No person shall, individually or through an agent or employee, enter upon the streets of the city to perform any function in proximity to high-voltage overhead lines or to engage in any excavation, demolition, construction, repair or other activity, or to erect, install, operate or store in or upon such premises any tools, equipment, machinery, materials or structures unless and until danger from electrical contact with said high-voltage overhead lines has been guarded against, as provided in this chapter.  (Ord. S-29555, 1976).