SECTION VI - IMPROVEMENTS
DESIGN STANDARDS
6.1 ROADWAY ITEMS
6.1.01 Curb and Gutter: The requirement, of curb or curb and gutter will vary in accordance with the characteristic of the area and the density of development involved. In urban or suburban areas curbs are necessary to control storm water runoff and to clearly define driving and parking areas. Where curbs exist on abutting properties, their extension will ordinarily be required throughout the proposed subdivision.
6.1.02 Open Ditches: Open ditches, when used for roadway drainage, shall have a minimum slope of 0.5% and be of the shape shown on the typical sections contained in the appendix.
6.1.03 Paving: Pavement structures shall be selected to correspond to the classification of' the proposed street. Four typical pavements and roadway sections entitled "A", "B","C", and "'D" are shown and described in the appendix. The County Engineer may approve other pavement structures if, in his opinion, they provide as adequate a street as those shown, and subject to approval of the Regional Planning Commission pursuant to Section 2.9.
The type of pavement to be used in an allotment shall be governed by the conditions shown in the following table:
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Lot Width
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Pavement Type
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75 to 110 feet with public water and sewer
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Type ²A²
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100 to 150 feet with centralized sewer
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Type ²B² or ²C²
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140 feet upward without centralized water and sewer
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Type ²C² or ²D²
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6.1.02 Intersections: Pavement at intersections shall be constructed with a radius of not less than thirty five (35) feet measured to the face of curb or edge of pavement.
6.1.05 Cul-de-sac: The paved area in a cul-de-sac shall have a minimum radius of forty (40) feet when parking is not allowed and fifty (50) feet when parking is allowed.
6.1.06 T-Turn-Around: The dimensions of T-Turn-Arounds shall be determined with the assistance of the County Engineer. Pavement shall be of the same material as that of the street involved.
6.1.07 Sidewalks: Sidewalks shall be provided where they are required for the convenience and protection of the public such as in the vicinities of schools, recreation areas, commercial developments churches and other appropriate high density locations. Sidewalks shall be parallel to and one foot inside the right-of-way line. The standard minimum section for Sidewalks shall be:
A) Five (5) feet in width
B) Four (4) inches thick with six (6) inches thick across driveways
C) Sub-base of four (4) inches of slag, cinders, or other suitable granular material
D) Cross slope of 1/4 inch per foot
E) Constructed of Class "C" Portland Cement concrete (Section 7.1) or equal.
6.1.08 Guardrail: Type and location of guardrail shall be as required by the County Engineer.
6.2 DRAINAGE FACILITIES
6.2.01 General Requirements: Subdivisions shall be protect from flood hazards and inundation by storm water, springs, and other surface waters by the design and construction of drainage facilities which will provide for the adequate collection, routing, and discharge from the subdivision of such water.
Existing water courses entering the subdivision shall be received and discharged from the subdivision as nearly as possible in the manner as existing prior to construction. Design of facilities to accommodate such a watercourse within the subdivision shall conform to the ultimate drainage plan for the area if such a plan exists.
6.2.02 Design of Drainage Facilities:
A) Hydrologic Design: Those waterways set forth in an adopted master drainage plan for Carroll County shall be designed for the quantities indicated in such plan. All other waterways shall be designed in accordance with the following frequencies:
1) Major Waterways: Those with a tributary area of over six (6) square miles, use a recurrence interval of fifty (50) years.
2) Secondary Waterways: Those with a tributary area of one-half (1/2) to six (6) square miles, use a recurrence interval of twenty (20) years to twenty five (25) years.
3) Minor Waterways: Those with a tributary area of less-than three hundred twenty (320) acres, use a recurrence interval of five (5) years to ten (10)'years.
B) Hydraulic Design
1) Catch basins, where used, should be spaced such that flow of storm water does not exceed curb height for a recurrence interval of five (5) years.
2) Flow calculations for conduits and channels shall be made. See Section 8.4 for list of data to be shown on Drainage Plans.
