170.33   SPECIAL PROVISIONS.  
The required front, side, or rear yards of each district shall be observed unless 50 percent or more of the lots on one side of the street between two intersecting streets are improved with buildings, the majority of which have observed an average yard less than that required in the district. In cases where the above is true, the average of the lesser yard dimensions may be used. However, where the lots improved with buildings are less than 40 percent of the total number of lots, including vacant lots, on one side of the street between two intersecting streets, the required minimum yards of the district shall be observed.
1.   A detached private garage or accessory building or structure, including a television satellite dish, may be located, erected, or established in a required side or rear yard of the district provided the private garage or accessory building or structure is located not nearer than five (5) feet to the side or rear lot lines, except when located adjacent to an alley line, in which case it may be located not nearer than three (3) feet to the alley line. A private garage or accessory building or structure, including television satellite dishes, shall not be located nearer to a street line than the required setback for a principal building. The detached private garage or accessory building or structure shall not occupy more than 35 percent of a rear yard. A private accessory building or structure is limited to the height of the principal building unless a greater height is permitted as a special use permit by the Board of Adjustment.
2.   Building Projections. Projections from buildings including eaves, canopies, chimneys, sills, cornices, or other similar architectural features may project or extend not more than two (2) feet into the required yard.
3.   Courts.
A.   Outer Courts. Courts or open spaces between two or more building walls that open on any yard on the lot and containing windows in one or more walls shall have a minimum width of twice the side yard requirements of the district, except court widths for buildings with a height in excess of 35 feet shall be increased by one foot for each foot of additional building height above 35 feet, or 50 feet, whichever is less.
4.   Fences, Walls, and Hedges. Fences, walls, and hedges are permitted in all districts in accordance with the following limitations:
A.   Any electrically charged fence, barbed wire or sharp pointed metal fence shall not be allowed unless approved by the Board of Adjustment.
B.   At any corner formed by intersecting street, it shall be unlawful to install any fence or wall or set out any hedge or shrubbery, natural growth or other obstruction within the triangle formed by the center line of the intersecting streets drawn from the point of the intersection back a distance of 70 feet with a line drawn to form a right triangle. The foregoing provisions shall not apply to fences, walls, or hedges of a height of less than 33 inches above the established grade.
C.   Tree branches which overhang the public sidewalk shall be kept trimmed to a height of at least eight feet above the sidewalk level. Tree branches which overhang the public street, shall be kept trimmed to a height of not less than 16 feet.
D.   Fence and perimeter wall heights in required yards in residential uses shall not exceed four feet between a primary structure and an adjacent street. The four feet limit shall apply to any such fence or perimeter wall between any street and any front building line extended to the lot line. All other perimeter fences shall not exceed six feet in height. Greater heights may be permitted by special use permit approved by the Board of Adjustment. The finished side of fences shall face outward from the enclosed space.
E.   Materials Permitted. With the exception of temporary fences as provided herein, and fences in the interior of a property around the perimeter of a garden or animal enclosures, permanent fences shall comply with the following:
(1)   Be constructed of customarily used materials such as, but not limited to: wrought iron, aluminum, metal, well-manicured hedges, stone, masonry, wood, polyvinyl chloride (PVC), chain link, composite and other similar materials that are durable and can be installed in such a way as to provide a clean finished appearance.
(2)   Fence building materials not permitted include, but are not limited to: Pallets, scrap lumber, scrap metal, snow fence and other materials not specifically designed or intended for fence construction.
(3)   Fences for the protection of gardens in single family zoning districts may be allowed in the interior of the property. Fences constructed of chicken wire or like material and not exceeding two (2) feet in height are permitted around the perimeter of a garden.
(4)   Temporary fences installed to provide site security and/or safety in conjunction with construction work shall be allowed to be comprised of cloth screening fabric and plastic snow fence type materials. Any such temporary fences shall be removed upon completion of construction, if construction ceases for a period of six (6) months, or upon issuance of an occupancy permit, including temporary occupancy.
(5)   All fences shall be constructed in a sound and sturdy manner and shall be maintained in an upright, non-sagging manner and in good condition, including the replacement of defective or missing parts, painting, and other acts required for upkeep and maintenance.
(6)   Any fence previously constructed that does not meet standards set forth by this ordinance and are presently existing on any property in the City of Carroll on the date of final passage of this ordinance shall be removed from such property or be brought into compliance with the provisions of this section within thirty (30) days of final passage of this ordinance.
(Ord. 2414 - Aug. 24 Supp.)
5.   Water Supply Well Separation Distances. No construction of any source of contamination shall be permitted within 100 feet of any City water supply well, except as provided in the section of the Iowa Administrative Code cited below.
Applicable definitions of terms and requirements for separation distances shall be controlled by Chapter 43 of Part 567 of the Iowa Administrative Code (455B.), specifically subrule 43.3(7) and Table A as amended and implemented by the Iowa Department of Natural Resources. For the purposes of reference, the current Table A is attached to this paragraph, but should be checked for updates prior to reliance thereon.
(Ord. 19-12 - Jan. 20 Supp.)
6.   Prohibited Uses with Respect to the Municipal Wastewater Treatment Plant. In all zoning districts, it shall be prohibited to construction, or utilize, land surrounding the municipal wastewater treatment plant for any of the following uses when said use would be located within the following distance of said wastewater treatment plant:
A.   Within 400 feet thereof:
(1)   Public deep wells.
(2)   Private wells.
(3)   Lakes or public water impoundments.
B.   Within 1000 feet thereof:
(1)   Inhabitable residence, commercial building, or other inhabitable structure. If there is a written easement and waiver of separation agreement with the owner of the building, the separation criteria shall not apply. Any such written agreement shall be filed with the county recorder for abstract of title purposes.
(2)   Public shallow wells.
C.   When the above separation distances cannot be maintained for the expansion, upgrading or replacement of existing facilities, the separation distances shall be maintained at no less than ninety (90%) of the existing separation distance on the site, providing no data is available indicating that a problem has existed or will be created.