An overlay designation is applied to a certain geographic area, already designated with one or more of the zoning districts as provided herein, to effectuate additional and unique regulations on land use development that are necessary for the public health, safety and welfare but are difficult or impossible to implement because of the standardized regulations of the underlying conventional zoning district or districts. The restrictions imposed by an overlay designation are in addition to, and not in lieu of, the restrictions placed by the underlying zoning district on the property subject to the overlay designation. (Ord. 88-010 § 2, 1988. 2004 Code § 18.48.010.)