Vegetation Management Program
Basin Electric has a vegetation management program to ensure the transmission of safe and reliable electrical power while minimizing adverse impacts on the environment. The Transmission System Maintenance Division (TSM) is responsible for the Transmission Vegetation Management Program that maintains approximately 1,900 line miles of electric transmission right of way, which are operated at voltages from 115 kV to 345kV.
Our vegetation management strategy:
- Non-compatible vegetation shall be cleared from the right-of-way when authorized by easements, landowner/tenant or controller.
- Compatible vegetation that does not interfere with access, operation or maintenance of the line shall be left undisturbed. The ultimate goal is to convert the right-of-way to low growing plants that keep tall growing vegetation out. Every effort will be made to preserve natural habitat whenever practical and possible. All pruning practices will follow modern guidelines and standards.
- Herbicide application to clear cut areas to prevent regrowth on right-of-way where applicable and to control small brush for right-of-way access for operation and maintenance of power lines.
Vegetation planted within Basin Electric rights-of-way must not exceed a maximum height of 12 feet at maturity, and may not interfere with Basin Electric's access and/or maintenance requirements. Vegetation planted on Basin Electric power line rights-of-way must be approved by Basin Electric Land Management.
Basin Electric's annual work plan
- Aerial patrol of all lines a minimum of three times per year to update and verify tree spans
- Ground patrol all tree spans a minimum of two times per year
- Remove or cut dangerous trees at time of ground patrol inspection
- Identify other problem trees during ground inspection for remedial action before June 15
- Document all activity on appropriate inspection and action forms
- Report all vegetation related outages as soon as possible
National Electric Safety Code requirements
The National Electrical Safety Code (NESC) requires that vegetation does not interfere with workers maintaining, upgrading or repairing a line. NESC requires removal of any trees or other vegetation that is a hazard to the power system or that could become a hazard to the system. Other requirements include:
- All transmission spans with non-compatible vegetation shall be identified and listed for each transmission line;
- A minimum of three aerial inspections will be performed annually of all transmission lines to update vegetation span list;
- A minimum of two ground inspections will be performed annually of all non-compatible vegetation spans;
- Side trees outside of the right-of-way that would strike the line when falling shall be removed or top trimmed at a 45 degree angle away from the line. Landowner permission shall be received before cutting trees outside of the right-of-way;
- Right-of-way width to be maintained:
- 115 kV = 100 feet
- 230 kV = 125 feet
- 345 kV = 150 feet
NESC required clearance
Distance between vegetation and energized conductors to be achieved at the time of vegetation management work:
- 115kV = 20 feet
- 230kV = 25 feet
- 345kV = 25 feet
Distance between vegetation and energized conductors:
- 115kV = 10 feet
- 230kV = 15 feet
- 345kV = 20 feet
Compatible vegetation does not exceed a maximum height of 12 feet at maturity and does not interfere with transmission facility access and/or maintenance requirements.