Transmission Line Maintenance
The Transmission right-of-way requires Integrated Vegetation Management
What are Transmisison Lines?
The lines that carry electricity from power plants across the state belong to the company's transmission system. This system carries power from 60,000 volts to 500,000 volts. Because of the higher voltages, greater clearance is needed between vegetation and transmission lines than what is required between vegetation and distribution lines.
The Wire Zone, Border Zone, and Outer Zone
The Wire Zone consists of low-growing shrub and grass communities directly under the transmission wires plus approximately 10’ on both sides. The Border Zone, which is the portion of the right-of-way that extends from 10’ outside of the wire to the edge of the right of way (ROW), is managed for taller shrubs, and brush plant community. This is the transition zone between the low-growing vegetation and taller. The Outer Zone is the zone outside of the ROW. Any tree growing in the outer zone that could contact the conductor will be evaluated for hazard potential (i.e. leaning, split top, ect.)
Vegetation Management of Transmission Rights-of-Way
SMUD utilizes a program of Integrated Vegetation Management (IVM) to manage vegetation on transmission right of ways. Properly maintained right of ways (ROW) are essential for the safety of the public and our workers. The long-term goal of our vegetation management program is to provide for public safety, worker safety, and environmental safety while providing for reliable service.
Integrated Vegetation Management
The first step to creating a low growing plant community is to clear the ROW of tall growing and incompatible plant species. This is typically accomplished either mechanically or manually. Cutting or mowing alone is ineffective because it encourages the biological response of re-sprouting. After clearing, ROW is monitored for re-sprouting and reinvasion by incompatible vegetation. Once this occurs, the ROW will be enhanced through various methods to provide the desired outcome of a low growing plant community. Many factors are considered before an appropriate method is chosen and implemented.
Establishing a Low Growing Plant Community
SMUD’s goal is to convert tall growing plant communities in transmission ROW to communities dominated by low growing plant species. By selectively controlling incompatible plants while preserving low growing grasses, herbs and woody shrubs we are able to accomplish our goal. With proper management, the low growing vegetation can eventually dominate the right-of-way and retard the growth of the tall growing vegetation, providing control of incompatible plants and reducing the need for future treatments. Studies show this type of meadow-like setting will enhance wildlife habitat by promoting vegetation preferred by birds, deer and other small animals. Only low growing ground covers and shrubs whose mature height is less than 10’ may be planted in the ROW.
Building or Improvements on the ROW
If you are planning any type of building or improvement on property in the ROW, an application must be filed with SMUD’s Real Estate Services group. Call SMUD’s customer service at 1-888-742-SMUD (7683) for application and details.
Access Roads
SMUD is required to maintain access roads to its facilities. Be sure not to build or plant anything that would interfere with the use of these access roads.
Helpful Links
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