7.6.8.   MAINTENANCE
   All required , irrigation systems, walls, screening devices, curbing, and detention basin landscape on the or within the shall be maintained as shown on the approved plans. The property owner is responsible for proper maintenance to achieve permanent, safe, and successful as required by this section. Failure to maintain the or required by this section constitutes a of the .
   A.   Plant Materials
      1.   Any plant material in areas of required that does not survive must be replaced with an equivalent size and species within 30 .
      2.   Plant material must be pruned as necessary to control size but not to disrupt the natural growth pattern or characteristic form of the plant except as necessary to achieve height clearance for visibility and pedestrian passage or to achieve a continuous hedge if required.
      3.   Clipping and pruning of the plant material are required to allow maximum shading while preserving surveillance opportunities and preventing obstructive overhang into walks, curb areas, drives, and line of sight triangles as required by the .
      4.   All dead or removed plant material must be replaced with plant material acceptable under the standards of the standards. Replacement material must be a minimum 15-gallon size for trees and five gallon size for shrubs.
      5.   Regular landscape maintenance shall ensure water efficiency and include, but not be limited to, pruning, mulching, weeding, litter removal, aerating and dethatching areas, and fertilizing nonnative plant materials, as necessary.
   B.   Inert Materials
      1.   Exterior , such as benches, walls, or ramadas, must be of durable materials appropriate to the desert climate. Material with integral coloring or stucco is preferred for seating fixtures and other permanent .
      2.   Inert materials used in the areas must be of a nature to withstand the extremes of the desert climate and minimize heat gain or reflected heat.
      3.   The inert materials must be replaced as needed due to displacement or .
   C.   Planting Areas
      1.   Inert materials must be used in inaccessible, narrow, or hard to maintain sections of the planting areas.
      2.   Landscaped areas must be kept free of trash, weeds, debris, and dead plant material and must be maintained in a clean and neat fashion.
      3.   Use of river rock is discouraged to windows.
   D.   Landscape Removal
      1.   Substantial modifications, as determined by the PDSD , and/or removal of plant materials or other landscape elements shall require review and approval of a revised by PDSD.
      2.   The removal or destruction of that has been installed according to an approved and not replaced constitutes a of the .
      3.   Minor modifications of the occurring as a result of routine maintenance, necessary replacement of elements because of damage or disease, or other causes is not subject to review by PDSD.
   E.   Screening and Wall Maintenance
      1.   Paint and stucco must be renewed on the surfaces of fences and walls as needed.
      2.   Wooden slats in chain link fences must be replaced as needed to retain the opacity of the .
      3.   Any screening device that has deteriorated to the point where it does not serve as a must be replaced by the property owner. Vegetation used to meet the screening standards may not be replaced with new vegetation after two years past the installation. Replacement must be with another option for screening, such as a fence or a wall, in order to achieve an immediate . This standard does not apply to the occasional replacement of single plants within a vegetative .
   F.   Irrigation System Maintenance
   Irrigation systems must be maintained and replaced as necessary to continue to conserve water. Detection and repair of leaky or broken pipes, valves, and fittings and malfunctioning and/or misaligned heads, emitters, and bubblers must be part of a regular maintenance program for the .
      1.   Automatic Irrigation Controllers are recommended to be reset a minimum of four times a year (spring, summer, fall, and winter) to adjust for plant water requirements that vary according to the season.
      2.   Whenever possible, repair of irrigation equipment must be done with the originally specified materials or their equivalent.