The California Public Utilities Commission (CPUC) adopted Resolution SPD-37, updating the state’s framework for expediting electric line undergrounding under SB 884 of 2022 and adding new cost, audit, and performance requirements intended to tighten wildfire-mitigation oversight.
The resolution, approved on December 4, 2025, revises guidelines first adopted in Resolution SPD-15 and aligns the CPUC’s undergrounding program with the Office of Energy Infrastructure Safety’s 10-Year Electric Undergrounding Plan standards. The changes are intended to ensure that undergrounding projects funded by ratepayers deliver measurable wildfire-risk reduction and are subject to consistent cost controls.
Resolution SPD-37 introduces a new Phase 2 application process requiring utilities to submit standardized project data, revenue-requirement models, and decision-making metrics. Utilities must provide more detailed cost tracking and are subject to annual audits of the one-way balancing account used to recover undergrounding costs. The resolution also establishes a cumulative memorandum-account cap to limit uncontrolled cost transfers to ratepayers.
Under the revised framework, utilities seeking cost recovery must demonstrate that proposed undergrounding projects outperform alternative wildfire-mitigation measures, comply with approved cost and benefit limits, and meet Energy Safety performance standards. Projects are generally required to meet a benefit-cost ratio of at least 1 and satisfy defined wildfire-risk thresholds. Utilities must also provide additional justification for undergrounding work proposed outside high-fire-threat districts.
The commission described the changes as a recalibration of the SB 884 program toward “cost-efficient, high-value” projects that provide superior wildfire risk reduction relative to other options, such as covered conductors or system hardening. Commissioners emphasized that undergrounding remains a viable mitigation tool but should be deployed selectively, where it provides demonstrable safety benefits.
Utilities had opposed earlier versions of the proposal, Politico reported, particularly a cost-to-benefit methodology they argued was stacked against undergrounding. In response, the commission removed that provision and instead directed Pacific Gas & Electric (PG&E), Southern California Edison (SCE), and San Diego Gas & Electric (SDG&E) to develop and propose a revised analytical framework for evaluating undergrounding projects.
PG&E and SDG&E have argued in filings that undergrounding offers long-term advantages, including reduced maintenance costs and a lower probability of fire ignition compared with overhead infrastructure. Affordability advocates, however, urged regulators to prioritize lower-cost resilience measures, warning that large-scale undergrounding could significantly increase customer bills if not carefully constrained.
Resolution SPD-37 takes effect immediately and will govern future SB 884 undergrounding proposals as utilities prepare updated electric undergrounding plans under the state’s wildfire mitigation framework.