Marietta › Zoning Ordinance
Division 730 — Design Standards
§ 730.01
Streets
A.The arrangement, character, extent, locations, and grade of all streets shall be done in accordance with acceptable land planning principles and shall be considered in their relation to existing and planned streets, to topographical conditions, orientation to public convenience and safety, and in their appropriate relation to the proposed uses of land to be served by such streets. All proposed streets shall be designed in a manner which does not promote congestion. Single family developments containing more than 51 dwelling units, multi family developments containing more than 100 dwelling units and non-residential developments containing greater than 51,000 gross square feet shall provide at least two access points to arterial or collector streets.
B.The street pattern shall be in conformity with the most advantageous development of the entire neighborhood area. Proposed streets shall be extended to the boundary lines of the tract to be subdivided and provide normal circulation of traffic within the vicinity. Except where topographic conditions warrant, block lengths shall not exceed 1200 feet.
C.Subdivisions which abut or have included within the proposed area to be subdivided any arterial roadway as shown on the City’s Official Thoroughfare Map shall provide those treatments necessary for adequate protection residential properties and to afford separation of through and local traffic.
Intersections of minor subdivision streets with arterials shall be held to a minimum.
D.Unusable reserve strips. Unusable reserve strips controlling access to streets shall be prohibited. Land shall not be subdivided in a manner which omits part of the original tract or avoids drainage improvements.
E.Cul-de-sacs. Streets designed to have one end permanently closed shall provide a turnaround having a minimum roadway diameter of 80 feet and right-of-way diameter of 100 feet. Cul-de-sacs shall not exceed 700 feet in length.
F.Required right-of-way widths, paving widths and grades. The amount of right-of-way deemed reasonable to be required by dedication shall not exceed 100 feet in width. Along both sides of proposed major arterial streets, it is deemed reasonable to require an increased front setback of up to 20 feet more than that required by the zoning ordinance. Table L denotes the minimum specifications for all streets unless otherwise approved by the Public Works Director:
TABLE L. RIGHT-OF-WAY REQUIREMENTS
STREET TYPE RIGHT-OF-WAY WIDTH PAVING WIDTH (FT.) MAXIMUM
Table or figure — shown as printedverify at source ↗
(FT.) (measured from back of curb) GRADE Major arterial 100 52 5 Minor arterial 60 28 7 Collector 50 28 15 Local 50 24 15 Industrial 50 30 15
1.Minimum grades of any roadway shall not be less than one percent (1%) unless otherwise approved by the Public Works Director.
2.Cross drains shall be approved by the Public Works Director.
3.Vertical curves shall be such as to prevent abrupt change and shall be approved by the Public Works Director.
G.Paving specifications. Unless otherwise specifically set forth herein, all of the materials, method of construction and workmanship for work covered in reference to street construction shall conform to the latest specifications of the Georgia Department of Transportation.
1.Residential local streets—The base course shall consist of five inches of crushed stone base material thoroughly compacted and brought to grade. The base shall be primed with 0.25 gallon of R.C. 70 bituminous prime material per square yard and the prime shall be cured until it does not pick up under traffic, in no case shall the curing period be less than 24 hours. After the prime is cured, two inches of “B” binder shall be applied. A final one (1) inch of “F” topping with a tack coat shall be applied to the binder course at the rate of 0.05 gallon per square yard shall be applied as a wearing course when any of the following occurs:
a)90 percent of the houses on the street are completed.
b)The maintenance agreement or bond between the developer and the City is within one month of expiring.
c)The Public Works Director approves or orders the final topping course to be applied.
2.Streets other than local residential streets—One of the following combinations of base course, binder, and topping must be used:
a)Eight (8) “ crushed stone base, two inches of “B” binder and one and one-half (1 1/2) “ of “F”
topping; or
b)Six inches crushed stone base, three and one-half (3 1/2) inches “B” binder and one and one-half (1 1/2) “ of “F” topping.
c)Prime and tack shall be placed in the same amount and time frame as for residential local streets outlined above. The final topping coat shall be applied when one of the following occurs:
1)percent of the lots are developed or 90 percent of the development is complete where land is not subdivided.
2)The maintenance agreement or bond between the developer and the city is within one month of expiring.
3)The Public Works Director approves or orders the final topping course to be applied.
H.Alignment and Visibility.
1.Minimum radii of horizontal curvature of the centerline shall be not less than 100 feet.
2.Tangent lengths between reverse curves shall be approved by the Public Works Director. A minimum tangent of 100 feet shall be introduced between reverse curves on major arterials.
3.Visibility. Clear horizontal visibility, measured along the centerline, shall be provided for at least 400 feet on major arterials; 300 feet on minor arterials; 200 feet on collector and local streets.
I.Intersections.
1.Submission of a grading plan, showing existing conditions and a detailed design for intersections which are unusual or located on different terrain may be required by the Public Works Director.
2.Acute angles at street intersections are to be avoided and in no case will an angle of less than 60 degrees be permitted.
3.Minimum radii of intersections.
a)Property lines at all street intersections shall have chords in place of a radius. The chords shall connect the points where the radii for beginning and end of curb radius intersects the right-of-way lines.
b)Roadway and curb intersections shall be made concentric and shall be rounded by a radius of not less than 25 feet.
