News & Media

How does a utility determine if the power needs to be shut off?

November 30, 2023

Turning off the power is a last resort to maintain public and customer safety during extreme fire risk conditions.  The factors that determine if a utility will implement a Public Safety Power Shutoff (PSPS) depends on the circumstances of each situation.

A utility will consider a combination of many factors when making a decision to implement a power shutoff.  These factors include but are not limited to:

  • Extreme fire danger threat levels, as classified by the National Fire Danger Rating System
  • A Red Flag Warning declaration by the National Weather Service
  • Low humidity levels
  • Sustained high winds
  • Site-specific conditions like temperature, terrain and local climate
  • Critically dry vegetation that could serve as fuel for a wildfire
  • On-the-ground, real-time observation from TID or other agency field staff

One situation that may warrant a public safety power shutoff is an active fire. An active fire may necessitate disconnecting power to an area surrounding the fire for the duration of the emergency situation to provide for public safety. Power would be restored once the fire is out, system integrity and safety can be confirmed, and power can be safely reconnected.