The City Manager or a designee may approve minor variations in the location of required landscape materials due to unusual topographic constraints, siting requirements, preservation of existing stands of native trees or similar conditions, or to maintain consistency of established front yard setbacks. These minor changes may vary the location of required landscape materials, but may not reduce the amount of required landscape area or the required amount of landscape materials. The landscape plan shall be submitted to the administrative official or a designee and shall specify the modifications requested and present a justification for such modifications.