The open storage of any industrial equipment, vehicles and all materials, including wastes, shall be screened from public view, from a public street and from adjoining properties by an enclosure consisting of a wall not less than six feet in height, which may, depending on land usage, be required to be eight feet in height. Whenever such open storage is adjacent to a residential zone in either a front, side or rear lot line relationship, whether immediately abutting or across a right-of-way from such zone, there shall be provided an obscuring masonry wall or wood fence of at least six feet in height.

(Code 1979, § 17.30.040)