Tree Care

Tree Care

UI's Vegetation Program is intended to reduce the amount of vegetation that threatens power lines during storms.

Severe storms including Tropical Storm Irene in 2011 and Super Storm Sandy in 2012 serve as reminders of the threat that trees can pose to the integrity of our electrical system, the reliability of your service and the safety of our customers and employees.

These storms left hundreds of thousands of customers without electrical service, in some cases for extended periods. The largest cause of these outages was damage from trees located close to power lines and other equipment.

Trees near power lines therefore are a key focus at UI as we review the lessons learned from these storms and now implement measures to harden our systems to ensure they are safe, resilient and reliable in all weather.

Neighborhood Surveys

Going forward, UI contractors will be visiting your neighborhood to survey and determine the tree work required to reduce the threat to reliable electric service and public safety. This will be a tree-by-tree evaluation based on a number of factors considered by the UI arborist, the tree warden and/or UI contractor work planners.

These contractors will contact property owners to provide information about the extent and type of the tree work required, if any, and the timing for the work to be completed. You may receive an in-person visit, or receive an information packet at your address. Please contact UI's contractor directly at the number provided in the information packet, if you have any questions.

Reducing Threats to our Electrical System

This area survey process is part of a wider effort to reduce threats to our electrical system. UI has revised its vegetation management specifications to increase the distance between the vegetation and power lines.

  • The new specification calls for creating a "Utility Protection Zone" which extends horizontally 8 feet out from the outermost electric conductor or wire, from the ground to the sky. This will reduce vegetation that may come into contact with the electric infrastructure and cause outages during storms, as well as during fair weather.
  • Trees will also be designated for pruning or removal if they pose a threat to power lines, or risk falling into or encroaching on the Utility Protection Zone and causing damage to the electric system or outages due to their height and growth pattern.
  • Desirable low-height or ornamental trees that are already growing within the Utility Protection Zone, or that do not pose a risk, will not be removed.

Managed Roadside Forest

UI promotes a managed roadside forest that beautifies streets, neighborhoods and communities, but also enhances the benefits of reliable electric service and public safety.

UI is committed to working in partnership with property owners to ensure they can help their neighbors and community, and understand their rights under the law. Privately owned trees will not be trimmed or removed without the owner's consent, except when they are in direct contact with our energized conductors and present an imminent danger.

For trees in public areas or in the public right-of-way, Section 60 of Public Act 13-298 (An Act Concerning Implementation of Connecticut's Comprehensive Energy Strategy and Various Revisions to the Energy Statutes) requires that utilities provide notice to all property owners abutting the public right-of-way 15 days prior to the start of any vegetation management that is to occur within the newly defined Utility Protection Zone, with the exception of trees that pose an imminent threat. Abutting property owners who object to the proposed tree work must send their objection in writing to the utility and town tree warden or state DOT within 10 days of receiving the notice. The tree warden or state DOT must make a decision within 15 days that may be appealed to the Public Utility Regulatory Authority (PURA) by the property owner or utility. The complete objection and appeal process can be found on the State of Connecticut website.


If you have specific questions regarding the program, please call us at 866.829.4461, or email us at and please use Tree Trimming in your subject line.


Please read the Frequently Asked Questions below for additional information. 


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UI has on staff a licensed arborist who oversees and provides directions to the work planners. UI has provided a specification that they follow. The work planners UI currently have are very experienced and have done this type of work for many years. Also, the final decision of what work is performed is always a collaboration between the work planner and the property owner as well as the municipal tree warden.

There is a tree warden appointed in all of UI's 17 municipalities that we have historically worked with.

UI and many other entities have been investigating this issue since Tropical Strom Irene. This topic has been given extensive study and the record is extremely voluminous. A number of formal proceedings and studies have been conducted throughout this time frame. UI has studied a number of options such as undergrounding the system, pole hardening, and vegetation management. The undergrounding option has been examined by numerous utility commissions such as Florida, North Carolina, Oklahoma, Virginia and Maryland. This topic was also studied by the Edison Electric Institute. The consensus of these reports indicates that wholesale under grounding is extremely cost prohibitive. Some estimates indicate a monthly cost increase of 125% for residential customers and as high as 162.6% and 216% for commercial and industrial customers respectively. UI, with its urban and fully built out system would have similar results. Although there are benefits to underground the cost of doing so would be prohibitive. Additional disadvantages include the need to underground other utilities such as phone and cable, the moving or re positioning of existing underground utilities such as sewer, water and gas, the need for private homeowners to underground their exiting overhead service (which could be a one-time cost in excess of $1500), the need to acquire easements and private property to locate underground facilities such as splice chambers, vaults, transformers, and switches.

UI's only concern is to restore vital electric service to its customers so that they can be safe from the damage and hardships caused by loss of power for medical needs, heating and cooling, food and medicine spoilage, sewage treatment, water and food supplies, fuel supplies, food spoilage, communications, 911 services, shelters, and a host of other benefits of electric service. UI is a public service company obligated to keep the lights on.

