There is much more to putting transmission lines underground than just burying them. Overhead and underground lines make use of very different technologies.

Underground lines can more easily be routed through highly developed urban areas, ideally within tunnels beneath city streets. And the fact that the lines are out of sight once they are constructed appeals to most people – especially those who live along the route. But whereas overhead lines can span wetlands and other waterways, constructing underground lines requires disturbing every foot of the route, increasing construction impacts on roadways, traffic, wetlands, and wildlife habitats.

Overhead lines are typically bare wire that is “insulated” by the air and spacing maintained between the conductors and with the ground.

Underground cables, because they are placed close together and are surrounded by ground, require heavy insulation surrounding the conductive core of the cable. The thickness of the resulting cable means that only relatively shorter lengths can fit onto reels to be transported along roadways to the construction site, and these relatively shorter segments of cable must be spliced together in concrete “vaults” the size of a large room, to avoid a short on the cable and to allow for worker safety. All these factors make an underground line significantly more expensive than a comparable length of overhead line.

Finally, high voltage underground lines also have different electrical characteristics compared with overhead lines, which adds to the complexity of operating the power grid.

Right-of-Way Acquisition

Understanding Rights-of-Way and Easements

To provide electrical service to its customers, Northeast Utilities’ electric companies, The Connecticut Light and Power Company and Western Massachusetts Electric Company (referred to collectively as the “company”) own and maintain transmission lines throughout Connecticut and western Massachusetts. These transmission lines are primarily located on land that is owned by third parties (homeowners and businesses) over which the company has acquired a property interest that is referred to as a “right-of-way” or “easement.”

Most of the company’s transmission lines are located on rights-of-way that were acquired decades ago. At the time these easements were acquired, the company compensated the owner of the land crossed by the right-of-way and acquired permanent easement rights, which remain intact even upon a sale of the land. Therefore, anyone who purchases land that is crossed by a company right-of-way acquires that land subject to the company’s permanent easement rights. Potential land owners have advance notice of the company’s owned rights-of-way because easement documents are filed on the appropriate land records for each town, and can be identified as part of a routine title search.

The Company’s Rights within the Right-of-Way

The easement documents recorded on the land records outline certain of the company’s rights within the right-of-way, which usually includes, among other things, the ability to trim or remove any trees. In addition to those rights specified in the easement document, the company has all rights necessary to implement those rights. For example, a typical company easement states that the company has the right to construct transmission facilities. Since the construction of those facilities requires the use of equipment, the company can operate construction equipment within its right-of-way, even though this activity is not specifically referenced in the easement document.

The Rights of Property Owners within the Right-of-Way

As a general rule, the owner of a property crossed by a right-of-way can still use the property for his/her own personal use as long as such usage does not interfere with the company’s use of its easement.

A property owner may plant grass in the right-of-way if he/she so chooses. However, a property owner cannot construct or place anything within the right-of-way that might interfere with the company’s facilities or with the company’s right and ability to pass freely over the right-of-way in the course of maintaining its existing lines or constructing new lines. For instance, a property owner could not construct a wall or fence that blocks passage along the right-of-way.

For More Information

To learn more, contact ROWinquiry@nu.com.