4.Location of intersections.
a)Intersections of new subdivision streets with arterial and collector streets must be aligned with existing street intersections located along the frontage of the proposed project. The Public Works Director may approve other intersection locations when it is determined that alignment with an existing intersection is not appropriate.
b)Acceleration and deceleration lanes are required to be constructed when new subdivision streets intersect with arterial and collector streets. Deceleration lanes and acceleration lanes must be a minimum lane width of 12 feet wide with 24 inches curb and gutter and a minimum length of 200 feet including 50 foot taper. Tapers on auxiliary lanes may be reduced or squared off on non-curbed roadways where lane extensions or widening is expected and on curbed roadways where its does not present a problem to traffic maneuverability, safety, drainage and sidewalk tie-ins. However, a painted delineation taper (50 ft.) must be provided in these conditions. In all cases auxiliary lanes shall be designed in accordance to American Association of State Highway and Transportation Officials Policy on Geometric Design of Highways and Streets. The Public Works Director may approve reduced dimensions based upon existing site conditions.
(Code 1996, Sec. 7-8-4-10-020; Ord. No. 5688, 5/14/97, Sec. 1)
§ 730.02
Street and subdivision names
No street or subdivision name shall be used which will duplicate by spelling or sound or otherwise be confused with the names of existing streets in Cobb County. All streets which are not dedicated to the City shall be subject to the same conditions with the additional condition that an agreement be entered into between the City and the developer (and all future owners) which states that the name of the street and the assigned address may only be changed with the approval of City Council. This agreement shall be placed on file as a covenant with the Clerk of Cobb County Superior Court. (Code 1996, Sec. 7-8-4-10-040; Ord. No. 6152, 8/9/2000, Sec.1)
§ 730.03
Lots
A.The lot size, width, depth, shape and orientation, and the minimum building setback line shall be appropriate for the location of the subdivision and for the type of development and use contemplated.
B.Lot dimensions shall conform to the requirements of the zoning ordinance and the requirements of the Cobb County Health Department. In such cases where requirements may conflict, the stricter requirement shall govern.
C.Depth and width of properties reserved or laid out for commercial and industrial purposes shall be adequate to meet off-street parking and loading requirements.
D.In no case shall a lot abut a public street for less than 40 feet unless access to a public street is provided by means of a recorded easement, subject to the approval of the Planning Commission.
E.Double frontage and reverse frontage lots shall be avoided, except where essential to overcome specific disadvantages of topography and orientation. In such cases the applicant shall provide a rear buffer not less than 20 feet in width across which there shall be no right-of-access.
F.Side lot lines shall be substantially at right angles to streets, except on curves where they shall be radial.
(Code 1996, Sec. 7-8-4-10-060)
§ 730.04
Easements
A.Easements shall be provided for utilities and drainage where necessary and shall not be less than 15 feet wide and are encouraged to be located along rear or side lot lines. Easements for overhead power lines shall not be relocated into any buffer but may be relocated into a rear or side setback.
B.Where a subdivision is traversed by a water course, drainage way, channel or stream, there shall be provided a storm drainage easement or right-of-way conforming substantially with the lines of such drainage way as approved by the Public Works Director. The width of such drainage easement or right-of-way shall be sufficient to contain the ultimate channel and maintenance way for the tributary area upstream, in no case less than 20 feet, unless approved by the Public Works Director. Storm drainage easements are provided to identify the area within a subdivision and on each lot that is reserved for the unrestricted passage of storm water runoff.
C.Lots and easements shall be arranged in such a manner as to eliminate unnecessary easement jogs or off-sets and to facilitate the use of easement for power distribution, telephone service, drainage, water and sewer services. (Code 1996, Sec. 7-8-4-10-070)
§ 730.05
Drainage and inundation
A.Adequate provisions shall be made within each subdivision to provide drainage facilities needed within the subdivision taking into account the ultimate development of the tributary area.
B.Off-premise drainage easements and improvements may be required to handle the runoff of subdivisions into the natural drainage channel.
C.The Public Works Director may require of the developer or his agent additional engineering information necessary to make decisions on acceptability of development in an area of questionable drainage. Such additional information would be in writing and the certification of a qualified engineer may be required.
D.Lakes, ponds and similar areas will be accepted for maintenance only if sufficient land is dedicated as a public recreation area or park or if such area constitutes a necessary part of the drainage control system. Such park areas are subject to approval by the Department of Parks and Recreation.
E.Wetlands may not be developed or subdivided unless the Public Works Director establishes:
1.The nature of the land use (i.e. recreation areas) would not lend itself to damage by water to an appreciable extent: or that
2.The area may be filled or improved in such a manner to prevent such periodic inundation; or that,
3.Minimum floor elevations may be established to prevent damage to buildings and structures,
4.All applicable state and federal regulations have been adhered to, including obtaining any necessary permits from the Environmental Protection Agency.
(Code 1996, Sec. 7-8-4-10-080)
Editor’s note—Section 730.05 was originally numbered as 730.5. The section number has been changed by the editor in order to maintain consistency in numbering.