Electric Power Distribution Overhead transmission and distribution of electric power is a major source of ignition for the conflagrations that have destroyed many hundreds of homes in California and elsewhere in recent years. Contrary to popular belief the large high-voltage transmission lines are not the worst offenders. In one study they accounted for less than 8 percent of the fires over 5000 acres in size. This proportion was exceeded only by arson and was equalled by machine use. All other fire causes were smaller in number.
Primary circuits bring the power from the substation to the user's transformer.
Primary electric power distribution circuits are a serious cause of wildland conflagrations. The thousands of miles of these lines present a tremendous exposure and an almost insurmountable problem of inspection and maintenance. In the foreseeable future, even higher voltage lines can be installed underground. The subdivision codes of many cities now require such installation in all new subdivisions, although usually for visual esthetic reasons. The same requirement could be imposed in rural and wildland areas for fire protection reasons.