The APS Forestry and Special Programs Department conducts vegetation management on approximately 11,400 miles of distribution lines (lines carrying 4,000 to 21,000 volts) and over 6,000 miles of transmission lines (lines carrying 60,000 to 500,000 volts).
Vegetation interference with power lines is one of the most common causes of electrical outages on distribution systems, and also has resulted in transmission grid failures subjecting millions of people to lengthy blackouts. Vegetation management is necessary for safety, system reliability, access to facilities, regulatory compliance, security, and fire risk. Vegetation, if unmanaged, can cause electric service interruptions, can ignite wildfires, and become a safety risk to the public. It is the Forestry Department’s responsibility to maintain vegetation to reduce these risks to the public and to the utility resources.