All landscaping shall be permanently maintained in good condition with at least the same quality and quantity of landscaping as initially approved. In order to present a healthy, neat and orderly appearance, all landscaped areas including interior parking lot islands and grass areas shall be provided with adequate irrigation for the maintenance of grass, shrubs, ground covering and other landscaping. An underground irrigation system shall be installed, operated and maintained to meet the intent of this Section. Such systems shall be required for all new developments and redevelopments projects. For sites proposing additions and/or expansions, an underground irrigation system shall be installed, operated and maintained to meet the intent of this Section, where physically practical and reasonable, as determined by the Planning and Zoning Commission.