It is the intent of this section to provide surface drainage to all areas and to prevent property damage, inconvenience and deterioration caused by ponding water and flooding.
(a) Grading.
(1) A grading plan shall be required of the entire subdivision for the purpose of providing good drainage. Such plan shall be approved by the City Engineer.
(2) The area around a residence shall be graded away from the residence in such a manner as to allow surface runoff to escape from the immediate area around a residence.
(b) All necessary improvements, including storm sewers or open drainage ditches, shall be made to provide for the adequate disposal of storm water and to maintain any natural drainage course. All construction shall be in accordance with plans approved by the City Engineer and shall be carried out under City supervision. Storm water discharge shall also be in compliance with Section 931.01, Storm Water Discharge.
(c) When an adequate public storm sewer is available at the plat boundary, the subdivider shall construct a storm sewer to connect with such storm sewer line. If such a storm sewer is not accessible, natural drainage channels shall be provided as determined by the City Engineer and approved by the Planning Commission and shall connect to an adequate drainage outlet.
(d) Easements For Drainage. Storm sewers shall be located within the right-of-way or within an easement. Whenever any stream or important surface drainage course is located in an area being subdivided, the subdivider shall provide an adequate easement along each side of the stream or ditch for the purpose of widening, deepening, sloping, improving or protecting the drainage course and such easement shall be dedicated to the City or other appropriate public agency. The width of such easement shall be determined by the City Engineer.
(e) When, in the opinion of the City Engineer, the natural watercourse receiving storm sewer discharge is not adequate, the developer or subdivider shall, at his or her expense, undertake to give such natural watercourse the directional and velocity control as may be deemed necessary, even though such work lies outside the boundaries of his or her development or subdivision. The subdivider shall acquire such permission as is necessary to construct drainage structures, ditches, etc., outside the boundaries of his or her development or subdivision.
(f) Whenever the construction of streets and the required storm water drainage is such that the direction of storm water flow is diverted to affect surrounding property, the subdivider shall obtain adequate drainage easements to provide for efficient disposal of surface water.
(g) Bridge and Culverts. Where natural drainage channels intersect any street right- of-way, it shall be the responsibility of the subdivider to have satisfactory bridges and/or culverts constructed. Where culverts are required, minimum requirements shall be observed as follows:
(1) All bridges and culverts shall be designed according to Ohio Department of Transportation design standards.
(2) Driveway culverts shall have a minimum length of 20 feet, and a minimum diameter of eight (8) inches. The driveway culverts shall be laid so as to maintain the flow lines of the ditch or gutter. Head walls will not be permitted.
(h) The developer shall adequately protect all ditches to the satisfaction of the City Engineer.
(1) Ditch protection shall conform to the State of Ohio Department of Transportation Construction and Material Specifications for seeding (Item 659) and sodding (Item 660), or jut or excelsior matting (Item 667 or 669).
(2) The following shall be the allowable ditch velocities for seeding, sodding, and jute or excelsior matting on various soil types.
Allowable Ditch Velocities (ft. per second).
Soil Type | Seed Lining (659) | Sod Lining (660) | Jute or Excelsior Matting (667 or 669) |
Sand | 1.5 | 3.5 | 3.0 |
Firm loam | 2.0 | 4.0 | 4.0 |
Clay | 2.5 | 5.0 | 4.0 |
Gravel | 3.5 | 6.0 | 5.0 |
Weathering Shale | 4.5 | 6.0 | 5.0 |
(3) When the outlet velocity of culvert pipes, drive pipes, or side drains is in excess of the above allowable velocities, sufficient length of paved gutter (ODOT Item 601.09), shall be provided for transition to allowable velocity.
(4) Item 601.09 ODOT, S.H.D. specifications shall consist of the construction of a brick, concrete, approved broken concrete or stone paved gutter and shall be used in all road ditches where the grade exceeds two and one-half percent (2 ½%).
(5) Computations, drawings and drainage area maps used to design the above ditch protection shall be submitted to the City Engineer along with the plans and profiles as a basis for approval. In all cases the road ditches shall be in a stable condition free from either erosion or sedimentation at the time of final approval. Ditch easement, on each side of the ditch measured from top of slope, shall be 30 feet.