During the third quarter of 2005, the North American Electric Reliability regions reported 15 vegetation-related outages for transmission lines of 200 kV and higher. These included eight 230 kV, two 345 kV, four 500 kV, and one 765 kV transmission outages caused by tree contact inside or outside of the right-of-way. The Vegetation-Related Transmission Outages report for the third quarter, which NERC published in December, provides a brief description of each of these outages and the actions taken to prevent further outages.
NERC collects information on vegetation-related transmission outages from the regions in accordance with NERC Reliability Standard FAC-003-0 — Vegetation Management Program. Monitoring and reporting vegetation-related transmission outages addresses recommendation 4 of the NERC report called "Aug. 14, 2003 Blackout: NERC Actions to Prevent and Mitigate the Impacts of Future Cascading Blackouts." This report and others related to the 2003 blackout are available at www.nerc.com/~filez/blackout.html.
The third-quarter Vegetation-Related Transmission Outages report is available at www.nerc.com/~comply/vegetation_management_reports.html.