After extreme weather events, we do bring in more crews to restore customers and address tree damage. After Hurricane Sandy in 2012 UI was managing six times the normal number of UI field crews. However, the company is constrained by the number of available crews and its ability to administer that many crews. Extreme weather events are widespread regional events that impact numerous utilities that all need to increase the number of crews. Although UI is continuously striving to develop plans to manage more crews there is no guarantee additional crews will even be available. UI was found to have done an adequate job in restoring customers during the last extreme weather events. A very thorough investigation was performed by PURA to support that conclusion. UI was asked to improve communications and storm resiliency to both improve customer communications as well as reduce the number of outages that do occur. UI has responded with technology projects for communications, substation flood mitigation improvements and this latest vegetation management plan.

No. UI will not bill individual customers or municipalities for damage caused to the electric infrastructure by private or municipal owned trees. These costs, as has been the case are spread to all customers in UI's seventeen towns and cities. UI will document locations of trees in which objections were upheld so that after the next extreme weather event UI can determine if these trees caused damage and customer outages. This data will be reported as part of the normal after action review.

This program is an eight year program and UI is bound by the process of the state law in its implementation. Extreme pains will be taken to ensure proper notification and consideration time is given as outlined by the law. UI intentionally started the program as a very limited pilot in only 4 of its 17 towns and only on 40 of its 2800 miles of overhead service territory in the next six months. These circuits were selected due to poor performance and criticality of certain municipal facilities on these circuits. This pilot has allowed UI to exercise the new state law and provide communications to the UI customers. Although the full plan was approved in 2013 with a start date of January 1, 2014 UI determined that a full start on January 1 was not prudent, which is the reason for the pilot. UI also has developed the complete 8 year schedule which can be shared with the municipal officials, state representatives and public prior to the start of any assessment work. For example, UI is not planning to assess any work in the Hamden Spring Glen neighborhood until 2016, and this will include six streets in the neighborhood in which the circuit back bone (carrying large numbers of customers) runs. The remaining streets will not be assessed until 2020. UI views this program as collaboration with private residents and municipal tree wardens and PURA.

UI has no rights to take away private property without permission of the owner of the property, except when they are in direct contact with an energized conductor or show signs of burning. UI will make several attempts to contact the home owner including leaving a door hanger that includes what work is being proposed as well as a contact number to schedule a meeting with UI's representative to discuss the work. If contact cannot be made UI will document the work that was to be performed and move on without performing the work. For trees that are in or overhanging public roads the town tree warden has care and control over these trees and UI must work with the tree warden to gain permission. In these cases, residents also have the right to object to work on town trees and can file these objections with both UI and the tree warden. UI is obligated to notify all residents who are in the vicinity of the town tree work prior to the work and the municipal tree warden is required to publicly post any town trees that will be removed so that public notice is given. If the town tree receives objections the tree warden will hold a public hearing to further understand concerns. The tree warden's final decision can be appealed to the Public Utilities Regulatory Authority by the utility or the residents. If UI decides to appeal the tree wardens decision; UI will provide specific cost and benefit information, including information that supported the tree warden's decision, related to the specific locations to support PURA in its final decision.

An explanation of the State law (in English).

UI will evaluate any tree within the Utility Protection Zone (the UPZ is an 8 foot area on each side of UI wires from ground to sky) that is a risk to the electric infrastructure during extreme weather events such as Tropical Storms, Hurricanes, Ice storms and Snow storms when full tree canopy is present (e.g. the 2011 October Snow storm). These trees have the highest probability of damaging the infrastructure if they fail, due to the very close proximity. UI will also assess hazardous trees (dead, diseased or dying) outside of the UPZ. Addressing any and all trees that may fall on the electric system is not practical and excessive which is why the narrow band of the UPZ makes better sense.

It is not a question of rarity but of probability. Put another way, extreme weather events such as Tropical Storms and Hurricanes have a certain re-occurrence probability that has been calculated based on historical data. The weather patterns that produce these storms occur each year and the risk is there for UI's territory each year. Certain storms have enough of a regular occurrence that return periods have been calculated. For example, the return period for a Category 1 Hurricane is every 17 years. This does not mean if we don't get a Category 1 Hurricane this year the probability goes up, the return period remains 1 in 17 years. However, if we go beyond the 17 years without this storm occurring we are beyond what the probabilities predict.

UI has historically employed these techniques and it has worked well for normal reliability or non-extreme weather reliability. So our system is already at this stage. However, we have found that when extreme weather occurs, the system is vulnerable to tree and tree part failure as evidenced by the recent events. This new program looks to reduce the outages and hazards associated with extreme weather events. Areas in which we cannot achieve the new specification will not suffer for average weather but will suffer during extreme weather."

No. The Public Utility Regulatory Authority (PURA) has determined it is too costly for all utility rate payers.

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