SACRAMENTO – The Office of Energy Infrastructure Safety (Energy Safety) today issued its approvals of the 2026-2028 Wildfire Mitigation Base Plans (WMP) for Trans Bay Cable (TBC) and Horizon West Transmission (HWT). Energy Safety’s approvals followed a 30-day public comment period for each WMP.
TBC and HWT are independent transmission operators, transmission-only electrical corporations with no end-use customers. These electrical corporations have limited assets and footprints compared to the large investor-owned utilities and small and multi-jurisdictional investor-owned utilities.
In its 2026-2028 Base WMP, TBC demonstrated continued progress in setting up quarterly vegetation management inspections. TBC’s wildfire consequence is very low due to its buried and submerged assets, however, in establishing these measures TBC is reinforcing its commitment to maintaining its facilities and further reducing its already minimal vegetation-related wildfire risk. Energy Safety is recommending that TBC consider coordinating with adjacent property owners to promote proactive vegetation risk reduction and support long-term system safety.
In its 2026-2028 WMP, HWT demonstrated that it continues to improve and expand its asset inspection practices. HWT conducts monthly visual asset inspections which now include aerial drone inspections in addition to on-the-ground inspections. HWT’s consideration of an additional water tank reflects a proactive effort to enhance firefighting and emergency response capabilities, but HWT did not provide a clear evaluation process or timeline. HWT must provide further details in its next WMP Update on the evaluation or construction of an additional water tank, along with progress to date and decision-making criteria.