16-13-4-5: PRESERVATION OF EXISTING TREES:

   A.   Existing trees, when located appropriately, may be used to comply with the requirements for buffer yards, street trees, and to meet the tree requirements for parking areas. Existing trees used to satisfy these requirements shall be in good health prior to and following site development.

   B.   The same minimum separation distances that are required of new plantings must be observed when possible; except, that existing groupings of two (2) or more trees may be preserved. Trees or branches must be removed from such groupings in the interest of public safety and/or to assure survival of the specimen.

   C.   The roots of a tree must be protected during site development with barrier fencing extending at least as far as the drip line of the tree. Any limbs that might be damaged during construction must be pruned.

   D.   No paving or construction shall be allowed within the drip line of a preserved tree.

   E.   Any preserved tree that dies shall be replaced by the same number of trees for which it substituted during the same or immediately following planting season.

   F.   The schedule below shows the acceptable substitution ratio for existing trees to required trees:

 

Diameter Of Existing Tree	Substitution Ratio
36 inches or more	3 required trees
12 to 36 inches	2 required trees
2 to 12 inches	1 required tree

 

The substitution value for groupings of trees approved by the city shall be based upon the diameter of the largest tree in the group.

(Ord. 52-09, 10-19-2009)

16-13-4-6: PARKING LOT LANDSCAPING:

   A.   A landscaped buffer strip shall be provided along the frontage of all surface parking areas at least ten feet (10') wide along the public right of way. The buffer strip shall consist of shade trees, low shrubs, perennial flowers, and/or other plant materials approved by the city planner. Landscaped earth berms and/or decorative walls and fences are permitted provided they are integrated with the landscape screening described above. The use of biofiltration methods of landscape and drainage design is encouraged.

   B.   A landscape buffer at least seven feet (7') wide shall be provided along the remaining sides of all surface parking lots. This area shall be planted with any combination of shade trees, coniferous trees, and/or shrubs.

   C.   Parking lot landscaping and trees shall be dispersed throughout the parking lot in accordance with subsection 16-13-3-5D of this chapter.

      1.   For single parking bays, landscaped islands shall provide at least one parking space of landscape area, measuring at least nine feet by eighteen feet (9' x 18'), and shall be planted with a combination of one tree, low shrubs, perennial flowers, turf, and/or ground cover/ornamental grasses but shall not be planted entirely with turf.

      2.   For double parking bays, both the end landscaped islands and the intermediate landscaped islands shall provide a double parking space of landscape area, measuring at least nine feet by thirty six feet (9' x 36'), and shall be planted with a combination of one shade tree or two (2) ornamental/dwarf trees, low shrubs, perennial flowers, turf, and/or ground cover/ornamental grasses measuring no more than three feet (3') in height, but shall not be planted entirely with turf.

   D.   No tree, shrub, hedge, or berm shall be placed or encroach into an area the city engineer determines is an obstruction to visibility, or extends into a visibility triangle affecting the public right of way.

(Ord. 52-09, 10-19-2009)

16-13-4-7: STREET TREES:

   A.   Street trees shall be planted within a landscaped parkway or in tree pits within the sidewalk area according to section 6-8-1 of this code and the "City Of Dubuque Street Tree And Landscaping On Public Right Of Way Policy".

   B.   Street trees planted within the sidewalk area shall be planted using best management practices. (Ord. 52-09, 10-19-2009)

16-13-4-8: SCREENING REQUIREMENTS:

   A.   All commercial and industrial uses that abut residential, office, or institutional districts, shall maintain screening not less than six feet (6') along the abutting property line or lines.

   B.   Screening required by this section 16-13-4 shall be equivalent to the following:

      1.   Fences with at least fifty percent (50%) opaque construction; or

      2.   Hedges, shrubs or evergreen trees of at least thirty percent (30%) opacity at the time of installation and fifty percent (50%) opacity maintained within three (3) years of installation; or

      3.   Berms or graded slopes of not less than three feet (3') of mean height. Such berms or graded slopes shall contain at least fifty percent (50%) living material. (Ord. 52-09, 10-19-2009)

16-13-4-9: EXTERIOR TRASH COLLECTION AREAS:

   A.   Exterior trash collection areas shall include collection bins, dumpsters, and similar waste receptacles for the short term storage and collection of trash. Trash shall include garbage, scrap, recyclables, debris and similar materials.

   B.   The storage of trash shall be limited to that produced by the principal permitted use and accessory uses of the lot. Exterior storage of trash, which could be blown into the air or strewn about by the wind, shall be prohibited.

   C.   The ground area coverage of the exterior trash collection areas shall be the area contained inside the required screening.

   D.   Exterior trash collection areas shall be located in rear or side yards only. Exterior trash collection areas shall not encroach into a front yard. The city planner may grant a waiver to this requirement when, due to topographic conditions or lack of a side or rear yard, conformance with this requirement is impractical.

   E.   All exterior trash collection areas and the materials contained therein shall be screened from view from the adjacent public right of way.

   F.   The screening shall be a completely opaque fence, wall or other feature of a height between six (6) and ten feet (10') measured from the ground level outside the line of the screen. Screens built on sloping grades shall be stepped so that their top line shall be horizontal. If a ten foot (10') high screen fails to shield the exterior trash collection area from view of the adjacent public right of way, evergreen plantings may be required in addition to the screening. Evergreen plant materials shall be selected and designed so that they will screen the area from the adjacent public right of way within five (5) years.

   G.   Exposed materials used to construct the opaque screen shall be similar in appearance to materials used for exterior building walls. All exterior entrances to a screened trash area shall be provided with a gate or door of similar design to that of the screen. (Ord. 52-09, 10-19-2009)

16-13-4-10: EXTERIOR STORAGE IN NONRESIDENTIAL DISTRICTS:

Screening for exterior storage is intended to buffer surrounding property from the negative visual impact created by the storage of raw or finished goods, materials and equipment that can adversely impact the value of adjacent property. Exterior storage areas shall conform to the following:

   A.   Exterior storage of materials which could be blown into the air or strewn about by the wind shall be prohibited.

   B.   Exterior storage, where allowed, shall be screened from view from the adjacent public right of way and abutting residential districts or uses to a minimum height of six feet (6').

   C.   The screening height shall be measured from the ground level outside the line of the screening. Screens built on sloping grades shall be stepped so that their top line shall be horizontal.

   D.   Exterior storage shall not encroach to a front yard.

   E.   All exterior entrances to a screened storage area shall be provided with a gate or door of similar design to that of the screen.

   F.   The city planner may grant a waiver to allow screening to exceed the maximum height allowed when topography or height of individual finished products or equipment could make it impossible to completely screen a storage area from every vantage point. The city planner may not grant waivers to the maximum screening height for raw materials or stacked goods.

   G.   Long term storage of products or materials in semitrailers or shipping containers is permitted only in accordance with title 14, chapter 8 of this code, as amended. (Ord. 52-09, 10-19-2009)

16-13-4-11: INSTALLATION, MAINTENANCE AND REPLACEMENT OF LANDSCAPING AND SCREENING:

   A.   Plantings shall be installed prior to the issuance of a certificate of occupancy unless seasonal conditions exist that may reduce the survivability of the plantings, in which case the plantings shall be installed within six (6) months of the issuance of a certificate of occupancy.

   B.   Plantings shall be properly maintained in a healthy manner. Plantings that become diseased or die shall be replaced with similar plant materials. Replacement plantings shall be installed during the same or immediately following planting season.

   C.   All required screening and fencing shall be maintained and, whenever necessary, replaced in accordance with the provisions of this chapter. (Ord. 52-09, 10-19-2009)