility line maps have been improved in southwestern Connecticut, which will help improve the accuracy of tree proximity maps for this area.


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    Proximity areas (red) where trees are close enough to contact utility lines (black).

Team Members

Jason Parent, Assistant Research Professor in the Department of Natural Resources and the Environment, University of Connecticut, leads the project task.

John Volin, Professor and Department Head of Natural Resources & the Environment, University of Connecticut

Tom Meyer, Professor in the Department of Natural Resources and the Environment, University of Connecticut

Michelle Kosmo, Graduate Researcher in the Department of Natural Resources and the Environment, University of Connecticut


Contact Information

For more information, please contact Jason Parent (jason.parent@uconn.edu)

Members of the media, please contact Center Manager Malaquias Pena (mpena@uconn.edu) directly.

Eversource Energy Center  | Address: 261 Glenbrook Road, Unit 3276, Storrs, CT 06269-3276 | E-Mail: eversourceenergycenter@uconn.edu