Smoky sky and sun with trees in the foreground
Wildfire and Outage Prevention 09/10/2020

On Monday, September 7, EWEB shut down four substations and delayed restoration to a feeder line in order to mitigate the risk of wildland fires, impacting more than 3,000 customers in the south hills and areas east of Thurston. 

Conditions allowed crews to restore power to south Eugene residents by the following day. However, active fire, smoke and other hazardous conditions for several days thwarted attempts to assess and safely re-energize power lines serving customers from Thurston to Walterville. 

Power lines can cause wildfires under a variety of "Red Flag" conditions when a combination of warm temperatures, very low humidity, and strong winds produce an increased risk of a rapidly spreading fire.

Downed Lines

Our power distribution system contains fuses and circuit breakers that detect fault conditions and protect the system if something goes wrong, much like the breaker panel in your home or business but on a larger scale. Even as the protection systems do their job, arcs and sparks can happen before the electricity is removed and an arcing downed line can quickly ignite grass and other vegetation, particularly in very dry conditions, and the fire can spread rapidly in high winds or gusts.

Falling Tree Branches

Tree branches can cause fires in multiple ways. A tree falling across a line can tear the line down. If a limb falls on the line, it can ignite and may even produce an electrical arc. The arc itself can spark a fire, and if the branch remains in contact with the line, it can eventually break the line.

Equipment Failure and Operation

Equipment such as switches, insulators, and transformers can deteriorate as they age, causing arcing and sparking when they fail or are stressed. Also, the normal operation of some protective fuses can cause sparks to fall into the ground. In severely dry and windy conditions, the sparks can ignite nearby vegetation.

Wildfire and outage prevention

Here in the northwest, we are all too aware that wildfires often result in loss of life and property.

To help prevent tree-related outages and mitigate wildfire risk, we proactively prune trees to help keep our equipment clear. Crews trim around 300 line miles of vegetation annually to minimize falling trees and branches for ongoing reliability maintenance, with an additional 250 line miles inspected and pruned specifically for fire protection in high-risk areas.

When there is a high risk for a wildfire, we may temporarily shut off power to certain neighborhoods to prevent our electric system from becoming the source of an ignition. As each weather situation is unique, we work closely with other agencies such as Lane County Emergency Management, U.S. Forest Service, and Oregon Department of Forestry, and carefully review a combination of factors when deciding if power must be turned off, including:

  • Red Flag Warning - Declared by National Weather Service
  • High Wind Forecast - Sustained winds over 20 mph and gusts above 30 mph
  • Wind-Related Outages - An indication of falling branches and/or downed power lines
  • Low Humidity Levels - Generally 20 percent and below
  • Dry Material on the Ground - Can quickly ignite sparks
  • Situational Awareness - Real-time observations by crews in the field

We realize this proactive approach of preemptively shutting off power can present challenges, especially for those who live in rural areas and rely on electric pumps for wells. If your power has been shut off, we will restore power as soon as the conditions permit, and crews have inspected the system to confirm it is safe to re-energize power lines.

You can help mitigate wildfire risks

Just as we manage vegetation to keep trees away from power lines, it's important for you to create a line of defense around your property by clearing dead trees and brush away from your property, particularly if you live in the south hills and other heavily forested areas of our community.

When selecting a new tree to plant, follow the "Right Tree, Right Place" approach. By picking the proper species and planting procedure, you can increase public safety, reduce power outages, reduce the need for routine pruning, and promote healthy, beautiful trees.

You should also have a plan for how you and your family will stay safe from wildfire. Find more information at https://www.ready.gov/wildfires