All multi-family and mobile home developments' principal and accessory uses (except signs) which are situated on a parcel which abuts a single-family residential zone and all business and industrial developments' principal and accessory uses (except signs) which are situated on a parcel which abuts a residential zone shall be screened from such a zone by an approved wall or fence not less than six feet in height above the level of the adjacent property at the zone boundary. Walls or fences of lesser heights or planting screens may be permitted by the city if there is a finding that nature or extent of the use being screened is such that a lesser degree of screening will adequately promote the use and enjoyment of the properties within the adjacent residential zone, or there is a finding that a screening of the type required by this title would interfere with the provision of adequate amounts of light and air to same properties. All required screening devices shall be designed so that they are architecturally harmonious with the principal structures on the site and they shall be properly maintained so as not to become unsightly, hazardous or less opaque than when originally constructed.
(Ord. 1178 § 6.8, 1987)