Transmission lines require regular maintenance and are only insulated by air. Company, industry and federal standards have been developed to ensure the safe and reliable delivery of electricity to customers, which includes maintaining minimum clearances of objects from transmission lines. Mississippi Power's integrated vegetation management program ensures the transmission system meets these requirements while also providing access to maintain facilities.
In most cases, Mississippi Power transmission lines are built to a standard for reliability that allows for vegetation that reaches a maximum height of 10 feet to exist under the line and maintain proper clearance as defined by company, industry and regulatory standards. Topping of vegetation that can exceed 10 feet is only a short-term solution that results in a tree, or shrub, with more potential conflicts with the transmission line(s). In addition to utility conflicts, topping is not a professionally recognized method of tree pruning and promotes starvation, shock, insect, disease, weak branching, irregular growth and aesthetic problems that typically result in an undesirable or dead tree.
In most cases, Mississippi Power's transmission lines are built within easements across private property and are not owned by Mississippi Power. Mississippi Power periodically mows these easements to provide access to its facilities and to maintain acceptable vegetation on the rights-of-way. More frequent mowing to meet local ordinances, aesthetics or other requirements is the responsibility of the property owner.
Typically, the easement agreements obtained by Mississippi Power prior to construction of a transmission line include the right of ingress and egress to and from rights-of-way.
Mississippi Power understands the desire of property owners to maintain plantings on the portions of their properties located within Mississippi Power easements. Currently, Mississippi Power allows vegetation that reaches a published maximum height of 10 feet or below to be planted on transmission rights-of-way. However, the provision of reliable electric service must remain paramount. The permission for plantings may be modified or revoked, in whole or in part, at any time and from time to time by Mississippi Power, in its sole discretion. Current and future rules, regulations and orders of federal and state authorities may also be applicable to and restrict or prohibit plantings. In connection with any such restriction, prohibition, modification or revocation, whether by Mississippi Power or pursuant to such rules, regulations or orders, Mississippi Power reserves the right to require trimming or removal, at Mississippi Power's sole discretion, of plantings previously permitted. If there are any questions to the acceptability of a planting, please contact Mississippi Power prior to planting.
Mississippi Power uses qualified contractors to apply herbicides as part of an integrated vegetation management program that also includes mechanical and manual practices. All contractors are trained and licensed to handle, transport and utilize herbicides and pesticides as required by the state of Mississippi. All herbicides utilized on the transmission rights-of-way are non-restricted. Use of herbicides allows for the selective removal of undesirable vegetation with minimal impact to the surrounding environment while extending the time interval between more invasive practices such as mechanical mowing. Rights-of-way maintained with an integrated vegetation management program that includes herbicides frequently result in more ecologically healthy and aesthetically pleasing corridors than those maintained only by mechanical means.
Typically, easements state Mississippi Power has the right to maintain the rights-of-way free and clear of vegetation. Unless legally recorded otherwise, Mississippi Power reserves the right to require removal, at Mississippi Power's sole discretion, of plantings previously permitted. This type of change most likely would occur in response to revisions of electrical standards and/or regulations requiring modifications to acceptable vegetation clearance requirements to maintain safety and reliability of the transmission system.
The burying of transmission lines is extremely expensive, in comparison to above-ground construction, and cost prohibitive to the ability of providing affordable electricity to customers. In addition to cost, underground transmission lines still require rights-of way that are free of shrubs and trees.