(A) Type of channels. Man-made channels located on the rear lot lines shall be either:
(1) Swales with side slopes no steeper than 8:1 with the bottom rounded four feet on each side of the channel centerline of V-type bottom.
(2) Flat bottom channel with side slopes no steeper than 4:1.
(3) Swales in lieu of flat bottom channels are desirable where feasible.
(B) Channel capacity. Channels will be designed for the selected storm frequency to carry peak flows as calculated by the method specified in § 156.04.
(C) Submission of data. Data and design calculations will be submitted to the Village Engineer.
(D) Points of design. Open channels will be designed by considering each point along the channel where a concentrated flow enters the channel, at each change of longitudinal grade, and at various points as necessary throughout its length. The entire reach under consideration shall be designed for the discharge at the lower end of the reach.
(E) Storm frequency and velocities. Velocity in the channel shall be no less than 2.5 fps nor more than 5.0 fps based on a storm of 25-year frequency.
(F) Roughness coefficient. Manning's n will be 0.04 for sod.
(G) All channels shall be constructed with sod. If the soil is not capable of supporting vegetation, appropriate action must be taken to bring the soil to a condition which will support the growth of sod. In areas where sod growth is not assured, such as continuous running streams, other means of controlling erosion acceptable to the Village Engineer and the Hamilton County Soil and Water Conservation District may be utilized.
(H) Easements. Private drainage easements will be granted for every designed man-made open channel.
(I) Typical section. A typical section of all proposed man-made open channels shall be shown on the improvement plan and shall contain at least the following information:
(1) Side slopes.
(2) Flat bottom width, if applicable.
(3) Depth of water at design storm.
(4) Width of sod lining.
(J) Design. Channels shall be so designed that the water surface for the 100-year storm is two feet below the lowest opening of building subject to flooding by the channel unless approved by the village.
(Ord. C-604, passed 9-8-86)