Can California bury its wildfire risk?

No one disputes that wildfires in California are becoming more frequent and more devastating. According to Gov. Gavin Newsom's April 12 Strike Force Report, "Wildfires and Climate Change: California's Energy Future," 10 of the most destructive wildfires in California's history have occurred since 2015, more than 25 million acres of California's wildlands are now classified as very high or extreme fire-risk areas and approximately 25 percent of California's population (11 million residents) live in high fire-risk areas.

The California Department of Forestry and Fire Protection has determined that over the past five years, California's electric utilities' infrastructure (wires, poles, equipment, etc.) have caused 9 percent of California's wildfires, but those wildfires represent 21 percent of the total amount of acres burned. The problem for California's electric utilities is that they operate and maintain tens of thousands of miles of electric distribution and transmission lines and associated equipment in California's high fire-risk areas, and fires ignited in those areas, usually during extreme wind events, spread quickly and are difficult to suppress. In particular, one-third of Pacific Gas & Electric's overhead electric system, or nearly 30,000 miles of distribution and transmission lines, are located in elevated or extreme wildfire risk areas in California.

California's electric utilities are subject to strict liability in inverse condemnation actions for damages resulting from wildfires caused by electric utility infrastructure. In response to the growing wildfire danger and liability risks faced by the electric utilities, a variety of wildfire mitigation solutions have been proposed.

One in particular, the burial or "undergrounding" of the electric utilities' overhead power lines located in high fire risk areas, has been the focus of the California Legislature and the California Public Utilities Commission in recent months. For example, Senate Bill 70, which recently passed out of the Senate and will be considered by the Assembly, would add new Division 2.2 to the Public Utilities Code to establish the "Electrical Infrastructure Underground Working Group" for the purpose of promoting the undergrounding of electrical infrastructure in the areas of California "affected by wildfires ... during the rebuilding and restoration phases of those areas" and to "prioritize undergrounding along those streets and highways that serve as county-designated evacuation routes." SB 70 also would amend Section 8386 of the Public Utilities Code to require that electric utility wildfire mitigation plans submitted for review and approval by the CPUC include a "description of where and how the electrical corporation considered undergrounding electrical distribution lines within those areas of its service territory identified to have the highest wildfire risk in a CPUC fire threat map."

While undergrounding electric power lines may seem the obvious and best solution to reduce wildfire risks associated with electric utility infrastructure located in high fire threat areas, especially for wind-related incidents (i.e., tree limbs blowing into power lines, two power lines coming into contact, etc.) undergrounding electric power lines is a very expensive solution with physical and timing constraints that are problematic, at least in the near term, for dealing with the growing wildfire threat in California.

PG&E and Southern California Edison both have reported that undergrounding electric distribution power lines can cost as much as $3 million per mile, or roughly four times the cost to construct overhead distribution power lines, and undergrounding electric transmission lines can cost even more. That means that requiring that PG&E underground just 10 percent of its electric distribution lines in high fire threat areas could cost $9 Billion or more, a cost that must be borne by electric utilities' customers or California taxpayers.

In addition, underground power lines take much longer to install than overhead power lines and, unlike overhead power lines, underground power lines must follow the ground and go around obstacles. In many places, undergrounding lines may be nearly impossible due to difficult terrain conditions, such as the presence of bedrock. Further, underground power lines are not impervious to natural disasters, as they can be damaged by landslides and earthquakes. Damage to underground lines can be more difficult to locate and repair and usually takes longer to repair than damaged overhead lines. Finally, and although unrelated to wildfire risks, the ability of telecommunication companies to install and operate new wireless 5G networks may be impaired if significant miles of existing electric utility above ground infrastructure are undergrounded, since wireless 5G equipment generally must be installed above ground.

Considering the costs and potential physical limitations of undergrounding electric utility infrastructure in high fire threat areas, and the time required to do so, undergrounding of electric utility power lines may not be the optimal solution, especially not in the near term, to mitigate the growing wildfire threat in California and the liability risks faced by California's electric utilities.

In fact, there are a variety of other wildfire mitigation measures, which, while individually not viewed as the complete solution expected from undergrounding, are less costly, can be implemented more quickly, and, in the aggregate, can mitigate wildfire threats and risks in a much more necessary and timely fashion. These measures include installing insulated electrical lines in high-risk areas, replacing wood poles with steel poles and adding monitoring equipment to identify power line breaks and prevent sparks. For example, Southern California Edison has reported that it is installing covered conductors on its power lines, which it claims is up to eight times less expensive, can be installed far more quickly and which can provide much of the fire risk reduction benefits of undergrounding power lines.

So, while California may be currently focused on undergrounding electric utility infrastructure, other, less expensive and quicker to install wildfire risk mitigation measures, if they prove efficient and effective in reducing wildfire threats and electric utility liability risks, ultimately may change the perception that burying California's wildfire risks is the best solution.