State Clearance Regulations:

Trees and other vegetation growing in proximity to overhead utility facilities must adhere to federal and state regulations. These laws address potential vegetation conflicts with public safety, service reliability, and fire prevention. In California, three state regulations apply to vegetation and power line/utility clearances.

General Order 95., Rule 35

The first regulation is General Order 95., Rule 35. This rule requires a minimum of 18" (inches) of clearance between vegetation and energized conductors (wires) carrying more than 750 volts. This law covers all of California regardless of location and defines the minimum clearance required at all times. Utility vegetation management programs must often achieve greater clearance than 18" to address regrowth of affected vegetation and all potential weather/climatic conditions which can affect the vegetation and the conductors. Length of time between maintenance cycles can also increase the amount of clearance required.
Visit CPUC website for complete regulations. (search for General Order 95 Rule 35)

Public Resource Code 4293

The second regulation is Public Resource Code 4293. This code requires a minimum of 4' (feet) of clearance between vegetation and energized conductors (wires) carrying more than 750 volts. This law covers all "State Responsibility Areas" in California. State responsibility lands are generally outside city limits where the California Department of Forestry and Fire Protection (CDF) is the Direct Protection Agency. Utility vegetation management programs must often achieve greater clearance than 4' (feet) to address regrowth of affected vegetation, higher voltage transmission lines, and all potential weather/climatic conditions which can effect the vegetation and the conductors. Length of time between maintenance cycles can also increase the amount of clearance required.

Public Resource Code 4292

The third regulation is Public Resource Code 4292. This code requires a minimum of 10' (feet) radial clearance at the base of poles carrying certain protective equipment and connectors of ground vegetation clearance and the limbing of tree branches to 8' (feet) in height around these poles. This law also covers all "State Responsibility Areas" in California. State responsibility lands are generally outside city limits where the California Department of Forestry and Fire Protection (CDF) is the Direct Protection Agency. Utility vegetation management pole clearing programs must also address regrowth of affected vegetation, and all potential weather/climatic conditions which can effect the vegetation. Length of time between maintenance cycles can also change the amount of clearance required.

Title 14, California Code of Regulations

(further defines the Public Resource code)

Section 1254
Minimum Clearance Provisions PRC 4292

Section 1256
Minimum Clearance Provisions - PRC 4293
Complete regulations for Title 14 - sections 1250 & 1258
(Note: Click Title 14, Go to Division 1.5, Go to Chapter 7, Go to Article 4)

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