Wildfire plans and tree clearing in California: the CPUC and General Order 95
What the California Public Utilities Commission's General Order 95 says about vegetation clearance from power lines: Rule 35, the Table 1 radial clearances for Cases 13 and 14, the Appendix E trim-time guidelines in feet by voltage, and the exceptions.
Checked against the sources at the bottom of this page on October 8, 2026. Rules, fees and pay change: the source has the last word.
This page reports what the official source says. It is not legal advice: ask the office named here. It restates three pages of the California Public Utilities Commission's General Order 95 (GO 95), the rules for overhead electric line construction, as read on October 8, 2026: Rule 35 on vegetation management, Table 1, and the Appendix E guidelines to Rule 35. The pages of the Office of Energy Infrastructure Safety, which reviews the utility wildfire mitigation plans, returned an access block on October 8, 2026, so what those plans file is not described here. The comparison of every region is on the guide to utility wildfire plans and tree clearing.
What Rule 35 says
Rule 35 says that where overhead conductors pass through trees and vegetation, the minimum clearances in Table 1, Cases 13 and 14, measured between line conductors and vegetation under normal conditions, are to be maintained. It applies to all overhead electrical supply and communication facilities covered by the order, including those on land owned by California state and local agencies. It says that when a company knows, through normal operating practice or notification, that dead, rotten or diseased trees, or such parts of healthy trees, overhang or lean toward a span and may fall into it, they should be removed. For circuits at 750 volts or less, including service drops, the rule says they should be kept clear of vegetation in new construction and when repaired, whenever practicable. It adds that contact between vegetation and a conductor does not by itself break the rule.
The exceptions are specific. The rule does not apply to conductors under 60,000 volts, or compliant aerial cable, where trimming or removal is not practicable and the conductor is separated from the tree with suitable materials. It does not apply where the company made a good faith effort to get permission to trim or remove and was refused or could not get it, which the rule defines as a minimum of an attempted personal contact and a written communication. It also exempts mature trees whose trunks and limbs sit more than six inches from primary distribution conductors, though closer than the Table 1 clearance, if they are strong enough not to reach the six inch minimum in foreseeable weather. The rule puts the risk of that judgment on the utility and the final say on the Commission.
The clearances in feet and inches
This is the part that sets California apart. Table 1, Case 13 is the radial clearance of bare line conductors from tree branches or foliage, and Case 14 is the radial clearance from vegetation in Extreme and Very High Fire Threat Zones in Southern California. The table puts 18 inches in Case 13 for conductors from 750 to 22,500 volts, and 48 inches in Case 14 for the same class, with a footnote letting the Case 14 figure fall to 18 inches for conductors under 2.4 kV. Another footnote allows a reduction for conductors under 60,000 volts when protected from abrasion and from grounding by contact with the tree. For conductors from 22.5 to 300 kV, Case 14 gives 48 inches, and a footnote raises it to 72 inches from 72 kV to 110 kV and 120 inches above 110 kV. The Appendix E guidelines call a second set of figures recommended minimum clearances to be established at the time of trimming, where practicable.
| Line voltage | Case 13 at time of trim | Case 14 at time of trim |
|---|---|---|
| 2,400 volts or more, under 72,000 | 4 feet | 12 feet |
| 72,000 or more, under 110,000 | 6 feet | 20 feet |
| 110,000 or more, under 300,000 | 10 feet | 30 feet |
| 300,000 or more | 15 feet | 30 feet |
The guideline page says reasonable practice may call for more than these figures to hold until the next scheduled maintenance, and that each utility may apply additional clearances considering line voltage, span length, sag, maintenance cycles, species, growth rate, climate and fire risk, and trimming requirements for State Responsibility Area lands under Public Resources Code sections 4102 and 4293.
Sources
- California Public Utilities Commission, General Order 95, Rule 35 Vegetation Management, read October 8, 2026
- California Public Utilities Commission, General Order 95, Table 1 (Cases 13 and 14), read October 8, 2026
- California Public Utilities Commission, General Order 95, Appendix E guidelines to Rule 35, read October 8, 2026