C) Structural Design
1) Catch basins, manholes, .inlet structures, headwalls, etc. shall conform to the standard plans of the Ohio State Highway Department or to standard plans on file at the County Engineer's office.
2) Closed conduits and culverts shall be of the size as required by hydrologic and hydraulic calculations and of a type acceptable to the County Engineer. The minimum size of any conduit or culvert shall-be twelve (12) inches.
Alignment of closed conduits shall be as nearly straight as practicable without undue bends and angle points; manholes or catch basins shall be provided at all angle points and at intervals as required by the size of pipe. In areas having run-off water with acid content or other corrosive effects, all pipe shall be protected with additional lining or otherwise protected to assure a useful life of fifty (50) years.
3) Driveway culverts shall be a minimum of twelve (12) inches in diameter and twenty (20) feet long.
4) Open channels shall have side slopes of 2:1 or flatter with a minimum bottom width of three (3) feet (except for roadway ditches). When swales are used through a subdivision, it is recommended they be relatively wide and shallow with side slopes of 4:1 or flatter to enable the area to be mowed.
5) Minimum centerline radii of constructed channels shall be five (5) times the top width of the channel. Bank and stream bed stabilization using riprap or similar treatment may be required along constructed or natural channels if the velocities are sufficient to cause erosion. Channel construction areas shall be blended into the surrounding terrain and all exposed earth areas prepared and seeded in accordance with State of Ohio Department of Highway Specifications for rural areas.
D) Bridges: All drainage structures having a span or diameter greater than ten (10) feet shall be defined as bridges and all plans and calculations shall be submitted to the County Engineer for approval.
6.2.03 Easements for Drainage Purposes:
See Sect on 5.5 ²Easements²
6.3 SANITARY FACILITIES
6.3.01 Public System: If a proposed subdivision can be served by the reasonable extension of existing public sanitary servers, as determined by the Commission and provided the authority administering the sewage system will agree to an extension of their services, the subdivider shall employ this method for disposal of sanitary waste. Laterals shall be run from the collector to a point inside the lot lines.
6.3.02 Private System: Where a public sanitary sewer system is not available, the proposed subdivision may be serviced by one of the following:
A) Group Disposal System (Package Plant)
A disposal plant system shall have the design and plant site approved by the State Board of Health and the Carroll County Health Department.
B) Septic Tank System (See Appendix pages N)
Individual lot disposal systems may be used if such use is approved by the County Health Department. When this method is used, lots shall confirm to the requirements of Section 5.1.02.
6.3.03 Sewer Lines: Minimum size of any public sanitary sewer shall be eight (8) inches with manholes at all points of grade change or alignment change and at intervals not to exceed four hundred (400) feet. Sewer pipe shall meet A.S.T.M. Designation C200-65T with joints meeting A.S.T.M. Designation C425-66T. Manhole sections shall meet A.S.T.M. Designation C478-67 and gaskets between sections shall meet A.S.T.M. Designation C443-67. Subsequent later editions of A.S.T.M. Designations which require better quality shall be used for sewer pipe and manholes as they are issued and printed.
6.4 WATER SUPPLY
6.4.01 Public System: If a proposed subdivision can be served by the reasonable extension of existing public water lines, as determined by the Commission and provided the authority administering the water system will agree to an extension of their services, the subdivider shall employ this method to provide a water supply. Service lines shall be run to a point inside the lot lines.
6.4.02 Private System: Where a connection to an existing public water supply system cannot be made, water supply may be accomplished by one of the following:
A) A group distribution system with its own source and treatment facilities. The design of such a system is subject to approval by the State Board of Health and the Carroll County Health Department.
B) Individual wells: Where individual wells are to be used, the subdivider shall supply acceptable evidence of the availability of water. The subdivider may be required to make one or more test wells in the area to be platted if such evidence is deemed not acceptable. The availability of water shall have the approval of the County Health Department. Copies of logs of existing wells within the area may be submitted to the County Health Department for approval in lieu of drilling test wells.