NV Energy and Liberty Utilities outline wildfire mitigation plans for Lake Tahoe

SOUTH LAKE TAHOE, Calif. - With electrical transmission lines found to be at fault in recent California fires, agencies responsible for supplying electricity to communities have been creating plans to prevent fires in the future.

Both companies that supply power to Lake Tahoe, NV Energy and Liberty Utilities, have announced new mitigation efforts to reduce the risk of fire.

To the west of Tahoe, the Gas and Electric Company (PG&E) has already started shutting down power when conditions are ripe for fire: high winds and dry vegetation. Both NV Energy and Liberty Utilities will do the same along with updated field and systems operational practices.

Liberty Utilities contacted their customers on Tuesday to outline their plans, and NV Energy will be starting a series of public outreach meetings along with social media and website notifications.

Liberty filed a Wildfire Mitigation Plan with the State of California in February to comply with legislation requiring that electric utilities prepare and submit plans to prevent, combat and respond to wildfires affecting their service territories. They serve multiple communities in Alpine, El Dorado, Mono, Nevada, Placer, Plumas and Sierra counties, all of which have been designated either “High” or “Very High” Fire Hazard Severity Zones by CAL FIRE.

Their released plans:

Vegetation Management
Increased investments. Liberty Utilities is increasing its annual investment in tree trimming activities from $2.5 million to $4 million to ensure invading vegetation is removed and does not come in contact with electric infrastructure.

Advanced program cycle. Liberty Utilities is adopting an aggressive three-year cycle for their vegetation management program to ensure trees near power lines are inspected on a more regular schedule.

Improved safety practices. Liberty Utilities is required to maintain a 4-foot clearance between vegetation and electric infrastructure. To ensure this standard is consistently met over time, Liberty Utilities goes above and beyond by trimming trees back to a 12-foot clearance.

Infrastructure Improvements
Undergrounding lines. In an effort to reduce the danger posed to electric lines and poles, Liberty Utilities is continuing efforts to underground their infrastructure over time. They are coordinating with the Tahoe Regional Planning Agency (TRPA) to ensure their undergrounding projects improve Tahoe’s scenic goals and contribute to the region’s sustainability efforts.

Substation rebuilds. Liberty Utilities plans to replace the current wooden designs of the Brockway and Stateline substations with steel structures, as well as relocate the Brockway Substation to a nonresidential area. These improvements will remove the heightened fire risk currently present for these two substations.

Protocol Enhancements
Proactive de-energization. Liberty Utilities has permission from the State of California to proactively shut off power in high-risk areas when extreme weather conditions present a clear danger to public safety. Our crews continuously monitor weather conditions, local forecasts and fire danger ratings to assess the wildfire threat to the greater Tahoe region and determine if “at risk” power lines need to be de-energized to ensure the safety of our community. If de-energization is a possibility, Liberty Utilities will alert customers, local government and safety agencies of the potential need to shut off power and keep the community apprised as weather conditions evolve.

NV Energy serves the east side of Lake Tahoe along with the rest of northern and southern Nevada.

Their mitigation efforts:

Operational Practices
They have implemented field and systems operations practices to mitigate wildfire risk, including field procedures, reclosing strategy, and a no-test policy. They have used a one-shot, non-reclosing policy during fire season in northern Nevada for several years and completed circuit patrols prior to any reclosing or testing during fire season.

Inspections and Corrections
Their overhead equipment inspection frequency, identification of fire-risk conditions and correction time frames are designed to mitigate against utility ignition. They will move in more utility trucks during Red Flag days were danger of fire is greatly increased.

System Hardening
They are working to install equipment with less ignition risk - categories include covered conductors, metal poles, non-expulsion cutouts, relays, pole warp, and other protective devices. The metal poles are replacing wood ones and in Lake Tahoe, the conductors will be covered. Other areas of Nevada do not need the same type of system changes. They will also work on moving power lines on trees over to poles.

Vegetation Management
NV Energy's vegetation management practices are focused on clearance distances and removal of hazard trees to minimize the chances of vegetation striking lines. Previously they addressed shrub and tree growth around their power lines every eight years and they are now on a four-year cycle in high-risk fire areas and taking immediate corrective action based on other patrols and inspections.

Situational Awareness
Information about fire conditions can help guide other mitigation measures, including information from weather stations and cameras. They said they are working with UNR to install another 10-15 wildfire alert cameras and with Desert Research Institute to install weather stations in high fire risk areas. They have meteorologists on board to determine fuel, temperature and humidity conditions in Lake Tahoe. They will issue an eight-day head's up notice to fire, water, law enforcement, and other agencies to alert them of a possible elevated risk event. They will then follow up with a four-day notice and the public will be notified with a 48-hour lead time.

Proactive De-energization
Under extreme wildfire weather conditions, proactive de-energization of pre-identified circuits, or sections of circuits, will be done to mitigate against potential electric facility-caused ignitions in high fire risk areas.

In Lake Tahoe, NV Energy said they will have "wire watcher" and trouble responder numbers beefed up in the event of a high fire risk event. They can de-energize one of all six sections of their service area in Tahoe, depending on the need. Restoration takes 2-3 hours.

In the event Liberty Utilities de-energizes an area, NV Energy won't automatically follow. During a recent meeting with Douglas County emergency management staff, NV Energy said they will reply on USFS, the fire departments, and NOAA to determine de-energize days. Based on past data they estimate they'll only to follow those procedures once a year.

More information on both company's fire mitigation efforts will be shared in the months to come.

-South Tahoe Now Staff Report